The Use of a Compression Device as an Alternative to Hand-Sewn and Stapled Colorectal Anastomoses: Is Three a Crowd?

A total of 23 patients (9 men and 14 women) underwent a left-sided colectomy and subsequent compression anastomosis (12 laparoscopic and 11 open) with the CAR™ 27 device. Age at operation ranged from 34 to 78 (mean age, 60.0 years) and BMI ranged from 20.0 to 36.5 (mean BMI, 26.0). A majority of the patients were Caucasian (78%). The ASA classification for the population was: ASA II, 65% and ASA III, 35%. The most common patient comorbidities included hypertension (57% of patients), malignancy (26%), obesity (22%), diabetes mellitus (17%), and coronary artery disease (13%). Diagnoses leading to surgery included rectal prolapse (eight patients), chronic diverticulitis (sux patients), diverticular colonic fistula (five patients), and malignancy (four patients; Table 1). Of note is that one patient had a sigmoid colectomy for diverticulitis with a concomitant distal pancreatectomy performed by a pancreatic surgeon for a previously diagnosed neuroendocrine tumor.

The duration of surgery range for this patient population was 75–330 min (median, 149 min). Estimated blood loss ranged from 20 to 700 mL (median, 150 mL), and none of the 12 laparoscopic procedures required conversion to an open operation. For each of the 23 anastomoses, the average time for creation was 5.7 min (range, 3–17 min). The ease of CAR deployment, assessed by the operating surgeon, was also recorded (1 = very difficult to 5 = very easy). Overall, the operating surgeons thought that the CAR™ 27 device was easy to use (mean score, 4.5). The score was 1 (very difficult) in 4.3% of patients, 3 (difficult) in 4.3%, 4 (easy) in 26.1%, and 5 (very easy) in 65.2% of patients. The reason for a lower score (3 or less) in two patients was failure of the device to fire appropriately on first attempt. No case had to be converted to a stapled or hand-sutured anastomosis. The distance from the anal verge to the anastomosis ranged from 9 to 20 cm (mean distance, 14 cm).

The median time to return of bowel function as indicated by the passage of flatus was 4 (range, 2–31) days. The median length of hospital stay was 5 (range, 3–41) days, and the median postoperative follow-up was 91 (range, 14–214) days. Of note is that one patient failed to return for 1- and 3-month follow-up visits. Time to ring expulsion was difficult to measure since most patients were surprisingly unaware of this event. However, one patient stated that the ring passed without complication on the tenth postoperative day.

Overall, surgical complications were grouped into two categories: (1) minor morbidities, 3 of 23 (13%) patients, which included one small postoperative abscess requiring antibiotics alone and two postoperative anastomotic strictures (diagnosed by flexible sigmoidoscopy at 3-month visit) receiving balloon dilation and (2) major morbidities, 1 of 23 (4%) patients, which included a partial anastomotic dehiscence/leak requiring a return to the operating room for dismantling of the anastomosis and diversion. The patient had a prolonged hospital course but slowly improved and was discharged home on postoperative day (POD) 41 tolerating a regular diet. Of note is that air testing for anastomotic integrity just after completion of the anastomosis did not demonstrate a leak in any patient.

At 1-month follow-up, all patients were tolerating a regular diet and all except one patient reported having normal bowel movements. This patient had intermittent episodes of loose bowel movements prior to operation, most likely as a result of rectal prolapse. Postoperatively, the patient continued to have intermittent episodes of loose bowel movements with improved frequency that finally resolved by the 3-month follow-up visit. At 3-month follow-up, all patients were tolerating a regular diet and all reported having normal bowel movements, except two patients who reported mild abdominal pain and bowel movements with a string-like consistency. Flexible sigmoidoscopy of the anastomotic sites of both patients performed at this time revealed tight strictures. Both patients subsequently underwent endoscopic balloon dilation to resolve their strictures and both have made full recoveries. Flexible sigmoidoscopy of all remaining patients was unremarkable (Table 2).

Use of the newer CAR™ 27 compression anastomotic device has the advantage of overcoming several obstacles previously encountered with earlier compression devices. Older devices resulted in the creation of lumen too narrow for the passage of intestinal contents, retention of foreign material within the tissue, necrosis at the anastomotic site, and problems with passage of the device. The CAR™ 27 device has an anatomical design not unlike that of current stapling devices used to create end-to-end anastomoses and therefore eliminates the previous problems of passage and withdrawal of the device from the anus. Compression of the two ends of bowel to be connected creates a controlled region of necrosis isolated within the compression ring only, allowing a more rapid healing outside the ring. Because the ring is expelled early in the healing process, retention of foreign material ceases to be an issue. In addition, the CAR™ 27 device has potential advantages over current methods of large bowel anastomosis, most notably the lag phase of anastomotic healing.13 The tissue compression exerted through the CAR™ 27 device provides a strong seal circumferentially immediately at the time of surgery secondary to the exhibition of super elasticity and shape memory, and the ability to eliminate the permanent implantation characteristics inherent in stapled anastomosis by the nitinol-based compression ring. In addition, the longitudinally orientated metal prongs further fixate both bowel ends and prevent tissue slippage from axial movements. The overall goal of such a design is the creation of a safe and effective anastomosis with mitigation of complications commonly seen with current methods of large bowel anastomosis, namely leaks, strictures, and bleeding.

Improvements in these outcomes have been observed in earlier studies with the CAR™ 27 device on human subjects. D’Hoore et al.13 demonstrated early promising findings with the CAR™ 27 device. In ten patients who underwent left-sided colectomy, no anastomotic leakage occurred, median hospital stay was 4 days, and only three patients noticed passage of the ring. Ring passage was verified with a plain abdominal X-ray 3 weeks after operation. Similar findings were reported in 12 patients after use of the compression device resulting in no complications related to the anastomosis, with only two patients noticing ring passage.15

In comparison, our study involving 23 patients resulted in an anastomotic leak in one patient (4.3%) and stricture formation in two patients (8.6%). The patient with the anastomotic leak required complete dismantling of the anastomosis and creation of an end colostomy. Investigation into possible reasons for anastomotic failure initiated by the operating surgeon and the device manufacturer failed to elucidate any definitive cause. The early presentation of the leak (POD 4) and the intraoperative findings suggested that premature necrosis of the tissue may be a contributor. This patient’s preexisting comorbidities (i.e., diverticulitis and moderate malnutrition) may also have been a contributing factor. In the two patients who developed strictures, one possible explanation was a retained ring for a longer duration than is typically experienced, inciting an ongoing inflammatory response causing scarring. Although, since neither patient noticed ring passage, this is only conjecture. Fortunately, balloon dilation easily resolved their symptoms.

Overall the operating surgeons felt that the device was easy to use; however, in two different patients, device failures occurred. In both instances, the circular blade within the device that cuts the tissue within the ring malfunctioned, preventing removal of the anvil from the anastomotic site. This required manual withdrawal of the anvil and device, resection of this anastomotic site, and creation of a new anastomosis. The second attempt was successful for each patient and neither experienced further sequelae. Time to creation of anastomosis was relatively short, as was time to return of bowel function and length of hospital stay, further enhancing the attractiveness of this device. Only one patient noticed passage of the ring, indicating no postoperative concern by both patient and surgeon for retained foreign objects. Furthermore, flexible sigmoidoscopy performed at 3 months postoperatively confirmed a well-healed anastomosis and verified ring passage.

The present study consists of a small number of patients using a new compression anastomotic device to create colorectal anastomoses. Although there was only one definitive anastomotic leak translating to a 4.3% leak rate for high rectal anastomoses, such a small sample size makes it impossible to draw firm conclusions regarding the efficacy and safety of the CAR™ 27 device. This leak rate is within the range expected for this level of anastomosis (3–5%).16‐18 Additionally, the two strictures encountered, although easy to manage, raise questions regarding the frequency of this complication relative to current stapled anastmoses. Finally, although the two “misfirings” of the device are troubling, they may be related to the learning curve and therefore can be avoided with further training. Larger, randomized trials with a head-to-head comparison to stapled and/or hand-sewn anastomoses will be necessary to accurately assess this new technique.