Veterinary Surgical Principles Flashcards

A 7-year-old Labrador Retriever undergoes a celiotomy for intestinal resection and anastomosis. Intraoperatively, the surgeon notes the anastomosis site has adequate blood supply but is under moderate tension. Which suture pattern is MOST appropriate to minimize tension while maintaining mucosal apposition?

Answer: Gambee single-layer through-and-through pattern

The Gambee pattern is a single-layer interrupted through-and-through technique that passes through all layers including the mucosa. It provides excellent mucosal apposition, minimizes luminal narrowing, and distributes tension evenly across all intestinal layers — making it preferable when tension is a concern. Inverting patterns (Cushing, Lembert) can increase luminal stenosis and are two-layer approaches that add bulk without necessarily reducing tension better than a well-placed Gambee. Simple continuous appositional sutures provide good apposition but interrupted patterns are generally preferred when tension is an issue to prevent full-line failure.

During a thoracotomy via the 4th intercostal space in a cat, the surgeon inadvertently lacerates the accessory azygos vein. Which of the following best describes the correct anatomical management priority?

Answer: The vessel can be ligated without hemodynamic consequence since it is a low-pressure collateral with redundant venous drainage

The accessory azygos vein (present in cats, unlike dogs which have a single azygos) is a low-pressure venous collateral that can be safely ligated without significant hemodynamic consequence, as venous drainage of the thoracic wall is served by redundant pathways. While hemorrhage control is necessary, ligation is hemodynamically well-tolerated. It does not drain directly into the right atrium (that would be the azygos proper), and simple digital pressure alone is insufficient — proximal-distal ligation is still the correct operative technique, but without the urgent cardiac concern implied by option B.

A 5-year-old intact male German Shepherd is presented for scrotal urethrostomy following recurrent urethral obstruction from calcium oxalate uroliths. Postoperatively, the owner reports persistent urine scalding of the perineum. The MOST likely cause is:

Answer: Formation of a urethrocutaneous fistula secondary to incomplete mucosal-to-skin apposition

Perineal urine scalding after scrotal urethrostomy most commonly results from incomplete or dehisced mucosal-to-skin apposition creating a urethrocutaneous fistula, which allows urine to track subcutaneously and exit lateral to the stoma rather than directly through it. Stricture (option B) is possible but typically causes dysuria rather than scalding. Inadequate stoma width (option C) would produce obstruction, not lateral leakage. Concurrent castration is recommended to reduce the risk of perianal adenoma and testosterone influence on prostatic issues, but testosterone does not directly cause urethral spasm producing scalding.

A surgeon is performing a lateral approach to the hip joint in a dog for total hip replacement. The deep gluteal muscle is incised near its insertion. What is the PRIMARY reason surgeons prefer a muscle-splitting approach through the deep gluteal rather than complete tenotomy of its insertion?

Answer: Complete tenotomy risks iatrogenic injury to the sciatic nerve, which passes directly beneath the deep gluteal insertion on the greater trochanter

The sciatic nerve courses caudally in close proximity to the deep gluteal muscle's insertion on the greater trochanter. Complete tenotomy and aggressive retraction in this region substantially increases the risk of sciatic nerve traction injury or direct laceration, which is one of the most serious complications of total hip replacement surgery in dogs. The muscle-splitting approach limits retraction distance and maintains positional awareness of the nerve. The caudal gluteal artery supplies the deep gluteal muscle but is not the dominant femoral head blood supply (that is the femoral circumflex vessels). Options C and D, while having some merit in general surgical reasoning, are not the PRIMARY reason for the approach preference.

When closing a ventral midline celiotomy in a dog, which of the following suture materials and patterns carries the highest evidence-based risk of incisional hernia in the immediate postoperative period?

Answer: Polyglactin 910 (Vicryl) in a simple continuous pattern closing the linea alba

Polyglactin 910 (Vicryl) is a braided, rapidly absorbed suture that loses approximately 50% of its tensile strength by 2–3 weeks postoperatively and is essentially completely absorbed by 60–90 days. Used in a continuous pattern for linea alba closure, early tensile strength loss — especially in patients with delayed healing (hypoalbuminemia, corticosteroid use, obesity) — significantly increases incisional hernia risk before adequate fibrous union has occurred. Polydioxanone retains strength longer (~70% at 2 weeks, ~50% at 4 weeks). Poliglecaprone 25 retains ~50–60% at 1 week and ~20–30% at 2 weeks — also a concern, but PDS is the gold standard for linea closure precisely because of its prolonged retention. Nylon is non-absorbable and maintains strength indefinitely.

A 4-year-old Thoroughbred mare undergoes exploratory laparotomy for a right dorsal displacement of the large colon. The surgeon successfully reduces the displacement but notes the ascending colon is severely distended with gas. Before enterotomy, which vessel must be meticulously identified and preserved to avoid catastrophic ischemic compromise of the entire ascending colon?

Answer: The cecocolic fold vessels bridging the cecum to the right ventral colon

The cecocolic fold contains the only direct vascular anastomosis between the cecal and colonic circulations in the horse. The ascending (large) colon in the horse has a peculiar blood supply in that the right ventral and right dorsal colon receive their primary arterial inflow through vessels that travel within the cecocolic fold and the mesocolon of the right side. Inadvertent disruption of the cecocolic fold vessels during colon manipulation or during attempts to reduce a displacement can devascularize the entire right colon. The right colic artery supplies the right colon, but the surgical danger during displacement reduction specifically centers on the cecocolic fold vascular anatomy. The ileocolic artery primarily supplies the cecum and ileum. The pelvic flexure has a relatively poor blood supply making it a preferred enterotomy site, but it is not the vessel most critical to preserve during displacement reduction.