Initial clinical experience with a biofragmentable ring for sutureless bowel anastomosis

Transanal formation of anastomosis using C-REX device is feasible and effective in high anterior resection

PURPOSE

C-REX is a novel instrument for creating stapleless colorectal anastomosis by compression. The aim of this study was to evaluate the feasibility and effectiveness of C-REX in open and laparoscopic high anterior resections.

METHODS

A prospective clinical safety study on 21 patients reconstructed with C-REX colorectal anastomosis following high anterior resection of the sigmoid colon using two different devices for intraabdominal (n = 6) or transanal (n = 15) placement of the anastomotic rings. Any signs of complications were prospectively monitored by a predefined protocol. Anastomotic contact pressure (ACP) was measured via a catheter-based system, and time for evacuation of the anastomotic rings by the natural route was noted. Blood samples were collected daily, and flexible endoscopy was performed postoperatively to examine macroscopic appearance of the anastomoses.

RESULTS

One of six patients operated with the intraabdominal anastomosis technique with an ACP of 50 mBar had to be reoperated because of anastomotic leakage. None of the 15 patients operated with the transanal technique (5 open and 10 laparoscopic procedures) had anastomotic complications, and their ACP ranged between 145 and 300 mBar. C-REX rings were uneventfully expelled by the natural route in all patients after a median of 10 days. Flexible endoscopy showed well-healed anastomoses without stenosis in 17 patients and a moderate subclinical stricture in one patient.

CONCLUSION

These results indicate that the novel transanal C-REX device is a feasible and effective method for colorectal anastomosis following high anterior resections, irrespective of open or laparoscopic approach. Moreover, C-REX allows measurement of intraoperative ACP and thereby a quantitative evaluation of the anastomotic integrity.

Side-to-side duodeno-ileal magnetic compression anastomosis: design and feasibility of a novel device in a porcine model

BACKGROUND

Minimally invasive metabolic/bariatric surgery (MBS) may be further advanced by magnetic compression anastomosis (MCA) technology. The study aimed to develop a magnet sized to create a patent duodeno-ileostomy (DI) and verify its effectiveness in a porcine model.

METHODS

Developmental study phase: magnets with 4 different flange-offset dimensions were tested to identify a design that would successfully form a compression anastomosis. Verification phase: evaluation of the selected design's efficacy. In each 6-week phase (4 pigs/phase), one magnet was inserted laparoscopically in the jejunum, one placed gastroscopically in the duodenum. Magnets were aligned, gradually fused, formed an anastomosis, and then detached and were expelled. At necropsy, MCA sites and sutured enterotomy sites were collected and compared.

RESULTS

Developmental phase: the linear BC42 magnet with a 2.3-mm flange offset design was selected. Verification phase: in 4 swine magnets were mated at the target location, confirmed radiographically. Mean time to magnet detachment 16.0 days (12-22), to expulsion 24.5 days (17-33). MCA was achieved in all animals at time of sacrifice. Animals gained a mean 9.5 kg (3.9-11.8). Specimens revealed patent anastomoses of ≥ 20 mm with smooth mucosa and minimal inflammation and fibrosis compared to sutured enterotomies. One pig underwent corrective surgery for a mesenteric hernia without sequelae.

CONCLUSION

In a large-animal model, gross and histopathologic examination confirmed that the linear MCA device created a patent, well-vascularized, duodeno-ileal anastomosis. The novel MCA device may be appropriate for use in human MBS procedures.

A systematic analysis of controlled clinical trials using the NiTi CAR™ compression ring in colorectal anastomoses

Anastomotic leak following colorectal surgery can be a devastating adverse event. The ideal stapling device should be capable of rapid creation of an anastomosis with serosal apposition without the persistence of a foreign body or a foreign body reaction which potentially contribute to early anastomotic dehiscence or late anastomotic stricture. A systematic review was performed examining available data on controlled randomized and non-randomized trials assessing the NiTi compression anastomosis ring-(NiTi CAR™) (NiTi Solutions, Netanyah Israel) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards. A protocol for this meta-analysis has been registered on PROSPERO (CRD42016050934). The initial search yielded 45 potentially relevant articles. After screening titles and abstracts for relevance and assessment for eligibility, 39 of these articles were eventually excluded leaving 6 studies for analysis in the review. Regarding the primary outcome measure, the overall anastomotic leak rate was 2.2% (5/230) in the compression anastomosis group compared with 3% (10/335) in the conventional anastomosis group; this difference was not statistically significant (RR 0.75, 95% CI 0.25-2.24; participants = 565; studies = 6; I ² = 0%). There were no statistically significant differences between compression and conventional anastomoses in any of the secondary outcomes. This review was unable to demonstrate any statistically significant differences in favor of the compression anastomosis technique over conventional manual or stapled mechanical anastomoses.

Gastrointestinal tract anastomoses with the biofragmentable anastomosis ring: is it still a valid technique for bowel anastomosis? Analysis of 203 cases and review of the literature

PURPOSE

Biofragmentable anastomosis ring (BAR) is an alternative to manual and stapled anastomoses performed within the upper and lower gastrointestinal (GI) tract. The aim of this study was to evaluate the effectiveness of BAR utility for bowel anastomoses based on our own material.

METHODS

A retrospective analysis was performed to a total of 203 patients who underwent bowel surgery with the use of BAR anastomosis within upper and lower gastrointestinal tract between 2004 and 2014. Data for the analysis was collected based on medical records, treatment protocols, and the results of histological examinations.

RESULTS

The study group consisted of 86 women and 117 men. The most common underlying pathology was a malignant disease (n = 165). Biofragmentable anastomosis ring (BAR) size 31 was the most commonly used (n = 87). A total of 169 colocolic or colorectal anastomoses and 28 ileocolic and 8 enteroenteric anastomoses were performed. The mortality rate was 0.5 % (n = 1) whereas re-surgery rate within 30 days was 8.4 % (n = 17). Twenty-eight patients developed perioperative complications with surgical site infection as the most common one (n = 11). Eight patients developed specific complications associated with BAR including an anastomotic leak (n = 6) and intestinal obstruction (n = 2). The mean time of hospital stay after surgery was 12.7 days.

CONCLUSIONS

The use of BAR for the GI tract anastomoses is simple and rapid method and it is characterized with an acceptable number of perioperative mortality and complication rates. Based on our experience, we recommend the use of BAR anastomosis in different types of intestinal anastomosis in varying clinical scenarios.

Safety and efficacy of the NiTi Shape Memory Compression Anastomosis Ring (CAR/ColonRing) for end-to-end compression anastomosis in anterior resection or low anterior resection

PURPOSE

Compression anastomoses may represent an improvement over traditional hand-sewn or stapled techniques. This prospective exploratory study aimed to assess the efficacy and complication rates in patients undergoing anterior resection (AR) or low anterior resection (LAR) anastomosed with a novel end-to-end compression anastomosis ring, the ColonRing.

METHODS

In all, 20 patients (13 male) undergoing AR or LAR were enrolled to be anastomosed using the NiTi Shape Memory End-to-End Compression Anastomosis Ring (NiTi Medical Technologies Ltd, Netanya, Israel). Demographic, intraoperative, and postoperative data were collected.

RESULTS

Patients underwent AR (11/20) or LAR using laparoscopy (75%), robotic (10%) surgery, or an open laparotomy (15%) approach, with a median anastomotic level of 14.5 cm (range, 4-25 cm). Defunctioning loop ileostomies were formed in 6 patients for low anastomoses. Surgeons rated the ColonRing device as either easy or very easy to use. One patient developed an anastomotic leakage in the early postoperative period; there were no late postoperative complications. Mean time to passage of first flatus and commencement of oral fluids was 2.5 days and 3.2 days, respectively. Average hospital stay was 12.6 days (range, 8-23 days). Finally, the device was expelled on average 15.3 days postoperatively without difficulty.

CONCLUSIONS

This is the first study reporting results in a significant number of LAR patients and the first reported experience from South Korea; it shows that the compression technique is surgically feasible, easy to use, and without significant complication rates. A large randomized controlled trial is warranted to investigate the benefits of the ColonRing over traditional stapling techniques.

Compression anastomoses in colorectal surgery: a review

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.

Techniques for colorectal anastomosis

Colorectal anastomotic leak remains one of the most feared post-operative complications, particularly after anterior resection of the rectum with, the shift from abdomino-peritoneal resections to total mesorectal excision and primary anastomosis. The literature fails to demonstrate superiority of stapled over hand-sewn techniques in colorectal anastomosis, regardless of the level of anastomosis, although a high stricture rate was noted in the former technique. Thus, improvements in safety aspects of anastomosis and alternatives to hand-sewn and stapled techniques are being sought. Here, we review alternative anastomotic techniques used to fashion bowel anastomosis. Compression anastomosis using compression anastomotic clips, endoluminal compression anastomotic rings, AKA-2, biofragmental anastomotic rings, or Magnamosis all involve the concept of creating a sutureless end-to-end anastomosis by compressing two bowel ends together, leading to a simultaneous necrosis and healing process that joins the two lumens. Staple line reinforcement is a new approach that reduce the drawbacks of staplers used in colorectal practice, i.e. leakage, bleeding, misfiring, and inadequate tissue approximation. Various non-absorbable, semi or fully absorbable materials are now available. Two other techniques can provide alternative anastomotic support to the suture line: a colorectal drain and a polyester stent, which can be utilized in ultra-low rectal excision and can negate the formation of a defunctioning stoma. Doxycycline coated sutures have been used to overcome the post-operative weakness in anastomosis secondary to rapid matrix degradation mediated by matrix metalloproteinase. Another novel technique, the electric welding system, showed promising results in construction of a safe, neat, smooth sutureless bowel anastomosis. Various anastomotic techniques have been shown to be comparable to the standard techniques of suturing and stapling. However, most of these alternatives need to be accepted and optimized for future use.

Circular 'superelastic' compression anastomosis: from the animal lab to clinical practice

The recent development of a compression device using shape memory Nitinol technology to create an end-to-end anastomosis has renewed the interest in sutureless anastomotic techniques. A phase II, prospective open label clinical trial was started in May 2007 to evaluate the feasibility and safety of this new anastomotic device. Fourty patients who need left colectomy or high anterior resection for either diverticular disease or adenocarcinoma will be recruited in two academic hospitals (Uppsala,Sweden and Leuven, Belgium). Clinical leakage is the primary endpoint. Only preliminary results are available to date as the recruitment is ongoing. The median age of the first ten patients is 57.5 years (44-72). No anastomotic leakage occurred. The median hospital stay was 4.0 days. Only three patients noticed the passage of the ring through the anal canal. By three weeks no ring was sustained in the gastrointestinal tract as was objectified by plain X-ray. First clinical use of this new anastomotic device seems promising. Final results for the total phase II trial are awaited. A prospective randomized trial to compare the efficacy of the EndoCar 28 with conventional stapling should be the next step.

Comparison of biofragmentable anastomosis ring and sutured anastomoses for subtotal colectomy in cats with idiopathic megacolon

OBJECTIVE

To report use of a biofragmentable anastomosis ring (BAR) device in cats with idiopathic megacolon (FIM) and compare outcome after subtotal colectomy with sutured colocolic anastomosis.

STUDY DESIGN

Retrospective study.

ANIMALS

Nineteen cats with megacolon.

METHODS

Medical records (January 1990-January 2004) of cats treated surgically for idiopathic megacolon with sutured (SUT) or BAR anastomosis were retrieved and reviewed. Operative, short- and long-term complications, and survival times were recorded and Kaplan-Meier survival analysis used to assess outcome.

RESULTS

There were 11 SUT and 8 BAR cats. One BAR cat had anastomotic dehiscence 36 hours after surgery. Mild serosal tearing during BAR insertion in 6 cats was corrected by suture reinforcement. One SUT cat developed anastomotic stricture at 32 days. Short-term complication rates at 3 and 7 days were 18% and 45% in the SUT group and 25% and 87.5% in the BAR group, respectively (P=.058). Two SUT cats had persistent loose stool consistency and were euthanatized 254 and 1661 days after surgery. One BAR cat had recurrence of constipation which was managed medically. Long-term complication rates were not significantly different between SUT and BAR (P=.61). The 1 and 4-year survival rates were 90% for SUT and 100% for BAR (P=.29).

CONCLUSIONS

No difference was detected for short and long-term complication rates and survival times between SUT and BAR groups.

CLINICAL RELEVANCE

The BAR device can be used for colocolic anastomosis in cats with idiopathic megacolon. Serosal tearing during BAR insertion was a common intraoperative complication. Regardless of anastomotic technique, survival outcome after colonic resection is excellent for cats with FIM.

Sutureless intestinal anastomosis with the biofragmentable anastomosis ring: experience of 632 anastomoses in a single institute

PURPOSE

Uncertainty with the safety of the biofragmentable anastomosis ring makes surgeons hesitate in its widespread use in intestinal surgery. This study was designed to evaluate the validity of the biofragmentable anastomosis ring as a routine anastomotic device in enterocolic surgery.

METHODS

The study analyzed the nine-year experience of 632 biofragmentable anastomosis ring anastomoses performed in 617 patients: 525 (83 percent) as elective procedures and 107 (17 percent) as emergency. Three classic types of anastomosis, end-to-end (n=354), end-to-side (n=263), and side-to-side (n=15), were performed with a standard technique.

RESULTS

Anastomotic sites included ileocolic/ileorectal in 283 patients (45 percent), colorectal in 148 (23 percent), enteroenteric in 101 (16 percent), and colocolic in 100 patients (16 percent). Anastomotic leakage with clinical relevance was observed in five patients (0.8 percent): three elective cases, and two emergency (2 colorectal anastomoses and 1 ileorectal required diversions). Among 13 instances (2.1 percent) with postoperative intestinal obstruction, only 1 required relaparotomy for closed-loop obstruction. Seven patients (1.1 percent; 4 elective cases, and 3 emergency) died postoperatively; no deaths were directly related to the biofragmentable anastomosis ring technique.

CONCLUSIONS

Our data suggest that the anastomosis using the biofragmentable anastomosis ring is a uniform and highly reliable technique even in high-risk emergency surgery. Along with its clinical validities, clinical application of the biofragmentable anastomosis ring in different types of anastomoses in enterocolic surgery is expected to be expanded with a high level of technical safety.

Estudo comparativo de anastomoses colorretais com anel biofragmentável e com grampeador em cães submetidos à irradiação gama pré-operatória

OBJETIVO: Comparar os resultados precoces entre anastomoses colorretais realizadas com anel biofragmentável e com grampeador circular após irradiação pélvica. MÉTODOS: Foram utilizados 40 cães beagle, em dois grupos de 20 animais, submetidos ou não à irradiação gama pré-operatória, com dose única de 500 cGy. Cada grupo foi dividido em dois subgrupos de dez animais, sendo denominado A o grupo em que se utilizou o anel biofragmentável e B aquele em que se empregou o grampeador. Os animais foram submetidos à secção completa do intestino grosso ao nível da junção retossigmóide, com reconstrução do trânsito sendo efetuada por uma das técnicas, após sorteio. Os animais foram sacrificados no sétimo dia de período pós-operatório. RESULTADOS: Houve dois óbitos antes da reoperação: um em animal do grupo teste, por ruptura da anastomose realizada com anel biofragmentável; outro por peritonite generalizada em animal do grupo controle com anastomose efetuada por grampeador. Aderências e infecções de parede ocorreram de forma similar. A análise histológica convencional e a análise morfométrica realizada por computador das áreas de cicatrização anastomótica identificaram comportamento análogo entre os grupos e subgrupos estudados. CONCLUSÃO: Os resultados precoces das técnicas empregadas para anastomose intestinal foram semelhantes nas condições de risco estudadas.

Estudo clínico comparativo entre anastomose colocólica com anel anastomótico biofragmentável e com sutura manual não absorvível

A anastomose com sutura é método consagrado, apresentando desvantagens teóricas representadas pelo trauma tecidual, edema e alteração da microcirculação. Além disso, o fio de sutura, sendo corpo estranho, determina reação inflamatória, propiciando a aderência e a proliferação de bactérias, assim como de células neoplásicas que seriam evitadas ao se usar método de anastomose sem sutura. A procura por método de anastomose em que não se utilizasse fio de sutura vem sendo realizada desde o início deste século. Com o advento das novas aquisições tecnológicas foi desenvolvido método de anastomose sem sutura através do anel biofragmentável. Esse anel sofre desintegração por hidrólise, sendo eliminado com a evacuação, não permanecendo corpo estranho na anastomose. Esse instrumento permite a realização de anastomose sem sutura, por meio da compressão das paredes intestinais justapostas. O objetivo desse estudo prospectivo e casualizado, foi o de comparar os resultados clínicos e endoscópicos de anastomoses colocólicas, eletivas e de baixo risco, realizadas com anel biofragmentável e com fio de sutura não absorvível. CASUÍSTICA E MÉTODOS: A casuística foi composta por 36 doentes, divididos em dois grupos de 18, que foram denominados Grupo I (anel biofragmentável ) e Grupo II (sutura com fio não absorvível ), constituídos de doentes comparáveis. RESULTADOS: Os parâmetros de avaliação do período intra-operatório, revelaram que a anastomose com anel biofragmentável despende menor tempo para sua realização. Não se detectou diferença estatisticamente significante entre os dois grupos com relação à incidência de complicações pós-operatórias, mortalidade e avaliação clínica ambulatorial. A incidência de deiscência anastomótica só ocorreu no Grupo I. A análise endoscópica da anastomose no período pós-operatório não demonstrou diferença quanto à perviedade, contratilidade, elasticidade e grau de epitelização. O Grupo II apresentou maior incidência de fio de sutura na anastomose em relação ao Grupo I sendo esta diferença estatística significante. CONCLUSÕES: O anel biofragmentável permite a realização de anastomose de colo mais rápida do que aquela realizada com fio de sutura. Este método de anastomose determinou, na análise global da complicações clínicas, resultados semelhantes ao uso de fio de sutura. O método de anastomose sem sutura apresentou o inconveniente de determinar maior incidência de deiscência anastomótica e como vantagem estabeleceu presença de corpo estranho na anastomose em menor porcentagem.

Intestinal anastomosis by use of the biofragmentable anastomotic ring: is it safe and efficacious in emergency operations as well?

PURPOSE

Although sutureless anastomosis by use of the biofragmentable anastomotic ring is now accepted as an alternative to conventional manual sutured or stapled methods in elective enterocolic surgery, its applicability to emergency enterocolic surgery has not yet been established. The aim of this prospective study was to determine whether the biofragmentable anastomotic ring anastomosis in emergency enterocolic surgery could be performed as safely as in elective surgery or as emergency handsewn anastomosis.

METHODS

To evaluate the safety and efficacy of sutureless bowel anastomosis by use of the biofragmentable anastomotic ring in emergency enterocolic surgery, a prospective, randomized study was undertaken to compare the biofragmentable anastomotic ring with conventional handsewn anastomotic technique. One hundred nineteen patients who required emergency laparotomy were randomly assigned to two groups: 56 patients (47 percent) underwent 58 biofragmentable anastomotic ring anastomoses, and 63 patients (53 percent) underwent 65 sutured anastomoses. In addition, the safety and efficacy of the biofragmentable anastomotic ring in emergency surgery were compared with those of the biofragmentable anastomotic ring in 86 elective biofragmentable anastomotic ring anastomoses performed in 84 patients during the same period of time.

RESULTS

Specific intraoperative complications related to use of biofragmentable anastomotic rings occurred in six patients (10.7 percent), and another new biofragmentable anastomotic ring anastomosis was constructed in one patient. These reflected learning-curve errors, but they did not adversely affect the outcome. No statistical differences were observed among the groups with respect to wound complications, postoperative bleeding, intra-abdominal abscess, intestinal obstruction, or postoperative death. As for anastomotic leakage, six patients, two in each group, had complications of anastomotic failure, wherein four colonic fistulas required a diversion and two enteric fistulas closed spontaneously. Although there were no statistically significant differences in incidence of leaks among groups (P = 0.4522), two fistulas in colocolic anastomoses, one in the suture group and the other in the biofragmentable anastomotic ring group, manifested the risk of primary anastomosis in emergency colon resection. Seven patients, three in the elective biofragmentable anastomotic ring group and two each in the emergency suture and biofragmentable anastomotic ring groups, died after the operation, but no deaths were directly attributed to the anastomotic technique used.

CONCLUSION

The data suggest that the biofragmentable anastomotic ring is a safe and reliable alternative to conventional handsewn anastomosis in emergency enterocolic surgery, where the rapidity and security of anastomosis may be critical. Consideration, however, should be given to emergency primary colocolic or colorectal anastomosis, because of a high risk of anastomotic failure, although there are too few cases for a definite conclusion.

Randomized trial of a biofragmentable bowel anastomosis ring in high-risk colonic resection

BACKGROUND

Biofragmentable anastomosis ring (BAR) has been proven to be a safe anastomotic device in elective surgery. The use of this anastomotic ring in high-risk patients has not been established.

METHODS

During a 5-year period (1990-1995), 100 high-risk patients undergoing colonic resection and suitable for a primary anastomosis were allocated randomly to a standard suture technique or to anastomosis performed with a BAR. High risk was defined as large bowel obstruction, complicated diverticular disease, Crohn's disease, local cancer recurrence, previously irradiated colon, and trauma to the colon or rectum. The patients were equally distributed to the two groups regarding sex, age, emergency surgery and concomitant diseases.

RESULTS

In three patients allotted to the BAR group, the device could not be used. There were three (6 per cent) postoperative deaths in each group; none was related to anastomotic problems. Three anastomotic dehiscences were diagnosed, two (4 per cent) in the BAR group and one (2 per cent) in the suture group. Postoperative complications and postoperative recovery were similar.

CONCLUSION

This study shows that the BAR anastomosis probably is as safe as the standard band-sewn anastomosis in high-risk colorectal surgery. As the cost of a BAR anastomosis is substantially higher than that for a hand-sewn anastomosis, the latter technique is still the preferred method in the authors' unit.

Healing in the gastrointestinal tract

Healing in the GI tract is rapid when free of complications: Unlike cutaneous healing, in which progress can be observed on a daily basis and intervention instituted early if necessary, healing of the intestinal anastomosis is anatomically obscured from inspection, allowing the surgeon only the patient's parameters of general well-being to judge the success of the operation. For the same reason, complications usually require re-operation, with the associated morbidity of a laparotomy and additional general anesthetic. This places a great responsibility on the surgeon to be cognizant of all the preoperative, intraoperative, and postoperative factors relating to anastomotic healing that might compromise the healing process. Bearing these in mind, along with attention to technical detail, should limit complications to an acceptable level. Patients most at risk are (1) those who perioperatively develop physiologic problems that lead to shock, hypoxia, and resultant anastomotic ischemia, (2) those with radiation-induced tissue injury, (3) those with sepsis, and (4) those with preoperative bowel obstruction. Malnourishment, malignancy, diabetes, steroids, and age also influence outcome to varying degrees. Future advancement in the field of GI healing lies in our ability to manipulate the early struggle between collagen synthesis and collagen breakdown. A profound understanding of the molecular and biochemical pathways and the factors that control them will bring us closer to this goal. Clinically, this may be accomplished by the introduction of wound healing enhancers into the anastomotic site, possibly by incorporating them into suture materials, biofragmentable anastomotic rings, or staple materials. Already much is known about the influence of different cytokines and growth factors on collagen regulation, knowledge that will help resolve many of the long-standing problems associated with GI surgery.

Evaluation of a biofragmentable anastomosis ring for small intestinal anastomosis in ponies

Six ponies divided into two groups of three were used in a double crossover study design. Group 1 ponies had a small intestinal resection and anastomosis performed using a biofragmentable anastomosis ring (BAR); group 2 ponies had a hand-sewn small intestinal resection and anastomosis using a Gambee suture pattern. Approximately 30 days later, all ponies had a second celiotomy and anastomosed segments were removed. Group 1 ponies had a hand-sewn anastomosis performed and group 2 had a BAR. The anastomotic sites were collected at necropsy approximately 30 days later. Anastomosed intestinal segments were evaluated with ultrasound to determine lumen diameter, area, circumference, and wall thickness. Gross descriptions of adhesions were recorded and sections of the anastomotic site were taken for histological evaluation. Time to perform the BAR anastomosis was significantly less (P = .0004) than for the hand-sewn Gambee anastomosis. Ponies with handsewn anastomoses had no signs of colic, whereas five of six ponies with BAR anastomoses had several episodes of abdominal discomfort, between day 16 to 18, corresponding to the time of BAR disintegration as determined by abdominal radiographs. Hand-sewn anastomoses had a tendency to have more adhesion formation than BAR anastomoses, but all anastomoses, except one BAR anastomosis, were graded as having a low obstructive potential. BAR anastomoses had a significantly larger mean index of stenosis for intraluminal diameter (76% +/- 13.6), area (93.7% +/- 6.01) and circumference (75.8% +/- 14.0) than the hand-sewn anastomoses (26.6% +/- 11.9; 44.6% +/- 19.5; 26.8% +/- 12.7). The BAR anastomoses also had a significantly smaller mean intraluminal diameter (0.96 cm +/- 0.49), area (0.838 cm2 +/- 0.65) and circumference (3.28 cm +/- 1.63) than the hand sewn anastomoses (3.11 cm +/- 0.73; 7.99 cm2 +/- 3.9; 10.3 cm +/- 2.47). In addition, the BAR anastomoses had a significantly larger (P = .0069) bowel wall thickness at the anastomoses and a significantly larger (P = .047) wall thickness proximal to the anastomosis than the hand-sewn anastomoses, indicating some degree of hypertrophy because of chronic obstruction. No significant difference was found in the diameter, area, or circumference between bowel proximal and distal to the anastomosis for either the BAR or Gambee techniques, or between the BAR and Gambee anastomosis as a measure of chronic obstruction. There was a significantly higher (P = .0043) histological score (worse healing) for mucosal healing and continuity for the BAR, as well as a tendency to score higher for inflammation, anastomotic alignment, and anastomotic fibrosis. The BAR technique had a significantly higher (P = .0043) total histological score than the Gambee technique. Although the BAR was advantageous in many respects, results of this study suggest that it should not be used for equine small intestinal anastomosis because of the potential for stricture formation.

Gastrointestinal sutureless anastomosis using fibrin glue: reinforcement of the sliding absorbable intraluminal nontoxic stent and development of a stent placement device

Sutureless anastomosis of the gastrointestinal tract using fibrin glue and sliding absorbable intraluminal nontoxic stents (SAINTs) has two shortcomings, stent shaft breakage and the lack of a transanal insertion device (TID) for low anterior resection. Reinforcement of the sucrose base SAINT (R-SAINT) is described. Sutureless anastomosis is attempted using a stapleless mechanical stapler (SS) and used as preprototype to screen histologically and mechanically for TID anastomoses in the small intestine. Finally, a prototype absorbable head SAINT placement device (SAINT-PD) intended for TID, similar to the SS, is utilized on the small intestine. Fifty-seven Landrace pigs weighing 25-35 kg were used to perform 58 anastomoses, including the small intestine (15 manual, 19 SAINT, 11 SS, 5 R-SAINT, 6 SAINT-PD) and large intestine (2 R-SAINT). All anastomoses performed with the R-SAINT succeeded on the first attempt even if the shaft cracked. The SS technique proved impractical, but the histological screen results from 7 to 60 days did approximate those of corresponding SAINT anastomoses. The SAINT-PD demonstrated operational improvement over the SS, but the histological results were similar to both the SS and SAINT. The advantages of the R-SAINT and SAINT-PD are that they leave no foreign bodies or pressure clamping devices at the anastomostic site. Larger studies may show the R-SAINT and the SAINT-PD to be practical, new surgical tools in sutureless fibrin glue anastomosis.

New anastomotic gun for biofragmentable anastomotic ring in low anterior resection

PURPOSE

The biofragmentable anastomotic ring remains difficult to use for low rectal anastomosis. The authors report their experience of clinical application of the biofragmentable ring in low anterior resection with a newly designed instrument.

METHODS

In this series, 31 patients underwent sphincter-preserving low anterior resections for rectal tumors from May 1993 to November 1994. With the assistance of a self-developed anastomotic instrument (biofragmentable anastomotic ring gun), biofragmentable ring anastomoses were performed following low anterior resection.

RESULTS

There was no operative mortality. One patient had clinical evidence of anastomotic leakage. In postoperative follow-up, there was no anastomotic stenosis or incontinence.

CONCLUSION

Therefore, we believe biofragmentable ring rectal anastomosis is a safe and reliable alternative to other anastomotic methods in rectal surgery.

Esophageal transection using a biofragmentable anastomosis ring in dogs

Since the first publication on the new anastomosis technique using a biofragmentable anastomosis ring (BAR) by Hardy in 1985, various studies have been performed to investigate the superiority of this type of anastomosis, and it has since been reported that the BAR was safely used not only in large and small bowel anastomosis, but in cholecystojejunal and gastrojejunal anastomosis as well. In this study, the feasibility of the BAR for esophageal transection was investigated. Seven dogs were operated on, and one died of intraabdominal bleeding on the operative day while another died of leakage at the site of gastrotomy on the 3rd postoperative day. These deaths were all considered to be due to simple technical errors not directly related to the use of the BAR. The postoperative recovery of the other five dogs was uneventful, and the ring eventually disintegrated into several small fragments that passed out of the body in the faces between the 14th and 21st postoperative days. The dogs were killed on the 28th postoperative day, and both gross and histological examinations, revealed that the transection had been successful. Neither leakage nor significant stenosis at the site of transection was found. Our results suggested that the BAR could be used for esophageal transection and is thus recommended as an easy-to-learn, time-saving, and safe technique for esophageal operations.

Sutureless anastomosis using a biofragmentable anastomosis ring

The biofragmentable anastomosis ring (BAR) is composed of polyglycolic acid and barium sulfate. When used for intestinal anastomosis, the BAR fragments after the anastomosis is established. We used this device in 43 patients. In three patients, the anastomosis with BAR was abandoned due to technical difficulties. A total of 43 anastomoses with BAR were performed in 40 patients. The operations in which BAR was used included right hemicolectomy in 12 patients, transverse colectomy in 7, sigmoidectomy in 11, small bowel resection in 5 and other bowel resections in 8. The time spent for the BAR anastomsis ranged from 7 to 30 min with a mean of 15.2 min, which was significantly shorter than that of conventional hand-sutured anastomosis in 23 cases. The fragmentation and excretion of the BAR occurred from 14 to 49 days later with a mean of 21.8 days. There was only one instance of anastomotic leakage (1/40, 2.5%), which occurred in a patient with a cytomegaloviral infection of the intestine. A postoperative barium enema study in 28 patients showed no passage disturbance through the anastomosis. In conclusion, the anastomosis using BAR is considered to be a simple, safe, and fast method for performing either colonic or small intestinal anastomosis.

Sutureless anastomosis of the small intestine and the colon in pigs using an absorbable intraluminal stent and fibrin glue

A new sutureless anastomosis technique employing a sliding absorbable intraluminal nontoxic stent (SAINT) and fibrin glue with limited (minutes) stump margin pressure is described. Fifty-one (27 small intestine, 24 colon) SAINT anastomoses were performed in 31 Landrace pigs (25-35 kg). Controls consisted of 48 (26 small intestine, 22 colon) continuous single-layer submucosal anastomoses in 26 pigs. SAINTs, which dissolve in about 30-60 min, were formed from heated sucrose and water poured into handcrafted aluminum molds. Follow-up from 7 to 540 days showed no stenosis or anastomotic imperfections in the latter part of the experiment after the SAINT production and surgical techniques were improved. The SAINT group had fewer site adhesions, faster healing, less foreign body reaction, and fewer lymphocytes than the control group. Initial results indicate that the SAINT-fibrin glue procedure may be an effective sutureless anastomotic method from the duodenum to the sigmoid colon.

Comparison of a biofragmentable intestinal anastomosis ring with appositional suturing for subtotal colectomy in normal cats

A subtotal colectomy was performed on 12 normal adult cats using an interrupted apposing suture pattern of monofilament polyglyconate (n = 6) or a biofragmentable intestinal anastomosis ring (Valtrac, Davis and Geck Company, Danbury, CT) (n = 6) composed of polyglycolic acid and barium sulfate. Abdominal radiographs were made daily, beginning 10 days after surgery, to determine fragmentation rates of the anastomosis ring. The cats were euthanatized 30 days after surgery, and a gross and histopathological evaluation of anastomotic healing and stricture formation was performed. The technique for implantation of the anastomosis ring was easy to learn and required only two purse string sutures to complete. Intraoperative complications associated with the anastomosis ring were minor, and included problems with purse string suture placement, small serosal tears, and spasms of the colon that reduced the lumenal diameter. There were no intraoperative complications in the cats with sutured anastomoses. Postoperative recovery was uneventful in all cats. The anastomosis rings fragmented 12.2 +/- 1.1 days (mean +/- standard deviation [SD]) after implantation and passed in the stool 3.8 +/- 1.9 days later without clinical signs in five of six cats. There were no statistically significant differences between the time required to perform the anastomosis (P = .348), postmortem gross anastomosis grades (P = .088), or percent of lumenal stricture (P = .178) between the two groups. Histologically, the only significant differences were an increased muscular inversion in the anastomoses performed using the fragmentable ring (P = .039) and an increased muscular eversion in the sutured anastomoses (P < .001) compared with normal colonic architecture.

New device for biofragmentable anastomotic ring in low anterior resection

PURPOSE

The biofragmentable anastomotic ring (BAR) is now accepted as an alternative anastomotic method to handsewn and stapled anastomosis in colonic surgery. However, for a short rectal stump in a narrow pelvis, it is rather difficult to use the BAR in a low anterior resection.

METHOD

To overcome the difficulty, we designed and used a BAR-adapter to facilitate biofragmentable ring anastomosis following low anterior resection in eight patients with rectal cancers.

RESULTS

There was no case in our series having received conversion to other methods. There was no significant complication associated with this technique.

CONCLUSION

With the BAR-adapter, the applicability of the BAR can be greatly expanded in colorectal anastomosis following low anterior resection.

Cellular proliferation at sutured and sutureless colonic anastomoses

Elevated cellular proliferation in the vicinity of an anastomosis may explain the enhanced susceptibility to carcinogens. The aim of this study was to determine whether anastomotic cellular proliferation was altered by different suture materials and whether a rise in cell turnover also occurred after a "sutureless" closure. A transverse descending colon enterotomy was repaired with interrupted sutures of 5/0 silk (n = 20), stainless steel (n = 20), or Vicryl (Ethicon, Inc., Somerville, NJ) (n = 20) or by a sutureless technique (n = 20). Using a stathmokinetic technique, crypt cell production rates (CCPR) were calculated at the anastomosis and in the adjacent colon at varying intervals between one week and six months after treatment. Overall colonic cellular proliferation appeared to be elevated at a sutured colotomy for at least three months (P < 0.05). In contrast, no significant elevation in cellular proliferation was observed at sutureless anastomoses. The duration of elevated proliferative response varied among the sutures.

Murphy's Button revisited. Clinical experience with the biofragmentable anastomotic ring

Use of the biofragmentable anastomosis ring (BAR) was attempted in 33 patients at two New York City institutions and employed in 31 instances. Anastomoses performed were end-to-end enterocolic (n = 15), colocolic (n = 15), and side-to-side colocolic (n = 1). Patients ranged in age from 27 to 86 years, with the following diagnoses: primary colon cancer, 15; sessile adenoma, four; colostomy, five; diverticulosis, two; metastatic cancer with obstruction, multiple polyposis, perforated appendiceal mass, malignant carcinoid of appendix, intussuscepting right colon mass, one each. In two instances use of the device was aborted because of concern with the blood supply to the bowel wall in one and tissue edema in another. The average duration of postoperative ileus was 4.7 days. Two patients were subsequently treated for small bowel obstruction thought unrelated to use of the anastomotic device. There were no deaths and no evidence of stricture.

Experimental carcinogenesis at sutured and sutureless colonic anastomoses

This study explores the role of sutures and the healing colonic wound in experimental carcinogenesis. One hundred sixty rats underwent surgery with colotomy and repair using silk, steel, or Vicryl (Ethicon, Somerville, NJ) sutures or a sutureless technique. Forty rats had a sham procedure. All animals received azoxymethane for 12 weeks at a dose of 10 mg/kg/week. Half the rats commenced carcinogen before surgery, and half commenced it eight weeks after surgery. Animals with anastomotic tumors were found in 46 percent of the sham group (P less than 0.05 cf. sutured), 41 percent of the sutureless group (P less than 0.02 cf. sutured), and 68 percent of the sutured group. The corresponding figures for anastomotic carcinoma were 9 percent (P less than 0.001 cf. sutured), 22 percent, and 38 percent. No significant differences in tumor yield were noted among the different sutures. However, several differences were noted between the two carcinogen models. In those animals that received surgery first, there was a higher incidence of anastomotic tumors (P less than 0.002) and cancers (P less than 0.0001) in the sutured and sutureless groups, and those tumors that occurred in the sutured group were considerably larger than in those that had carcinogen first (15.9 mm cf. 4.9 mm; P less than 0.0001). Overall, all sutures seem to enhance anastomotic tumor formation, and we would suggest that a sutureless anastomosis may diminish this risk.

Small bowel anastomosis with the biofragmentable anastomosis ring and manual suture: a prospective, randomized study

A total of 170 patients undergoing upper gastrointestinal surgery requiring a jejuno-jejunal enteroanastomosis were randomized into two groups according to the method to be employed at the enteroanastomosis. The most common procedures were partial gastrectomy for benign disease (84 patients), partial or total gastrectomy for malignant disease (35 patients), and bilioenteral bypass (31 patients, 25 for malignant disease). The enteroanastomosis was created by manual suture (3-0 Dexon, two layers) in 89 patients and with the Biofragmentable Anastomosis Ring (Valtrac-BAR) in 81 patients. Both end-to-side (101 patients) and side-to-side (69 patients) reconstructions were done. No ruptures or obstructions of the jejuno-jejunal anastomosis occurred. The postoperative recovery of the gastrointestinal tract was similar in the two groups in duration of nasogastric drainage, intravenous fluid therapy, and intestinal paralysis. Nor was there any difference between the groups in the duration of the postoperative hospital stay. Ten patients, 7 in suture-group and 3 in BAR-group, died postoperatively of causes unrelated to the enteroanastomosis. Thus the mortality rate was 7.9% in the suture group and 3.7% in the BAR group. The biofragmentable ring offers a safe alternative to manual sutures for small bowel anastomoses.

Colonic anastomosis using the biofragmentable anastomotic ring and manual suture: a prospective, randomized study

One hundred and fifty consecutive patients undergoing colonic surgery were randomized into two groups: 71 underwent hand-suture with a two-layer anastomosis of resorbable suture material (3/0 Dexon) and 79 were fitted with the biofragmentable anastomotic ring (Valtrac-BAR). Five patients, two treated using the BAR and three by suturing, developed anastomotic leakage which required a Hartmann-type reoperation. This was successful in four; one patient in the suture group died after reoperation. One patient who underwent suture had an early anastomotic stricture with fatal sequelae. Three other patients (one in the BAR group and two in the suture group) died after operation from other causes. Thus the mortality rate was 6 per cent in the suture group and 1 per cent in the BAR group. During follow-up, one patient in each group underwent reoperation for anastomotic stricture. Recovery of the gastrointestinal tract was similar in the two groups regarding duration of nasogastric drainage, intravenous fluid therapy and ileus. There was no difference between the groups in duration of hospital stay. The BAR seems to be a safe and reliable alternative to conventional suture anastomosis in colonic surgery.

Sutureless intestinal anastomoses

Sutureless intestinal anastomoses can be achieved either by compression, where two inverted rings of bowel are compressed by a hollow circular device that subsequently sloughs away and is passed anally, or by the use of tissue glues or laser welding. Compression devices used clinically with success are the Valtrac biofragmentable anastomotic ring, the polypropylene rings described by Rosati and the AKA guns. Glued anastomoses have only been used in animals and seem to be unsafe. However, laser-welded intestinal anastomoses appear highly promising in experimental studies and further development of this technique is warranted.

The single-layer continuous suture for gastric anastomosis

The single-layer continuous suture technique has proven to be safe for all intestinal anastomoses of intraperitoneal small and large bowel segments. Since 1985, this technique has also been increasingly applied for gastroduodenostomy and gastrojejunostomy following partial gastrectomy. Through December 1989, we performed 96 gastroenteric anastomoses with the single-layer continuous suture technique. This accounts for 64% of all partial gastrectomies performed between 1985 and 1989. The technique was applied in 89.5% of the gastroenteric anastomoses during 1988 and 1989. The rate of complications after gastroenteric single-layer continuous suture technique was low; 2.1% clinical leakage was found, always in patients with perforated ulcer and peritonitis. We conclude that the single-layer continuous suture technique for gastroenteric anastomosis is safe, simple, easy to perform, quick and reliable.

Prospective, randomized trial of the biofragmentable anastomosis ring. The BAR Investigational Group

A randomized trial was undertaken to compare the biofragmental anastomotic ring (BAR) with conventional intraperitoneal colorectal anastomotic techniques. Patients were randomized into one of two schemes: BAR versus sutured or BAR versus stapled anastomosis. There were 782 patients entered into the study and 283 patients (36%) had a sutured anastomosis, 104 patients (13%) had a stapled anastomosis, and 395 (51%) had the BAR. Comparison of the BAR with combined suture and stapled controls revealed no significant differences in wound complication, abscess rate, bleeding, anastomotic leaks, ileus, obstruction, or deaths. There were no differences in return of bowel function, return to normal diet, or hospital stay. Intraoperative difficulties occurred in 46 BAR patients (17%), and this was significantly higher (p less than 0.001) than for sutured (3%) but not for stapled anastomoses (11%). The occurrence of these problems did not adversely effect the outcome. The data suggest that the BAR is a safe, satisfactory alternative to sutured or stapled colorectal anastomoses.

Non-suture anastomosis: the historical development

A wide range of devices for uniting the bowel has been invented. These are ligatures, prostheses, adhesives and staples. Denans' rings and Henroz' articulated rings were described in 1826, and Murphy's anastomosis button in 1892. Modern stapling began with Hültl in 1908 and Petz in 1924. Sophisticated stapling instruments were invented in Moscow by Androsov and others between 1950 and 1960. These were modified by Ravitch to produce, in 1967, a safe, disposable, presterilized, preloaded, interchangeable cartridge in a light instrument. The value of stapling is now beyond dispute.

Clinical application of a new compression anastomotic device for colorectal surgery

Fifty-six patients underwent large bowel anastomosis by the compression anastomotic device developed by the authors from May 1986 through December 1988. Operations performed were 40 left hemicolectomies or anterior resections of the sigmoid and rectum, 7 left colon resections, 7 right hemicolectomies, and 2 total colectomies. Twenty-one anastomoses were done on the extraperitoneal rectum, in 7 cases less than 4 cm from the anal verge and in 9 cases between 4.5 and 8 cm. Five intraoperative diverting colostomies were done (9%). The rings of the device were evacuated postoperatively after a mean of 11 days with little or no discomfort. Operative mortality was 1.8% (one patient died of myocardial infarction). Anastomotic complications were one (1.8%) clinical and one (1.8%) subclinical leak. Mean postoperative hospital stay was 14 days. This initial clinical experience shows that the anastomotic device is reliable.

Experience with the biofragmentable anastomotic ring (BAR) in bowel preoperatively irradiated with 6000 rad

Previous studies from the authors' laboratory using the biodegradable anastomotic ring (BAR) have demonstrated the safety of this device in animals irradiated preoperatively with the equivalent of 5000 rad; sutured, stapled, and BAR anastomoses all had leak rates of 10 percent or less in this setting. This study was undertaken to assess the safety of the BAR after irradiation with the equivalent of 6000 rad. Thirteen mongrel dogs underwent preoperative irradiation to the rectum and rectosigmoid, receiving 6000 rad according to the nominal standard dose equation. After a three-week rest period, each dog underwent anterior resection of the rectosigmoid and anastomosis with the BAR. The anastomoses were evaluated for early and late healing and anastomotic leaks. The results were compared with previous data from the authors' laboratory using an identical model. Radiographic leaks were found in 7 of 10 sutured anastomoses, 8 of 10 stapled anastomoses, and 3 of 13 BAR anastomoses (P less than 0.01). Comparative clinical leaks were 5 of 10 for sutured, 5 of 10 for stapled, and 3 of 13 for BAR anastomoses. These data suggest that the BAR may offer added safety to an anastomosis after preoperative irradiation. Whether this effect is due to the atraumatic technique of placing the device, improved blood flow to the anastomotic margins, or other factors, is still underdetermined.

Complete obstruction of the sigmoid colon treated by primary resection and anastomosis--an improved technique (preliminary report). Report of three cases

Three patients with complete colonic obstruction treated by primary resection and anastomosis with intraoperative colon tube decompression and bowel lumen sterilization without a protective colostomy are presented. An improved colonic decompressor was used. It is postulated that this procedure is an alternative safe technique in patients with colonic obstruction in whom an end-colostomy, mucous fistula, or Hartmann pouch would be necessary.

A new approach to rectal anastomotic stricture

A technique is presented that can serve as a solution for localized postoperative rectal stricture. This procedure was used after the failure of manual and instrumental dilatations. It consisted of cutting the prominent plication of the stricture, using the EEA stapler. Five patients successfully underwent this operation without morbidity or mortality, three after very low anterior resection and two after total colectomy, mucosal proctectomy, and ileoanal anastomosis.

Sutureless large bowel anastomosis: European experience with the biofragmentable anastomosis ring

Sutureless colonic anastomosis using a biofragmentable anastomosis ring (BAR) has been evaluated in a prospective randomized comparison with sutures and staples for elective colorectal surgery. One hundred and one patients underwent BAR anastomosis, 85 a sutured anastomosis, and 16 a stapled anastomosis. There were two anastomotic leaks in the patients undergoing BAR anastomosis, seven in patients having a sutured anastomosis, and one in a patient who had a stapled anastomosis. Wound infection occurred in ten BAR patients, ten sutured patients and no stapled patient. There was no statistically significant difference in these or in other postoperative complications between the groups. The BAR was easy to use and is a safe alternative to sutures and staples for large bowel anastomosis.

Comparison of the Valtrac biofragmentable anastomosis ring with conventional suture and stapled anastomosis in colon surgery. Results of a prospective, randomized clinical trial

In a randomized, prospective study of 438 patients, the safety and efficacy of the Valtrac biofragmentable anastomotic ring (BAR) was compared with stapling and with conventional suture techniques. There was no significant difference in the morbidity, mortality, and clinical course of the patients. The BAR can effect reestablishment of intestinal continuity somewhat more rapidly, but its major advantage is its uniform applicability to all areas of the intestinal tract, except the low rectum.

Initial continence testing of sleeved monolayer colonic anastomoses in sheep. A comparative bench study

It has been said that the most important cause of morbidity and mortality in surgery of the colon, rectum, and esophagus is dehiscence. The new method of anastomosis tested here immediately after its completion is a sleeved continuous monolayer anastomosis with full-thickness proximal bowel joined to the mucosa and submucosa of distal bowel. The 3 to 5-mm sleeve of distal seromuscularis fashioned by prior excision of a ring of distal mucosa is folded over the monolayer anastomosis and tacked on to proximal seromuscularis by a second continuous suture. In this bench study, sleeved seromuscularis monolayer anastomoses were compared for immediate ability to withstand air distention with conventional all-layer continuous and interrupted monolayer anastomoses. The results, even in fresh nonliving bowel, suggest that there may be benefits from sleeving monolayer anastomoses in vivo. It is noted that in the newly fashioned anastomosis, through-the-suture leaks were common on progressive distention, but were observed at higher pressures in sleeved and in extramucosal suture lines than in full-thickness monolayers.