A Prospective Evaluation of a Modified Belt-Loop Gastropexy in 100 Dogs with Gastric Dilatation-Volvulus
ABSTRACT
Gastropexy is a surgical technique performed to prevent and decrease the recurrence rate of gastric dilatation and volvulus (GDV). The objective of this prospective, a descriptive cohort study on 100 client-owned dogs who were presented with GDV, is to describe a modified belt-loop gastropexy and determine its intraoperative complications and long-term efficacy.
The transversus abdominis muscle was used to make an oblique belt-loop. A seromuscular antral fold, instead of a seromuscular antral flap, was passed through the belt-loop, and then, the passed portion of the antral fold was sutured to the dissected edge of the abdominal wall. Intraoperative complications related to gastropexy were recorded, and the incidence of GDV recurrence was determined a minimum of 1 yr postoperatively via telephone with the referring veterinarians and the owners. There were no intraoperative complications related to the modified belt-loop gastropexy technique. Based on follow-up conversations, none of the dogs presented signs of GDV recurrence during the follow-up period. Based on the results, there is strong clinical evidence that a modified belt-loop gastropexy prevents recurrence of GDV in dogs surviving an acute episode.
Introduction
Gastropexy is the surgical fixation of the stomach wall to the inner abdominal wall by the formation of a permanent adhesion at the gastropexy site. Indications for gastropexy include the prevention of occurrence of gastric volvulus in predisposed breeds and decreasing the reoccurrence of acute gastric dilatation and volvulus (GDV) after derotation/decompression of the stomach. It is also part of the treatment protocol for hiatal hernia. Failure to perform a right-sided gastropexy is associated with recurrence rates of up to 80%.1–3 A number of gastropexy techniques have been described.4–16 Incisional gastropexy, circumcostal gastropexy, belt-loop gastropexy, tube gastropexy, and laparoscopic-assisted gastropexy are the most commonly performed techniques.6–9,12,17 Incisional gastropexy is technically simple and associated with few complications; however, there is a risk of gastric mucosal perforation. Circumcostal and belt-loop gastropexy are more difficult to perform than incisional gastropexy but may result in stronger adhesions.18 Although specific data on incidence of complications are not available for circumcostal and belt-loop gastropexy, gastric mucosal perforation is an intraoperative risk in both of techniques, while rib fracture and iatrogenic pneumothorax are potential intraoperative complications of circumcostal gastropexy.11,12,16
The aim of this paper is to describe the complications and incidence of GDV recurrence in client-owned dogs who underwent a modified belt-loop gastropexy technique after derotation/decompression of the stomach following GDV. We hypothesized that this technique would have minimal or no intraoperative complications, could be rapidly performed, and would create a stable adhesion between the gastric antrum and the right abdominal wall.
Materials and Methods
Study Design
A descriptive prospective cohort study was conducted at the Clinica Veterinaria Lago Maggiore. All patients underwent preoperative stabilization and surgical treatment according to their individual needs. The breed, sex, age, body weight, additional surgical procedures other than gastropexy (necrotic gastric wall invagination and partial gastrectomy), the time required for gastropexy, intraoperative complications of gastropexy, and recurrence of GDV were recorded at least for 1 yr following the surgery. Possible intraoperative complications included tearing of the transversus abdominis muscle during the belt-loop procedure, perforation of the gastric wall during the gastropexy procedure, and excessive tension on the suture line. As in this technique, thicker gastric wall tissue is included in the belt-loop, so tensions on the suture line could lead to excessive inflammation, necrosis, suture dehiscence, and eventually gastropexy failure. A follow-up was planned to be performed via telephone a minimum of 1 yr postoperatively to determine the recurrence rate of GDV. Necropsy and histological evaluation of the gastropexy were planned to be performed in case of death for any reason.
Inclusion/Exclusion Criteria
Dogs suffering from an acute episode of GDV and who had surgical correction were enrolled in the study. There were no breed, age, or sex restrictions. Dogs were excluded from the study if lost to follow-up. All owners signed an informed consent form for surgery and postoperative follow-up.
Preoperative Treatment
At admission, clinical vital signs (temperature, heart rate and respiratory rate, capillary refill time, mucous membrane color, and mentation) together with electrocardiography, noninvasive blood pressure, and hematological parameters (packed cell volume, total solids, glucose, lactate, electrolytes, and blood gas) were assessed. In the meantime, dogs received 60–90 mL/kg/hr of a crystalloid solution (acetated Ringer’s solution or lactated Ringer’s solution)a IV and/or 20 mL/kg/hr of a synthetic colloid solution (dextran 70 in 0.9% saline)b IV, until improvement of vital signs and perfusion parameters at the discretion of the attending veterinarian. Initial stomach decompression was achieved by needle gastrocentesis. The dogs were premedicated with 0.004 mg/kg fentanylc or a combination of 0.002–0.004 mg/kg fentanylc and 0.001–0.002 mg/kg medetomidined administered IV, depending on their clinical status. Anesthesia was induced with 2–4 mg/kg propofole or a combination of 1.4 mL/kg of a 1:1 mixture of ketaminef and diazepamg administered IV. An orogastric tube was passed to allow gastric lavage immediately after that. A dose of 20 mg/kg cephalosporinh and a single injection of 0.2 mg/kg meloxicami were administered IV at the time of induction. Anesthesia was maintained with isofluranej in oxygen. A constant rate infusion of 0.004–0.008 mg/kg/hr fentanyl was administered IV during the entire period of anesthesia/surgery. All patients were monitored during surgery via electrocardiography, noninvasive blood pressure, respiratory rate, capnography, oximetry, and determination of end-tidal isoflurane concentration.
Surgical Technique
All procedures were performed by two surgeons. The dogs were placed in dorsal recumbency and routinely prepared for surgery. An incision was made in the ventral midline from the sternal xiphoid process to ∼2 cm caudal to the umbilicus. When necessary, derotation of the stomach and correction of gastric malpositioning was carried out. The gastric wall was inspected for areas of necrosis, which were then invaginated or resected. Splenectomy was performed when there was splenic torsion or visible splenic vessel thrombosis. For gastropexy, two parallel stab incisions (4–5 cm long and 2 cm apart) were made through the peritoneum and the transversus abdominis muscle on the right abdominal wall, 2 cm caudal to the costal arch and ∼5 cm from the linea alba (Figure 1A). The incisions were made at an oblique (ventrodorsal and craniocaudal) angle to the transversus abdominis muscle. Blunt dissection was used to create a 2 cm-wide belt-loop tunnel between the incisions (Figure 1B). A pair of Allis tissue forceps was passed from caudal to cranial, and a seromuscular fold of antral wall, ∼10–15 cm or less from the pylorus (depending on the size of the dog), was grasped. The forceps with the fold of antral wall were pulled back through the belt-loop (Figures 1C, D, 2A). The seromuscular fold was sutured to both the greater curvature of the stomach and the cut edge of the abdominal wall using 2-0 to 0 (depending on the size of the dog) nonabsorbable monofilament suture material (polypropylene). A continuous suture pattern was used, and each bite included serosa and muscularis of the stomach; serosa and muscularis of the seromuscular fold, fascia, and muscular tissue of transversus abdominis muscle; and peritoneum, in that order (Figures 2B, C, D). The continuous suture pattern adhering the gastric wall to the abdominal wall began caudally and progressed cranially over the gastropexy to relieve tension. The abdomen was routinely closed.
Citation: Journal of the American Animal Hospital Association 54, 5; 10.5326/JAAHA-MS-6596
Citation: Journal of the American Animal Hospital Association 54, 5; 10.5326/JAAHA-MS-6596
Postoperative Treatment
In all dogs, vital signs together with hematological parameters, electrocardiography, noninvasive blood pressure, and pulse oximetry were monitored a minimum of every 6 hr following surgery, depending on the patient’s needs. The dogs were fed as soon as possible after surgery. Antibiotics were discontinued postoperatively, unless signs of infection, e.g., fever, wound tenderness, or wound discharge, occurred. Opioid and anti-inflammatory drugs were continued for 1–7 days. When necessary, antiarrhythmic therapy was administered. Dogs were discharged 1–7 days postoperatively. Routine clinical follow-up examinations were performed on days 5 and 10 after discharge.
Results
In a period of 3 yr, 110 dogs with GDV were referred to the Clinica Veterinaria Lago Maggiore and underwent definitive surgical intervention.
Seven dogs were lost to follow-up, and 3 dogs died during surgery prior to the gastropexy being performed; therefore, they were excluded, leaving 100 dogs for evaluation in this study. Eleven dogs (11%) died within 5 days of surgery, and none of the owners consented to a postmortem. Of these, 3 died immediately after surgery. All of them showed signs of end-stage hypovolemic/septic shock and cardiac arrhythmias from admission, which were unresponsive to medical treatment. The 8 remaining nonsurvivors presented significant hypovolemic shock and severe gastric wall necrosis at surgery and died 1–5 days following surgery. One dog died 3 mo after surgery because of splenic hemangiosarcoma diagnosed at necropsy. Ten dogs died of unknown causes within 1 yr of surgery. According to the owners and referring veterinarians, none of them had a GDV recurrence. Unfortunately, in these dogs, necropsy was not allowed, and therefore, their cause of death is unknown. Seventy-eight dogs had a median follow-up of 850 days (range 450–1200, mean 709) postsurgery. Based on postoperative follow-up conversations with the owners and referring veterinarians, GDV did not recur in any of the 78 dogs; weight loss, despite adequate food intake, was reported in 1 dog.
There were 92 purebred dogs, including 35 German shepherd dogs; 14 Great Danes; 8 boxers; 8 Dobermans pinschers; 5 chow chows; 3 Italian Mastiffs, 3 bobtails; 2 Bernese mountain dogs, English setters, Irish setters, Maremmano sheepdogs, and Newfoundlands; and 1 dachshund, Spinone Italiano, bullmastiff, Dalmatian, rottweiler, and briard. Additionally, there were 11 mixed-breed dogs. Of the dogs, 58 were male (5 castrated) and 45 were female (19 spayed). The dogs ranged in age from 2 to 15 yr (mean 8.9) and weighed from 6 to 75 kg (mean 37.3 kg). In 35 cases, gastric volvulus was confirmed by radiography, while in the remaining 68 cases, a definitive diagnosis was made at surgery.
Concurrent splenectomy was carried out in 4 (4%) dogs, invagination of necrotic gastric wall in 11 (11%) dogs, and both splenectomy and gastric wall invagination in 7 (7%) dogs. Gastrotomy for the removal of a gastric foreign body was performed in 8 (8%) cases, and gastric rupture was diagnosed before surgery in 1 (1%) dog, who underwent partial gastrectomy of the necrotic gastric wall and abdominal lavage with 0.9% saline solution. Gastropexy was the sole procedure performed in 69 (69%) dogs, and all of them recovered uneventfully. For 78 dogs, the follow-up period free of recurrence ranged from 450 to 1200 days.
The duration of surgery ranged from 25 to 68 min (mean 36 min), and the mean operative time for the gastropexy procedure was 3.75 minutes (ranging from 1.5 to 4 min; median 3.5 min). There were no intraoperative complications related to the gastropexy procedure.
Three dogs died and underwent necropsy during the study period; one was euthanized 3 mo after gastropexy because of a splenic hemangiosarcoma, one was hit by a car 15 mo after GDV surgery, and the other died of unknown causes ∼3 yr after GDV surgery. In these dogs, a 10 × 5 cm section of the gastric antrum and a 10 × 10 cm section of the right flank were placed in formalin and examined histologically.
Diffused edema and peritoneal inflammation were observed in the gastric tissue sample obtained 3 mo postoperatively. Blood vessels, arterioles, and venules associated with small multifocal areas of fibroblastic hyperplasia were visible in the submucosa. The striated muscle of the belt-loop created with the transversus abdominis muscle contained myocytes, which were characterized by large vesiculated nuclei and a single nucleolus.
In the gastric tissue sample obtained 1 yr after surgery, the gastric submucosa and the smooth muscle layer were characterized by the presence of fibrous tissue and absence of edema. The skeletal muscle cells in the belt-loop were normally shaped and had rare activated nuclei.
In the sample obtained 3 yr after surgery, there was fibrous connective tissue in the submucosal and peritoneal regions and no signs of inflammation. The striated muscle in the belt-loop appeared normal.
The stomach mucosa was not wrapped around the belt-loop in any of the tissue samples.
Discussion
The most widely performed gastropexy techniques are incisional gastropexy, belt-loop gastropexy, and circumcostal gastropexy, all of which have been shown to prevent GDV recurrence by creating an adhesion or healing of sutured wound edges.7–9,12 However, these techniques have been associated with a variety of intraoperative complications (perforation of gastric wall, rib fracture, pneumothorax).7,11,12,16 The modified belt-loop gastropexy technique described in the present study was not associated with intraoperative complications in any of the 100 dogs who underwent the procedure. Extreme attention was paid during surgery for not overlooking intraoperative complications such as gastric wall rupture, belt-loop failure (trasversus abdominis muscle breakage), gastric fold weakness, and failure and cardiovascular imbalance because of surgical maneuvers. It has been reported that the muscular body wall loop and seromuscular gastric flap in the belt-loop gastropexy fail with equal frequency when tested immediately after their attachment; the seromuscular flap therefore could represent potential weakness in the belt-loop gastropexy technique.3,18,19 In our technique, a thicker seromuscular fold of gastric antrum was used instead of a seromuscular gastric flap. The thickness of the antral fold may offset problems related to thinner flaps and suture tearing through the tissue.
Perforation of the gastric mucosa during creation of the seromuscular antral flap has been reported for belt-loop and circumcostal gastropexy.11,12 Incisional gastropexy is also associated with the risk of gastric mucosal perforation because it involves incision of the seromuscular layer of the stomach. Accidental gastric mucosal perforation is a complication that requires extension of surgery and anesthesia time and may result in leakage of gastric contents and to potential complications. The modified belt-loop technique described in this study does not require a seromuscular antral flap, decreasing the chance of intraoperative complications. Moreover, when seromuscular gastric flap dissection is not required, the surgery time is reduced. This is an important factor to consider when operating critically ill patients with GDV.
The modified belt-loop gastropexy was shown to prevent recurrence of GDV in a long-term follow-up. None of the 89 dogs who survived the immediate postoperative period had a GDV recurrence in the follow-up period; 78 of them had a follow-up of 450–1200 days, the other 11 died prior to 450 days with no reported GDV recurrence. The recurrence rate of GDV was determined by a follow-up phone call to the referring veterinarians and to owners after discharge of the patients. The probability of owners recognizing signs of recurrent GDV was shown to be high, and for this reason, the data collected was considered reliable.20 Furthermore, necropsy of three dogs who died 3 mo, 1 yr, and 3 yr after the modified belt-loop gastropexy revealed that the gastropexy was intact. Long-term prevention of GDV recurrence is mainly attributable to the formation of adhesion or healing of wound edges.1,2,8,19,21,22 The results of histological analysis of tissue samples in the present study show that adhesion does occur after a period of inflammation with dense fibrous tissue infiltration of submucosa and peritoneum. Necrosis, inflammation, or other degenerative lesions were not seen in the muscle tissue. In none of these samples was found suture material penetrating gastric mucosal layer; however, we cannot make conclusions about inadvertent and undiagnosed gastric lumen penetration by sutures. An endoscopic exam would be required to definitively demonstrate that did not happen.
Because only three necropsies were performed in the patients who died within the follow-up period, our data regarding early and late postoperative complications of this novel gastropexy technique are inconclusive.
All 14 dogs (13.6%) who died in the first 5 days after surgery were affected at presentation by severe gastric necrosis or perforation, cardiac arrhythmias, and end-stage secondary cardiovascular and metabolic effects of the syndrome, which have been reported to be the worst prognostic factor for survival.2,23 The reported short-term mortality rate for acute GDV episodes is 16.2%.23 Our data (13.6% death rate in the first 5 days postsurgery) is in line with the reported data.
Ten dogs (9.7%) died before the 1 yr follow-up. According to follow-up data, none of them had a GDV recurrence or died of a GDV episode. All owners were instructed to record signs of abdominal pain; abdominal dilatation; and other gastrointestinal problems such as anorexia, vomiting, or diarrhea. In the owners’ opinions, none of the 10 dogs died of a gastrointestinal-related problem. Unfortunately, none of the owners allowed necropsy; therefore, the cause of death cannot be determined, and any relation to late complications of the gastropexy technique cannot be excluded.
None of the 78 patients for whom we have a long-term follow-up (450–1200 days) presented any early- or late-gastropexy–related complications.
The results of breed, sex, and age distribution; procedures other than gastropexy; and the time required for gastropexy were similar to those described in other studies.2,3,23 In the majority of our cases, gastric dilatation and GDV were not differentiated. The authors feel that in an emergency, it does not matter whether the dog has gastric torsion or gastric dilatation because the treatment is the same for both. Treatment starts with stabilization of the patient and evacuation of food and gas from the stomach. This is followed by surgery, which is advised also in cases of simple gastric dilatation to prevent volvulus. Two other interesting findings of this study were radiographically confirmed GDV in a 6 kg dachshund and gastric foreign bodies that were removed via gastrotomy in 8.7% of dogs with GDV. It is assumed that GDV complex generally affects large or giant, deep-chested dogs, but this disorder has also been reported in small-breed dogs and cats.24,25 The role of gastric foreign bodies in dogs with GDV has been investigated in a recent study.26 In another study, Beck et al. (2006) reported that 12 of 166 (7.2%) dogs with GDV required gastrotomy, although this procedure was sometimes used to remove excess food. In our patients, most of the food was evacuated by orogastric intubation before surgery, so that gastrotomy was performed exclusively to remove foreign materials.
Although a definitive conclusion about the recurrence rate of GDV cannot be drawn from descriptive studies or from the results of the three histopathological analyses, our results indicate that modified belt-loop gastropexy effectively prevents GDV recurrence in this population of dogs.27
The small number of surgeons, the composition of the study group (client-owned dogs), the absence of a control group, and the impossibility to perform a postmortem on the dogs who died in the follow-up period are limitations of the present study. Multicentric investigations involving more surgeons with different skill levels are required to better test the feasibility, complications, and efficacy of modified belt-loop gastropexy.
A group composed of client-owned dogs rules out the possibility of standardizing the time of gastropexy and collection of samples for histological and tensile strength evaluations. However, the maximum tensile force needed to prevent GDV in vivo is unknown, and the use of a mechanical test to evaluate the efficacy of a gastropexy may be controversial.17 Ultrasonographic examination would be more useful and reliable from a clinical standpoint for evaluating the presence of gastropexy adhesion.28 A prospective study based on ultrasonography of the gastropexy site may better clarify the absence of GDV recurrence in this cohort of dogs.
Conclusion
This study supports the use of a modified belt-loop gastropexy technique for the surgical treatment of GDV in dogs. No recurrence was noted in surviving dogs who were followed for a minimum of 1 yr. A prospective, multicenter trial with a variety of surgeons is recommended to fully evaluate the procedure and any potential complications.
A belt-loop, 2 cm in width and 4–5 cm in length, is created on the right abdominal wall, 2 cm caudal to the last rib by two stab incisions (A) and blunt dissection (B). The belt-loop runs obliquely with respect to the fibers of the transversus abdominis muscle. A fold of antral wall is grasped with Allis tissue forceps and passed through the belt-loop (C, D). (*) Indicates the diaphragmatic insertion on the costal arch. Right: cranial, Left: caudal; the white asterisk depicts diaphragmatic insertion on the costal arch.
A seromuscular fold of antral gastric wall (∼10–15 cm from pylorus) is grasped with Allis tissue forceps and passed through the belt-loop (A) and sutured on both the free part of the stomach wall and the abdominal wall with a nonabsorbable monofilament suture material (polypropylene, 0) in a continuous pattern (B, C, D). Right: cranial, Left: caudal.
Contributor Notes
