Author

Stephen J. Birchard DVM, MS, Diplomate ACVS

Wednesday, April 12, 2017

Acute Traumatic Abdominal Hernia in Dogs and Cats: Key Point: Always do a complete abdominal exploratory!

Case Report

Cass is a 2 year old spayed female who presented to the emergency service after been bitten by another dog. She had no pertinent history of other health problems. On physical examination Cass had a palpable soft tissue subcutaneous swelling on the left lateral abdomen. A defect in the abdominal wall was palpable deep to the swelling and viscera were thought to be in the subcutaneous space. 

Plain radiographs of the abdomen confirmed a left lateral abdominal hernia. (Fig. 1) No other radiographic abnormalities were found. 
Fig. 1; Ventrodorsal radiograph of Cass showing the hernia of the left lateral abdomen (arrows).
Cass was initially treated with supportive care consisting of intravenous fluids with a balanced electrolyte solution, analgesics, and antibiotics. Preoperative CBC and serum chemistry profile were within normal limits. Cass was placed under general anesthesia and the ventral abdomen was clipped and prepared for aseptic surgery. (Fig. 2) 
Fig. 2: Cass in dorsal recumbency after clipping and prepping for  abdominal surgery.
Note the bulge on the left lateral abdomen at the site of the hernia.
A ventral midline abdominal approach was made. On thorough exploratory of all abdominal structures herniation of a portion of jejunum was found in a left sided abdominal wall defect.(Fig. 3, 4) 
Fig. 3: Intraoperative view of the abdominal cavity on Cass. (Head is to the left.)
Note herniated bowel and omentum (arrow).
Fig. 4: Same intraoperative view as figure 3 after reduction of the hernia showing the muscular defect.
Gentle traction on the herniated bowel reduced the hernia and the bowel mesentery was bruised but all tissues were viable. The abdominal muscle defect was closed from within the abdominal cavity with 2-0 PDS simple continuous pattern.(Fig. 5) 
Fig. 5: Same intraoperative view as figures 3 and 4 showing closure of the hernia.
The ventral abdominal incision was closed routinely. 

Postoperatively supportive care (IV fluids, analgesics, and antibiotics) was continued. Cass made an uneventful recovery and was discharged the day after surgery. At suture removal 10 days postoperatively Cass was doing well.

Discussion

In animals with severe abdominal trauma, hernias can be missed on initial physical examination. Serial, thorough physical examinations and careful analysis of abdominal imaging is recommended to fully assess trauma patients. Intestine and omentum were the 2 most commonly herniated structures in the study previously mentioned. (1)

Bite wounds were the most common cause of traumatic abdominal hernias in one study, with vehicular trauma being the next most common cause. (1) This is in contrast to an older study that found blunt trauma to be the primary cause of traumatic hernias.(2) Additional injuries, such as bowel perforation, are common complications of abdominal hernias. 

Key Point: Dogs and cats with acute traumatic abdominal hernias should have a complete abdominal exploratory via routine ventral approach. The hernias can be repaired from within the peritoneal cavity by closing the affected interior muscle layers. (3)


References
1. Shaw, Scott P; Rozanski, Elizabeth A; Rush, John E. Traumatic body wall herniation in 36 dogs and cats. JAAHA 39:35-45 2003.
2. Waldron DR, Hedlung CS, Pechman R. Abdominal hernias in dogs and cats: a review of 24 cases. JAAHA, 22:817-822,1986 
3. Smeak, DD. Abdominal wall reconstruction and hernias. In: Veterinary Surgery Small Animal, eds. Tobias KM, Johnston, SA. Elsevier, St. Louis, pg. 1368.

Friday, January 27, 2017

When Is Umbilical Hernia in Dogs An Emergency Operation? Here's a Great Example

Case Report

A 7-year-old spayed female mixed breed dog named Lola presented with acute vomiting and rapid enlargement of a mass over her umbilicus.(Fig.1) 
Fig. 1: Lola, a 7 year old female spayed dog
The owners reported that she had a hernia there since birth but it just recently got much larger. The mass was soft, painful on palpation, and not reducible. An umbilical hernia containing abdominal viscera was suspected.

Plain film abdominal radiographs were obtained and confirmed an umbilical hernia with loops of intestine in the hernia sac. (Fig.2)  The remainder of the abdomen was radiographically within normal limits. 
Fig. 2: Lateral abdominal radiograph in Lola showing
an umbilical hernia with incarcerated bowel (arrow)
Complete blood count and serum chemistry profile were unremarkable. An intravenous catheter was placed and a balanced electrolyte solution administered to correct dehydration. Under general anesthesia the ventral abdomen was clipped and prepared for aseptic surgery. (Fig.3) 
Fig. 3: Appearance of the hernia in Lola after clipping for surgical repair
A ventral abdominal approach was performed with care taken to not injure structures within the hernia. A strangulated loop of jejunum was found in the hernia. (Fig.4) The remainder of the abdomen was normal. 
Fig. 4: Intraoperative photo of Lola during abdominal exploratory showing the
strangulated portion of jejunum after it was reduced.
The affected segment of intestine was resected and an end to end anastomosis performed (see http://drstephenbirchard.blogspot.com/2013/10/intestinal-anastomosis-made-simple.html for details on technique for intestinal anastomosis).  Debridement of the tissue edges of the hernia was not necessary and it was repaired as part of the routine linea alba closure with 2-0 PDS, simple continuous pattern. The remainder of the abdominal incision was closed routinely. Postoperative abdominal radiographs confirmed satisfactory closure of the hernia. (Fig. 5) 
Fig. 5: Lateral abdominal radiograph of Lola 1 day after repair of the umbilical hernia.
Lola recovered well from surgery and was released from the hospital 2 days postoperatively.

Discussion

Lola is an example of a dog with an incarcerated (non-reducible), and strangulated (loss of blood supply of the hernia contents) umbilical hernia. Umbilical hernias are common in dogs and cats but rarely do they contain intestine or other abdominal organs.(1) More commonly umbilical hernias are small and contain a portion of the falciform ligament or greater omentum. 

Plain film radiographs were diagnostic for the hernia in Lola. Ultrasonography can also be useful to determine if a hernia is present and if organs are located in the hernia sac. 

The clinical signs of acute vomiting and pain on palpation were suggestive of intestinal obstruction, and possibly strangulation. Vomiting was predictive of non-viable intestine in inguinal hernias in dogs in one study.(2) Emergency surgery is indicated when this type of hernia is suspected. 

In Lola the hernia repair was straightforward since adequate local tissues, i.e. rectus muscle fascia, was available for closure without tension across the suture line. Larger defects may require a muscle flap or mesh implant, such as polypropylene mesh, for effective repair. Mesh is well tolerated in dogs and provides a strong and stable closure for abdominal wall defects with minimal complications.(3)

Complications of hernia repair include pain, seroma, infection, reoccurrence and mesh rejection requiring removal.   However, complications are rare and the prognosis for successful repair of congenital and traumatic hernias is generally good. 

This is the first in a series of Veterinary Key Points blogs addressing congenital and acquired hernias in dogs and cats. Watch for future articles on other hernia types and their treatment.

References

1. Ruble RP, Hird DW. Congenital abnormalities in immature dogs from a pet store: 253 cases (1987-1988). J Am Vet Med Assoc. 202(4) 633-636, 1993

2. Water DJ, Roy RG , Stone EA. A retrospective study of inguinal hernia in 35 dogs. Vet Surg 22:44, 1993

3. Bowman K, Birchard SJ, Bright RM. Complications associated with implantation of polypropylene mesh in dogs and cats: A retrospective study of 21 cases (1984-1996). J Am An Hosp Assoc 34:225-233, 1998