A controlled trial of inverting versus everting intestinal suture in clinical large-bowel surgery

The Colorectal Anastomosis: A Timeless Challenge

Colorectal anastomosis is a sophisticated problem that demands an elaborate discussion and an elegant solution. "Those who forget the past are condemned to repeat it." George Santayana, Life of Reason , 1905.

Systematic Review and Meta-Analysis on Colorectal Anastomotic Techniques

Purpose

Anastomosis creation after resective gastrointestinal surgery is a crucial task. The present review examines the techniques and implants currently available for anastomosis creation and analyses to which extent they already address our clinical needs, with a special focus on their potential to enable further trauma minimization in visceral surgery.

Methods

A multi-database research was conducted in MEDLINE, Scopus, and Cochrane Library. Comparative controlled and uncontrolled clinical trials dealing with anastomosis creation techniques in the intestinal tract in both German and English were included and statistically significant differences in postoperative complication incidences were assessed using the RevMan5.4 Review Manager (Cochrane Collaboration, Oxford, UK).

Results

All methods and implant types were analyzed and compared with respect to four dimensions, assessing the techniques’ current performances and further potentials for surgical trauma reduction. Postoperative outcome measures, such as leakage, stenosis, reoperation and mortality rates, as well as the tendency to cause bleeding, wound infections, abscesses, anastomotic hemorrhages, pulmonary embolisms, and fistulas were assessed, revealing the only statistically significant superiority of hand-suture over stapling anastomoses with respect to the occurrence of obstructions.

Conclusion

Based on the overall complication rates, it is concluded that none of the anastomosis systems addresses the demands of operative trauma minimization sufficiently yet. Major problems are furthermore either low standardization potentials due to dependence on the surgeons’ levels of experience, high force application requirements for the actual anastomosis creation, or large and rigid device designs interfering with flexibility demands and size restrictions of the body’s natural access routes. There is still a need for innovative technologies, especially with regard to enabling incisionless interventions.

Development and in vivo Assessment of a Rapidly Collapsible Anastomotic Guide for Use in Anastomosis of the Small Intestine: A Pilot Study Using a Swine Model

Various conditions in human and veterinary medicine require intestinal resection and anastomosis, and complications from these procedures are frequent. A rapidly collapsible anastomotic guide was developed for small intestinal end-to-end anastomosis and was investigated in order to assess its utility to improve the anastomotic process and to potentially reduce complication rates. A complex manufacturing method for building a polymeric device was established utilizing biocompatible and biodegradable polyvinylpyrrolidone and polyurethane. This combination of polymers would result in rapid collapse of the material. The guide was designed as a hollow cylinder composed of overlaying shingles that separate following exposure to moisture. An in vivo study was performed using commercial pigs, with each pig receiving one standard handsewn anastomosis and one guide-facilitated anastomosis. Pigs were sacrificed after 13 days, at which time burst pressure, maximum luminal diameter, and presence of adhesions were assessed. Burst pressures were not statistically different between treatment groups, but in vivo anastomoses performed with the guide withstood 10% greater luminal burst pressure and maintained 17% larger luminal diameter than those performed using the standard handsewn technique alone. Surgeons commented that the addition of a guide eased the performance of the anastomosis. Hence, a rapidly collapsible anastomotic guide may be beneficial to the performance of intestinal anastomosis.

Evidence according to Cochrane Systematic Reviews on Alterable Risk Factors for Anastomotic Leakage in Colorectal Surgery

Anastomotic leakage reflects a major problem in visceral surgery, leading to increased morbidity, mortality, and costs. This review is aimed at evaluating and summarizing risk factors for colorectal anastomotic leakage. A generalized discussion first introduces risk factors beginning with nonalterable factors. Focus is then brought to alterable impact factors on colorectal anastomoses, utilizing Cochrane systematic reviews assessed via systemic literature search of the Cochrane Central Register of Controlled Trials and Medline until May 2019. Seventeen meta-anaylses covering 20 factors were identified. Thereof, 7 factors were preoperative, 10 intraoperative, and 3 postoperative. Three factors significantly reduced the incidence of anastomotic leaks: high (versus low) surgeon's operative volume (RR = 0.68), stapled (versus handsewn) ileocolic anastomosis (RR = 0.41), and a diverting ostomy in anterior resection for rectal carcinoma (RR = 0.32). Discussion of all alterable factors is made in the setting of the pre-, intra-, and postoperative influencers, with the only significant preoperative risk modifier being a high colorectal volume surgeon and the only significant intraoperative factors being utilizing staples in ileocolic anastomoses and a diverting ostomy in rectal anastomoses. There were no measured postoperative alterable factors affecting anastomotic integrity.

The art of bowel anastomosis

Anastomotic techniques have greatly improved over the past two centuries, and postoperative complications have fallen accordingly. Factors contributing to anastomotic failure include location and systemic diseases such as sepsis and hemorrhagic shock. Factors that have not demonstrated any difference in outcome include stapled versus hand sewn anastomosis, continuous versus interrupted sutures, and single versus two layer anastomosis. Successful intestinal anastomosis necessitate adequate exposure and access, gentle tissue handling, absence of tension and distal obstruction, hemodynamic stability with adequte tissue oxygenation, and meticulous surgical technique.

[Anastomotic techniques for the gastrointestinal tract]

The correct suture technique for anastomoses of the gastrointestinal (GI) tract is a major task in the daily practice of surgery and a basic requirement for a successful operation. This article provides an overview of the surgical principles and techniques involved in the creation of intestinal anastomoses, including the differentiated use of various suturing aids in the GI tract. Hand sewn and stapled anastomotic techniques are illustrated and discussed. The ongoing discussion and question as to which technique is best for GI anastomoses remains unanswered as there is no obligatory standard, even though the requirements are well defined. An ideal anastomosis should fulfil the following criteria: it must be well vascularized, safe, tension-free and spillage from the operation field should be avoided.

Local ischaemia does not influence anastomotic healing: an experimental study

The role of local ischaemia in the pathogenesis of colorectal anastomotic leakage (AL) is not known. This study investigates the role of local ischaemia caused by sutures in an experimental colonic anastomosis model. 36 mice were assigned to three types of anastomosis, all using running sutures; in the first group 5 stitches were used, in the second group 12 stitches were used, and in the third group at least 30 stitches were used. After 7 days the mice were re-operated, signs of AL were scored, and coronal sections of the anastomosis were histologically analyzed. The distribution of weight was not significantly different between the three groups. Mortality was 44% and not significantly different between the groups (group 1: 5/12, group 2: 4/12, and group 3: 7/12, p = 0.72). Faecal and purulent AL were observed in 6 animals in group 1, 2 in group 2, and 3 in group 3 (group 1: 50%, group 2: 17%, and group 3: 25%, p = 0.19). The distance between the two colonic edges (group 1: 0.51 μm, group 2: 1.34 μm, and group 3: 0.53 μm, p = 0.18), the diameter of the lumen at the site of the anastomosis (group 1: 2.92 μm, group 2: 4.06 μm, and group 3: 3.2 μm, p = 0.9), and the largest diameter of the lumen proximally to the anastomosis (group 1: 2.05 μm, group 2: 3.1 μm, and group 3: 2.6 μm, p = 0.25) were not different between the groups. Histological parameters of wound healing were not significantly different for the three groups. In this study no macroscopic and microscopic differences were observed between colon anastomosis with 5 stitches versus 12 and >30 stitches. This might indicate that local ischaemia does not negatively influence colonic wound healing.

Single layer versus double layer suture anastomosis of the gastrointestinal tract

BACKGROUND

Gastrointestinal anastomosis (GIA) is an essential step to maintain the continuity of gastrointestinal tract following intestinal resection. GIA is still a source of significant controversy among surgeons due to the use of variety of approaches. Adequate apposition by single layer or double layer anastomosis may affect outcome after GIA OBJECTIVES: The objective of this review is to compare the effectiveness of single layer GIA (SGIA) versus double layer GIA (DGIA) being used in general surgery. The particular question we would attempt to answer will be; is single layer hand made GIA in surgical patients is as effective as double layer?

SEARCH METHODS

The CCCG (Colorectal Cancer Cochrane Group) Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 1, 2011), MEDLINE (until April 2011) , EMBASE ( The Intelligent Gateway to Biomedical & Pharmacological Information until April 2011), LILACS (The Latin American and Caribbean Health Sciences Library until April 2011 ) and Science Citation Index Expanded (SCI-E until April 2011) using the medical subject headings (MeSH) terms were searched without date, language or age restrictions.

SELECTION CRITERIA

Randomised, controlled trials comparing the effectiveness of SGIA versus DGIA DATA COLLECTION AND ANALYSIS: At least two review authors independently scrutinised search results, selected eligible studies and extracted data.

MAIN RESULTS

Seven randomised, controlled trials encompassing 842 patients undergoing SGIA versus DGIA were retrieved from the electronic databases. There were 408 patients in the SGIA group and 432 patients in the DGIA group. All included studies were small, with sample sizes ranging from 60 to 172. There was no heterogeneity among the included trials. Therefore, in the fixed effects model, incidence of anastomotic dehiscence, peri-operative complications and mortality was statistically equivalent between two techniques of GIA. Average hospital stay following SGIA and DGIA was also comparable. However, SGIA was superior in terms of shorter operative time. Sensitivity analysis of relatively good quality and poor quality trials supported same conclusion.

AUTHORS' CONCLUSIONS

SGIA can be performed quicker as compared to double layer GIA. SGIA is comparable to DGIA in terms of anastomotic leak, peri-operative complications, mortality and hospital stay. SGIA may routinely be used for GIA following bowel resection. However, since this conclusion is derived from smaller number of patients recruited in relatively moderate quality trials, further trials should be aimed to reduce the limitations of this review.

An analysis of the causes of bladder neck contracture after open and robot-assisted laparoscopic radical prostatectomy

OBJECTIVES

To evaluate the difference in outcome of bladder neck contracture (BNC) and its causes between large groups of patients undergoing open radical prostatectomy (ORP) and robot-assisted laparoscopic prostatectomy (RALP).

PATIENTS AND METHODS

We analysed 200 consecutive RPs performed by one surgeon for prostate cancer, 100 by ORP and 100 by RALP, between March 2003 and September 2007. The operative techniques of bladder neck repair and urethro-vesical anastomosis were different. The ORP patients had a conventional stomatization and 'racquet handle' repair of the bladder if necessary, with mucosal eversion and a direct circular interrupted 'end-to-end' suture anastomosis between the bladder and urethra. The RALP patients had no bladder neck reconstruction or mucosal eversion and their anastomosis was by the continuous suture 'parachute' technique.

RESULTS

There was no BNC in the RALP group, whilst 9% of the ORP group developed a BNC (P < 0.005). Apart from surgical technique, other variables, including patient age, previous transurethral resection of the prostate, Gleason score, T stage, urine infection rate, urinary leakage, blood loss, drain tube removal, anastomotic suture material, catheter type and catheter removal times were statistically comparable in both groups.

CONCLUSION

This series suggests that the major factor involved in the cause of bladder neck contracture after ORP, relates to the stomatization or 'racquet handle' bladder neck repair, and the end-to-end anastomosis between the urethra and stomatized bladder. Mucosal eversion might also contribute. Normal postoperative urinary leakage when the anastomotic apposition is good seems unlikely to be a significant aetiological factor in the development of BNC. Prolonged urinary leakage results from an anastomotic gap, which heals by second intention, thereby causing scarring and BNC. The RALP 'parachute' technique, which expands the anastomosis towards the bladder, appears to protect against BNC. Mucosal eversion is not necessary in the parachute repair.

Efeito de aderências dirigidas em anastomoses cólicas isquêmicas em ratos

OBJETIVO: Avaliar o efeito das aderências dirigidas sobre a resistência mecânica de anastomoses realizadas em cólon isquêmico através da aplicação dos testes Resistência à Pressão de Explosão e Resistência à Força de Tração. MÉTODOS: Quarenta ratos foram distribuídos igualmente em dois grupos. O Grupo 1 era constituído de vinte animais em que as anastomoses cólicas isquêmicas foram recobertas por uma película de polivinilcloreto (P.V.C.) para impedir a formação de aderências sobre as linhas de sutura e o Grupo 2 era constituído por 20 animais em que as anastomoses cólicas isquêmicas foram recobertas pela gordura epididimal, de forma a constituir uma aderência dirigida sobre a linha de sutura, sendo ainda recobertas por uma película de P.V.C. para impedir a formação de outras aderências. RESULTADOS: A média da Pressão de Ruptura à Distensão por Líquidos da anastomose foi de 10 mmHg no grupo sem aderência e de 55,2 mmHg no grupo com aderência (p < 0,05). A média da Força de Ruptura à Tração das anastomoses foi de 142,5 gf no grupo sem aderências e de 262 gf no grupo com aderência (p < 0,05). CONCLUSÃO: As aderências mostraram ser benéficas, elevando a resistência intrínseca das anastomoses tanto na Resistência à Distensão por Líquido quanto na Resistência à Força de Tração.

Feasibility of early closure of loop ileostomies: a pilot study

PURPOSE

A loop ileostomy is constructed to protect a distal anastomosis, and closure is usually performed not earlier than after two to three months. Earlier closure might reduce stoma-related morbidity, improve quality of life, and still effectively protect the distal anastomosis. This pilot study was designed to investigate the feasibility of early closure of loop ileostomies, i.e., during the same hospital admission as the initial operation.

METHODS

Twenty-seven consecutive patients with a protective loop ileostomy were included. If patient's recovery was uneventful, water-soluble contrast enema examination was performed, preferably after seven to eight days. If no radiologic signs of leakage were detected, the ileostomy was closed during the same hospital admission.

RESULTS

Twenty-seven patients (8 females; mean age, 60 years) were analyzed. Eighteen patients had early ileostomy closure on average 11 (range, 7-21) days after the initial procedure. In nine patients the procedure was postponed because of leakage of the anastomosis (n = 3), delayed recovery (n = 1), small bowel obstruction (n = 1), gastroparesis (n = 1), logistic reasons (n = 2), or irradical cancer resection followed by radiotherapy (n = 1). There was no mortality and four mild complications occurred after early closure: superficial wound infection (n = 2), intravenous-catheter sepsis (n = 1), small bowel obstruction (n = 1).

CONCLUSION

Closure of a loop ileostomy early after the initial operation was feasible in 18 of 27 patients and was associated with low morbidity and no mortality.

Randomized clinical trials in colon cancer

Prospective randomized trials involving the surgical and chemotherapeutic treatment of resectable colon cancer are reviewed. Emphasis is placed on those trials that have impacted the current management of primary colon cancer.

Single-layer continuous versus two-layer interrupted intestinal anastomosis: a prospective randomized trial

OBJECTIVE

To determine the suitability of a single-layer continuous technique for intestinal anastomosis in a surgical training program.

SUMMARY BACKGROUND DATA

Several recent reports have advocated the use of a continuous single-layer technique for intestinal anastomosis. Purported advantages include shorter time for construction, lower cost, and perhaps a lower rate of anastomotic leakage. The authors hypothesized that the single-layer continuous anastomosis could be safely introduced into a surgical training program and that it could be performed in less time and at a lower cost than the two-layer interrupted anastomosis.

METHODS

The study was conducted during a 3-year period ending September 1999. All adult patients requiring intestinal anastomosis were considered eligible. Patients who required anastomosis to the stomach, duodenum, and rectum were excluded. Patients were also excluded if the surgeon did not believe either technique could be used. Patients were randomly assigned to one- or two-layer techniques. Single-layer anastomoses were performed with a continuous 3-0 polypropylene suture. Two-layer anastomoses were constructed using interrupted 3-0 silk Lembert sutures for the outer layer and a continuous 3-0 polyglycolic acid suture for the inner layer. The time for anastomosis began with the placement of the first stitch and ended when the last stitch was cut. Anastomotic leak was defined as radiographic demonstration of a fistula or nonabsorbable material draining from a wound after oral administration, or visible disruption of the suture line during reexploration.

RESULTS

Sixty-five single-layer and 67 two-layer anastomoses were performed. The groups were evenly matched according to age, sex, diagnosis, and location of the anastomosis. Two leaks (3.1%) occurred in the single-layer group and one (1.5%) in the two-layer group. Two abscesses (3.0%) occurred in each group. A mean of 20.8 minutes was required to construct a single-layer anastomosis versus 30.7 minutes for the two-layer technique. Mean length of stay was 7.9 days for single-layer patients and 9.9 days for two-layer patients; this difference did not quite reach statistical significance. Cost of materials was $4.61 for the single-layer technique and $35.38 for the two-layer method.

CONCLUSIONS

A single-layer continuous anastomosis can be constructed in significantly less time and with a similar rate of complications compared with the two-layer technique. It also costs less than any other method and can be incorporated into a surgical training program without a significant increase in complications.

The treatment of wounds of the gastrointestinal tract

This update reviews the management of certain types of gastrointestinal wounds and the complications which may affect healing

Prospective study of hand-sutured anastomosis after colorectal resection

A total of 370 patients underwent colorectal resection: 320 had a primary single-layer seromucosal anastomosis without a protective colostomy, 22 had Hartmann's procedure and 28 abdominoperineal resection. There were 260 elective procedures and 110 patients had peritonitis and/or bowel obstruction at the time of surgery. Overall the mortality rate was 2.7 per cent, the morbidity rate was 18.3 per cent and clinical anastomotic leak rate 3.4 per cent. After elective operation, the leak rate for intraperitoneal anastomosis was 0.6 per cent and for low extraperitoneal anastomosis 7 per cent. The mortality rate was 1.2 per cent and morbidity rate 11.9 per cent. Patients with peritonitis had a significant increase in morbidity rate (46 per cent) in comparison with those having elective surgery (chi 2 = 31.5, 1 d.f., P < 0.0001). Patients who had bowel obstruction and no bowel preparation had a significantly higher morbidity rate of 26 per cent and mortality rate of 7 per cent, compared with those having an elective procedure (chi 2 = 11.2, 1 d.f., P < 0.001; chi 2 = 8.7, 1 d.f., P < 0.005 respectively). Patients having palliative surgery had the highest mortality rate (19 per cent), compared with those operated on with curative intent (1.5 per cent) (chi 2 = 28.7, 1 d.f., P < 0.0001). Cost-saving hand-sutured anastomosis is effective and, in experienced hands, technically feasible after all kinds of colorectal resection and should remain the standard in colorectal surgery.

Laparoscopic colonic and rectal resection

The technology that has permitted the rapid advance of minimal access surgery has now made it feasible to perform laparoscopically assisted colon resections safely. As the instrumentation improves, specimen removal problems are solved, surgeons' sewing skills improve, and other anastomotic methods are devised, an increasing amount of colonic surgery will be done using laparoscopy. It is clear that the techniques now in use are evolving, and will be substantially different a few years hence. Previously accepted surgical principles may continue to be challenged by new techniques, which must be evaluated under strict protocol before being widely accepted. These operations should be performed by surgeons who are able to achieve the same level of radical operation that they would achieve through a laparotomy. Special training in advanced laparoscopic techniques including microsurgical suturing is a distinct advantage in performing these operations successfully. It may be best for surgeons to start with palliative procedures or operations for benign diseases of the colon, to avoid the risk of jeopardizing an operation for cancer.

Suturing or stapling in gastrointestinal surgery: a prospective randomized study. West of Scotland and Highland Anastomosis Study Group

A prospective randomized study of 1004 patients is reported, comparing surgical stapling and manual suturing techniques in the construction of gastrointestinal anastomoses. The incidence of clinical leaks was similar between the two groups (sutured 3.2 per cent, stapled 4.7 per cent; P = 0.22), while for radiological leaks the incidence was significantly higher in the sutured group (12.2 per cent versus 4.1 per cent, P less than 0.05). Stapling instruments afforded significantly quicker anastomoses, mean(s.e.m.) 28.1(0.7) versus 14.3(0.5) min (P less than 0.001), and quicker operations, 115.5(2.4) versus 103.8(2.2) min (P less than 0.001). The two groups were found to be comparable in other respects such as operative mortality, requirements for blood transfusion, incidence of infective complications, recovery of gastrointestinal function and postoperative hospital stay.

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.

A view of the development of intestinal suture. Part II. Principles and techniques

During the 19th century, the principles of suturing and operating upon the bowel were developed. Lembert published his technique, emphasizing the importance of the serosa in 1826. This brought about sudden transition from the ancient methods of intestinal surgery. Considerable controversy followed. Dieffenbach reported the first clinical success with this suture in 1836. Lister introduced aseptic sutures and the principles of antisepsis to the intestine which allowed the subsequent developments. The importance of the submucosa in anchoring a stitch, so that divided surfaces could stay opposed, was drawn to surgeons' attention by Gross and by Halsted. Mall described the histologic changes and pointed out that necrosis would occur if sutures were too close or too tight. More than 200 modifications were described by the beginning of the 20th century. During the 1950s, everting suture was compared with inverting anastomoses, and the safety of this method was realized.

A retrospective study of colostomies, leaks and strictures after colorectal anastomosis

A review was undertaken of 360 patients undergoing elective left-sided colonic or rectal resections with primary anastomosis, under the care of one surgeon, over a nineteen year period. The incidence, aetiology and management of anastomotic leaks and strictures was studied and the role of proximal diverting colostomy considered. Perioperative mortality was 2.7%. The incidence of anastomotic leaks was 24.4%. Leaks were more common when anastomoses were low, were sutured or were constructed by trainees. Strictures developed in 5.8%. Local recurrence of tumour was the cause of 25% of these strictures. Anastomotic leakage was the principal cause of benign strictures; those developing in association with leaks were more likely to require surgical intervention. There was no evidence that delay in colostomy closure contributed to the development of benign anastomotic strictures. It was not possible to determine whether the presence of a colostomy affected the incidence of leaks but the local effects of such leaks were mitigated in patients with colostomies. Where a minor leak had occurred it was not necessary to wait for complete anastomotic healing before closing the colostomy. After major leaks, colostomy closure before complete healing was associated with further anastomotic problems in 16.0% of cases.

Continuous single-layer gastrointestinal anastomosis: a prospective audit

Single-layer bowel anastomoses have conventionally been constructed using an interrupted suture technique. A single-layer continuous technique has been avoided on the grounds that it may predispose to ischaemia of the bowel ends. We have routinely used a single-layer continuous suture technique with an absorbable suture material (polyglycolic acid) to construct all recent intraperitoneal bowel anastomoses, and we present a 3-year audit of this technique. A total of 131 patients were studied of whom 66 had undergone upper gastrointestinal resections and 65 had had colonic resections. Twenty-two patients had emergency operations. Anastomotic failure was noted in 4.5 and 6.2 per cent of patients in each group respectively. The incidence of minor wound infection was 1.5 and 7.7 per cent respectively. The overall mortality rate was 8.4 per cent. This study suggests that a single-layer continuous suture technique gives acceptably reliable results when used in gastrointestinal anastomosis.

Evaluation of two techniques for large intestinal resection and anastomosis in the horse

Six normal adult horses had large colon resections at the sternal and diaphragmatic flexures. Stainless steel staples were used to close the stumps of the dorsal and ventral colons in all six. Intestinal continuity was restored with a side-to-side anastomosis of the dorsal and ventral colons. Three of these anastomoses were performed with staples, and three with a double inverting suture pattern. After one month, the horses were surgically reevaluated, and the anastomotic sites were examined. There was no significant difference between the stoma sizes in the two groups. No complications were observed with either of the methods. However, the stapling procedure was faster to perform and resulted in less contamination of the surgical field. For these reasons, the authors preferred the stapling technique. No adverse effects from large colon resection were observed. Although the results described are quite good, resection of more extensive portions of the large colon can be more demanding and more problematic.

Colorectal anastomotic healing and intracolonic bypass procedure

Intestinal anastomoses continue to be complicated by leakages even in the best of hands despite the development of new surgical techniques, suture materials, devices, and stapling instruments. One may explain such persistence of anastomotic leakage on the basis of the dynamic effect that multiple factors have on the healing of an anastomosis. Awareness of these factors and proper precautions by the surgeon can make a high-risk anastomosis less prone to leakage. The intracolonic bypass procedure is an alternative to a temporary colostomy. It does not prevent an anastomotic dehiscence but can prevent anastomotic leakage with its associated complications in those situations where dehiscence is most likely to occur.

Intestinal anastomosis in the rat facilitated by a rapidly digested internal splint and indigestible but absorbable sutures

A stenosis is produced when a rat's transected small intestine is repaired with a conventional inverting line of silk or catgut sutures. In the new technique, the cut surfaces are apposed over a splint made of dry macaroni of suitable diameter, and then joined end-to-end with polyglactin stitches. The internal splint is quickly softened and digested. The suture material is absorbed without concomitant inflammation, and does not interfere with the cutting of sections for histology. Examination revealed, in every case, a fully patent anastomosis with alignment of the layers of the intestinal wall. This is preferable to an inverting anastomosis for investigations of intestinal wound healing and for physiological studies of the propagation of movements along the gut.

Analysis of techniques and results in 347 consecutive colon anastomoses

We have reported our experience with 347 consecutive colon anastomoses in 321 patients seen over an 8 year period. The overall anastomotic failure, mortality, and complication rates were 1.4, 2, and 10 percent, respectively, for the entire series. The complication and death rates were significantly higher in patients whose anastomoses were completed as part of an emergency procedure. Even though various one- and two-layer inverting techniques, suture materials, and staples were used, we could not identify any one method as being clearly superior in preventing anastomotic complications, although the results do suggest that some caution may be appropriate before mechanical stapling devices are universally applied. The results support that adherence to accepted surgical principles of reducing the solid content and fecal flora of the colon prior to operation, insuring an excellent blood supply to both bowel ends, even approximation of the bowel ends with inverting sutures which include the submucosal layer of the bowel, absence of tension, meticulous hemostasis, and avoidance of anastomosis in the presence of peritonitis are the primary means of avoiding dehiscence of colon anastomoses.

Gastrointestinal anastomoses. Factors affecting early complications

A retrospective review of gastric and colonic anastomoses during a recent 12-month period was performed at the Mayo Clinic. One hundred sixty-nine patients had gastroduodenal or gastrojejunal anastomoses (Group I). Five hundred nineteen patients had ileocolonic or ileorectal (222) and colocolonic or colorectal (297) anastomoses (Group II). Major anastomotic complication rates for Group I patients were: leaks, 1%; hemorrhage, 2%; and stenosis or obstruction, 2%. Reoperations and deaths secondary to anastomotic complications during the postoperative period were 2% and 0.6%, respectively. Corresponding rates for Group II were 2%, 1%, and 4%, with reoperative and anastomotic death rates of 1% and 0.2%, respectively. In Group I patients, length of operation had a significant effect (p less than 0.01) on anastomotic complications. In Group II patients, a significant increase in complications was related to the presence of obstruction (p less than 0.001), recent weight loss (greater than 10 pounds) (p less than 0.02), malignancy (p less than 0.04), and sepsis (p less than 0.05).

Use of a single layer extramucosal suture for intestinal anastomosis in children

We report our experience using an interrupted single layer extramucosal suture technique to construct both large and small bowel anastomoses in children. There were 75 anastomoses constructed in 68 children without any clinical evidence of a leak or any complications attributable to the anastomosis. Function after completion of the anastomosis was rapid. The median time for the passage of the first stool after operation was 46 h. This technique allowed construction of an end to end anastomosis with minimal reduction of the lumen even when there was great disproportion between the ends of intestine. It was therefore particularly suitable for the anastomosis of bowel of very small calibre.

Low colorectal anastomoses. An experimental assessment of two sutured and two stapled techniques

Extraperitoneal colorectal anastomoses were constructed in dogs by four methods: one layer of sutures (N = 10), two layers of sutures (N = 10), EEA staples (N = 10), and SPTU staples (N = 10). Dehiscence occurred in eight sutured and one stapled anastomosis (P less than 0.05). The four leaks following two layer sutured anastomoses caused three deaths, whereas all four leaks following one-layer sutured anastomoses were only detected radiologically (P less than 0.02). In the stapled group, the single leak followed EEA anastomosis and was fatal. Anastomotic narrowing was greater in sutured than stapled groups (P less than 0.05). Two layers of sutures produced gross narrowing compared with one layer (P less than 0.002). Two rows of staples (EEA) produced more narrowing than one row (SPTU) (P less than 0.01). Mean hydroxyproline concentrations and bursting pressures on the seventh postoperative day were higher in stapled than sutured anastomoses (P less than 0.05). Submucosal alignment, mucosal continuity, tissue viability, and stage of healing were all inferior for two-layer sutured anastomoses, reaching statistical significance for tissue viability (P less than 0.05). Stapled anastomoses were completed significantly faster (32.6 +/- 7.3 minutes) than sutured (54.1 +/- 8.4 minutes) (P less than 0.01). This experimental study has demonstrated that stapling is a fast and reliable method of colorectal anastomosis with a low complication rate. The shortcomings of the standard two-layer sutured anastomosis are discussed.

Closure of double-barrel colostomy with stapling instruments

A technique for closure of double-barrel colostomies using the GIA and TA 90 stapling instruments is described. The method is straight forward and time saving, and represents a further application of automatic staplers to gastro-intestinal surgery.

The healing of single- and double-row stapled circular anastomoses

The healing of anastomoses performed by single- or double-row circular stapling instruments is analyzed in the dog colon. Mucosal healing is better in single-row stapled anastomoses. Apposition of the outer intestinal layers is superior in double-row stapled anastomoses. Bursting pressure and circular wall tension values are identical in both anastomotic types except at 24 hours after surgery when the strength of a double-row stapled anastomosis is superior. A cost-benefit analysis is still in favor of single-row circular instruments. In our opinion, adequate preoperative bowel preparation and a thorough surgical technique, when preparing the cut edges to be anastomosed and placing purse-string sutures, are infinitely more important than making a choice between single- or double-row stapling machines.

Collagen dynamics of partial small bowel obstruction

The response of intestinal collagen to obstruction and stress was studied in the rat. Partial small bowel obstructions were created. Preobstruction collagen was measured by injection of tritium labeled proline. New collagen formation after obstruction occurred was followed by injection of carbon-14 labeled proline. At 3 weeks, collagen fractions were identified. Throughout the study, preexisting preobstruction intestinal collagen was metabolically stable with no breakdown or remodeling demonstrable. New collagen formation was rapid and occurred to the largest degree close to the obstruction.

[Causes of anastomotic dehiscence]

The healing of intestinal anastomoses has many physiological, biochemical and morphological aspects. In each stage it can be disturbed or blocked. Nearly each factor of normal healing can under changed circumstances, favour anastomotic dehiscence. Dehiscence can be caused by one severe disturbing factor; in most cases, however, there is more than one factor that forms rupture of the anastomosis. The intestine itself can become a disturbing factor as well as changed biological circumstances and last but not least insufficient tactics and techniques of building an anastomosis.

Collagen formation during the healing of colonic anastomoses

To study new collagen formation in the healing of anastomoses in the right colon, five male Sprague-Dawley rats had single-layer colonic anastomosis performed. Five additional rats had suture of the colon with interrupted sutures without transection of the colon. Ten animals served as controls. One week after surgery, animals were given 3H-proline repeatedly to label new collagen formation during the second and third weeks. Animals were sacrificed three weeks after suturing or anastomosis. Two- or 10-mm segments were precisely excised on either side of the suturing or anastomoses. Total collagen and its total radioactivity were measured per segment. Collagen hydroxyproline and its radioactivity increased (100 per cent) only within 1 cm of the anastomosis or suture alone. No local or distant decrease in collagen was observed. Collagen formation in colonic wounds appears to be a local process.

Use of circular stapling gun with peranal insertion of anorectal purse-string suture for construction of very low colorectal or colo-anal anastomoses

A technique is described for construction of the colorectal or colo-anal anastomosis in low rectal resection by using an automatic circular stapling device and inserting the anorectal purse-string suture peranally from below. This method was employed in 4 patients resulting in complete healing in 3 cases and a moderate leak in 1, which, however, eventually healed satisfactorily.

Telescoping anastomosis of the colon: a comparative study

The incidence of large-intestinal anastomotic leaks remains unacceptably high. For this reason, we studied the resistance to dehiscence of a telescoping type of anastomosis and compared it with the conventional one-layer, two-layer, and stapled anastomoses in a canine model. These experiments demonstrated that the telescoping anastomosis provided a more resistant suture line during the early postoperative phase and did not cause encroachment of the lumen by the diaphragm, which was consistently produced when an inverting suture line was used. Three days postoperatively the mean bursting pressures of the one-layer, two-layer, and stapled anastomoses were 31 +/- 12, 120 +/- 46, and 52 +/- 21 mm Hg, respectively. The telescoping anastomosis had a mean bursting pressure of 210 +/- 44 mm Hg, which was significantly (P less than 0.01) higher than those of all the other anastomoses tested. However, seven and 14 days after operation, there was no statistically significant difference among the bursting pressures of the various anastomoses. When the different types of anastomoses were examined histologically, it was found that there was considerably more suture-line inflammation, edema, micro-abscess formation, mucosal ulceration and pericolic inflammation of the fat in the one-layer, two-layer, and stapled anastomoses than in the telescoping anastomosis.

The autosuture surgical stapling instruments: preliminary experience

Stapling instruments for gastrointestinal surgery are relatively new in the surgical armamentarium of Australian surgeons. In an attempt to assess their safety and handling characteristics laboratory experience has been obtained in dogs. This has shown that these instruments are effective and easily handled, although costly in routine use. It seems likely that they will provide an appropriate alternative to certain conventional anastomotic techniques.

Single-layer anastomosis of the colon. A review of 165 cases

One hundred sixty-five patients undergoing elective colorectal or colonic anastomoses with a one-layer technic are presented. One death from suture line dehiscence was noted, and the overall mortality was 2.4 per cent. The usual technic for esophagogastrointestinal suturing in French surgical centers is described and the importance of suture technic in the etiology of anastomotic leaks is discussed.

Healing of experimental colonic anastomoses. The effect of suture technic on collagen concentration in the colonic wall

The present experimental study in rats has demonstrated a marked difference in the healing process of anastomoses in the left colon following two different suture technics: continuous and interrupted sutures. Rats having anastomoses constructed of continuous suture showed a high incidence of complications and a marked decrease of collagen concentration in the anastomosis and in the colonic wall proximal to the anastomosis during the first week of healing. In animals with anastomoses made of interrupted sutures there were fewer complications, the decrease in collagen concentration was confined to the anastomotic region, and the recovery of collagen concentration occurred earlier. The findings indicate that the interrupted suture technic is preferable for anastomosis in the left colon.

A controlled comparison one- and two-layer techniques of suture for high and low colorectal anastomoses

A controlled trial of one- and two-layer inverting techniques of sutures for the contruction of high and low colorectal anastomoses was conducted on 137 patients, the integrity of the suture lines being assessed clinically and by routine radiological examination after a small Gastrografin enema. A clinical diagnosis of anastomotic leakage was made in 9 patients (or perhaps more accurately in 5 only), but subclinical dehiscence was demonstrated radiologically in a further 39 patients (or perhaps 43). There was a slightly greater incidence of dehiscence after the one-layer technique of suture for both high and low anterior resection.

Prevention of wound sepsis in gastro-intestinal surgery

After gastro-intestinal operations wound infection is usually caused by the inoculation of bacteria present within the intestinal tract into the incision during the surgical procedure. In theory, wound sepsis may be minimized by the following methods: (a) avoiding intestinal contamination of the incision; (b) altering the normal flora of the intestinal tract by adding oral antimicrobials to bowel preparation; (c) using topical or systemic prophylactic antibiotic administration for certain high-risk patients. The relative importance of these methods of prophylaxis is described.