2024 Flashcards
A 45-year-old man is scheduled to undergo abdominal wall reconstruction after being involved in a major motor vehicle collision that resulted in multiple intra-abdominal injuries 1 year ago. He underwent trauma laparotomy, which resulted in an open abdomen and a prolonged hospital course. Skin grafting of the bowel was performed, and the patient has since been living with a large ventral hernia. Preoperative injection of botulinum toxin type A into the lateral abdominal wall will most likely result in which of the following?
* A) Decreased incidence of wound healing complications
* B) Decreased length of hospital stay
* C) Increased infection rate
* D) Increased likelihood of primary fascial closure
* E) Prolonged ventilator dependence
The correct response is Option D.
Prehabilitation of the abdominal wall through botulinum toxin type A (BTA) injections into the lateral abdominal wall musculature of patients with large ventral hernias and loss of domain has been demonstrated in multiple studies and meta-analyses to increase the likelihood of primary fascial closure. Advocates for its use have used varying types of BTA, doses, number of injections, and timing of injections, but results have consistently shown that its use has decreased the number of patients requiring bridging of the repair. Based on the mechanism and peak effect of BTA, studies using the injections at the time of repair have been less effective than their use 2 to 4 weeks prior to the planned operation. Radiologic assessment of the patients at the time of injection and immediately prior to surgery have demonstrated a lengthening of the lateral abdominal wall musculature and decrease in the width of the midline hernia. This lengthening and relaxation results in the decreased excursion distance and improved compliance of the abdominal wall, thus allowing for increased numbers of primary fascial closures with or without component separation. Larger scale studies are needed to determine other benefits of its use in this population. There are mixed results related to improved pain control, with some studies reporting a reduction in oral morphine equivalents, while others show no statistical difference. Improvement in complication rates such as hospital stay and recurrence are not consistent across studies. The use of tissue expanders and progressive preoperative pneumoperitoneum have also shown promise as adjuncts to abdominal wall reconstruction. These have been used alone and in conjunction with BTA injections with improved results regarding achieving primary fascial closure. Since these are more invasive procedures, they do carry unique risks (tissue expander infection/extrusion, intra-abdominal organ injury) that need to be factored into the operative plan. The use of prehabilitation with BTA has not been shown to decrease length of hospital stay or incidence of wound breakdown, nor has it been shown to prolong ventilator dependence or increase infection rate.
References(s)
- Timmer AS, Claessen JJM, Atema JJ, Rutten MVH, Hompes R, Boermeester MA. A systematic review and meta-analysis of technical aspects and clinical outcomes of botulinum toxin prior to abdominal wall reconstruction. Hernia. 2021;25(6):1413-1425. doi:10.1007/s10029-021-02499-12.
- Soltanizadeh S, Helgstrand F, Jorgensen LN. Botulinum toxin A as an adjunct to abdominal wall reconstruction for incisional hernia. Plast Reconstr Surg Glob Open. 2017;5(6):e1358. doi:10.1097/GOX.0000000000001358
- Bueno-Lledó J, Carreño-Saenz O, Torregrosa-Gallud A, Pous-Serrano S. Preoperative botulinum toxin and progressive pneumoperitoneum in loss of domain hernias-our first 100 cases. Front Surg. 2020;7:3. doi:10.3389/fsurg.2020.00003
- Wegdam JA, de Vries Reilingh TS, Bouvy ND, Nienhuijs SW. Prehabilitation of complex ventral hernia patients with botulinum: a systematic review of the quantifiable effects of botulinum. Hernia. 2021;25(6):1427-1442. doi:10.1007/s10029-020-02333-0
- Weissler JM, Lanni MA, Tecce MG, Carney MJ, Shubinets V, Fischer JP. Chemical component separation: a systematic review and meta-analysis of botulinum toxin for management of ventral hernia. J Plast Surg Hand Surg. 2017;51(5):366-374. doi:10.1080/2000656X.2017.1285783
- Alam NN, Narang SK, Pathak S, Daniels IR, Smart NJ. Methods of abdominal wall expansion for repair of incisional herniae: a systematic review. Hernia. 2016;20(2):191-199. doi:10.1007/s10029-016-1463-0
A 42-year-old man with HIV infection who is compliant with antiretroviral therapy presents with facial lipoatrophy. He is interested in improving his temporal hollowing. Which of the following is the most appropriate next step in management?
A) Administering botulinum toxin type A to the temporalis muscles
B) Augmenting oral diet with parenteral nutrition and assessing prealbumin concentration weekly
C) Autologous fat grafting to the temporal area
D) Contouring with a parascapular free flap
E) Discontinuing HIV medications for 3 months and reassessing
The correct response is Option C.
The patient has HIV-associated facial lipodystrophy. This is characterized by redistribution of adipose tissue, resulting in central fat deposition including dorsocervical (ie, “buffalo hump”) or atrophy of subcutaneous adipose tissue including malar and temporal. Treatment for facial lipoatrophy includes use of fillers in the areas of subcutaneous deficiency; poly-l-lactic acid has been described as well as autologous fat transfer.
Although nucleoside reverse transcriptase inhibitors can cause lipodystrophy, stopping the medication does not typically reverse the facial lipoatrophy. In addition, stopping HIV medications in general would not be advisable. While nutrition is important, parenteral nutrition would not reverse HIV-related lipodystrophy. Contouring with a parascapular free flap can sometimes be performed in cases of progressive facial hemiatrophy (Parry-Romberg syndrome), but this would be an excessive next step in management of HIV-associated facial lipodystrophy. Administration of botulinum toxin type A to the temporalis muscle can be used for temporal headaches. It would not help the soft-tissue atrophy found in this patient.
A 28-year-old woman undergoes cosmetic augmentation mammaplasty with silicone implants. Which of the following organisms is most likely to contribute to a biofilm associated with this patient’s procedure?
A) Candida albicans
B) Citrobacter koseri
C) Enterococcus faecalis
D) Escherichia coli
E) Staphylococcus epidermidis
The correct response is Option E.
A biofilm is a microbial community that produces an extracellular polymeric substance matrix, which allows the microorganisms to adhere together and to surrounding surfaces.
Biofilms are prevalent, pervasive, and may contribute to up to 80% of all infections. Biofilms are a significant risk when associated with indwelling medical prostheses. A strong clinical correlation is found in human clinical studies between the presence of biofilm and subclinical infection leading to capsular contracture of breast implants. This is related to the chronic inflammatory state of a biofilm, which may upregulate proinflammatory cytokines, which can activate myofibroblasts and contribute to capsular contracture.
Multiple interventions to decrease implant contamination at the time of surgery have been studied, including occlusive nipple shields, implant funnels, antimicrobial pocket irrigation fluids, intravenous antibiotics, and surgical techniques including choice of incision and implant pocket.
The detection of a subclinical infection in the form of biofilms has recently been confirmed in multiple studies. Staphylococcus epidermidis is part of the microflora of the skin and endogenous breast flora, and it has been implicated in the majority of detected breast implant biofilms. These bacteria could gain access to implants during surgery, particularly when a peri-nipple-areola or trans-nipple-areola approach is performed. Enterococcus faecalis, Escherichia coli, Candida albicans, and Citrobacter koseri all may contribute to breast implant biofilm and infection, but multiple studies have shown that one of the most common organisms associated with breast implant biofilm is coagulative-negative staphylococci.
A 75-year-old White woman is evaluated because of an 8-month history of a lesion with indistinct borders along a pre-existing scar at the junction of the lower right eyelid and cheek. The patient underwent resection of a basal cell carcinoma of the right cheek 19 months ago. Examination of a specimen obtained on biopsy of the eyelid-cheek junction lesion 2 weeks ago confirms the diagnosis of basal cell carcinoma. Which of the following is the most appropriate next step in management?
A) Application of topical 5-fluorouracil
B) Cryotherapy
C) Mohs micrographic surgery
D) Radiation therapy
E) Wide local excision
The correct response is Option C.
The patient has a recurrent basal cell carcinoma in a cosmetically sensitive area. Basal cell carcinoma is the most common type of skin cancer and originates in the epidermis. Risk factors include age, smoking, ultraviolet radiation exposure, and basal cell nevus syndrome. Basal cell carcinomas grow locally invasive, causing extensive destruction if not treated.
The standard treatment of basal cell carcinoma is excision with adequate margins. Many treatment modalities exist; however, some do not provide a tissue sample to confirm adequate tumor clearance (eg, radiation therapy, cryotherapy, electrodessication, and topical 5-fluorouracil).
In this clinical scenario, Mohs micrographic surgery is the most appropriate treatment modality, as the lesion represents tumor recurrence with indistinct borders in a cosmetically sensitive area. When compared with wide local excision, Mohs micrographic surgery has been demonstrated to be associated with decreased recurrence rates while preserving the greatest degree of uninvolved tissue.
A 45-year-old woman presents to the clinic for autologous breast reconstruction. Reconstruction with a lumbar artery perforator flap is planned. The pedicle of this flap travels between the erector spinae muscle and which of the following other muscles?
A) Latissimus dorsi
B) Psoas major
C) Psoas minor
D) Quadratus lumborum
E) Transversus abdominis
The correct response is Option D.
The lumbar artery perforator flap is an option for autologous breast reconstruction. Within the flap, the cluneal nerve can be harvested for sensation. The flap is based off of the lumbar artery perforator (L4), which runs lateral to the erector spinae muscle, with the quadratus lumborum muscle on the other side. The perforator does not run in between the other muscles listed.
A 45-year-old woman with right-sided breast cancer undergoes bilateral mastectomy and immediate breast reconstruction with abdominally based free flaps. During microvascular anastomosis, topical papaverine is used. Which of the following best describes the mechanism of action for this drug?
A) Alpha-adrenergic receptor antagonist
B) Calcium channel blocker
C) Direct smooth muscle spasmolytic agent
D) Phosphodiesterase inhibitor
The correct response is Option D.
The mechanism of action of papaverine is a phosphodiesterase inhibitor.
Papaverine is one of the most commonly used antispasmodic medications during microsurgical cases. It belongs to a class of drugs known as phosphodiesterase inhibitors. The usual concentration used is 30 mg/dL. Phosphodiesterase inhibitors antagonize phosphodiesterase, the function of which is to inactivate cyclic guanosine monophosphate. Increased concentration of this second messenger within vascular smooth muscle cells inhibits the action of myosin light chain kinase, ultimately resulting in relaxation and vasodilation. Calcium channel antagonism may be an additional mechanism of vasodilation. It acts within 1 to 5 minutes.
Topical nicardipine (1.5 mg/25 mL) has been used as a spasmolytic agent too. It is a calcium channel blocker. Topical 2% lidocaine (20 mg/mL) is another topical agent used, and though its exact mechanism of action for this activity is unknown as of yet, it is a direct smooth muscle spasmolytic. Other drugs that cause vasodilation, such as phentolamine, act as antagonists on the vascular smooth muscle alpha-adrenergic receptors.
A 60-year-old woman with a history of hormone-positive breast cancer presents for consultation for autologous breast reconstruction with deep inferior epigastric artery perforator flaps in a delayed fashion. She is currently taking anastrazole. To address thromboembolic risk, this drug should be held for which of the following intervals at the time of the operation?
A) 0 weeks before and 0 weeks after surgery
B) 2 weeks before and 0 weeks after surgery
C) 2 weeks before and 2 weeks after surgery
D) 4 weeks before and 0 weeks after surgery
E) 4 weeks before and 2 weeks after surgery
The correct response is Option A.
Anastrazole is an aromatase inhibitor, a type of hormonal therapy that is given for treatment of postmenopausal women diagnosed with hormone-positive breast cancer. Aromatase inhibitors are a class of drug that do not need to be stopped (held) perioperatively for microvascular operations. Other types of hormonal agents, like tamoxifen, have a known risk for blood clotting and therefore have historically been felt to have an increased risk for microvascular thromboses and flap loss. The data on tamoxifen, a selective estrogen receptor modulator, are mixed, with some studies finding an increased risk for microvascular compromise, while others do not. The original publication by Kronowitz in 2012 found an increase in flap loss and decrease in flap salvage in patients who had been treated with tamoxifen within 28 days of microvascular surgery, and as a result recommended holding it for 28 days prior to operation. Other papers have since reported no increased events in shorter time period (ie, 2 weeks) or no increased events without holding it at all. While the data are inconclusive on whether to hold tamoxifen, and for how long, multiple studies have demonstrated no increased microvascular risks in allowing patients to continue their aromatase inhibitors.
A 19-year-old woman comes to the office for consultation regarding improvement of the appearance of her breasts. As an avid athlete, she declines latissimus flap reconstruction. A photograph is shown. Which of the following is the most appropriate next step in management?
- A) Bilateral prophylactic skin-sparing mastectomy with a prepectoral custom-made implant
- B) Deferring surgical management until age 21 years
- C) Left vertical mastopexy
- D) Placement of a total submuscular tissue expander in the right breast
- E) Reconstruction with a right deep inferior epigastric artery perforator free flap
The correct response is Option E.
Poland syndrome is a congenital condition characterized by complete or partial pectoralis major muscle agenesis, breast and nipple aplasia or hypoplasia, and chest wall and rib malformation. A subset of patients have ipsilateral arm/hand maldevelopment, including brachydactyly and possibly syndactyly.
Reconstruction with a deep inferior epigastric artery perforator free (DIEP) flap is the best option from the choices. Because of the chest wall abnormalities, the anatomy of the internal mammary artery should be considered in selecting the recipient vessel. The internal mammary artery may be abnormally small or course retrosternal, and the thoracodorsal artery may need to be considered. The images show a staged postoperative picture following DIEP and before revision.
Although expansion of the skin may be a reasonable initial choice, placement of a total submuscular tissue expander would be difficult because of the aplasia of the sternocostal head of the pectoralis major muscle and possibly the entire muscle. While a custom-made silicone implant would be a good choice for this patient, bilateral prophylactic mastectomy is not indicated for Poland syndrome in the absence of breast cancer or genetic elevated risk for breast cancer, such as BRCA. Earlier surgical management is preferred to improve psychosocial development, and waiting until age 21 years has no advantage. Left-sided mastopexy alone would not address the volume discrepancy between the right and left breast causing asymmetry.
A 40-year-old woman participates in a telehealth consultation to discuss abdominoplasty. She reports that she has hyperextensible skin and hypermobile joints, and she says that she bruises easily. This patient most likely has which of the following disorders?
A) Ehlers-Danlos syndrome
B) Leukoderma
C) Osteogenesis imperfecta
D) Systemic lupus erythematosus
E) Systemic sclerosis
The correct response is Option A.
Ehlers-Danlos syndrome is a group of connective tissue disorders characterized by joint hypermobility, skin hyperextensibility, tissue fragility, and poor wound healing. It is caused by abnormalities in collagen production or extracellular matrix expression.
Osteogenesis imperfecta, also known as brittle bone disease, is the most common inherited form of bone fragility. It is a heterogenous group of disorders, with the most common problem being disordered collagen type 1 production. Depending on disease severity, patients may have fractures from mild trauma, long bone bowing, kyphoscoliosis, craniofacial abnormalities, and dental abnormalities.
Systemic sclerosis, also known as scleroderma, is an autoimmune connective tissue disease. It is characterized by fibrosis of the skin and internal organs. The earliest clinical sign of disease is usually Raynaud phenomenon. Rate of progression of disease depends on the disease subtype. Skin fibrosis starts in the distal fingers and progresses proximally. Interstitial lung disease is the leading cause of death. Other organs involved include the kidneys, heart, gastrointestinal tract, and musculoskeletal system.
Systemic lupus erythematosus is a chronic autoimmune disease affecting the skin and internal organs like the kidneys, lungs, and heart. It is relapsing and remitting, with heterogenous clinical presentation. Malar rash and photosensitivity are pathognomonic clinical features.
Leukoderma, also known as vitiligo, is a localized area of skin depigmentation caused by loss of melanin.
A 5-year-old girl is evaluated because of dry, scaly skin and several lesions consistent with squamous cell carcinoma. The child’s parents report that she has a history of multiple sunburns with minimal sun exposure. The genetic cause of this patient’s condition is most likely a defect of which of the following?
A) Copper transport
B) Elastin
C) Fibrillin
D) Lysyl hydroxylase
E) Nucleotide excision repair
The correct response is Option E.
Xeroderma pigmentosum is caused by a defect in nucleotide excision repair. Affected individuals have sunburn with minimal exposure, dry skin, extensive photoaging, and a tendency for early development of nonmelanoma skin cancer.
Defects in fibrillin are implicated in Marfan syndrome.
Lysyl hydroxylase is crucial for collagen cross-linking. It requires vitamin C and is implicated in scurvy and other conditions with impaired collagen cross-linking.
Elastin deficiency or defects result in loss of skin elasticity. This is the case with cutis laxa.
Defects of copper transport are implicated in Menke disease. These patients have poor muscle tone, growth failure, failure to thrive, and brittle hair.
A 1-day-old male newborn is evaluated because of an omphalocele. Which of the following embryologic processes is most likely responsible for this anomaly?
A) Incomplete closure of umbilical ring fascia
B) Patent processus vaginalis
C) Persistence of physiologic midgut herniation
D) Pleuroperitoneal fold defect
E) Rupture of amnion along the umbilical cord
The correct response is Option C.
Abdominal wall defects occur in up to 1 in 2000 live births. The two most common are omphalocele and gastroschisis. In an omphalocele, the abdominal wall defect is in the central abdomen in the umbilical region, and the intestinal contents are covered with a membrane. In gastroschisis, the defect is to the right of the umbilicus and intestinal contents are not covered by a membrane. There is no clear consensus about the exact etiology of these abdominal wall defects. Omphalocele is thought to be caused by failure of intestines to return to the abdominal cavity. During gestational week 6, the intestines herniate into the umbilical cord because of rapid intestinal elongation. They return to the abdominal cavity at 10 weeks. Failure of this return results in an omphalocele. One of the most widely accepted theories about the pathogenesis of gastroschisis is that it occurs because of rupture of the amniotic membrane along the right side of the umbilical cord. This allows evisceration through the abdominal wall defect.
Incomplete closure of the fascia of the umbilical ring leads to infantile umbilical hernias; most of these close spontaneously. The processus vaginalis is a protrusion of the peritoneum into the scrotum. Failure of obliteration results in hydroceles or inguinal hernias. The pleuroperitoneal folds separate the pleural and abdominal cavities. Failure of fusion of these folds results in congenital diaphragmatic hernias.
A 52-year-old man is evaluated because of a 2-month history of left axillary lymphadenopathy. Physical examination of the axilla shows no wound and a palpable enlarged lymph node, and a perspiratory malodor is noted. Which of the following types of glands is most likely responsible for the malodor?
A) Apocrine
B) Eccrine
C) Mammary
D) Meibomian
E) Sebaceous
The correct response is Option A.
Sweat glands include eccrine glands and apocrine glands. Apocrine sweat glands are prominent in the axilla and groin. They are activated during puberty and produce an odorous, viscous product. Eccrine glands are exocrine sweat glands found in the skin that function in thermoregulation by evaporation of sweat secreted by the gland. Mammary glands are milk-producing glands found in the breast. Meibomian glands are found in the tarsal plate and secrete meibum, an oily substance that prevents evaporation of tear film. Sebaceous glands are found in the skin and secrete sebum into the hair follicles to lubricate the skin and hair.
A 65-year-old man is scheduled to undergo mandible reconstruction with a fibula osteocutaneous free flap. Which of the following is most likely to increase the risk for pedicle thrombosis during this procedure?
A) Absence of postoperative systemic anticoagulation
B) Use of end-to-end anastomosis rather than end-to-side
C) Use of vasopressors to optimize hemodynamics
D) Vascular anastomosis to irradiated recipient vessels
E) Venous anastomosis to external jugular vein rather than internal jugular vein
The correct response is Option D.
Anastomoses performed in radiated fields have higher rates of flap loss compared with nonradiated recipient vessels in head and neck reconstruction. There is no difference in pedicle thrombosis rates between end-to-end and end-to-side arterial or venous anastomoses, as shown in a recent meta-analysis. There is no difference in vessel patency rates between the internal jugular and external jugular systems. Perioperative use of vasopressors for hemodynamic management has not been shown to increase the risk for flap pedicle thrombosis. However, intraoperative hypotension and large volume fluid administration are associated with increased risk for flap loss. Routine anticoagulation does not decrease the risk for flap pedicle thrombosis. It does, however, increase the risk for bleeding and hematoma formation.
A 45-year-old man is diagnosed with subungual melanoma in situ of the thumb. Which of the following is the most appropriate treatment to recommend?
A) Amputation at the carpometacarpal joint
B) Amputation at the interphalangeal joint
C) Amputation at the metacarpophalangeal joint
D) Wide local excision of the nail bed
The correct response is Option D.
The best recommendation is wide local excision of the patient’s nail bed.
Melanomas of the digits (including melanoma in situ and subungual melanomas) are often unnoticed and initially misdiagnosed, and therefore they are often present at a more advanced depth. Historically, these melanomas were thought to be more aggressive and treated with amputation of the involved digit; however, there is no evidence in the literature that demonstrates that amputation results in improved disease-specific or overall survival. Thus, there has been recent movement toward digit-preserving wide local excision (especially for melanoma in situ) with local flap reconstruction or full-thickness skin grafting.
A 20-year-old cisgender woman (46,XX karyotype) comes to the clinic seeking vaginal reconstruction for vaginal agenesis. Physical examination shows normal secondary sex characteristics with no limb or genitalia changes. Laboratory studies show normal sex hormone concentrations for a genetically female patient. Three-dimensional echocardiography shows no abnormalities. Abdominal and pelvic ultrasonography demonstrates normal renal anatomy and vaginal agenesis. Which of the following is the most likely diagnosis?
A) Complete androgen insensitivity syndrome
B) Hydrometrocolpos syndrome
C) Klinefelter syndrome
D) Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome
E) Partial androgen insensitivity syndrome
The correct response is Option D.
Patients with Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome have a female chromosome pattern (46,XX) with a congenital disorder of the reproductive tract, arising from Müllerian duct aplasia, characterized by the failure of the uterus and vagina to develop properly. Embryologic development of the Müllerian ducts forms the uterus, fallopian tubes, cervix, and upper third of the vagina. Patients with MRKH syndrome have normal ovarian function and normal external genitalia. Normal secondary sexual characteristics develop during puberty, except for the failure to begin a menstrual cycle (primary amenorrhea). Sex steroid concentrations are normal, including testosterone concentrations found in the normal female range. The disorder affecting only reproductive organs is classified as MRKH syndrome type 1. When hearing loss, renal developmental abnormalities, or cardiac defects are present, the condition is classified as MRKH syndrome type 2. The patient described in this scenario presents with MRKH syndrome type 1. Women with MRKH syndrome type 1 may present with absence of the vagina alone (vaginal agenesis) or absence of both the uterus and vagina. Vaginal agenesis can be diagnosed on physical examination with added information from ultrasonography or MRI studies. Patients with vaginal agenesis have options for both nonsurgical vaginal dilation and surgical vaginal reconstruction to permit sexual function.
Partial and complete androgen insensitivity syndrome (PAIS and CAIS) patients are genetically male (46,XY), with the syndrome occurring as a result of an X-linked recessive mutation in the AR gene that is responsible for making the androgen receptor. Patients with CAIS present at birth with female external sex characteristics and possible presentation of short or small vagina. PAIS patients may have varying degrees of female or male external sex characteristics at birth. All affected patients have undescended testes and testosterone concentrations in the “normal male range.” Androgen insensitivity syndrome patients are typically raised female. An initial clinical sign of CAIS or PAIS is the failure to start menstruation, which may prompt ultrasound studies that will demonstrate the absence of a uterus, fallopian tubes, and ovaries.
Klinefelter syndrome is a sex chromosome disorder in men that results from the presence of an extra X chromosome resulting in 47,XXY trisomy and development of male reproductive organs and presenting with small testes and primary testicular insufficiency.
Women born with McKusick-Kaufman syndrome present with hydrometrocolpos, postaxial polydactyly, and congenital cardiac defects. Hydrometrocolpos is a rare condition caused by distal vaginal obstruction with accumulation of blood (hemato-) or mucus (hydro-) secretions in the vagina and uterus. The most common cause of hydrometrocolpos is an imperforate hymen. The classifications of hydrometrocolpos are: type I (imperforate hymen), type II (vaginal septum), type III (distal vaginal atresia or agenesis), type IV (vaginal atresia with persistent urogenital sinus), and type V (vaginal atresia with cloacal anomaly).
A 30-year-old woman with a saddle-nose deformity is scheduled to undergo rhinoplasty. Placement of a costal cartilage graft is planned. Which of the following techniques is most effective for minimizing graft warping in this patient?
A) Harvesting the central portion of the costal cartilage
B) Irradiating the graft
C) Preserving the perichondrium
D) Scoring the cartilage
E) Using the seventh costal cartilage
The correct response is Option A.
Warping of cartilage grafts is a phenomenon that occurs unpredictably in costal cartilage grafts. The theory behind it is that there are interlocking stresses in a cartilage graft that when disrupted lead to warping. To date, the most effective technique to minimize costal cartilage warping is harvesting the central portion of the costal cartilage. This concept was introduced by Gibson in 1958. Although this decreases warping, it does not totally eliminate it. Gillies advocated for the removal of perichondrium to balance the intrinsic interlocking stresses of the graft; there is no conclusive evidence that perichondrial stripping or preservation decreases warping. Warping is also not affected by the level of cartilage graft harvest. Scoring of cartilage leads to breakage of interlocking stresses, resulting in bending of cartilage to the opposite side. This property of cartilage is used for correction of prominent ears. Irradiation does not result in decreased warping. Recently, oppositional suturing techniques and oblique split techniques have been proposed as methods to decrease cartilage warping.
A 14-year-old girl with Poland syndrome and significant breast asymmetry is brought to the office by her mother. The patient reports a negative impact to her social and mental well-being. On physical examination, the right breast is a DD cup size with otherwise normal appearance. The left side has a significantly smaller breast and absence of the pectoralis major muscle. Which of the following is the most appropriate next step in management?
A) Delayed reconstruction until patient is fully grown
B) Direct-to-implant reconstruction
C) Immediate autologous reconstruction
D) Staged reconstruction with tissue expander
The correct response is Option D.
The most appropriate next step in management is to plan a staged, implant-based reconstruction.
Poland syndrome is a congenital disorder involving the chest wall. The sequence of findings may vary but typically involves absence of the sternal portion of the pectoralis major muscle and lack of development of the soft tissue of the chest, including the breast in female patients. This may include partial or complete absence of the breast or musculature and structure of the arm. This patient has demonstrated that the abnormality is significantly affecting her quality of life and may further impact her social and emotional development. It is reasonable to consider starting reconstruction at this time. Given that her right breast is very large, at some point she may benefit from a reduction mammoplasty to help balance the dramatic difference of her chest size. Placing a tissue expander is ideal since it may be adjusted over time as she further develops on the right side. In addition to breast asymmetry, there may also be poor soft-tissue quality of the chest wall, necessitating additional procedures like a latissimus dorsi flap or fat grafting. Once the expander is successfully placed and expanded, the patient can decide when she would like to have definitive reconstruction and at what size. This should be done when she has stopped developing on the right side. Definitive reconstruction can be done with either autologous tissue or an implant depending on the patients body habitus and wishes.
Delaying her reconstruction until she has fully grown is likely to cause the patient to undergo a prolonged period of emotional suffering that may not be easily overcome. Performing definitive reconstruction at this time is not advisable since the patient has not fully developed.
A 57-year-old woman who was recently diagnosed with advanced rectal cancer is referred to the office for preoperative evaluation. History includes abdominoplasty and bilateral medial thigh lift. The patient is status post neoadjuvant chemotherapy and radiation. The colorectal surgery team plans abdominoperineal resection with posterior vaginectomy. Reconstruction with which of the following flaps is most appropriate for this patient?
A) Anterolateral thigh
B) Fasciocutaneous pudendal
C) Profunda artery perforator
D) Transverse upper gracilis
E) Vertical rectus abdominis myocutaneous
The correct response is Option A.
Advanced rectal cancer continues to be frequently treated with abdominoperineal resection. Depending on the extent of the tumor, posterior vaginectomy may be necessary, thus resulting in a type IB vaginal defect. The surgical principles guiding reconstruction in these cases include vascularized tissue transfer for the purpose of providing stable skin coverage, reconstruction of the posterior mucosal defect, and pelvic dead space obliteration. Naturally, one should strive to accomplish these goals while keeping donor site morbidity to a minimum.
Common reconstructive techniques include the vertical rectus abdominis myocutaneous (VRAM) flap, anterolateral thigh flap, or profunda artery perforator (PAP) flap.
The patient’s history of abdominoplasty precludes the use of a VRAM flap, while the history of bilateral medial thigh lift precludes the use of medial thigh flaps (ie, PAP flap, transverse upper gracilis flap, pudendal flap). Of the flaps listed, only the anterolateral thigh flap would be appropriate.
A 53-year-old woman comes to the office to discuss treatment of fine rhytides caused by smoking and photoaging. Topical retinoid therapy is planned. Which of the following best describes the effect of this treatment in this patient?
A) Decrease in collagen production
B) Decrease in hyaluronic acid production
C) Thinning of the dermis
D) Thinning of the epidermis
E) Thinning of the stratum corneum
The correct response is Option E.
Tretinoin (all-trans-retinoic acid) is one of the best long-term topical therapies available for chronically photo-damaged skin. Long-term use of tretinoin is associated with improved skin texture, decreased sallowness, a decrease in fine rhytides and actinic keratosis, fading of pigmented macules, and an overall improvement in skin appearance. Increased exfoliation results in compaction/thinning of the most superficial layer of the skin, the stratum corneum. Additional histologic effects of tretinoin include increased epidermal and dermal layer thickness, elimination of dysplasia, atypia, and microscopic actinic keratoses; uniform dispersion of melanin granules; increased collagen and glycosaminoglycan deposition in the papillary dermis; and diminished dermal elastosis and angiogenesis.
The mechanism of action of retinoids is regulated through specific nuclear receptors. Ultraviolet radiation activates a series of phosphokinases that stimulate c-Fos and c-Jun proto-oncogenes and thereby activates AP-1 transcription factor. AP-1 causes activation of metalloproteases such as collagenase, gelatinase, and stromatolysin, which then break down collagen. Tretinoin results in a 70% inhibition of AP-1 transcription factor binding to DNA and a significant decrease in protease activity.
Tretinoin side effects include erythema, photosensitivity, and desquamation. Patients are initially started on a low dose with nightly application until tolerance is achieved. Because tretinoin is a photosensitizer, sunscreen use is absolutely imperative. Topical retinoids should be used for a minimum of 3 to 4 months, with the greatest improvement after 1 year of use. Patients who use alpha hydroxy acids concomitantly with topical retinoids will see a synergistic effect, and this combination is tolerated well in most patients.
A 7-day-old premature male newborn, born at 30 weeks’ gestation, is found to have intravenous catheter infiltration in the left leg with peripheral parenteral nutrition. Which of the following is the most likely primary mechanism for tissue injury to occur in this patient?
A) Arterial leakage resulting in limb ischemia
B) Cytotoxicity of the infiltrated agent on the soft tissue
C) Direct local vasoconstriction resulting in tissue necrosis
D) Hyperosmolarity causing cellular dysfunction, fluid shifts, and hypoperfusion
E) Hypotonicity of the substance leading to cellular dehydration
The correct response is Option D.
Peripheral parenteral nutrition (PPN) and total parenteral nutrition (TPN) are hypertonic, osmotically active agents that cause an imbalance between intracellular and extracellular compartments, resulting in fluid shifts, cellular dysfunction, and injury. Hypotonicity of the substance is incorrect because PPN and TPN are hypertonic, not hypotonic.
Extravasation of vasopressors, such as dobutamine or vasopressin, leads to direct local vasoconstriction, causing tissue ischemia and necrosis. Direct cytotoxicity of the infiltrated agent describes chemotherapeutic drugs such as vesicants (eg, doxorubicin) or exfoliants (eg, cisplatin). Some have advocated using local hyaluronidase to treat hypertonic and chemotherapeutic extravasations. Arterial leakage would manifest as a hematoma and compartment syndrome and is not directly related to PPN injury to soft tissue. Compartment muscles may be injured if fasciotomy is not performed emergently.
A 45-year-old woman who underwent abdominoplasty 2 weeks ago is brought to the emergency department because of abdominal wound dehiscence. History includes ulcerative colitis treated with oral prednisone 40 mg daily for the past 8 months. The patient does not have diabetes and does not use nicotine-containing products. Physical examination shows no sign of infection in the abdominal wound. Which of the following most likely contributed to the pathophysiology of this patient’s wound healing deficiency?
A) Aggressive binding of carbon monoxide to hemoglobin
B) Decreased macrophage infiltration into the healing incision
C) Inhibition of DNA, RNA, and protein synthesis
D) Interference with prostacyclin-mediated vasodilation and stimulation of catecholamines
E) Upregulated expression of cytokines such as transforming growth factor beta and interleukin-1 alpha
The correct response is Option B.
The patient has a corticosteroid-related wound healing deficiency, which can be present in patients with a history of more than 30 days of systemic corticosteroid use prior to a surgical procedure or skin injury. Broadly, patients with chronic corticosteroid use at the time of surgery may encounter a two- to three-fold increase in dehiscence and a four-fold increase in mortality.
Chronic corticosteroid use impedes all three phases of cutaneous wound healing: inflammatory, proliferative, and remodeling. During the inflammatory phase, normal wound healing involves rapid upregulation of cytokines such as transforming growth factor beta, platelet-derived growth factor, and interleukin-1 alpha, all of which generate the chemotactic stimulus for macrophage infiltration. Corticosteroid use decreases the expression of the cytokines that start this cascade.
During the proliferative phase, the macrophages from the inflammatory phase produce growth factors that drive angiogenesis and fibroplasia, creating the substrate of a maturing scar. Corticosteroids decrease expression of keratinocyte growth factor, which is an important driver of wound re-epithelialization. Of note, vitamin A administration helps resolve corticosteroid wound-healing deficiency by promoting re-epithelialization.
During the remodeling phase, wound contraction via myofibroblasts is stimulated by the presence of transforming growth factor beta, type III collagen is digested by macrophages, and type I collagen accumulates, increasing tensile strength. Due to decreased cytokine and macrophage involvement, remodeling is hampered in patients taking corticosteroids.
The remainder of the choices are not related to corticosteroid administration. Interference with prostacyclin and stimulation of catecholamines are part of the mechanism of action of nicotine-induced cutaneous vasoconstriction and are not related to corticosteroid administration. Carbon monoxide, which is present in cigarette smoke, can bind hemoglobin, decreasing oxygen availability for healing tissues. Inhibition of DNA, RNA, and protein synthesis is characteristic of many chemotherapy agents such as doxorubicin, which can have profound effects on wound healing as well.
A 39-year-old woman presents for ostomy takedown and repair of an upper midline incisional hernia. Separation of components by transversus abdominis release is planned. Which of the following best describes the plane of dissection lateral to the semilunar line?
A) Between the external oblique muscle and internal oblique muscle
B) Between the neurovascular bundles and the semilunar line
C) Between the rectus abdominis muscles and transversalis fascia
D) Between the transversus abdominis muscle and internal oblique muscle
E) Between the transversus abdominis muscle and transversalis fascia
The correct response is Option E.
The transversus abdominis release technique involves incision of the transversus abdominis muscle medial to the neurovascular bundles. Dissection continues between the transversus abdominis muscle and the transversalis fascia above the arcuate line and between the transversus abdominis and the peritoneum beneath the arcuate line.
The plane between the external oblique and internal oblique muscles is the plane for an anterior component separation.
The plane between the rectus abdominis muscles and transversalis fascia describes the retrorectus plane, which is medial to the semilunar line.
The plane between the transversus abdominis and the internal oblique muscles is the plane for anesthetic infiltration for transversus abdominis plane blocks. This plane contains neurovascular bundles and would risk denervation of the rectus abdominis muscles.
Dissecting between the neurovascular bundles and the semilunar line would also risk denervation of the rectus abdominis muscles.
A 46-year-old woman is brought to the emergency department after being involved in a high-speed motor vehicle collision. Physical examination shows a soft-tissue contusion over the lateral thigh with associated closed pelvic fractures but no femur fracture. On follow-up examination 3 weeks later, there is a large, slowly expanding fluid collection over the lateral thigh. Aspiration yields a large volume of bloody fluid. This fluid is most likely located between which of the following layers of tissue?
A) Deep fascia and muscle
B) Deep fat and deep fascia
C) Dermis and subcutaneous fat
D) Muscle and bone
E) Superficial fascia and deep fat
The correct response is Option B.
This is a Morel-Lavallée lesion, which is a closed injury with internal degloving of superficial soft tissues from fascial layers specifically just above the deep fascia. This was first described by French surgeon Victor-Auguste-François Morel-Lavallée 1863. The primary causes of Morel-Lavallée lesions include high-energy, tangential or blunt force trauma, or crush injuries. The sheared vasculature and lymphatics drain into the potential space created between the two planes, resulting in a collection of blood, serosanguinous fluid, and necrotic fat, which stimulates further cellular permeability and leakage into the space. They are commonly found overlying the greater trochanter. Morel-Lavallée lesions should be actively looked for when treating patients with pelvic trauma. Conservative management only of this lesion is likely to fail and progress to necrosis of the overlying skin. Prompt diagnosis and intervention improves the chances for success of nonsurgical intervention, including compression bandaging, percutaneous aspiration, and sclerodesis. For chronic lesions (one third of patients present months or years after the original injury), MRI is the diagnostic imaging modality of choice, and percutaneous aspiration should not be used in isolation. Sclerodesis using doxycycline is appropriate for lesions up to 400 mL, where evidence suggests high degrees of efficacy. Larger lesions should be treated with open surgery. Quilting sutures, curettage, and low-suction drains are useful adjuncts.
The layers of the skin from superficial to deep include: dermis, subcutaneous fat, superficial fascia, deep fat, deep fascia, muscle, and bone. Hematoma due to fracture accumulates between the bone and muscle. Bruising or ecchymoses from mild soft-tissue injury as a result of damage to the subdermal plexus accumulates between the dermis and subcutaneous fat. Blood also accumulates in the region between the superficial fascia and deep fat, as this deep fat is the target of liposuction. Trauma to the muscle resulting in hemorrhage would accumulate blood between the deep fascia and muscle.
A 3-day-old female newborn is evaluated in the neonatal intensive care unit because of a myelomeningocele. Physical examination shows an intact 5 × 4-cm sac in the lower lumbar area with evidence of clear fluid drainage. The primary reason for early operative repair in this patient is to decrease which of the following?
A) Need for cerebrospinal fluid shunt placement
B) Need for future surgeries
C) Risk for bacterial meningitis
D) Risk for permanent motor damage
The correct response is Option C.
Failure of the neural tube to close during the fourth week of gestation results in a myelomeningocele. There is exposure of the spinal canal and neural elements, allowing for cerebrospinal fluid leakage and risk for infection. The primary indication for early intervention is to prevent bacterial meningitis. Initial care involves keeping the sac sterile and hydrated. Many of these patients have hydrocephalus and will require a shunt to decrease intracranial pressure and cerebrospinal fluid leakage. Further workup for cardiac, urologic, orthopedic, and other neurologic abnormalities is required, with many of these patients requiring multiple future surgeries. Early intervention has not been shown to improve the return of motor function but may improve bladder function.
After stabilization of other medical conditions, some authors have proposed placement of a temporary split-thickness skin graft until definitive repair is undertaken. Definitive correction will require repair of the dura to prevent further cerebrospinal fluid leakage, followed by placement of a well-vascularized layer of tissue between the dura and skin repair. Various flaps have been used for providing vascularized coverage of the dura. These include paraspinous fascia turnover flaps, paraspinous muscle advancement flaps, local/regional fasciocutaneous flaps, gluteal advancement flaps, and latissimus turnover flaps. The vascularized layer will prevent contact with cutaneous bacteria and subsequent meningitis if either the dural or skin repairs fail.
