Ch 93 colon Flashcards

Question

List options for colonic wound closure

Answer 1

Suture Staples (GIA, EEA, TA, Skin) Biofragmentable anastomotic ring Laser Cyanoacrylates Fibrin Glue - A topical haemostat, sealant and tissue adhesive comprised of thrombin and fibrinogen that is approved by the US FDA for colonic sealing in humans. Experimentally mixed results…

Answer 2

- single-layer, simple interrupted, appositional pattern - low complication rate > “the current standard of care in veterinary surgery.” - appositional anastomosis produced less scar tissue and morbidity than inverting or everting material - monofiliament absorbable - debate as to the efficacy of triclosan-coated suture material in reducing colonic surgical site infection rate

Answer 3

- Meta-analysis of the human literature suggests that stapled colonic wounds are at a reduced risk for leakage and dehiscence compared to hand-sutured wounds - EEA device, which creates a true inverting anastomosis - device can be placed transcecally, through an enterotomy, or transrectally

Answer 4

- thorough clinical examination, including hydration, bloodwork etc - RADS: extraluminal masses or malunion of pelvic bone, - retrograde contrast or air study - colonic ultrasonography may be challenging, good for imaging mesenteric and sublumbar (medial iliac) lymph nodes endoscopy - advantage of providing access for direct biopsy - patient should be fasted for 24 to 48 hours

Answer 5

Barium sulphate diluted 1 part barium to 4 parts warm water and 8ml/kg is allowed to flow under the influence of gravity through a balloon catheter to fill the colon and caecum

Answer 6

No preparation needed. Do not want to make the faeces liquid. No oral preoperative antibiosis required but perioperative IV ABx are recommended 1hr prior to surgery and repeated intra-op as needed. Combo of cefazolin and metronidazole recommended

Answer 7

Carprofen has been shown to cause sloughing of the colonic epithelium and erosion of the colonic mucosa Epidural is controversial as it can alter the myoelectrical impulses causing uncordinated propulsion. This combined with early feeding has been shown to lead to intussusception Ketamine - Provides no basic change in gastrointestinal motility. A good choice Opioids - Can cause ileus Paracetamol - a useful alternative to NSAIDS. NOT in cats

Answer 8

High-residue, low-fat diet to promote normal motility suggested. The ideal diet has not been determined

Answer 9

Inversion, impaction, perforation, severe inflammation neoplasia - Continuous Parker-Kerr suture pattern (over haemostat) recommended (to invert edges), can be reinforced with a continuous inverting Lembert - Alternatively, a TA or GIA stapling device may be used across the base of the cecum. Stapling creates everted wound edges *ileocecal fold and the small accessory ileocecal fold that attaches the ileum to the proximal colon are transected, taking care not to damage the antimesenteric ileal vessels* | after closing cecocolic wound, always change gloves and instruments

Answer 10

megacolon, neoplasia, perforation, trauma chronic intussusception - Ligation of individual vasa recta rather than occlusion of main blood vessels - subtotal or total colectomy, distal transection approximately 2 cm cranial to the pelvic brim and 1 cm caudal to the site where the caudal mesenteric artery penetrates the serosa - ileocolic valve is to be preserved, as in subtotal colectomy - Luminal disparity can be addressed by spatulating the small lumen - hadn sewn: appositional, 4-0 or 3-0 polydioxanone or polyglyconate - omentum should be tacked along the anastomosis site. - staplers EEA - Biofragmentable Anastomosis Ring

Answer 11

EEA stapling deviced are recommended to be used transcaecally in cats as apposed to transrectally. 2/10 cats which underwent a transrectal approach developed a stricture at the anastomosis site Furniss Purse-string instrument Most cats require a 25 or 21mm cartridge | Ovoid sizers are essential to allow measurement of bowel diameter

Answer 12

Furniss pursestring instrument (To be used as part of EEA stapler)

Answer 13

End-on colostomy Flank loop colostomy

Answer 14

end-on colostomy - entire end of the proximal segment of the colon is brought full thickness through the body wall at a perpendicular angle. - Interrupted sutures between the serosa and abdominal wall musculature - end of the colon (mucosa and submucosa) is anastomosed to the skin. - If the distal colon is retained, the procedure is potentially reversible flank loop - colon is left intact, and a small segment is prolapsed through a lateral abdominal wall incision. - a plastic subcutaneous rod entraps the colon segment superficially. - A 4-cm-diameter circle of skin is removed, and the colonic mucosa is sutured to the skin - Flank loop colostomy can be reversed by resecting the mucocutaneous junction and closing the stoma - render the patient fecally incontinent

Answer 15

- located in the descending colon that extend into the cranial to middle third of the rectum - midline caudal celiotomy is performed - to make the procedure feasible, the proximal retained portion of the colon must be able to reach the distal rectum, and the anastomosis must not be under tension - colon is divided 5 cm or more from the cranial aspect of the tumor - Colonic ends are oversewn with a continuous Parker-Kerr - two colonic ends are then tied together + laparotomy is closed. - rectal wall is everted through the anus, and the rectum is incised full thickness at least 1.0 to 1.5 cm from the anus to preserve the distal rectum - sutured colonic stumps are pulled through the anus - the colonic end is anastomosed to the distal rectum

Answer 16

Bleeding and tenesmus are expected - usually self limiting and resolve within 2 weeks Faecal incontinence - Usually resolves if 1-1.5cm of distal rectum has been left in placed. Resolution can take up to 5 months Wound dehisence and subsequent peritonitis - Commonly reported

Answer 17

Simple appositional Incisional | indications: rectal prolapse, perineal hernia

Answer 18

Inversion - may present with acute signs of obstruction. - Confirmation of diagnosis requires positive-contrast radiography, ultrasonography or colonoscopy. - Management involves colotomy and typhlectomy Impaction Neoplasia - GIST most common, adenocarcinomas and undifferentiated sarcomas - The treatment of choice is mass removal. Excision may require resection of the cecum, distal ileum, and proximal colon to achieve adequate tumor-free margins. - Prognosis good with complete excision. MST 681 days, 1yr and 2yr recurrence free in 83.3% and 61.9%

Answer 19

End-stage obstipation characterised by colonic hypomotility and a permanent increase in the diamter of the colon as a result of severe and irreversible dilatation. Can be mechanical, functional or commonly idiopathic

Answer 20

Mechanical Causes - Hypertrophic megacolon can develop with any form of outlet obstruction and is potentially reversible if the cause of the obstruction is removed early in the disease process - pelvic fracture malunion is the most common cause of hypertrophic or obstructive megacolon in cats Functional Causes Acquired megacolon secondary to neuromuscular dysfunction occurs as a consequence of spinal cord disease,

Answer 21

62% idiopathic; 23% pelvic stenosis, 6% neurologic disorders, 5% Manx cats with idiopathic megacolon present with a dilated colon and no evidence of physical or functional obstruction. There is thought to be a generalized dysfunction of longitudinal and circular smooth muscle (casue or effect of obstruction?) feline megacolon is rarely successfully managed medically

Answer 22

Normal colon diameter is approx equal to the length ot the **vertebral body of L2** on a lateral projection Megacolon is diagnosed if the colonic diameter is 1.5x the length of the verteral body of L7 on a lateral projection

Answer 23

When the colon has been dilated for 6 months or longer. Medical management consists of stool softeners, warm-water enemas with lubricant, IV ABx during manual deobstipation, dietary fibre, lactulose, cisapride Cisapride is no longer available on the market due to its cardiotoxicity and fatal arrhythmias seen in humans. This is exacerbated by the concurrent use of macrolide antibiotics or antifungals Surgical treatment is a subtotal colectomy

Answer 24

Laxatives Addition of dietary fiber is well tolerated, effective, and more physiologic than other laxatives - lactulose: disaccharide that is not hydrolysable by mammals; instead, it is metabolized by colonic bacteria, resulting in the formation of low-molecular-weight organic acids. These acids increase intraluminal colonic osmotic pressure

Answer 25

They cause rapid dehydration, hypocalcaemia, hypophosphataemia and death

Answer 26

- preserve the ileocolic junction and transects the ascending colon 1 to 2 cm distal to the cecum. The descending colon is resected 2 cm cranial to the pelvic brim - 4/0 PDS | correct pelvic fracture or perineal hernia if <6mths duration

Answer 27

This is a debated topic… Ileocolic valve helps to prevent retrograde movement of colonic material into the small intestine and subsequent bacterial overgrowth Increased incidence of severity of diarrhoea seen with removal of ileocolic junction however there is no greater incidence of recurrence in cats which do not have the junctions removed. Preservation of the ICJ is recommended where possible

Answer 28

Loose stools initially due to decreased absorptive capacity and transit time. With time, the remaining intestine adapts by increasing villus heigth, enterocyte number and density (Experimentally, normal enteric motility takes 8 weeks to reestablish) Cats in which the ICJ is removed are likely to have poorly formed faeces for up to 3 months and some may be incontinent. A small proportion will have soft faeces for years Recurrence is uncommon (usually be managed medically unless an obstruction is present i.e stricture > consider repeat Sx)

Answer 29

rare - some involved the left colic and caudal mesenteric vessels, resulting in ischemia of the transverse and descending colon - Cecocolic volvulus compromises the cranial mesenteric artery, similar to that seen in true mesenteric volvulus - Cecocolic volvulus therefore results in dilatation, congestion, and ischemia of the cecum and small intestine and colonic dilatation. - Abdominal radiographs reveal marked gaseous distention of intestine loops, particularly in the caudal abdomen. - Treatment includes aggressive fluid resuscitation, antibiotics, analgesics, and exploratory celiotomy.

Answer 30

Depends on the duration and degree of the volvulus. However, 3 of 6 dogs described in the literature and the only cat, died despite intensive treatment

Answer 31

Following OVH or castration - prognosis good after resection of the fibrous band compressing the colon Following rupture of the duodenocolic ligament in a GSD and a St. Bernard - colon and small intestine are located in the right side of the abdomen because of herniation through the torn duodenocolic ligament.

Answer 32

Dogs - Most common adenocarcinoma (MST with Sx 6-22m) Cats - Most common lymphoma and adenocarcinoma. Highly metastatic (80% ADC, 75% lymphoma, 75% MCT). MST 49 - 138d, can be increased to 280d with chemo Recommended margins are 5-8cm of healthy intestine on each side Placement of a colonic stent is an option for palliative care - mixed results in the literature

Answer 33

- Surgical resection is advocated for nonmetastatic nonlymphomatous lesions - enterocolic, colocolic, or colorectal anastomosis. - Colorectal anastomosis can be either immediately cranial to the pelvic brim, within the pelvic canal via osteotomy or via a combined abdominal transanal pull-through procedure. - preoperative metastasis is present, surgery is palliative, and adjunctive procedures, such as chemotherapy or intraoperative irradiation of metastatic lymph nodes, should be considered.

Answer 34

Type 1 - The duplications is limited to the colon and rectum Type 2 - The duplication is associated with other congenital abnormalities such as urogenital duplication and vertebral column abnormalities Subclassified into spherical noncommunicating, tubular noncommunicationg and tubular communicating Surgical treamtent is recommended even if asymptomatic as they have been associated with neoplastic transformation in humans. Surgical options include division of the common septum, side-to-side anastomosis, excision of noncommunicating portion, mucosal stripping.

Answer 35

Retrospective. Complications cecal or colonic surgery in dogs: 79 complication and mortality rates full thickness vs partial thickness not statistically different. Dehiscence colonic anastomosis (8.5%). prolonged healing and increased collagenase activity theoretically increasing the risk for intestinal dehiscence dehiscence and mortality rates of 10% and 17%, respectively (Latimer et al., 2019). Five out of the nine dogs diagnosed with dehiscence died or were euthanased

Answer 36

Study design: Randomized, experimental cadaveric study. Animals: Twenty-four fresh canine cadavers (TA 30 V3 2.5 mm, TA 60 3.5 mm, and TA 60 4.8 mm). The results of this cadaveric study support the use of any of the stapler sizes evaluated in similarly sized dogs. A prospective study is needed to be able to correlate stapler size and clinical outcome

Answer 37

166 client-owned cats. retrospective cohort study Major perioperative complications 10% dehiscence rate was 2.1% (3/142) 14% (12/87) of cats died as a direct result of treatment or complications of megacolon. revision surgery (3/24 [13%]). The median survival time was not reached Constipation recurrence occurred in 32% ICJ removal was associated with long-term liquid feces and a fair or poor outcome on owner assessment

Answer 38

Animals: Colon from 11 canine cadavers. hand-sewn colonic anastomoses performed with 4-0 glycomer 631 (G) and 4-0 barbed glycomer 631 (BG), and circular stapled colonic anastomoses using 4.8 mm Endto- End Anastomosis (EEA C4.8mm) and 3.5 mm End-to-End Anastomosis (EEA C3.5mm), Anastomoses leaked at lower pressures when stapled rather than hand-sewn Use of the EEA stapler with a staple height of 3.5 mm did not result in safe colonic anastomoses. Clinical significance: These results provide evidence to support handsuturing colonic anatomoses with G and BG in dogs. The 4.8 mm staples may be considered in anatomical locations difficult to reach.

Answer 39

The overall dehiscence and survival to hospital discharge rates were 8.3% (7/84 cats) and 94% (79/84 cats colonic trauma or dehiscence and postoperative intestinal dehiscence were associated with failure to survive to hospital discharge Factors suggestive of systemic illness were associated with colonic dehiscence or death, and focused prospective studies of risk factors are warranted Factors associated with dehiscence only included hypoalbuminemia, renal dysfunction, administration of blood products or > 2 classes of antimicrobials, and intra-abdominal fecal contamination.

Answer 40

Experimental, ex vivo. Sample population: Grossly normal cecal segments from 24 adult canine cadavers. simple continuous closure with a Parker-Kerr pattern with 4-0 polydioxanone (group 1), closure with a 60-mm gastrointestinal stapler loaded with a 3.8-mm staple cartridge (group 2), and placement of a Cushing suture to augment the stapled closure (group 3). provide evidence to support placement of a Cushing suture pattern to augment the staple line for typhlectomies in dogs, although in vivo studies are required to determine the clinical significance of these findings.

Answer 41

The case described here represents a unique combination of anatomic anomalies including a communicating colonic duplication and a concomitant anogenital cleft

Answer 42

retrospective 90 dogs death and intestinal dehiscence following full-thickness large intestinal incisions dehiscence and mortality rates were (10%) and (17%). Preexisting colon trauma or dehiscence, preexisting peritonitis, administration of blood products, administration of > 2 classes of antimicrobials associated with development of intestinal dehiscence. 5/9 intestinal dehiscence died/euthanized. failure to survive > suggestive of sepsis. dehiscence rate may not be as high as previously reported, theorised more likely because: poor collateral blood supply, high intraluminal pressure of faecal boluses, and higher bacterial load

Ch 93 colon Flashcards

(68 cards)