This study aimed to evaluate the safety and efficacy of a new nickel-titanium shape memory alloy compression anastomosis ring, NiTi CAR 27, in constructing an anastomosis for colorectal cancer resection compared with conventional staples.

In total, 234 consecutive patients diagnosed with colorectal cancer receiving sigmoidectomy and anterior resection for end-to-end anastomosis from May 2010 to June 2012 were retrospectively analyzed. The postoperative clinical parameters, postoperative complications and 3-year overall survival in 77 patients using a NiTi CAR 27 compression ring (CAR group) and 157 patients with conventional circular staplers (STA group) were compared.

There were no statistically significant differences between the patients in the two groups in terms of general demographics and tumor features. A clinically apparent anastomotic leak occurred in 2 patients (2.6%) in the CAR group and in 5 patients (3.2%) in the STA group (p=0.804). These eight patients received a temporary diverting ileostomy. One patient (1.3%) in the CAR group was diagnosed with anastomotic stricture through an electronic colonoscopy after 3 months postoperatively. The incidence of postoperative intestinal obstruction was comparable between the two groups (p=0.192). With a median follow-up duration of 39.6 months, the 3-year overall survival rate was 83.1% in the CAR group and 89.0% in the STA group (p=0.152).

NiTi CAR 27 is safe and effective for colorectal end-to-end anastomosis. Its use is equivalent to that of the conventional circular staplers. This study suggests that NiTi CAR 27 may be a beneficial alternative in colorectal anastomosis in Chinese colorectal cancer patients.

Recently, a nickel-titanium (NiTi) memory-shape device has been successfully used in gastrointestinal anastomosis. The aim of this study was to investigate the feasibility and safety of the device.

Four databases, reference lists, and the World Health Organization International Clinical Trials Registry Platform were systematically searched for randomized controlled trials assessing the clinical efficacy of a NiTi memory-shape device compared with that of a stapler in gastrointestinal or colorectal anastomosis.

Seven randomized controlled trials regarding the use of compression anastomosis clips (CACs) were enrolled for meta-analysis. The use of CACs was associated with a significant reduction in hospital duration (mean = -0.88 d; 95% confidence interval [CI], -1.38 to -0.38), the time to flatus (mean = -0.36 d; 95% CI, -0.08 to -0.04), and the start of oral intake (mean = -0.45 d; 95% CI, -0.83 to -0.06), as well as a nonsignificant change in postoperative complications and mortality. These clinical outcomes did not significantly change with the use of compression anastomosis rings.

Colonic anastomosis with a CAC is likely to reduce hospital duration, time to flatus, and the start of oral intake without influencing mortality or postoperative complications and may be a safe and preferable choice in colonic anastomosis. Further well-designed trials should be performed to determine the safety and efficacy of the newly developed compression anastomosis ring in both ileocolic and colorectal anastomosis.

Compression anastomotic ring-locking procedure (CARP) is a novel procedure for creating colonic anastomoses. The surgical procedure allows perioperative quantification of the compression pressure between the intestinal ends within the anastomosis and postoperative monitoring of the anastomotic integrity. We have recently shown that CARP is a safe and effective method for colonic anastomoses in pigs, and the purpose of the present study was to evaluate CARP for colonic anastomoses in humans.

This is a prospective study on 25 patients undergoing elective left-sided colonic resection. Time for evacuation of the anastomotic rings, perioperative compression pressure, and adverse effects were recorded. Postoperative blood samples were collected daily, and flexible sigmoidoscopy was performed 8-12 weeks after surgery to examine the anastomoses.

Fourteen out of 25 patients underwent CARP. CARP was not used in 11 patients due to advanced tumor disease (two cases) and size restrictions (nine cases). No case of anastomotic leakage, bowel obstruction, or stenosis formation was observed. No device-related perioperative adverse events were noted. The surgical device evacuated spontaneously in all patients by the natural route after a median of 10 days. Perioperative compression pressure ranged between 85 and 280 mBar (median 130 mBar). Flexible sigmoidoscopy revealed smooth anastomoses without signs of pathological inflammation or stenosis in all cases.

Our results indicate that the novel suture-less CARP is a safe and effective method for creating colonic anastomoses. Further studies are warranted in larger patient populations to compare CARP head-on-head with stapled and/or hand-sewn colonic anastomoses.

Compression anastomoses might represent an improvement over traditional hand-sewn or stapled techniques. Herein, we describe a novel concept of sutureless colonic anastomosis named compression anastomotic ring-locking procedure (CARP).

The surgical device consists of two anastomotic rings and their associated helping tools, facilitating the placement of the rings into the intestinal ends. Furthermore, four catheters are connected to the surgical device, allowing the evaluation of the anastomosis during and after surgery. A total of 31 pigs underwent a low colocolic anastomosis using the anastomotic rings. The compression pressure was measured perioperatively and up to 96 h after surgery. Anastomotic integrity and morphology were analyzed by use of radiology and histology, respectively. A long-term follow-up was conducted in a subgroup of pigs up to 108 days after surgery when the bursting pressure and stricture formation were examined.

All animals recovered uneventfully, and macroscopic examination revealed intact anastomoses without signs of pathological inflammation or adhesions. The perioperative compression pressure was inversely proportional to the gap size between the anastomotic rings. For example, an anastomotic gap of 1.5 mm created a colonic anastomosis with a perioperative compression pressure of 91 mbar, which remained constant for up to 48 h and resulted in a markedly increased compression pressure. Contrast infusion via the catheters effectively visualized the anastomoses, and no leakage was detected within the study. The surgical device was spontaneously evacuated from the intestines within 6 days after surgery. Histology showed collagen bridging of the anastomoses already 72 h after surgery. Long-term follow-up (54-108 days) revealed no stricture formation in the anastomoses, and the bursting pressure ranged from 120 to 235 mbar. The majority of bursts (10/12) occurred distant from the anastomoses.

We conclude that the surgical device associated to CARP is safe and efficient for creating colonic anastomoses. Further studies in patients undergoing colorectal surgery are warranted.

The performances of compression and stapled devices were compared previously in porcine colorectal anastomosis. The compression anastomosis was associated with elevated bursting strength and anastomotic patency in this model as compared with the stapled anastomosis.

The purpose of this work was to compare the histopathologic features between compression and stapled methods in the healing of colorectal anastomoses using a porcine model.

This was a blinded comparison study.

The study was conducted at a single university surgery department.

Fifty crossbred pigs were used in this study.

Fifty crossbred pigs underwent rectal transection 20 cm from the anal verge and end-to-end compression or stapled anastomosis. The anastomotic tissues were harvested 3, 7, 30, and 90 days postoperatively (n = 5-6). Tissue repair parameters associated with the wound healing were analyzed using image analysis morphometry and histological architecture assessments.

A different microscopic pattern of the anastomotic area was shown between groups. Foreign body response was rated (p < 0.001) as minimal in the compression and moderate in the stapled group. The scarring area in the compression anastomosis group, on postoperative day 90 (4 ± 3 × 10(5) μm) was lower (p = 0.016) than in the stapled group (2 ± 1 × 10(6) μm). In addition, the anastomotic line was narrower (p = 0.003) 90 days after surgery in the compression samples (0.77 ± 0.20 mm) compared with that in the stapled group (1.86 ± 0.19 mm). Lastly, in terms of inflammatory cells, the compression biopsies showed lower (p < 0.001) numbers of mononuclear cells, polymorphonuclear cells, and lymphocytes in the anastomotic tissues 30 and 90 days from surgery.

The long-term effect of the compression technique on the anastomotic patency in colorectal anastomoses should be further investigated in human studies.

Compression anastomotic healing was associated with less foreign body reactions, scarring, and inflammation as compared with stapled anastomoses in a large animal model.

Giving the ever-rising trend of pediatric minimally invasive surgery besides early neonatal surgical interventions, intestinal anastomosis turns out to be a time consuming stage due to several anatomical as well as technical difficulties. A perfect bowel anastomosis method should be easy, rapid, safe and reliable in creation of bowel continuity with minimal tissue damage. In this light, sutureless anastomotic methods have been introduced, using compression based anastomosis with biofragmentable rings or powerful magnets. Accordingly, this experimental animal model study has evaluated the result of an easy, rapid intestinal sutureless anastomotic technique via simple tying over an intraluminal ring, in comparison with conventional handsewn bowel anastomosis.

Thirty Wistar-Albino male rats were enrolled and small bowel was transected via a midline laparotomy. A grooved plastic ring was inserted into the ileal lumen and both intestinal cutting ends were fixed over the ring with a simple tie in the first group. On the other hand, enteroenterostomy was performed by the conventional method of handsewn anastomosis in the second group. After 14 days, rats were sacrificed to evaluate for intraperitoneal adhesion and abscess formation in addition to other evidences of anastomotic leakage. Furthermore, the anastomotic site integrity, tensile strength and healing stage were assessed microscopically.

The mean operative time and intraoperative bleeding in the tie over ring group were significantly less than those in the handsewn anastomosis group. Anastomotic stricture was more common in the conventional anastomosis group while the anastomotic tensile strength was significantly higher in the tie over ring group. Histopathological healing parameters and final healing score were almost similar in both groups but mean inflammatory cell infiltration in handsewn anastomosis was significantly higher.

"Tie over ring" is a simple method of anastomosis that is feasible, fast, safe and functionally effective for bowel reconstruction in animal models that could be reconsidered in human bowel anastomosis.

Surgical technique and perioperative management in rectal cancer surgery have been substantially improved and standardized during the last decades. However, anastomotic leakage following low anterior resection still is a significant problem. Based on animal experimental data of improved healing of compression anastomosis, we hypothesized that a compression anastomotic device might improve healing rates of the highest-risk anastomoses.

All low anterior resections for rectal cancer performed or directly supervised by the senior author between January 2004 and June 2012 were analyzed. Only patients with a stapled or compression anastomosis located within 6 cm from the anal verge were included. Until December 2008, circular staplers were employed, while since January 2009, a novel compression anastomotic device was used for rectal reconstruction exclusively.

Out of 197 patients operated for rectal cancer, a total of 96 (34 females, 35.4 %) fulfilled inclusion criteria. Fifty-eight (60.4 %) were reconstructed with circular staplers and 38 (39.6 %) using a compression anastomotic device. Significantly, more laparoscopic procedures were recorded in the compression anastomosis group, but distribution of gender, age, body mass index, American Society of Anaesthesiologists score, rate of preoperative radiotherapy, tumor staging, or stoma diversion rate were similar. Anastomotic leakage was observed in seven cases (7/58, 12.1 %) in the stapled and twice (2/38, 5.3 %) in the compression anastomosis group (p = 0.26).

In this series, rectal reconstruction following low anterior resection using a novel compression anastomotic device was safe and (at least) equally effective compared to traditional circular staplers concerning leak rate.

The main serious risks of anastomotic construction in the colon and rectum include dehiscence and stricture formation. There is a resurgence of interest in sutureless anastomoses formed by compression elements since the introduction of shape memory alloy (SMA) systems, which evoke minimal early inflammatory response whilst maintaining anastomotic integrity. Currently, the most commonly used SMA is the nickel-titanium (NiTi) alloy that is highly biocompatible, returning to its pre-deformed stable (austenite) shape under different mechanical and thermal loads for use in humans. Pre-clinical data for shape memory alloy systems in colorectal anastomoses are limited, but it appears to be safe in porcine and canine models with limited leakage and reduced stricture formation. There does not appear to be any difference in tissue biochemistry of inflammatory markers when compared with conventional stapled techniques, although the few studies available show a markedly reduced early inflammatory response at the anastomotic site with the NiTi device. The majority of the clinical data concerning compression anastomoses are derived from the biofragmentable anastomotic ring device. This device has fallen out of use because of reported leaks, instrumental failure and problems with device expulsion. A novel SMA device, the NiTi anastomotic ring, permits construction of a low rectal anastomosis construction during open or laparoscopic procedures. The preliminary data demonstrate a safety comparable to conventional staple technology. This device also provides the potential of benefit of reduced anastomotic inflammation, because the compression ring results in direct serosa-to-serosa (or alternatively serosa-to-muscularis propria) apposition without the persistence of residual foreign material. This type of construction could lead to a reduced incidence of early anastomotic leakage and/or the development of anastomotic stenosis. Randomized clinical trials employing a NiTi arm for elective, emergency and high-risk colorectal anastomoses are required to determine its indications and clinical profile as well as to assess whether such technology may selectively obviate the need for proximal diversion in low colorectal anastomoses.