You will be provided with the titles and abstracts of a collection of medical RCT reports studying a clinical question -- for instance, the efficacy of an intervention on some medical outcome. Please write a few sentences synthesizing the findings of these reports, which could serve as a conclusion section for a systematic review article. Your response should not include any other text. The RCT reports are below.



Title 1:
A prospective randomised study of drains in infra-peritoneal rectal anastomoses.
Abstract 1:
Although increasing evidence suggests that prophylactic drainage after intra-peritoneal colorectal anastomoses is unnecessary, drains for infra-peritoneal rectal anastomoses, where the leak rate is higher, are widely employed still. The aim of this study was to assess the effect of prophylactic drainage after anastomosis below the peritoneal reflection. All patients attending one specialist unit over an 8-month period for elective rectal cancer resection with an infra-peritoneal anastomosis were randomised to drainage or no drainage. The incidence of anastomotic leak and complications specific to the drain as well as other complications were compared. Fifty-nine patients were analysed (31 with drain). Twenty-five of the drained and 16 of the no-drain patients had a defunctioning stoma (p=ns). The groups were comparable for demographic data, operation and anastomotic height from the anal verge. There were three leaks (10%) in the drain group and five leaks (18%) in the no-drain group (p=ns). There were 2 (7%) patients in each group with a clinical leak. There were no specific drain complications and the incidence of other complications was similar in both groups. In conclusion, this study supports the contention that there is no difference in morbidity with or without the use of a drain for infra-peritoneal anastomoses.


Title 2:
A prospective, controlled study of prophylactic drainage after colonic anastomoses.
Abstract 2:
A prospective, randomized, controlled trial was designed to study the influence of a corrugated latex drain on anastomotic integrity, wound infection, and respiratory complications after elective colonic resections above the pelvic peritoneum. Sixty patients entered the trial; 28 were drained and 32 undrained. Three patients in the undrained group died soon after surgery of causes unrelated to their colon anastomoses. There were no other differences in the incidence of postoperative complications in the two groups. When an anastomosis leaked, neither feces nor pus emerged via the drain. It is concluded that while the drains did not increase the incidence of postoperative complications, neither did they accomplish the purpose for which they were inserted. If, in addition, the economic cost of drainage is considered, it would seem that there is no advantage in inserting prophylactic drains after colonic anastomoses and their routine use needs to be reconsidered.


Title 3:
[Uses and risks of drainage following elective colon resection. A prospective, randomized and controlled clinical study].
Abstract 3:
The results of a controlled randomized and prospective clinical study including 113 patients from March 1987 until August 1988 showed that prophylactic drainage in elective resection for cancer of the colon was not necessary. 60 patients received a drain, 53 patients were not drained. The drain turned out to be ineffective even concerning its expected function of draining intraabdominal fluid: its diagnostic and therapeutic value failed in clinical practice. The rate of surgical complications--i.e. anastomotic leakage, impaired wound healing and relaparotomy--was significantly higher in the drained group. In elective colon resection the use of a drain as a routine procedure cannot be recommended.


Title 4:
Is prophylactic pelvic drainage useful after elective rectal or anal anastomosis? A multicenter controlled randomized trial. French Association for Surgical Research.
Abstract 4:
We investigated the role of drainage in the prevention of complications after elective rectal or anal anastomosis in the pelvis. Anastomotic leakage after colorectal resection is more prevalent when the anastomosis is in the distal or infraperitoneal pelvis than in the abdomen. The benefit of pelvic drains versus their potential harm has been questioned. Drain-related complications include (1) those possibly benefiting from drainage (leakage, intra-abdominal infection, bleeding) and (2) those possibly caused by drainage (wound infection or hernia, intestinal obstruction, fistula).
                Between September 1990 and June 1995, 494 patients (249 men and 245 women), mean age 66 +/- 15 (range 15 to 101) years, with either carcinoma, benign tumor, colonic Crohn's disease, diverticular disease of the sigmoid colon, or another disorder located anywhere from the right colon to the midrectum undergoing resection followed by rectal or anal anastomosis were randomized to undergo either drainage (n = 248) with 2 multiperforated 14F suction drains or no drainage (n = 246). The primary end point was the number of patients with one or more postoperative drain-related complications. Secondary end points included severity of these complications as assessed by the rate of related repeat operations and associated deaths as well as extra-abdominally related morbidity and mortality.
                After withdrawal of 2 patients (1 in each group) both groups were comparable with regard to preoperative characteristics and intraoperative findings. The overall leakage rate was 6.3% with no significant difference between those with or without drainage. There were 18 deaths (3.6%), 8 (3.2%) in those with drainage and 10 (4%) in those without drainage. Five patients with anastomotic leakage died (1%), 3 of whom had drainage. There were 32 repeat operations (6.5%) for anastomotic leakage 11 in the group with drainage and 4 in the group with no drainage. The rate of these and the other intra-abdominal and extra-abdominal complications did not differ significantly between the 2 groups.
                Prophylactic drainage of the pelvic space does not improve outcome or influence the severity of complications.


Title 5:
Prophylactic abdominal drainage after elective colonic resection and suprapromontory anastomosis: a multicenter study controlled by randomization. French Associations for Surgical Research.
Abstract 5:
Only 4 controlled trials have investigated whether prophylactic abdominal drainage was of value after colonic resection. None have been able to find any statistically significant difference, but the number of patients was small and the beta error risk was high.
                To compare patients who underwent abdominal drainage with those who did not for the rate and severity of complications after elective colonic resection followed immediately by anastomosis of the suprapromontory colon and to compare suction drains with nonsuction drains.
                Between September 1990 and June 1995, 319 patients (135 men and 184 women), whose mean age was 67 years (range, 22-95 years), with carcinoma, benign tumors, or colitis, located anywhere between the ascending and sigmoid colons, were included in the study. Patients were comparable for demographic characteristics, except that there were more patients with ascites in the group that did not undergo abdominal drainage (P<.02).
                After 2 protocol violations, 156 patients were randomized to the abdominal drainage group and 161 to the no abdominal drainage group. All 317 anastomoses were tested for airtightness intraoperatively and repaired if leakage was found (n=71), and all patients with anastomoses received a routine diatrizoate sodium enema to detect infraclinical leakage.
                The postoperative complications possibly influenced by drainage included (1) deep complications for which drainage can lead to early diagnosis, such as generalized or localized peritonitis, intraabdominal hemorrhage, or hematoma; (2) complications believed to be enhanced by drainage, such as an operative wound (an abscess, disruption, or incisional hernia) or pulmonary (microatelectasis) and intestinal obstructions; and (3) complications directly due to the drains, such as ulcerations leading to fistulae, hemorrhages, drainage tract infections, difficulty in removal, intra-abdominal retention, and incisional disruptions. Subsidiary end points were the severity of these complications as assessed by the number of related subsequent operations and deaths.
                Twenty-six patients overall (8%) had postoperative complications possibly influenced by drainage (9% in the group that underwent abdominal drainage and 8% in the group that did not). This difference was not statistically significant (P<.90). One patient had a fistula directly imputable to drainage. There was no difference between suction and nonsuction drainage (P<.90).
                Routine abdominal drainage after colonic resection and immediate anastomosis decreases neither the rate nor the severity of anastomotic leakage. It can, occasionally, be detrimental.
There is insufficient evidence showing that routine drainage after colorectal anastomoses prevents anastomotic and other complications.