Anorectal Atresia and Cloacal Malformations Flashcards
(91 cards)
1
Q
A newborn male is born without an anus. If a fistula is present, what is the most likely location?
A. Rectovestibular
B. Rectourethral
C. Rectoperineal
D. Rectovesicular
E. Rectoenteric
A
ANSWER: B
COMMENTS: The most common site of a fistula associated with imperforate anus in males is rectourethral, while rectovestibular fistulas are the most common in females.
Only 5% of patients with imperforate anus do not have a fistula.
If meconium is passed in the urine, a fistulous connection to the urinary system should be suspected. If meconium is found on the perineum, a rectoperineal fistula is likely.
The initial management of an imperforate anus is to evaluate for other associated anomalies.
Babies with an imperforate anus have a 50%–60% likelihood of associated anomalies.
An imperforate anus is a part of the VACTERL group of associated congenital defects (vertebral anomalies, imperforate anus, cardiac abnormalities, TEFs, renal abnormalities, and limb abnormalities).
Babies born with any of these conditions should be evaluated for the presence of the others within the first 24 h of life.
Next, the level of the lower end of the rectal pouch must be determined.
Imperforate anus is usually divided into high and low types, and this will guide treatment.
Within 24 h of birth, gas will make its way through the GI tract and into the rectal pouch.
A cross-table radiograph of the infant will show the gas in the rectal pouch.
The high imperforate anus is diagnosed when air fails to pass below the level of the coccyx, and it is associated with more secondary anomalies compared with the low imperforate anus.
Once an imperforate anus is found, a fistula should be sought.
If a perineal fistula is present, the rectal pouch is usually low, and a perineal anoplasty can be performed in the perinatal period for definitive management.
If there is rectal gas below the coccyx but no fistula, a posterior sagittal anorectoplasty, or posterior sagittal anorectoplasty (PSARP), during the neonatal period could be considered.
However, if the level is high or if the infant has other significant defects and is not clinically stable, a colostomy should be constructed and definitive repair postponed.
2
Q
What is a high pressure distal colostogram?
A
A high pressure distal colostogram is performed through the mucous fistula at several months of life in order to delineate the length of the rectum, rectum to perineal distance, and the location of the fistula.
Without a properly performed distal colostogram, the surgeon will not know the precise location of the distal rectum.
There are risks of injuring adjacent structures including the vas deferens, urethra, seminal vesicles and bladder neck. Recent work with water injection and visualization using ultrasound could replace the use of ionizing radiation used during fluoroscopy.
3
Q
A 4-year old male presents with a history of an international adoption and prior anorectal malformation repair, (original malformation unknown). He voids incompletely and dribbles urine after voiding. How would you evaluate this child?
A
Children who have undergone surgery for an anorectal malformation who present with fecal and/or urinary incontinence always require a complete workup for associated anomalies especially in the setting where their surgical record is unknown.
In this case the child could have a remnant of the original fistula (ROOF) leading to urinary dribbling.
This can be evaluated by pelvic MRI and cystoscopy.
The possibility of a neurogenic bladder must also be investigated. A voiding cystourethrogram (VCUG) and video urodynamics (UDS) should be included in the work up as well.
4
Q
In a male with ARM, distal colostogram shows a high rectum with no fistula. On the contrast study the distal end of the rectum appears flat. What should be the next step in management?
A
Request a repeat distal colostomy with higher pressure.
5
Q
In a male ARM patient with a rectobladderneck fistula, mobilization of a very high rectum requires:
A
Dissection of the distal IMA branches thus preserving the intramural rectal blood supply to the distal rectum.
6
Q
In a male ARM patient, unilateral hydronephrosis is likely related to:
A
Vesicoureteral reflux.
7
Q
In a male ARM patient, the “no fistula” defect is almost always located at the level of:
A
Bulbar urethra.
8
Q
A previously repaired ARM patient is found to have mislocated anus with rectal prolapse. MRI of the pelvis reveals a mass behind the urethra. Reoperation is considered. The posterior urethral mass most likely represents:
A
R.O.O.F. Remnant Of Original Fistula.
9
Q
What are appropriate ways to manage an infant with imperforate anus and a rectovestibular or rectoperineal fistula?
A
This infant has several options depending on the comfort and expertise of the surgeon and parental preferences.
(1) A colostomy can be performed in the newborn period followed by repair at 3–10 months of age and eventually colostomy closure.
(2) Dilations of the fistulous tract to Hegar # 10 with delayed repair at 3 to 6 months of age.
(3) Primary PSARP in the newborn period with or without a protecting colostomy (Fig. 34.4).
10
Q
What are the indications for the treatment of a rectoperineal fistula in a female?
A
First, it is crucial to delineate the location of the fistula in relation to the sphincter complex.
The definitive diagnosis is with an examination under anesthesia with electrical stimulation of the sphincter complex.
The goals of the operation are then to relocate the anus within the sphincter mechanism, make the anal opening an appropriate size for patient’s age, and create an adequate length of perineal body. If, however, the anal opening is circumferentially surrounded by the sphincter muscle complex, then a short or inadequate perineal body alone is not an indication for operation.
11
Q
What are the key steps of a posterior sagittal anorectoplasty (PSARP)?
A
- Place a Foley catheter (Coude tip preferred)
- Position the patient prone, elevate the pelvis, prep and drape
- Identify the center of the sphincter complex with an electrical stimulator and mark the site
- Make a posterior sagittal incision
- Separate the fistula/rectum from the urethra
- Divide and close the fistula
- Stimulate the sphincter muscle complex again while the muscle complex is open to confirm the site of the anoplasty
- Reapproximate the levators and midline structures incorporating the rectum with at least 3–4 sutures to prevent prolapse.
- Place the rectum in the center of the sphincter complex
- Perform the anoplasty and size the neoanus with a Hegar dilator.
12
Q
What is a high pressure distal colostogram?
A
A high pressure distal colostogram is performed through the mucous fistula at several months of life in order to delineate the length of the rectum, rectum to per- ineal distance, and the location of the fistula.
Without a properly performed distal colostogram, the surgeon will not know the precise location of the distal rectum.
There are risks of injuring adjacent structures including the vas deferens, urethra, seminal vesicles and bladder neck.
Recent work with water injection and visualization using ultrasound could replace the use of ionizing radiation used during fluoroscopy [1].
13
Q
A 4-year old male presents with a history of an international adoption and prior anorectal malformation repair, (original malformation unknown). He voids incompletely and dribbles urine after voiding. How would you evaluate this child?
A
Children who have undergone surgery for an anorectal malformation who present with fecal and/or urinary incontinence always require a complete workup for associated anomalies especially in the setting where their surgical record is unknown.
In this case the child could have a remnant of the original fistula (ROOF) leading to urinary dribbling [2].
This can be evaluated by pelvic MRI and cystoscopy.
The possibility of a neurogenic bladder must also be investigated. A voiding cystourethrogram (VCUG) and video urodynamics (UDS) should be included in the work up as well.
14
Q
In a male with ARM, distal colostogram shows a high rectum with no fistula. On the contrast study the distal end of the rectum appears flat. What should be the next step in management?
A
Request a repeat distal colostomy with higher pressure.
15
Q
In a male ARM patient with a rectobladderneck fistula, mobilization of a
very high rectum requires:
A
Dissection of the distal IMA branches thus preserving the intramural rectal blood supply to the distal rectum.
16
Q
In a male ARM patient, unilateral hydronephrosis is likely related to:
A
Vesicoureteral reflux.
17
Q
In a male ARM patient, the “no fistula” defect is almost always located at the level of:
A
Bulbar urethra.
18
Q
A previously repaired ARM patient is found to have mislocated anus with rectal prolapse. MRI of the pelvis reveals a mass behind the ure- thra. Reoperation is considered. The posterior urethral mass most likely represents:
A
R.O.O.F. Remnant Of Original Fistula.
19
Q
What are appropriate ways to manage an infant with imperforate anus and a rectovestibular or rectoperineal fistula?
A
This infant has several options depending on the comfort and expertise of the surgeon and parental preferences.
(1) A colostomy can be performed in the newborn period followed by repair at 3–10 months of age and eventually colostomy closure.
(2) Dilations of the fistulous tract to Hegar # 10 with delayed repair at 3 to 6 months of age.
(3) Primary PSARP in the newborn period with or without a protecting colostomy (Fig. 34.4).
20
Q
What are the indications for the treatment of a rectoperineal fistula in a female?
A
First, it is crucial to delineate the location of the fistula in relation to the sphincter complex.
The definitive diagnosis is with an examination under anesthesia with electrical stimulation of the sphincter complex.
The goals of the operation are then to relocate the anus within the sphincter mechanism, make the anal opening an appropriate size for patient’s age, and create an adequate length of perineal body.
If, however, the anal opening is circumferentially surrounded by the sphincter muscle complex, then a short or inadequate perineal body alone is not an indication for operation.
21
Q
What are the key steps of a posterior sagittal anorectoplasty (PSARP)?
A
• Place a Foley catheter (Coude tip preferred)
• Position the patient prone, elevate the pelvis, prep and drape
• Identify the center of the sphincter complex with an electrical stimulator and mark the site
• Make a posterior sagittal incision
• Separate the fistula/rectum from the urethra
• Divide and close the fistula
• Stimulate the sphincter muscle complex again while the muscle complex is
open to confirm the site of the anoplasty
• Reapproximate the levators and midline structures incorporating the rectum with at least 3–4 sutures to prevent prolapse.
• Place the rectum in the center of the sphincter complex
• Perform the anoplasty and size the neoanus with a Hegar dilator.
22
Q
A female newborn is found to have only two perineal openings, what are the defects that could be responsible?
A
Rectovaginal fistula, urogenital sinus, a blind ending rectal fistula, vestibular fistula with vaginal atresia.
23
Q
Describe the anorectal malformation in which a female infant with imperforate anus, has only a single perineal opening?
A
Cloaca. In this malformation, rectum, vagina and urinary tract empty into a single common channel.
24
Q
You are asked to perform a fetal consultation for a pregnant woman with a 24-week female fetus who on prenatal ultrasound has a cystic pelvic mass, an absent radial bone, and a single kidney with hydronephrosis. What is the most likely diagnosis?
A
Cloaca. A single perineal orifice in a female that forms a common channel consisting of the urinary tract, reproductive tract and rectum.
The cystic mass is likely a vagina filled with mucous and urine (hydrocolpos), and the radial and renal anomalies are part of the VACTERL complex.
25
What is the incidence of cloaca?
1 in 50,000 females.
26
What is hydrocolpos?
Hydrocolpos is the distension of the vagina caused by accumulation of fluid in the vagina (mucous and urine).
It may be problematic when it obstructs the distal ureters by compressing the bladder trigone and resulting in hydronephrosis.
In these cases, hydrocolpos needs to be drained.
27
In the management of a newborn with a cloaca, how do you determine whether a hydrocolpos requires drainage?
If there is hydronephrosis associated with the pelvic mass, the hydrocolpos will need to be drained.
28
How can a hydrocolpos be drained?
There are two options for the drainage of hydrocolpos.
(1) Intermittent catheterization of the common channel, with confirmation of decompression and resolution of hydronephrosis by ultrasound
(2) A transabdominal vaginostomy tube either by interventional radiology or at the time of colostomy creation.
29
Which anatomic details are vital to surgical planning in cloaca?
Length of the common channel (<3 cm short common channel vs. >3 cm long common channel) and urethral length (measurement based on a cloaca up to one year of age).
These are vital in deciding whether a total urogenital mobilization or a urogenital separation with preservation of the common channel as urethra should be performed [6] (Fig. 34.5).
30
Identify key steps in the newborn management of cloacal malformations.
* Identify the single perineal opening and confirm the diagnosis.
* Divert the fecal stream via a divided descending colostomy
* Determine whether a hydrocolpos causing hydronephrosis is present, and if so drain it via perineal catheterizations or vaginostomy.
* Evaluate for associated anomalies (VACTERL)
* Perform a cystoscopy, vaginoscopy, and a contrast study to visualize the anatomy (3D reconstructed fluoroscopy) at 5 to 6 months of age
* Perform a definitive cloacal repair between 6 months to 1 year of age.
31
A 13 years old previously repaired cloacal patient, presents with cyclical, monthly left lower quadrant abdominal pain. What is the most likely diagnosis?
Hematometrocolpos associated with an obstructed Mullerian structure.
32
What is the most common indication for a reoperation in patients with previously repaired cloaca?
Persistent urogenital sinus, i.e. only the rectal component was previously repaired.
33
In a patient with previously repaired ARM patient, what is the most important predictor of continence? Type of malformation? Status of the spine? Quality of the Sacrum?
All three are important variables to consider when counseling patients on their continence potential. We use Fig. 34.6 to counsel families. A recent study has shown that the type of ARM was the only factor that predicted fecal continence in children with ARM.
34
An ARM patient has successful bowel management program with enemas and requests an antegrade enema route. For his urine, he does intermittent catheterization but leaks at 2 h. What is the next step in management? What are his options for antegrade route?
For patients on intermittent catheterization leaking at 2 h, strong consideration should be given to urology referral.
The patient should undergo urology evaluation with urodynamics, VCUG, and renal ultrasound.
If patient needs a Mitrofanoff, then consideration should be given to split appendix Malone/Mitrofanoff.
If the length of the appendix is not adequate then appendix should be used for Mitrofanoff and neomalone should be constructed.
If the cecum is not amenable to neomalone due to vascular supply, then a cecostomy should be considered (Fig. 34.7).
35
What is cloacal exstrophy?
It is a severe form of anorectal malformation with ventral abdominal wall defects.
The classic features of cloacal exstrophy include anorectal malformation, omphalocele, blind ending micro-colon, exstrophic hemibladders, and an everted cecum with prolapse between them.
Boys often have a rudimentary hemiphallic structures on each side.
Females may have many gynecologic anomalies.
The incidence of cloacal exstrophy is 1 in every 400,000 births with a male predominance [4].
36
Name the key steps in the management of a newborn with cloacal exstrophy.
* Careful preoperative investigation
* Omphalocele closure
* Separation of the gastrointestinal tract from the hemibladders with tubularization of the cecum and construction of an end colostomy (gastrointestinal stoma)
* Closure of hemibladders, if possible, or if not, joining them together and keeping them inverted
* Pelvic osteotomies of the time of bladder closure
* Delayed additional urogenital reconstruction, depending on gender assignment
* Colonic pullthrough plus malone if end stoma is capable of forming solid stool.
37
What is the pubococcygeal line?
It is a line that joins the upper border of the symphysis pubis to the sacrococcygeal junction.
A gas bubble situated above the PC line is designated as a “high” anomaly.
A gas bubble located between the PC line and I line is designated as an intermediate anomaly.
A gas bubble extends below the I line, it is called a “low” anomaly.
38
How do you do an invertogram for Anorectal Malformations?
The baby was originally positioned upside-down. This has been replaced by a prone, cross-table lateral position, with the hips elevated with a bolster (12-24h after birth to allow gas to reach the distal rectum). Strict lateral view is taken with the thighs flexed at the hip, and beam accurately centered on the greater trochanter.
Anal dimple and natal cleft should be outlined by barium paste, coin, metal pointer.
In a correctly taken radiograph:
- Both the ischial bone would accurately superimpose.
- The terminal blind bowel will be rounded and well-distended.
```
Things to evaluate in an invertogram:
- Level of gas in the blind pouch in relation to the bony pelvis, which in turn indicates the relation to the levator ani muscle complex.
3 specific lines:
1) Pubococcygeal line (PCL)
2) Ischial line (I line)
3) Anal pit line
```
* A gas bubble situated above the PC line is designated “high” anomaly.
* One located between the PC and I line or point “Intermediate” anomaly.
* If it extends below the I line (point), then it is called “low” anomaly.
- Congenital anomalies of the spine (ie, sacral agenesis)
- Presence of gas in the region of urinary bladder and vagina, which would indicate an underlying fistula.
39
What is false about the levator ani muscle?
A. Normally the rectum is surrounded laterally and posteriorly by levator ani muscle mechanism.
B. In imperforate anus with rectovesical fistula, levator ani lies posterior and lateral to rectum.
C. When levator ani contracts, it pushes the rectum forward.
D. All of the above are true.
E. All of the above are false.
D. All of the above are true.
40
Disadvantage of transverse colostomy, in comparison with descending colostomy in imperforate anus include all except:
A. Long segment is available for mobilization at the time of definitive procedure.
B. Metabolic acidosis and constipation
C. Increased fluid and electrolyte loss
D. Distal part difficult to wash
E. Increased incidence of UTI, if fistula.
A. Long segment is available for mobilization at the time of definitive procedure.
41
The goal of surgery for persistent cloaca includes all except:
A. Separation of rectum from vagina.
B. Separation of vagina from urethra.
C. Placement of rectum within sphincter mechanism.
D. Opening of vagina in its normal location
E. Reconstruction of old common channel as a neo-vagina.
E. Reconstruction of old common channel as a neo-vagina.
42
Regarding levator ani muscle, which of the following is false?
A. It is supplied largely by sympathetic and parasympathetic nerves.
B. The anterior fibres pass around the urethra and prostate (urethra and vagina in female) to the fibrous perineal body.
C. Its middle fibres pass medially around the rectum to the anococcygeal body.
D. The posterior fibres pass to the midline raphe and the coccyx.
E. It provides muscular support to the pelvic viscera and reinforces the rectal and urethral sphincter.
A
Levator ani muscle is supplied by third and fourth sacral nerves and the pudendal nerve and is under voluntary control.
Syed/MCQ
43
Regarding the anatomy of the rectum, all of the following are true, except:
A. It begins in front of the third sacral vertebrae.
B. It has no mesentery.
C. It has venous drainage to superior mesenteric vein.
D. Lymphatic drainage passes along the superior rectal vessels to the para-aortic and laterally to the internal iliac nodes.
E. It is lined by columnar epithelium.
C
The venous drainage through the superior rectal vein to the inferior mesenteric vein. There are also important anastomosis with the inferior rectal branches of the internal pudendal vein.
Syed/MCQ
44
A 6-year-old female patient born with imperforate anus (perineal fistula) that has been soiling and is unable to potty-train. She has a normal sacrum, and her contrast enema shows a dilated rectosigmoid with significant stool load.
What is the next best step?
Fecal disimpaction, then this may be followed by a trial of laxatives.
45
A 10-year-old male patient with no medical problems other than lifelong constipation, and no prior surgery, who has now been soiling. A contrast enema shows a dilated rectosigmoid. The contrast enema cleans out his colon of stool.
What is the next best step?
Laxatives
46
A 9-year-old female patient with cloacal malformation (common channel 5 cm long) and also has an absent sacrum. She has undergone a good surgical reconstruction, as well as a detethering of her cord. She comes to your clinic for management of her faecal incontinence.
What is the next best step?
Daily enemas
Patients with a poor prognosis for bowel control (‘high’ malformation, poor sacrum, tethered cord) have true incontinence and benefit from bowel management with a mechanical emptying of the colon with daily enemas. A Malone appendicostomy would be indicated if the patient stays clean with enemas and wishes to administer the enemas herself, but only after a successful trial of bowel management.
47
Regarding levator ani muscle, which of the following is false?
A. It is supplied largely by sympathetic and parasympathetic nerves.
B. The anterior fibres pass around the urethra and prostate (urethra and vagina in female) to the fibrous perineal body.
C. Its middle fibres pass medially around the rectum to the anococcygeal body.
D. The posterior fibres pass to the midline raphe and the coccyx.
E. It provides muscular support to the pelvic viscera and reinforces the rectal and urethral sphincter.
A
Levator ani muscle is supplied by third and fourth sacral nerves and the pudendal nerve and is under voluntary control.
Syed/MCQ
48
Regarding the anatomy of the rectum, all of the following are true except:
A. It begins in front of the third sacral vertebrae.
B. It has no mesentery.
C. It has venous drainage to superior mesenteric vein.
D. Lymphatic drainage passes along the superior rectal vessels to the para-aortic and laterally to the internal iliac nodes.
E. It is lined by columnar epithelium.
C
The venous drainage through the superior rectal vein to the inferior mesenteric vein. There are also important anastomosis with the inferior rectal branches of the internal pudendal vein.
Syed/MCQ
49
What is a sacral ratio?
A sacral ratio is an objective evaluation of the sacrum and can range from 0.0–1.0.
Line A: Most superior portion of iliac crests
Line B: Most inferior portion of sacroiliac joints
Line C: Line parallel to the preceding lines, at the most inferior point of the sacrum
Sacral ratio = BC/AB
The normal sacral ratio in children is 0.77.
Children with anorectal malformations have varying degrees of poor sacral development.
A ratio >0.7 is usually associated with good bowel control, whereas one <0.4 is associated with poor bowel function.
The sacral development seems to correlate with the development of the muscles and nerves of the pelvis, and therefore is a valuable objective measure of caudal regression.
50
How is a runner’s elbow used to depict levels of a rectourethral fistula?
Caudad to Cephalad
Elbow: Urethra-bulbar junction
Triceps: Urethra-prostatic junction
Shoulder: Bladderneck level
51
Which patients will require complex bladderneck work or closure with Mitrofanoff reconstruction?
Most patients with cloaca have a flaccid, smooth, large bladder that does not empty completely, but they do have a competent bladder neck, making them ideal candidates for intermittent catheterization, which can keep them completely dry.
However, exceptions occur such as:
1) the patient with a very long common channel and hemivaginas that are attached to the bladder neck, which were separated, leading to bladder neck damage during the reconstruction.
2) if a total urogenital mobilization was done in an infant with a very short urethra, the patient will leak.
3) a third exception is the rare baby born with separated pubic bones, a condition that is called a “covered exstrophy,” with a congenital absence of the bladder neck.
All of these exceptions will require complex bladder neck work, or bladder neck closure with Mitrofanoff reconstruction to achieve dryness.
52
A new born infant boy is born with no anal opening and history of meconium per urethra. A cross-table lateral abdominal film shows air in the rectum approximately 8 cm from the perineum.
What is the ideal surgical procedure for diversion of the fecal stream?
Choices:
1. Ileostomy
2. Mid-transverse loop colostomy
3. End proximal sigmoid colostomy with a mucus fistula
4. Colostomy with Hartman pouch
Answer: 3 - End proximal sigmoid colostomy with a mucus fistula
Explanations:
•An ileostomy would not provide appropriate access to the distal bowel for imaging studies in the future. This is key for surgical planning.
• A mid transverse loop colostomy would allow for spillage of stool into the distal bowel. The distal bowel should be split from the proximal bowel in order to eliminate spillage of fecal contents into the distal bowel to prevent urinary tract infections if there is a connection to the urinary system as well as to keep the obstructed distal segment decompressed.
•An end proximal sigmoid colostomy with a split mucus fistula is the correct answer. It leaves sufficient distal length for future pull through surgery. It also allows the colostomy to be bagged separately preventing stool from reaching the distal bowel.
•While the patient will have a colostomy, a Hartman pouch will leave a relatively obstructed segment of bowel and additionally, does not provide access to the distal bowel for contrast study that is essential for preoperative planning.
StatPearls
53
The most frequent anorectal defect seen in males is:
A a high defect
B anal membrane
C rectourethral fistula
D no fistula
E rectal atresia.
C
The most frequent anorectal malformation in male patients is rectourethral fistula.
The correct diagnosis of the malformation is important since it predicts the prognosis for bowel control.
There are two types of rectourethral fistula: rectobulbar urethral fistula (which carries the best prognosis) and rectoprostatic urethral fistula.
SPSE 1
54
The most frequent anorectal defect seen in females is:
A perineal fistula
B vestibular fistula
C no fistula
D rectovaginal fistula
E persistent cloaca
B
The most frequent anorectal malformation in female patients is rectovestibular fistula.
It is a malformation with excellent prognosis for bowel control.
The most important anatomical feature during the surgical repair is the presence of a common wall between rectum and vagina that requires a very meticulous dissection.
SPSE 1
55
In the newborn with anorectal malformation, radiological studies of the location of the rectum ideally must be done:
A during the first 6 hours of life
B from 6 to 12 hours of life
C from 12 to 18 hours of life
D after 18 hours of life
E after 48 hours of life.
D
When the patient is born, a radiological evaluation may not show the correct anatomy before 24 hours because the rectum is collapsed and it takes some time for the gas and meconium to pass through the bowel and to overcome the muscle tone of the sphincters that surround the lower part of the rectum.
A radiological evaluation performed too early will show a ‘high defect’, which will be an incorrect diagnosis in many cases. Imaging should wait until at least 18–24 hours after birth.
SPSE 1
56
In neonates with imperforate anus, when the clinical information does not allow one to make a decision about the opening of a colostomy, the next most valuable study is:
A magnetic resonance imaging (MRI)
B CT scan
C invertogram
D cross-table lateral film with patient in prone position
E ultrasound.
D
A cross-table lateral film with the patient in prone position is a good tool to measure the distance between the distal rectum and the anal dimple, in order to decide whether a primary repair (air below the coccyx) or a colostomy (air above the coccyx) is appropriate.
In the past, invertograms were the exam of choice, but they were very uncomfortable for the patients and there was a risk of vomiting, aspiration and cyanosis.
The same information can be obtained with a cross-table lateral film.
SPSE 1
57
The ideal colostomy in patients with anorectal malformation is:
A end colostomy with Hartmann’s pouch
B divided proximal sigmoid colostomy
C double-barrelled transverse colostomy
D loop colostomy
E none of the above.
B
The ideal colostomy in patients with anorectal malformation is a divided proximal sigmoid colostomy.
It is important to separate the stomas with enough distance that a bag can be adapted over the proximal stoma without including the mucous fistula in the same bag, that way faecal material coming from the proximal stoma does not enter the distal stoma.
The ideal technique opens the proximal stoma in the proximal sigmoid colon, just after the descending colon is attached to the left retroperitoneum; this avoids prolapse.
Placing the mucous fistula in the proximal sigmoid will provide enough distal bowel for the pull-through.
It should be exteriorised as a tiny orifice to avoid prolapse of the distal segment, since this portion of the colon is not naturally fixed.
other reasons for using this type of colostomy include: performing the distal colostogram with the mucous fistula, for the correct diagnosis of the malformation, and avoiding faecal material in the urinary tract (since the majority of patients have a communication with the urinary tract).
SPSE 1
58
Which of the following studies seems to be more accurate in demonstrating the location of the fistula?
A high-pressure distal colostogram
B MRI with contrast
C CT scan with contrast
D ultrasound
E voiding cystourethrogram
A
The high-pressure distal colostogram is the most important exam for the surgeon.
It shows the precise location of the fistula, the amount of colon available for the pull-through, and it also shows the rectum location in relation to the sacrum.
When the rectum can be seen below the sacrum, it means that it can be reached posterosagittally; when it is above the sacrum it means that a laparotomy/laparoscopy will be needed.
SPSE 1
59
What is the diagnosis and what would be the best surgical approach for this patient?
A perineal fistula, dilatation of the fistula
B anal membrane, perforation of membrane
C no fistula, posterior sagittal anorectoplasty
D anal stenosis, dilatation of stenotic tract
E anterior mislocated anus, cutback
C
This high-pressure distal colostogram shows an anorectal malformation without fistula.
The distal rectum is very close (about 1–2 cm) from the anal dimple and it is also below the sacrum.
This is very similar to the location of a rectourethral bulbar fistula type of anorectal malformation.
With that image the surgeon can open posteriosagittally and the first structure that will be found will be the rectum.
With mobilisation of the rectum an anoplasty can be performed.
SPSE 1
60
What is the diagnosis and what would be the surgical approach for this patient?
A rectoprostatic fistula, posterior sagittal approach only
B no fistula, posterior sagittal approach only
C recto-bladder neck fistula, posterior sagittal approach only
D rectoprostatic fistula, laparotomy/ laparoscopy and posterior sagittal approach
E recto-bladder neck fistula, laparotomy/ laparoscopy and posterior sagittal approach
E
This high-pressure distal colostogram shows a recto-bladder neck fistula with plenty of distal bowel left for the pull-though.
The colon is above the sacrum (as always occurs in recto-bladder neck fistulas), so a laparotomy/laparoscopy will be needed in order to reach the rectum and mobilise it.
After the mobilisation, a small posterior sagittal incision and anoplasty is performed.
SPSE 1
61
What is the diagnosis and how would you approach this patient:
A recto-bladder neck, posterior sagittal approach
B rectoprostatic, posterior sagittal approach
C rectobulbar, posterior sagittal approach
D rectoprostatic, laparotomy/laparoscopy
E rectobulbar, laparotomy/laparoscopy
C
This high-pressure distal colostogram shows a rectobulbar fistula.
The rectum is below the sacrum and it can be reached by a posterior sagittal approach.
An important anatomical characteristic of this malformation is the fact that it is the one that shares the longest common wall with the urethra, and therefore it requires a meticulous surgical dissection.
SPSE 1
62
You are asked to examine the perineum of a newborn patient, your diagnosis is:
A imperforate anus, high malformation
B imperforate anus, unknown malformation
C rectobulbar fistula
D anorectal malformation without fistula
E perineal fistula.
E
Following the scrotal raphe down, one identifies a small orifice that corresponds to a perineal fistula in a male patient.
A careful physical exam is the key to making this diagnosis.
The surgeon can expect to find the healthy rectum within 1–2 cm of the fistulous tract.
During the surgical repair, the surgeon has to be particularly careful with the dissection plane between the rectum and urethra, since these two structures are closely related.
SPSE 1
63
What malformation is this?
A vestibular fistula
B rectovaginal fistula
C perineal fistula
D cloaca
E no fistula
A
This is a vestibular fistula, the most common anorectal defect in female patients.
The physical exam is key to making this diagnosis.
The most important anatomical feature during the surgical repair is the common wall between rectum and vagina that requires a very meticulous dissection to achieve separation.
SPSE 1
64
The incidence of hydrocolpos in patients with cloaca is:
A 5%
B 10%
C 30%
D 60%
E 80%.
C
Hydrocolpos in patients with cloaca must be suspected, diagnosed and treated.
It occurs in 30% of these patients.
A pelvic ultrasound specifically looking for a cystic structure behind the bladder can make the diagnosis.
SPSE 1
65
The best treatment in a neonate patient with a persistent cloaca and a giant hydrocolpos is:
A colostomy and vesicostomy
B colostomy and vaginostomy
C colostomy and dilatation of the single perineal orifice
D colostomy and aspiration of the hydrocolpos content
E colostomy and ureterostomies.
B
The best treatment for a patient with cloaca and hydrocolpos is colostomy and vaginostomy performed in the newborn period.
The importance of draining the hydrocolpos is to avoid perforation of the hydrocolpos with consequent peritonitis; to avoid infection (pyocolpos) that might result in vaginal tissue damage, making it unavailable for the future repair; and to relieve ureterovesical obstruction, caused by a mass effect on the trigone, resulting in megaureters and hydronephrosis, and possible kidney damage.
SPSE 1
66
During the repair of a cloaca, with two hemivaginas, where must one look for the rectal orifice?
A in the right vagina
B in the left vagina
C on the posterior wall of the common channel
D in the septum that separates the two hemivaginas
E on the anterior wall of the common channel
D
In the presence of two hemivaginas in a patient with a cloaca, the rectum usually can be found opening in the septum between the two hemivaginas.
SPSE 1
67
Which one of the following urologic problems is more frequently associated with an anorectal malformation?
A hypospadias
B absent kidney
C cryptorchidism
D ureteropelvic obstruction
E ureterocele
B
The most frequent urologic malformation associated with anorectal malformation is absent kidney, occurring in 11%.
The more complex the malformation (recto-bladder neck fistula, cloaca), the higher is the chance of having an associated urologic abnormality (90% in those complex malformations mentioned compared with 10% in perineal fistulas).
SPSE 1
68
Which one of the following defects is more frequently associated with an anorectal malformation?
A vesicoureteral reflux
B horseshoe kidney
C ureterocele
D cryptorchidism
E hypospadias
A
The most frequent urological defect in patients with anorectal malformation is vesicoureteral reflux, occurring in 21%.
The first hint of this problem is the finding of hydroureter on kidney ultrasound.
SPSE 1
69
Down’s syndrome in children with imperforate anus is most frequently associated with:
A perineal fistula
B rectourethral fistula
C recto-bladder neck fistula
D cloaca
E imperforate anus with no fistula.
E
Anorectal malformation without fistula occurs in about 5% of patients with anorectal malformation.
When one looks specifically at patients with Down’s syndrome, 95% of those born with an anorectal malformation have the no-fistula type of defect.
SPSE 1
70
Rectal atresia is a defect in which the anus and the anal canal are normal and there is an obstruction that separates the anal canal from the rectum, usually located about 1–2 cm from the skin level in the perineum. The frequency of this defect is approximately:
A 1%
B 10%
C 20%
D 30%
E 40%.
A
Rectal atresia is an extremely unusual defect.
The upper pouch is represented by a dilated rectum, whereas the lower portion is represented by a small anal canal that is in the normal location and is 1–2 cm deep.
The repair involves a primary anastomosis between the upper pouch and the anal canal.
SPSE 1
71
The frequency of imperforate anus with a rectovaginal fistula is approximately:
A 1%
B 10%
C 20%
D 30%
E 40%.
A
Rectovaginal fistulas are extremely rare, with an incidence rate of less than 1%. In the past, many rectovestibular fistulas or cloacas were erroneously named rectovaginal fistula.
In a true rectovaginal fistula (extremely uncommon), the rectum opens in the posterior wall of the vagina and it can only be seen inside the vagina.
The urethra and vagina must be visible as separate orifices in order to distinguish this defect from a cloaca.
SPSE 1
72
Anal dilatations post imperforate anus repair are ideally performed:
A once a week
B every 4 days
C every second day
D once a day
E twice a day.
E
The protocol for anal dilatation should be started 2 weeks after the repair, passing the Hegar dilator two times every day (30 seconds each time).
The patient is seen in clinic and the surgeon determines with which Hegar dilator to start (the one that can be passed without resistance and without causing pain), and also the Hegar dilator that is the goal for that child based on the age:
1–4 months = Hegar # 12
4–8 months = Hegar # 13
8–12 months = Hegar # 14
1–3 years = Hegar # 15
3–12 years = Hegar # 16
more than 12 years = Hegar # 17
Every week the parents change the Hegar to the next size, until they reach the goal Hegar dilator.
once the goal number passes easily and without pain, twice a day, the parents can start tapering the frequency of dilatations: once a day for a month, every other day for a month, every third day for a month, once a week for a month, once a month for 3 months.
Dilatations under anaesthesia at 1 week or more intervals will crack the anoplasty and lead to scarring and a fibrotic stricture.
SPSE 1
73
What is an H-type fistula?
An H-type fistula is probably the rarest type of anorectal malformation in a girl, representing less than 1% of all anorectal anomalies.
In this type of malformation, the anus may be normal, ectopic, or stenotic. The fistula is found between the distal rectum or anal canal and the vagina, vaginal fourchette, or labia.
The hallmark symptom is passage of stool through the vagina. Recurrent labial abscesses are a more rare presentation.
Since the anus is normal in most cases, the diagnosis should be suspected purely on history. It is confirmed by a rectal and perineal examination under anesthesia since the fistula is usually small and very difficult to localize on physical examination.
If the history is reliable or stool is seen emanating from the vaginal introitus, localization of the fistula can be performed just prior to the repair.
Multiple procedures have been suggested for this anomaly. Mobilization, division, and ligation of the fistula, followed by a limited Swenson procedure to cover the repair with healthy rectal wall, result in a low rate of recurrence.
Although not uniformly recommended, a temporary diverting colostomy should be strongly considered.
Figure 41.11 shows the findings and repair of an H-type rectovestibular fistula in a 6-week-old girl who presented with recurrent stooling through the vaginal orifice. Temporary diversion for 2 months with a loop sigmoid colostomy, performed through an infraumbilical incision, resulted in an excellent outcome.
Sherif
74
What are the goals in managing a cloaca?
This female malformation is managed by a variation of the posterior sagittal anorectoplasty. It is considered separately because of its complexity.
The reconstruction requires a delicate, meticulous technique, as well as creativity, imagination, and a resourceful, experienced surgeon.
Repair of this defect has three main goals: achievement of urinary control, bowel control, and sexual function. Because a spectrum of defects exists, these goals are achieved in some cases; in others, however, the defect is repaired anatomically, but the patients are left with functional sequelae that require extensive medical assistance to provide a good quality of life. During surgical exploration, the surgeon must be prepared to find bizarre anatomic arrangements of the rectum, vagina, and urinary tract.
A long midsagittal incision is made, extending from the middle portion of the sacrum through the sphincter mechanism and down into the single perineal opening.
Before undertaking repair of a cloaca, the surgeon should perform an endoscopy with the specific purpose of determining the length of the common channel. A contrast study of each of the three systems is valuable and can be done in three dimensions.
There are two well-characterized groups of patients with a cloaca. These two groups represent different technical challenges and must be recognized preoperatively.
The first group consists of patients with a common channel shorter than 3 cm; fortunately, this represents the majority. These patients can usually be repaired via a posterior sagittal approach alone, without laparotomy.
The second group consists of patients with longer common channels. These patients usually need laparotomy, followed by a decision-making process that usually requires intricate vaginal maneuvers or vaginal replacement, tricks to mobilize a high rectum, knowledge of bladderneck anatomy, and decision making related to ectopic ureters if found. This group should be cared for at centers with special dedication to the repair of these defects.
Coran
75
How do you manage a cloaca <3cm?
Cloacas with a Common Channel Shorter than 3 cm
The incision extends from the middle portion of the sacrum down to the single perineal orifice. The sphincter mechanism is divided in the midline.
The first structure that the surgeon will find after division of the sphincter mechanism is the rectum. The rectum is opened in the midline, and silk stitches are placed along the edges of the posterior rectal wall.
The incision is extended distally through the posterior wall of the common channel. The entire common channel is exposed to allow confirmation of its length under direct vision.
The rectum is then separated from the vagina. This is performed in the same way as for repair of a rectovestibular fistula because the rectum and vagina share the same common wall already described. In patients with a vaginal septum, the rectum must be searched for at the posterior aspect of this septum.
Once the rectum has been completely separated from the vagina, a maneuver called total urogenital mobilization is used. Before this advance, the vagina was separated from the urinary tract, which was a technically challenging maneuver associated with significant morbidity.
Total urogenital mobilization consists of mobilization of both the vagina and urethra as a unit without separating them. After the rectum has been separated, multiple silk stitches are placed through the edges of the vagina and the common channel to apply uniform traction on the urogenital sinus. Another series of fine stitches are placed across the urogenital sinus approximately 5 mm proximal to the clitoris. The urogenital sinus is transected between the last row of silk stitches and the clitoris.
The dissection takes advantage of the fact that there is a natural plane of separation from the pubis. Rapidly and in a bloodless field, one can reach the upper edge of the pubis. There, a fibrous, avascular structure that gives support to the vagina and bladder is identified.
This structure is called the suspensory ligament of the urethra and bladder. This ligament is divided, which immediately provides significant mobilization (between 2 and 3 cm) of the urogenital complex. One can then dissect the lateral and dorsal walls of the vagina to gain an extra 5 to 10 mm.
This dissection is enough to repair about 60% of all cloacas and is a reproducible maneuver. It has the additional advantage of preserving an excellent blood supply to both the urethra and vagina. It places the urethral opening in a visible location and provides a smooth urethra that can easily be catheterized.
What used to be the common channel is divided in the midline to form two lateral flaps that are sutured to the skin to create the new labia.
If a vaginal septum is present, it is removed. The vaginal edges are then mobilized to reach the skin to create the introitus. The limits of the sphincter are electrically determined.
The perineal body is reconstructed by bringing together the anterior limit of the sphincter.
The rectum is placed within the limits of the sphincter in the manner previously described.
Patients can eat the same day, and the pain is usually easily controlled. Patients are discharged 48 hours postoperatively.
Coran
76
How do you manage cloacas >3cm?
Cloacas with a Common Channel Longer than 3 cm
When endoscopy and a cloacagram show that the patient has a long common channel, the surgeon must be prepared to face several significant technical challenges.
Patients with a long common channel should receive a total-body preparation because it is likely that laparotomy will be required.
The rectum is separated from the vagina and urethra via a posterior sagittal incision or via laparotomy when it is located very high.
The presence of a long common channel (>5 cm) indicates there is no way that total urogenital mobilization will be sufficient to repair the malformation, and therefore it is advisable to leave the common channel in place, which can be used as urethra for intermittent catheterization.
In this situation the vagina should be separated from the urinary tract by placing multiple 6-0 silk sutures through the vaginal wall to try to create a plane of dissection between the vagina and the urinary tract. This is best done through the abdomen when the vagina(s) are high.
In such a high common channel case, when the vaginas are low and closer to the perineum, the surgeon may need to do a total urogenital mobilization and then deliver that mobilized urogenital complex into the abdomen.
Sometimes dissection in the abdomen then allows this complex to reach the perineum.
Often, though, at this point, the urinary tract and vaginas must be separated and the neourethra tubularized. These are delicate maneuvers.
Often, the bladder must be opened in the midline, and feeding tubes placed into the ureters to protect them. In these types of malformations there is an extensive common wall between vagina and bladder.
Both ureters run through that common wall, and therefore during separation of the vagina from the urinary tract, the ureters must sometimes be skeletonized and thus need to be protected.
Once the separation has been completed, if the vagina does not reach, the surgeon has to make decisions about the vaginal reconstruction on the basis of specific anatomic findings.
Within the abdomen, the patency of the mullerian structures are investigated by passing a No. 3 feeding tube through the fimbriae of the fallopian tubes and injecting saline. If one of the systems is not patent, the atretic mullerian structure should be excised, with great care taken to avoid damage to the blood supply of the ipsilateral ovary.
When both mullerian structures are atretic, they should be left in place.
The patient must be monitored closely and further investigated with ultrasound when she enters puberty.
Coran
77
Which patients are candidates for the vaginal switch maneuver?
A specific group of patients are born with hydrocolpos and two hemivaginas. The hemivaginas are large and the two hemiuteri are separated, the distance between them being longer than the vertical length of both hemivaginas.
In these cases it is ideal to perform a maneuver called a “vaginal switch” (Fig. 103-23).
One of the hemiuteri and the ipsilateral fallopian tube is resected with particular care taken to preserve the blood supply of the ovary.
The blood supply of the hemivagina of that particular side is sacrificed.
The blood supply of the contralateral hemivagina is preserved and provides for both hemivaginas.
The vaginal septum is resected, and both hemivaginas are tubularized into a single vagina by taking advantage of the long lateral dimension of both hemivaginas.
Then, what used to be the dome of the hemivagina where the hemiuterus was resected is turned down to the perineum.
This is a useful maneuver that can be performed only when these specific anatomic characteristics are encountered.
Coran
78
Which patients are candidates for vaginal replacement?
In a patient with a small vagina(s) or in the rare case of an absent vagina, a vaginal replacement is required. In such cases the choices are rectum, colon, or small bowel.
When the patient has internal genitalia or an upper blind vagina, the upper part of the bowel used for replacement should be sutured to the vaginal cuff.
When the patient has no internal genitalia (no vagina and no uterus), a vagina is created and left with its upper portion blind and used only for sexual purposes.
Rectum: This form of vaginal replacement is feasible only in patients who have a good size rectum that is large enough to be able to divide it transversely or longitudinally into a portion with its own blood supply that will form a new vagina and another portion with enough circumference to reconstruct an adequately sized rectum.
The blood supply of the rectum will be provided transmurally from branches of the inferior mesenteric vessels. This can also work for patients with a rectosigmoid long enough to allow the distal portion to be used as a new vagina with its own blood supply and the upper portion to be pulled down as the new rectum.
Colon: The colon is an ideal substitute to replace the vagina. However, sometimes the location of the colostomy interferes with this type of reconstruction.
The left colon or sigmoid work well because their arcades reach the perineum nicely. Sometimes taking the colostomy down and using its distal segment for the vaginal graft is a helpful maneuver.
Small Bowel: When the colon is not available, the most mobile portion of the small bowel is used for vaginal reconstruction. The mesentery of the small bowel is longest in an area located approximately 15 cm proximal to the ileocecal valve, which is the best portion of the small bowel for vaginal replacement. A portion of the ileum is isolated and pulled down while preserving its blood supply.
In the highest type of cloaca one may find two little hemivaginas attached to the bladder neck or even to the trigone of the bladder. In these cases the rectum also opens in the trigone.
Separation of these structures is done abdominally. Unfortunately, when the separation is completed, the patient is frequently left with either no bladder neck or a severely damaged one.
At that point the surgeon must have enough experience to make a decision whether to reconstruct the bladder neck or close it permanently.
In the first situation, most patients will require intermittent catheterization to empty the bladder. A vesicostomy is created in such cases, and the patient will require a continent diversion type of procedure and possibly a bladder neck procedure and/or bladder augmentation, done at the age of urinary continence (3 to 4 years old). In this particular type of malformation, the patient usually also needs a vaginal replacement, which should be performed in one of the ways previously described.
At the time of colostomy closure, endoscopy should be performed to be sure that the repair is intact and that there is no prolapse, stricture, or urethrovaginal fistula. If the cloaca repair did not require laparotomy, the time of colostomy closure is the opportunity to investigate the patency of the mullerian structures.
Coran
79
Among different anorectal malformation, which of the following condition does not needs colostomy?
A. Perineal fistula.
B. Rectourethral fistula.
C. Rectovesical fistula.
D. Imperforated anus without fistula.
E. Rectal atresia.
A
The perineal fistula needs only anoplasty.
Syed/MCQ
80
In the girls with anorectal malformation, which of the following conditions is the most common?
A. Rectovesical fistula.
B. Rectovestibular fistula.
C. Rectovaginal fistula.
D. Rectourethral fistula.
E. Common cloaca.
B
Rectovestibular fistula.
81
Which of the following is not a feature of low imperforate anus?
A. Skin tag.
B. Bucket-handle malformation.
C. Anal dimple.
D. Flat perineum.
E. Perineal fistula.
D
Flat perineum is a feature of intermediate or high anorectal malformation.
Syed/MCQ
82
What is false about the levatorani muscle?
A. Normally the rectum is surrounded laterally and posteriorly by levatorani muscle mechanism.
B. In imperforate anus with recto-vesical fistula, levatorani lies posterior and lateral to rectum.
C. When levator ani contracts, it pushes the rectum forward.
D. All of the above are true.
E. All of the above are false.
E
All the above statements are true.
Syed/MCQ
83
In persistent cloaca, a common channel of what length has poor sphincter mechanism?
A. >O.5 cm.
B. >1 cm.
C. >1 cm
D. >2 cm.
E. >3 cm.
E >3 cm
Syed/MCQ
84
In male neonates with anorectal malformation, clinical evidence is present on perineal inspection in what percentage of cases?
A. 50 percent.
B. 60 percent.
C. 70 percent.
D. 80 percent.
E. 90 percent.
E 90 percent
Syed/MCQ
85
In boys, the definitive procedure of intermediate type of imperforate anus is:
A. Anoplasty
B. Colostomy.
C. Posterior sagittal anoplasty.
D. Posterior sagittal anorectoplasty (PSARP).
E. Anal repositioning
D
Posterior segital anorectoplasty (PSARP). Colostomy is the early treatment for this condition.
Syed/MCQ
86
Disadvantage of transverse colostomy, in comparison to descending colostomy in imperforate anus include all except:
A. Long segment is available for mobilization at the time of definitive procedure.
B. Metabolic acidosis and constipation.
C. Increased fluid and electrolyte loss.
D. Distal part difficult to wash.
E. Increased incidence of UTI, if fistula.
A
This is an advantage to having long segment for mobilization at the time of definitive procedure.
Syed/MCQ
87
The goal of surgery in persistent cloaca include all except:
A. Separation of rectum from vagina.
B. Separation of vagina from urethra.
C. Placement of rectum within sphincter mechanism.
D. Opening of vagina in its normal location.
E. Reconstruction of old common channel as a neo-vagina.
E
Old common channel is reconstructed as neo-urethra.
Syed/MCQ
88
In a post-operative child with anorectal malformation, which of the following is true?
A. Dilatation is started on the second month.
B. A baby pushing during each bowel movement indicates that there is some feeling during defecation process, has good prognosis.
C. Few patients have functional disorder.
D. Gas during defecation is not felt by most of patients.
E. Loss of recto-sigmoid has good prognosis.
B
A baby pushing during each bowel movement indicates that there is some feeling during defecation process and have good prognosis. Anal dilatation is started on first month. Some degree of functional disorder after repair of anorectal malformation is experienced by most of patients, due to congenital deficiencies, which are not correctable. Liquid stool, which does not distend the rectum are not felt by most of patients. Procedure in which recto-sigmoid is lost indicates reservoir is lost, leading to greater tendency to pass stool constantly.
Syed/MCQ
89
High type anorectal malformation includes all except:
A. Anorectal agenesis with recto-urethral fistula.
B. Anorectal agenesis with rectovaginal fistula.
C. Anorectal agenesis without fistula.
D. Anocutaneous fistula.
E. Rectal atresia.
D
Anocutaneous fistula is considered as low anomaly.
Rectovestibular fistula is considered as intermediate/high anomaly.
Syed/MCQ
90
Features of high anomaly in anorectal malformation include all except:
A. Flat perineum.
B. Little musculature.
C. Long sacrum.
D. Recto-vestibular fistula.
E. Rectovaginal fistula.
C
Short sacrum is a feature of high anomaly.
Syed/MCQ
91
For the child with high-type imperforate anus with colostomy, the most important investigation required before definitive procedure is:
A. MRI.
B. CT scan.
C. Distal colostogram.
D. Micturating cystourethrogram (MCUG).
E. Renal ultrasound.
C
Distal colostogram to exclude distal obstruction, shows level of rectal pouch, and also shows fistula if any.
Syed/MCQ
