A procedural guide to canine ovariohysterectomy (OSH). Covers key steps from the ventral midline incision to proper ligation of the ovarian pedicles and uterine stump.

Canine Ovariohysterectomy Surgical Technique A Method for Veterinarians

Select a ventral midline incision, extending caudally from the umbilicus for 4 to 8 centimeters depending on the animal's size. This approach provides superior exposure of both the right and left ovarian pedicles and the uterine body. A flank entry, while an alternative, frequently complicates the exteriorization of the contralateral ovary, potentially extending the duration of the anesthetic event and increasing tissue manipulation.

The security of the intervention depends on meticulous hemostasis of the ovarian and uterine vessels. Employ a three-clamp method on each ovarian pedicle. Following this, place two circumferential or transfixing ligatures using a synthetic absorbable monofilament suture, size 2-0 or 3-0, within the crushed tissue bed created by the clamp. The uterine body must be securely ligated with a similar suture material just cranial to the cervix before its transection and removal.

Facilitate the exteriorization of each ovary by carefully stretching or digitally disrupting the suspensory ligament. Perform this maneuver with controlled pressure directed caudally and medially to prevent tearing of the ovarian vessels. Before beginning abdominal closure, a systematic inspection of both ovarian pedicles and the uterine stump for any evidence of hemorrhage is non-negotiable. Confirmation of complete hemostasis precedes the standard three-layer closure of the abdominal wall.

Canine Ovariohysterectomy: A Surgical Technique Guide

Position the patient in dorsal recumbency. The surgical field should be clipped from the xiphoid process to the pubis and laterally to the flank folds. Aseptically prepare the skin using a standard surgical scrub protocol, such as a chlorhexidine-alcohol sequence. Drape the patient to isolate the prepared ventral abdomen.

Perform a ventral midline incision. For most female canines, the incision begins approximately 2-3 cm caudal to the umbilicus and extends caudally for 4-8 cm. The length is adjusted based on the animal's size and condition (e.g., pregnancy, pyometra). Incise through the skin and subcutaneous fat to expose the linea alba. A small stab incision through the linea alba with a scalpel blade, followed by extension with Metzenbaum scissors, prevents accidental damage to abdominal viscera.

A spay hook may be inserted into the abdomen, directed laterally and dorsally along the internal body wall, to retrieve a uterine horn. Once exteriorized, follow the horn cranially to locate the ovary.

1. Break down the suspensory ligament to achieve adequate exteriorization of the ovary. This is accomplished by applying firm, steady traction on the ovary while digitally strumming the ligament near its attachment.
2. Create a window in the broad ligament caudal to the ovarian vascular pedicle. This isolates the vessels for ligation.
3. Apply a three-clamp technique to the ovarian pedicle. Place the most proximal hemostat (closest to the body wall) where the first ligature will be set. Place the other two hemostats distal to the first.
4. Place a circumferential ligature using 2-0 or 3-0 absorbable monofilament suture (e.g., PDS, Maxon) in the crushed tissue bed created by the proximal clamp. A second, transfixing ligature is placed between the circumferential ligature and the middle hemostat for added security.
5. Transect the pedicle between the middle and distal hemostats.
6. Grasp the pedicle with forceps and inspect for any hemorrhage before releasing it back into the abdominal cavity.

Repeat the ligation and transection process for the contralateral ovary. Following this, trace both uterine horns caudally to the uterine body. Ligate the uterine body cranial to the cervix.

• For the uterine body, a double ligation is standard. A series of transfixing and circumferential ligatures are placed using an appropriate size of absorbable suture material (0 to 2-0, depending on patient size).
• Clamps are placed across the uterine body cranial to the ligatures.
• The uterus is transected between the clamps and the ligatures, and the entire reproductive tract is removed.
• The uterine stump is inspected for bleeding prior to abdominal closure.

Closure involves three distinct layers:

1. Linea Alba: Close with a simple continuous or simple interrupted pattern using a long-lasting absorbable suture.
2. Subcutaneous Tissue: Appose this layer with a simple continuous pattern to reduce dead space. Use a smaller-gauge, rapidly absorbing suture.
3. Skin: An intradermal (subcuticular) pattern provides a cosmetic closure without external sutures. Alternatively, non-absorbable skin sutures or staples may be used.

Ventral Midline Celiotomy: Patient Positioning and Uterine Horn Exteriorization

Position the animal in dorsal recumbency. Secure the forelimbs cranially and the hindlimbs caudally with ties, ensuring they do not impede respiratory movement.  https://wazamba-gr.vip  tilt of the surgical table shifts abdominal organs cranially, improving access to the caudal reproductive tract. The surgical field should be prepared with a wide aseptic area extending from the xiphoid to the pubis and laterally beyond the mammary glands.

To locate the uterus, insert an ovariohysterectomy hook along the internal abdominal wall, sliding it caudally past the urinary bladder. Rotate the hook's tip medially and retract. This action typically snares a uterine horn or its associated broad ligament. Alternatively, use one or two fingers to palpate dorsally and caudally between the bladder and colon to identify the uterine bifurcation. Once a horn is identified, grasp it with atraumatic forceps or a moistened gauze sponge.

Apply gentle, continuous traction on the horn to follow it cranially towards the ovary. The suspensory ligament will become taut, limiting further exteriorization. To release the ovary, apply steady caudal and medial traction on the uterine horn while using a finger to palpate and digitally stretch or rupture the tight suspensory ligament near its dorsal attachment. After exteriorizing the first ovary, trace the horn back to the uterine body. Follow the bifurcation to the opposite horn and repeat the exteriorization procedure, taking care not to place excessive tension on the uterine tissue.

Applying the Three-Clamp Technique to Ovarian Pedicles and Uterine Body Ligation

Position three hemostatic forceps, such as Rochester-Carmalt, across the ovarian pedicle. Place the most proximal clamp (closest to the patient's spine) at the intended site of ligation; this instrument's primary function is to create a crushed tissue bed for the ligature. Place the middle clamp just distal to the first. The third, most distal clamp, is positioned on the proper ligament adjacent to the ovary itself. This final clamp is removed along with the resected gonad.

Place a circumferential ligature of absorbable suture material, like polydioxanone (PDS), in the crushed tissue groove created by the proximal clamp. A 2-0 or 3-0 suture size is appropriate for most female canines. For enhanced security, apply a second, transfixing ligature between the circumferential knot and the middle clamp. Sever the pedicle with a scalpel blade between the middle and distal clamps. Before releasing the pedicle, grasp its tip with tissue forceps and briefly loosen the middle clamp to inspect the stump for any hemorrhage.

For the uterine body, adapt the clamp application to the larger tissue mass. Place two or three clamps just cranial to the cervix. The first, most caudal clamp, crushes the tissue for the initial ligature. Place subsequent clamps cranially. Ligate the uterine stump using a circumferential ligature in the groove of the most caudal clamp. Follow this with one or more transfixing ligatures placed through the uterine wall between the first and second clamps. The number of transfixing ligatures depends on the diameter of the uterine body. Transect the uterus between the most cranial ligature and the adjacent clamp. Meticulously inspect the uterine stump for bleeding before abdominal closure.

Three-Layer Abdominal Wall Closure and Management of Intraoperative Hemorrhage

Close the abdominal wall by first apposing the external rectus fascia using a monofilament absorbable suture, such as polydioxanone, in a 2-0 or 3-0 size. For giant breeds, a size 0 suture provides adequate strength. A simple continuous pattern is rapid; however, a simple interrupted pattern offers greater security against dehiscence. Place bites 5-10 mm from the fascial edge and 5-8 mm apart, incorporating only the fascia to minimize tissue reaction and seroma formation.

The second layer, the subcutaneous tissue, is closed to eliminate dead space. Use a 3-0 or 4-0 absorbable suture like poliglecaprone 25 in a simple continuous pattern. Take care to appose the tissue gently without causing strangulation, which can lead to fat necrosis.

For the final layer, an intradermal closure is preferable to avoid external sutures. Employ a 4-0 monofilament absorbable suture in a continuous pattern within the dermis. This approach negates the need for suture removal post-procedure. If this method is not possible, use non-absorbable skin sutures or surgical staples.

When encountering unexpected bleeding, immediately apply firm pressure to the source with a laparotomy sponge and notify the anesthesia monitor. Increase the intravenous crystalloid fluid rate, administering a bolus of 10-20 mL/kg while monitoring blood pressure. The primary goal is to stabilize the patient while identifying the origin of the hemorrhage.

A bleeding ovarian pedicle is a frequent complication. To locate a retracted right pedicle, use the descending duodenum and its mesentery to retract the abdominal contents medially, exposing the right gutter. For the left pedicle, use the descending colon and its mesocolon. Once exposed, grasp the vessel with a hemostat.

Control the bleeding vessel by placing a secure circumferential or transfixing ligature proximal to the hemostat. Use a 2-0 or 3-0 absorbable suture material. For hemorrhage from the uterine stump, apply additional transfixing ligatures. Before beginning the closure sequence, lavage the abdomen with warm sterile saline to remove clots and perform a final inspection of both pedicles and the stump for any weeping. A meticulous sponge count is mandatory before closing the linea alba.