Single-Incision, Laparoscopic-Assisted Jejunal Resection and Anastomosis Following a Gunshot Wound

Introduction

Abdominal gunshots are an uncommon condition in veterinary medicine and outcome is variable depending on the type of ballistic, velocity of the ballistic, as well as the total energy absorbed.¹ The current recommendation in veterinary medicine is surgical exploration after penetrating abdominal gunshot wounds because of the high incidence of internal organ damage.^2,3 Acute penetrating abdominal gunshot wounds require immediate attention but many cases of small caliber, low velocity ballistics are either missed and/or misdiagnosed as either bite wounds or lacerations.¹ Because clinical signs and finances are sometimes used to guide diagnostic and treatment regimens, diagnostic imaging including both radiography and ultrasonography may not be performed in every case. In the dog reported herein, it is unknown when the gunshot injury occurred, but survey radiography at the time of injury and onset of clinical signs would likely have been diagnostic and would potentially have led to earlier treatment.

Intramural mechanical obstruction of the intestine in small animals is most commonly caused by neoplasms of the intestinal wall, such as lymphoma, leiomyosarcoma, and less commonly, by fungal granulomas such as those associated with either Pythium or Laganidium spp.^4,5 There are single case reports of obstructions caused by intestinal hematomas, abscessation, as well as pyogranulomas associated with intramural foreign bodies; however, the case presented herein is unique as the foreign body was readily identified on orthogonal survey radiographs, which localized to the region of the abnormal intestinal segment.^6–8 A definitive association with the intestine was confirmed with ultrasonography. Due to those findings, as well as the discrete nature of the lesion, laparoscopic-assisted surgery was thought to be a reasonable treatment option. The purpose of this report is to describe the imaging, surgical technique, and outcome of a patient who underwent laparoscopic assisted resection and anastomosis for a unique cause of gastrointestinal obstruction.

Case Report

A 2 yr old castrated male Pomeranian weighing 3.4 kg was referred to the University of Florida Small Animal Hospital with a 6 wk history of chronic vomiting, intermittent anorexia, and lethargy. The dog was current on vaccinations and was housed indoors with three other dogs. The dog was found as a stray by the owners ~1 yr previously with an unknown history. The most recent episode of vomiting occurred 3 days prior to initial examination, which the owner noted consisted of brown, formed material. The dog was lethargic and inappetent for 24 hr following the vomiting episode but then returned to normal activity. The owner had attempted symptomatic therapy for chronic vomiting with an unknown quantity of bismuth subsalicylate and diet change without improvement.

On physical examination the dog was bright, alert, hydrated, and had a body condition score of 4 out of 9. The rectal temperature was 38.3°C and the pulse was 140 beats/min. Auscultation of the heart and lungs was unremarkable. Abdominal palpation revealed a nonpainful, soft-tissue structure within the midabdominal region. The remainder of his physical examination appeared to be within normal limits.

Results of hematology revealed a mild leukocytosis (14.3 × 10⁹/L; reference range, 5–13 × 10⁹/L) characterized by a mature neutrophila and mild thrombocytosis (463 × 10⁹/L; reference range, 134–396 × 10⁹/L). Serum biochemical profile revealed a mild hypoalbuminemia (24 g/L; reference range, 29–38 g/L). Right and left lateral and ventrodorsal radiographs identified a 7 mm long conical, metal foreign body in the middle of the caudoventral aspect of the peritoneal space that appeared to be an air rifle pellet (Figure 1). At that level, there was a focal dilation of the small intestine measuring 4.5× the midbody height of the fifth lumbar vertebral body. That segment of the small intestine contained heterogeneous, formed, soft-tissue opaque material. Surrounding that intestinal segment and metal foreign body, there was an ill-defined, soft-tissue opaque region measuring ~2.2 cm in diameter. The radiographic interpretation was mechanical ileus with an intraperitoneal metallic ballistic foreign body and associated granuloma, abscess, and/or adhesions.

View Figure

• Download as Powerpoint
• Download Figure

Abdominal ultrasonography revealed a 2.6 mm × 4.2 mm hyperechoic structure (airgun pellet) with reverberation artifact located within the muscularis layer of a segment of jejunum. There was a focal, eccentric, 8.4 mm thickening of the jejunal wall surrounding the hyperechoic structure (the normal jejunal wall thickness ≤4.1 mm in dogs up to 20 kg).⁹ Additionally, there was altered wall layering, which was characterized by thickening of the muscularis layer, measuring up to 6.1 mm. There was focal dilation and corrugation of the jejunum orad to the lesion, which maintained a normal wall thickness. Hyperechoic mesentery surrounded the jejunal lesion. Those findings were consistent with a focal eccentric jejunal wall thickening (predominantly the muscularis layer), associated with a mural metallic ballistic foreign body resulting in a partial mechanical obstruction and regional granuloma formation or peritonitis. Based on those findings, abdominal exploratory surgery was recommended.

The dog was premedicated with acepromazine^a (0.03 mg/kg intramuscularly) and hydromorphone^b (0.1 mg/kg intramuscularly), induced with ketamine^c (5 mg/kg IV) and diazepam^d (0.25 mg/kg IV), and maintained with sevoflurane^e in 100% O₂ and fentanyl^f (0.3 µg/kg/min). Perioperative cefazolin^g (22 mg/kg IV) was administered, and the dog was placed in dorsal recumbency. A 20 mm ventral midline incision was made at the umbilicus through the skin, subcutis and linea alba. A single-incision laparoscopic surgery (SILS) port^h was placed into the incision using a modified Hasson technique. Three 5 mm inner cannulae were inserted in the SILS port. The abdomen was then insufflated to a maximum pressure of 8 mm Hg using CO₂ gas. The abdominal cavity was explored using a 0° 5 mm × 29 cm laparoscopic telescope.ⁱ The initial exploratory findings included focal scarring of the left transversus abdominis and splenic surface (Figure 2). Following initial exploration, the dog was rotated into right and then left oblique recumbency for evaluation of the abdominal gutters, descending duodenum, and descending colon. The dog was then rotated back to dorsal recumbency and a limited intracorporeal exploration of the small intestines was performed. A mass-like lesion with omental adhesions and erythematous jejunum was noted. An adjacent section of grossly normal jejunum was then grasped with 5 mm × 43 cm laparoscopic Babcock forceps^j and exteriorized from the abdominal cavity after removal of the SILS port. The abdominal wall margins were isolated using moistened laparotomy sponges. That section of intestine was examined extracorporeally in an orad direction to the ascending duodenum and aborad to the descending colon. The mass was identified in the midjejunum and was exteriorized with no resistance through the 20 mm celiotomy (Figure 3). Omental adhesions were freed using radiofrequency cautery and a routine, extracorporeal, sutured^k intestinal resection and anastomosis was performed. After saline leak testing, the bowel was gently replaced into the abdominal cavity. The abdominal laparotomy sponges were discarded, and gloves and instruments were changed. The SILS port was then replaced, and the abdominal cavity was examined to ensure there was no intestinal malposition and to allow laparoscopic omentalization of the anastomosis. The linea alba, subcutis, and skin were closed routinely. Operative time from skin incision to wound closure was 90 min.

View Figure

• Download as Powerpoint
• Download Figure

View Figure

• Download as Powerpoint
• Download Figure

The dog recovered uneventfully from anesthesia and was comfortable based on serial subjective pain scores using the Modified Glasgow pain score performed for 16 hr postsurgically.¹¹ Methadone^l (0.2 mg/kg IV) was administered q 6 hr overnight. Enteral feeding was started 8 hr after surgery, and the patient had a good appetite. The patient was discharged from the hospital the day following the procedure with tramadol^m (3.8 mg/kg per os) to be given as needed. Follow-up phone calls at 2 and 8 wk postsurgically indicated that the patient was doing well with no clinical signs of illness.

Discussion

This report describes the successful laparoscopic-assisted intestinal resection and anastomosis in a dog with partial obstruction secondary to an abdominal gunshot injury. Although laparoscopy has been used in humans with abdominal gunshot wounds as a diagnostic tool to avoid negative exploratory surgeries, to the authors' knowledge, there have been no documented reports of similar use of laparoscopy in veterinary medicine.¹⁰ However, laparoscopic-assisted surgery is gaining popularity among veterinary surgeons with many techniques having previously been described.^11–13 The potential advantages of laparoscopic-assisted surgical procedures include smaller incisions, decreased soft-tissue trauma, decreased postoperative pain, decreased hospitalization time, and greater visualization compared with conventional surgeries.^11–16,17

Similarly, reducing port size and number, a concept that has gained popularity in human medicine, is now progressing in veterinary minimally invasive surgery.^{13–15,17–19} To that end, specially designed single-incision devices, such as the SILS port, have allowed the use of multiple instruments through a single port and have helped to facilitate surgical advances.^13,19

One potential difficulty with laparoscopy is performing a thorough exploration of the peritoneal cavity, which has likely limited its use in veterinary gastrointestinal surgery.¹² In the case reported herein, a somewhat limited abdominal exploratory was performed. The initial exploration was performed with the patient in dorsal recumbency, but the patient was rotated into right and left oblique recumbency for exploration of the abdominal gutters. Using that technique, the stomach, descending duodenum, and majority of the aborad descending colon were not palpated extracorporeally; however, intracorporeal visualization and palpation of those structures using a blunt laparoscopic probe was thought to be adequate. Additionally, preoperative abdominal radiography and ultrasonography demonstrated no indication of disease in those organs. It is the authors' recommendation that laparoscopic assisted intestinal procedures be undertaken with caution and only following a thorough preoperative work-up because indications and exclusionary criteria have yet to be determined in veterinary medicine.

Although gastrointestinal-assisted laparoscopy has some limitations, it may also have some unique benefits. Namely, the magnification and illumination afforded by the laparoscope appeared to be helpful in identifying the entrance wound in the left body wall. Additionally the relatively small lesions along the splenic surface were also easily visible. A careful exploratory laparotomy would have likely identified those abnormalities; however, it might have been more difficult to determine the trajectory of the bullet because the organs need to be exteriorized during a standard abdominal exploratory procedure, thus altering their relative orientation. The use of the SILS port in this case allowed for minimization of the surgical wound while allowing for intestinal resection and anastomosis. All procedures were performed through the original 20 mm celiotomy, and no enlargement of the incision was needed. In addition to the potential for less postoperative discomfort compared to a more traditional laparotomy, it is possible that the relatively smaller incision helped minimize contamination and tissue manipulation with that approach. It has recently been suggested that minimally invasive procedures may reduce postoperative infection rates compared to conventional techniques.¹⁶ Whether or not this is the case for laparoscopic-assisted intestinal procedures remains to be answered but is worth future investigation.

A major limitation of utilization of a SILS port is that this multi-lumen port device decreases external space for triangulation and increases potential collision of instruments. Specifically designed articulated instruments are helpful to overcome this obstacle. Articulated instruments are commonly used in human surgery but are not routinely employed in veterinary surgery at this time.¹⁹

Conclusion

Although there are a few publications on the use of a SILS port for laparoscopic surgery in dogs, to the authors' knowledge, this is the first report of a laparoscopic-assisted resection and anastomosis using a SILS port.^17,19 The patient in this report had a short postoperative hospitalization time and had no major anesthetic or operative complications. The success of the procedure in the patient described herein was likely due to a thorough diagnostic evaluation, case selection, and experience of the surgery team. Future investigations into laparoscopic-assisted intestinal surgery are indicated prior to routine clinical use.