Laparoscopic colopexy for recurrent rectal prolapse in a Maltese dog

Abstract

A 2.5-kg castrated male Maltese dog, suspected to be older than 10 y, was presented with a prolapsed mass at the anus. This had occurred on 2 previous occasions within the last 4 mo and had been managed with manual reduction and purse-string sutures. The rectal prolapse had viable tissue and was reducible but resulted in straining and fecal accumulation. Colopexy (with intracorporeal sutures) was performed laparoscopically using 3 ports; the distal colon was retracted cranially and attached to the abdominal wall with 3 simple interrupted sutures in a single row. The dog recovered uneventfully, had good appetite and normal activity, did not strain, and defecated without issues. There were no wound-healing complications and at 12-month post-operative examination, the patient was in good condition without clinical signs. Based on this case report, laparoscopic colopexy is clinically practical for management of rectal prolapse in small-breed dogs.

Rectal prolapse (RP) occurs partially or completely in dogs and cats with prolonged tenesmus (1). Any urogenital or anorectal conditions causing straining can contribute to RP, including intestinal neoplasia, foreign body, urolithiasis, constipation, perineal hernia, prostatic disease, dystocia, or previous surgery in the posterior portion of the body, e.g., perineal herniorrhaphy. Rectal prolapse is common in young animals, and most frequently associated with severe internal parasitic infestation and diarrhea (1,2). There is no breed predisposition, except Manx cats with their anal laxity (1). Rectal prolapse should be differentiated from a prolapsed intussusception by insertion of a finger or probe alongside the prolapsed mass; an intussusception has a fornix that allows a probe to pass between the anus and the prolapsed tissue, whereas this is not possible in rectal prolapse (3). The prolapsed tissue may be simply red and swollen, or with excoriation, laceration, hemorrhage, desiccation, necrosis, or ulceration, depending on the duration of the RP (1,3). Self-mutilation and trauma may worsen the condition, and therefore, should be prevented (3).

The treatment of choice depends on the degree of prolapse, tissue viability, reducibility, chronicity, and previous treatment attempts. Most patients with rectal prolapse can be managed by manual reduction, transient (3 to 5 d) purse-string suture, and stool softener or low-residue diet. Importantly, the underlying causes must be addressed to prevent recurrence (1,3). Surgical treatment options include rectal amputation with resection and anastomosis for non-reducible/traumatized cases, and colopexy for multiple recurrences (1–3).

Colopexy creates a permanent adhesion between the colonal serosa and abdominal wall, preventing caudal displacement of the colon and rectum (1,2). It is commonly used for management of recurring RP with viable tissue, and in complicated perineal hernia, to prevent post-operative RP or recurrence of the perineal hernia (1,4). Furthermore, colopexy can be used for RP due to anal sphincter laxity (5) and a descending colonal torsion (6).

Open colopexy is most often performed; however, with increasing interest in minimally invasive surgery, a laparoscopic approach is becoming more common. During colopexy, sutures should be placed without penetrating the colon or putting excessive tension on the colon with cranial traction (1,4,7). This is important for ensuring a successful outcome, preventing local infection, or preventing failure of adhesion formation between the colon and body wall. Both incisional and non-incisional types of colopexy are effective (2).

Case description

A castrated male Maltese dog (2.5 kg), retrieved from an animal shelter, was presented with RP. The dog had a history of 2 previous surgeries (purse-string suture) since being rescued 4 mo ago. However, the RP did not resolve completely, and there was occasional bleeding. There was no internal parasitic infestation, but heartworm disease was diagnosed and treated by the referring veterinarian. The dog had dyschezia and straining on defecation, but otherwise, was bright and alert, with good appetite and normal activity. The RP had a relatively healthy mucosal eversion, ~1 cm long, that was reduced manually but relapsed soon after. Screening tests [thoracic/abdominal radiography, abdominal ultrasonography, complete blood (cell) count (CBC), serum chemistry, electrolytes, and urinalysis] revealed no specific findings except fecal accumulation. The dog was started on oral lactulose (0.5 mL/kg, q12h), and feces were manually expressed.

Laparoscopic colopexy was performed 2 wk later, under general anesthesia with isoflurane inhalation (Figure 1). Midazolam (0.2 mg/kg, IV), butorphanol (0.2 mg/kg, IV), propofol (4 mg/kg, slow IV) were used for premedication and induction. Cefazolin (20 mg/kg, IV) and meloxicam (0.2 mg/kg, IV) were also given. The dog was placed in dorsal recumbency, and the surgical table was tilted as needed, to the right and laterally. The primary surgeon was on the right side of the dog, and an assistant who handled the camera stood on the left. Three 5-mm ports were placed using the Hasson technique: primary port (cranial to umbilicus) for the telescope (5 mm, 0°, 1488 HD; Stryker, Portage, Michigan, USA), and second and third instrumental ports (right paramedian around the prepuce for debakey forcep, babcock forcep, j-hook, and 2 laparoscopic needle holders with different jaw type; 1 flat and 1 curved, each) (Figure 2). Intra-abdominal pressure was maintained at < 10 mmHg throughout the procedure.

Figure 1.

Laparoscopic colopexy in a dog with recurrent rectal prolapse. A — Colopexy sites on both sides indicated with cauterization; B — Final confirmation of tension before suture placement of colopexy; C — The seromuscular suture bite of the colon; D — Placement of the first caudal anchoring suture; E–G — The second and third suture bites; H — The completed colopexy; and I — The colopexy site without tension during deflation. Black arrow — Peritoneal incision of the abdominal wall with cauterization; White arrow — Pinpointed cauterization of the colon; C — Colon; O — Omentum; SI — Small intestine; UB — Urinary bladder.

Figure 2.

Portal sites for laparoscopic colopexy in a dog with rectal prolapse (after surgery). * Xyphoid process; Arrow — Primary port for camera.

Intra-abdominal exploration revealed that the omentum had adhered around the internal inguinal ring; it was cauterized with a j-hook. The distal colon was exposed and retracted cranially under external visual inspection by a nonsterile assistant to determine the degree of retraction required to resolve the RP with appropriate tension (Figure 3 A,B). Subsequently, it was lifted upward, and colopexy sites were chosen. Locations where the first anchoring suture was to be placed were indicated by pin-pointed cauterization on the colon and on the parietal peritoneum. To promote a strong adhesion, a 2-cm incision was made on the peritoneum, progressing anterior from the indicated point. Using 3-0 polydioxanone with tapered-round needle and a square knot, 3 simple interrupted sutures were placed intracorporeally, joining the abdominal wall and seromuscular layer of the colon. Intra-abdominal pressure was lowered when the first anchoring suture was tied, to allow both sides to approximate more easily, with less tension on the colon. The 2 following sutures were placed from the caudal to the cranial direction, more than 5 mm apart from each other. There was no suture failure, and bleeding was minimal. The colon was confirmed to be fixed to the body wall without a gap when the colopexy site was explored. Intra-abdominal conformation and tension on the colon were assessed during pneumoperitoneum deflation. The portal sites were closed routinely after bupivacaine infiltration.

Figure 3.

Gross appearance of rectal prolapse in a Maltese dog, before (A) and after (B) cranial retraction of the colon during laparoscopic colopexy, and on post-operative day 21 (C).

The dog recovered uneventfully and had a good appetite and normal activity after surgery. Mild subcutaneous emphysema developed but resolved. He urinated and defecated with no indications of wound infection, peritonitis, or gastrointestinal signs. The dog had a positive perineal reflex, and the straining resolved (Figure 3 C). Compared to pre-surgery, feces were longer and of normal shape. The C-reactive protein concentration was within the normal range (10 mg/L, reference range: 0 to 20 mg/L) on post-operative day (POD) 1. Lactulose was discontinued on POD 7. There were no specific findings on abdominal radiography or ultrasonography on POD 5 and POD 37 and the colopexy maintained its intended site. A mild and transient protrusion of edematous anal mucosa was observed on POD 37. At the 12-month follow-up, he was doing well, without recurrence of RP.

Discussion

This report describes a laparoscopic colopexy in a clinical patient, a small-breed dog presenting with recurring RP despite 2 previous treatment attempts. Colopexy was achieved using a totally laparoscopic procedure with a 3-portal system, resulting in a favorable outcome. There was no need to convert, and there were no post-operative complications. This was attributed to a mild degree of prolapse of the external anal sphincter, despite the chronic pathologic course.

This is the first report of a completely laparoscopic colopexy procedure with detailed surgical information, in the English clinical literature. Previous veterinary studies on laparoscopic colopexy reported the laparoscopic-assisted technique that mostly used extracorporeal suturing and an paramedian incision of up to 5 cm (5,6,8–10). Zhang et al (6) reported less surgical trauma with a significantly lower serum C-reactive protein concentrations through this technique using a 3 to 4 cm mini-laparotomy compared to open colopexy. The C-reactive protein level in the present case was normal on POD 1, the time when these values are highest in the absence of progressive complication (6). Apart from the colopexy site, the 3 holes (each 5 mm) were the only other surgical trauma to the abdominal wall.

Laparoscopic colopexy requires skill and often considerable time to perform intracorporeal sutures, with practice needed to achieve proficiency. The author is a right-handed surgeon, and taking oblique suture bites instead of bites perpendicular to the longitudinal axis of the colon/cauterized abdominal wall, may have been more convenient for driving the needle. Furthermore, a shorter needle or ski needle with knotless barbed sutures would also have made this easier. In addition, when intracorporeal suture is not possible, a transparietal/percutaneous suture with skin only incision could be considered (11).

Regarding suture arrangement, in conventional open colopexy, the recommendation is 2 parallel rows with 5 to 8 sutures in each row, in an interrupted, continuous, or horizontal mattress pattern (1,3,5). This was also maintained in previous studies on laparoscopic-assisted colopexy (6,8,10), especially for an incisional technique. In the present case, only 3 simple interrupted sutures were placed in a single row, which induced no specific complications. This may be due to the small size and body weight of the patient; however, it is unclear how this method would work in larger patients. For example, more sutures could be placed, depending on the degree of stability. This method was supported by a study on laparoscopic-assisted colopexy that used 5 simple interrupted sutures in a single row in 7 healthy dogs (mean body weight, 13.2 kg) (11) that resulted in a favorable colopexy without complications. Necropsy and histopathology at 11 wk after surgery revealed a tight adhesion between the colon and abdominal wall, measuring 3 to 3.5 cm in length.

Five laparoscopic colopexies were included in a previous canine study (4); 3 resulted in wound complications, including local abscess formation at the colopexy site, requiring revision of laparotomy in 2 dogs for definitive treatment of infection. In another study, 1 dog had a laparoscopic-assisted colopexy but was euthanized due to bacterial peritonitis resulting from colonic leakage on POD 11 (12). Unfortunately, there was no detailed information available for surgical procedures in either report; therefore, laparoscopic colopexy may not have been attempted. In contrast, in the present case, there was no wound infection or leakage at the colopexy site, either perioperatively, or up to 12 mo after surgery. Although laparoscopy does not allow surgeons to work directly on the tissue with tactile sensation, it provides magnified visualization, which is preferable for precise suture placement in the seromuscular wall of the colon. Although the condition of the colon and its healing from surgical trauma in healthy dogs could differ from that in clinical cases with RP, previous laparoscopic colopexy in 8 healthy dogs reported no complications associated with wound infection at the colopexy site, and an appropriate permanent adhesion was achieved (7). In that study, intracorporeal sutures were performed with simple interrupted sutures in 2 rows and 3 sutures in each row.

The findings in this case supported the use of laparoscopic colopexy in small-breed dogs. It is a practical treatment option in clinical cases. However, further studies with a greater number of clinical patients and longer follow-up periods are warranted. CVJ