Efficacy of Incisional Gastropexy for Prevention of GDV in Dogs

Introduction

Gastric dilatation-volvulus (GDV) is most often an acute, life-threatening emergency in which the stomach rotates along its longitudinal axis, with subsequent gastric dilatation (GD) and cardiovascular compromise. Though the aforementioned description is one hypothesized pathogenesis of GDV, it remains unknown whether torsion either causes or follows GD.¹ GDV is most commonly seen in large- and giant-breed dogs and has been identified in patients associated with increasing age, being underweight, history of GDV in a first-degree relative, rapid eating, once daily feedings, exercising either before or following meals, fearful/anxious temperaments, increased thoracic depth/width ratio, and increased hepatogastric ligament length.^1–12 A recent history of splenectomy may be associated with GDV, but reports evaluating this are conflicting.^12,13

Standard treatment of GDV patients prior to surgery includes aggressive fluid therapy and gastric decompression via either orogastric intubation or trocarization. Surgical treatment of GDV includes decompression and derotation of the stomach and excision of devitalized tissue. A gastropexy is then performed to create an adhesion between the pyloric antrum and the right lateral abdominal wall to prevent recurrence. Failure to perform a gastropexy in dogs following gastric derotation has been associated with as high as an 80% risk of recurrence.¹

Risk of recurrence was reported in < 5% of dogs following gastropexy, although the type of gastropexy was not standardized.¹⁴ Several techniques have been described, including incisional gastropexy (IG), right-sided tube gastropexy, belt-loop gastropexy, circumcostal gastropexy, incorporating gastropexy, gastrocolopexy, and endoscopically assisted gastropexy.^15–32 Belt-loop gastropexy, circumcostal gastropexy, and gastrocolopexy techniques have recurrence rates of 0%, 4.3%, and 15%, respectively.^{18,21,30,31,33–35} Other gastropexy procedures have not been evaluated for recurrence of disease. Although considered a routine and widely accepted gastropexy method, the efficacy of IG has not been solely evaluated for the prevention of GDV.

In addition to performing a gastropexy after derotation of the stomach in dogs with GDV, prophylactic gastropexy is indicated for the prevention of GDV in at-risk dogs. Prophylactic gastropexy is performed using either open or laparoscopically assisted techniques. The efficacy of prophylactic gastropexy has not been reported. The purpose of this study was to evaluate the efficacy of IG performed either during the surgical treatment of GDV or as a prophylactic measure. The authors’ hypothesis was that IG would be equally, or more, effective at preventing GDV than other common gastropexy techniques.

Materials and Methods

Medical records obtained from the University of Georgia Veterinary Teaching Hospital (UGA VTH) between 2000 and 2010 were retrospectively evaluated for dogs in which an IG procedure was performed. Inclusion criteria were dogs that were diagnosed with GDV and dogs presenting for prophylactic gastropexy due to familial history, breed predisposition for developing GDV, or episodes of chronic GD. Dogs presenting with other indications for emergency abdominal surgery, deemed by the surgeon to be at risk for GDV based on breed, body conformation, and previous history of bloat, and underwent prophylactic IG were also included.¹³ Cases that underwent IG utilizing a minimally invasive, laparoscopic-assisted technique were also included.²⁴ Dogs with IG performed outside the UGA VTH, dogs that died prior to discharge from the hospital, and dogs for which follow-up data with a definitive cause of death could not be obtained from either the referring veterinarian or owner were excluded.

Medical records were evaluated for signalment, the use of laparoscopic techniques, and immediate complications. Follow-up information regarding recurrence of GD and GDV was obtained by telephone conversations with owners and/or referring veterinarians.

All dogs were treated with a similar anesthetic protocol using an opioid/benzodiazepine premedication, along with an induction agent for intubation. Maintenance inhalant anesthesia was used throughout the procedure. All dogs were maintained on IV fluids at10 mL/kg/hr, which was adjusted based on the individual case. Analgesia was provided with an opioid and/or anti-inflammatory for all dogs in this study. Surgery was performed by either a Diplomate of the American College of Veterinary Surgeons or surgery resident with supervision. Surgical treatment of dogs with GDV included an exploratory laparotomy, gastric decompression (by either an orogastric tube or needle gastrocentesis), gastric derotation, and IG. Patients in which a prophylactic IG was performed underwent either an open approach with routine abdominal exploration or a minimally invasive approach with laparoscopic assistance. The open IG was performed by creating a 4–5 cm seromuscular incision in the gastric antrum, either parallel or perpendicular to the long axis of the stomach. A corresponding incision was made through the peritoneum and transversus abdominus muscle on the right abdominal wall approximately 2–3 cm caudal to the last rib. The gastric and abdominal incisions were apposed with either monofilament absorbable or nonabsorbable suture in a simple continuous suture pattern. The laparoscopic-assisted IG procedure was performed using a similar technique as described by Rawlings et al. in 2001.²⁴ Either partial gastrectomy or gastric wall invagination were performed when necessary by assessing viability of the stomach based on color, pulse quality, and response to reperfusion after derotation. Splenectomy was performed based on the presence of thrombosed blood vessels and response to reperfusion. Postoperatively, dogs were maintained on IV fluid therapy and analgesia protocols based on clinician preference.

The overall follow-up time was defined as the time from the date of surgery until the date of either death or last date of contact. Follow-up date of GD occurrence following IG was recorded. Signs of abdominal discomfort/pain, any gastrointestinal signs after the surgery, and cause of death were also recorded.

Results

Records for 61 dogs were included in this study. The majority of dogs (54.1%) were either large- or giant-breeds, including 13 Great Danes (21.3%), 7 German shepherd dogs (11.5%), 6 Labrador retrievers (9.8%), and 7 large mixed-breeds (11.5%). The median weight for all dogs was 35 kg (range, 15.7–100 kg). In total, 23 of 38 male dogs and 18 of 23 female dogs were castrated and spayed, respectively. The mean age at the time of presentation for all dogs was 6.1 ± 4.0 yr. The mean age of dogs undergoing prophylactic IG was 4.1 ± 3.8 yr.

At the time this manuscript was prepared, 31 of 61 dogs (50.8%) were alive. The remaining 49.2% of the dogs had documented deaths unrelated to either GDV or IG. The majority of those dogs died for reasons related to poor quality of life and old age (n = 19). Other documented causes of death included neoplasia (n = 5, such as multiple myeloma, osteosarcoma, pulmonary adenocarcinoma, rectal adenocarcinoma, and a brain tumor), septic peritonitis (n = 4, secondary to an omental abscess, pancreatic abscess, mesenteric volvulus with gastrointestinal necrosis, and gastrointestinal perforation due to impaction and gastrointestinal parasites), obstructive foreign body (n = 1), and chronic renal disease (n = 1). Median follow-up time for all dogs was 717 days (range, 49–2,511 days) as shown in Figure 1.

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Dogs presenting for prophylactic IG either had a familial history of bloat, chronic GD, or a known breed predisposition. Of the 61 included dogs, 27 had a prophylactic IG performed (16 of 27 were laparoscopically assisted IGs and 11 of 27 were open IGs). Of the 11 dogs that had an open IG performed, 4 were patients with a history of GD documented by radiographs performed by referring veterinarians. Three of those 11 were Great Danes included in this study presented for emergency abdominal surgery (2 with jejunal foreign bodies and 1 with liver lobe torsion) had an IG performed at the time of their emergency procedure due to the breed predisposition for development of GDV. The remaining 4 dogs presented for emergency abdominal exploratory, including 1 dog that, in the days prior to presentation, had undergone gastric derotation without gastropexy and at presentation to UGA VTH required a partial gastrectomy; 1 dog with a bleeding splenic mass that underwent splenectomy; 1 dog that underwent an enterotomy for jejunal foreign body removal; and lastly, 1 dog that presented with an gastroesophageal intussusception. All of those dogs were deemed at risk for developing GDV based on breed, body conformation, and previous history of GD and/or GDV. The median follow-up time in the prophylactic IG group was 581 days (range, 53–2,511 days). The remaining 34 dogs in this study presented for GDV and had an IG performed as part of surgical treatment of GDV.

Postoperative complications were common, but were mild and seen in 28 of the 61 IG patients (45.9%), including both the GDV and prophylactic groups. Complications included ventricular arrhythmias (n = 9; 14.8%) with 5 of those 9 cases in the GDV group and the remaining 4 in the prophylactic IG group; aspiration pneumonia (n = 6; 9.8%) with 5 of those 6 cases in the GDV group and 1 in the prophylactic IG group; suture site reaction and/or infection (n = 5; 8.2%) with 4 of those 5 cases in the GDV group and 1 in the prophylactic IG group; gastrointestinal upset, including vomiting, diarrhea, and inappetance (n = 4; 6.6%) with 3 of those 4 cases in the GDV group and 1 in the prophylactic IG group; and regurgitation (n = 3; 4.9%) with 2 of those 3 cases in the GDV group and 1 in the prophylactic IG group. It cannot be determined definitively whether those complications occurred as a complication of GDV, IG, postoperative analgesia, or a combination of all of the aforementioned etiologies.

GD was reported in 3 of 34 patients (8.8%) in the IG following GDV group and in 3 of 27 patients (11.1%) in the prophylactic IG group. Overall, signs of GD (n = 6; 9.8%) occurred sporadically between 2 days and 4 yr postoperatively. None of the 6 dogs reported to have chronic GD after IG in this study developed GDV. Four of the 6 dogs with continued bloat were presented to UGA VTH and were confirmed via imaging studies to have GD without volvulus. The dogs were decompressed and managed medically. The remaining dogs with GD did not receive medical attention and were treated at home with smaller, more frequent meals and confined after meal times to avoid any excessive aerophagia. Diagnostic imaging was not performed in the remaining dogs; however, clinical signs of GD including bloating and/or belching resolved with rest and small frequent meals and did not require medical attention. At the time this manuscript was prepared, 3 of the dogs with continued GD were alive but the remaining 3 dogs died of reasons unrelated to either IG or GDV, including a brain tumor diagnosed with MRI, pulmonary adenocarcinoma, and poor quality of life due to severe osteoarthritis. At the time this study was completed, no dog experienced GDV after IG. When the data were evaluated using a binomial probability series, 0.05 = 0.9521⁶¹. Thus 1–0.921 = 0.048, suggesting the probability of torsion following IG was < 4.8% in this series.

Postmortem examinations were available in three dogs in this study. One dog was euthanized due to septic peritonitis that was later diagnosed with an omental abscess based on necropsy evaluation. Another dog was euthanized for poor quality of life with chronic rectal bleeding that was subsequently diagnosed as rectal adenocarcinoma. Lastly, the third dog submitted for necropsy was found dead, and although the body was severely autolyzed the most probable cause of death was from gastric impaction from a large amount of grass and sticks. It was unknown whether that dog died of complications of his IG. That dog was not reported to have continued GD after his IG procedure. Necropsy in all three dogs confirmed intact IG sites at 114 days, 821 days, and 1,314 days postoperatively.

Discussion

Prophylactic gastropexy has been reported to reduce mortality 29× compared with dogs that have not undergone gastropexy, and the lifetime risk for specific dogs predisposed to the development of GDV was estimated to be between 4% and 37%.³⁶ The study reported here supports the conclusions of many others that gastropexy is critical for the prevention of GDV. Various surgical techniques for gastropexy have been used for the prevention of GDV. Evaluation of each gastropexy technique involves many considerations, including technical difficulty, additional anesthesia time, management and complications, and recurrence rates. In the authors’ opinion, IG offers a rapid, simple technique to create a permanent adhesion of the stomach to the body wall compared to other techniques that involve dissection of muscular flaps, use of tubes, and/or carry the risk of either pneumothorax or rib fracture. In this report, postoperative complications that may have been related to the IG were mild and transient and included episodes of regurgitation, inappetence, and gastrointestinal upset.

For objective comparison, biomechanical testing has been reported for most commonly used gastropexy techniques.^{19,20,24,27,28,34,35,37,38} Although those quantitative results have been described, the absolute strength of gastropexy techniques required to prevent GDV is unknown. Efficacy for prevention of recurrence following gastropexy is more clinically relevant when choosing a technique for gastropexy. A prospective study following 74 patients after gastropexy performed during treatment of GDV documented 3 recurrences of GDV (4.3%); however, methods of gastropexy technique and diagnostics used to confirm the recurrences were not reported.¹⁴ The circumcostal gastropexy technique was previously evaluated in 30 dogs with a mean follow-up time of 411 days (range, 120–840 days). Recurrence was documented in 1 of the 30 dogs (3.3%) in that study.³⁴ Other studies evaluating circumcostal techniques confirmed similar results, with an overall recurrence rate of 4.3% (3 of 69 dogs).^18,34,35 The gastrocolopexy technique has a reported recurrence rate of 15%, based on a single study in which 3 of 20 dogs that underwent gastrocolopexy developed GDV that was confirmed either during surgery or necropsy. A fourth dog in that study died with GD without confirmation of volvulus.³⁰ No recurrence was reported over a 33 mo follow-up period in 21 dogs that underwent belt-loop gastropexy.²¹ A single case report was published describing recurrence of GDV following IG in 1 dog.³⁹ The authors of that case report hypothesized that recurrence was secondary to stretching of the gastropexy site, resulting from repeated subclinical GD episodes.³⁹ In the current report, recurrent episodes of GD in 6 dogs after IG were not associated with recurrence of GDV.

In this study, the authors confirmed that the efficacy of IG for the prevention of GDV in dogs was equivalent to reports of belt-loop gastropexy and superior to those of both circumcostal gastropexy and gastrocolopexy. To the authors’ knowledge, this is the first long-term study evaluating the development of GDV following IG.

Limitations of this study include its retrospective nature and the need for owners to recall their pet’s health history. Although it is possible that more dogs had recurrence of GD that was subclinical and gone unnoticed by the owners, it is unlikely that any dogs had GDV as this condition would have likely resulted in death. The cause of death was reported as secondary to conditions other than GDV in all dogs that died. Because GDV recurrence has been reported to occur in up to 56% of cases in the first 3 mo after an episode of GDV, no minimum follow-up time following IG was set as criteria of exclusion in this study so that early recurrences would not be excluded.⁴⁰ In addition, only 5 of 61 dogs (8.2%) in this study had follow-up times < 90 days. The binomial probability suggested that using 61 dogs, the chance or likelihood of GDV following IG was 4.8% at most. Although this study represents the largest population of dogs with IG retrospectively evaluated, the addition of more dogs would have increase the accuracy of that calculation. It is known that the risk of GDV increases with increasing age, so follow-up until time of death in all dogs would be ideal.¹¹

Conclusion

Studies support numerous gastropexy techniques that provide sufficient mechanical adhesion of the stomach to the body wall. Thus, other factors, such as technical difficulty, operative time, postoperative management, and recurrence rates, should be considered when adopting an optimal strategy for gastropexy. This study presents the longest follow-up data to date for IG and confirms that IG is an effective procedure for the prevention of GDV. IG may be performed rapidly, has few technical challenges, and minimal complications associated with it, making IG an ideal procedure for the treatment and prevention of GDV.