Randomised trials evaluation of surgical interventions are often designed and analysed as if the outcome of individual patients is independent of the surgeon providing the intervention. There is reason to expect outcomes for patients treated by the same surgeon tend to be more similar than those under the care of another surgeon due to previous experience, individual practice, training, and infrastructure. Such a phenomenon is referred to as the clustering effect and potentially impacts on the design and analysis adopted and thereby the required sample size. The aim of this work was to inform trial design by quantifying clustering effects (at both centre and surgeon level) for various outcomes using a database of surgical trials.
Intracluster correlation coefficients (ICCs) were calculated for outcomes from a set of 10 multicentre surgical trials for a range of outcomes and different time points for clustering at both the centre and surgeon level.
ICCs were calculated for 198 outcomes across the 10 trials at both centre and surgeon cluster levels. The number of cases varied from 138 to 1370 across the trials. The median (range) average cluster size was 32 (9 to 51) and 6 (3 to 30) for centre and surgeon levels respectively. ICC estimates varied substantially between outcome type though uncertainty around individual ICC estimates was substantial, which was reflected in generally wide confidence intervals.
This database of surgical trials provides trialists with valuable information on how to design surgical trials. Our data suggests clustering of outcome is more of an issue than has been previously acknowledged. We anticipate that over time the addition of ICCs from further surgical trial datasets to our database will further inform the design of surgical trials.
Surgery; ICC; multicentre; clustering
Different suture techniques and various suture materials are in use to close midline incisions after primary laparotomy. The ISSAAC study aimed to assess the safety and efficacy of the new ultra-long-term absorbable, elastic monofilament suture material MonoMax® for abdominal wall closure.
This is a single-arm, multicentre prospective study that included 150 patients undergoing a primary elective midline incision. The control group consists of 141 patients from the INSECT study who received MonoPlus® or PDS® for abdominal wall closure. The incidences of burst abdomen and wound infection until the day of discharge were defined as the primary composite endpoints. The rate of incisional hernias 1 year after surgery, the length of postoperative hospital stay and safety parameters served as secondary endpoints. The study has been registered under www.clinicaltrials.gov [NCT005725079].
Eleven patients in the ISSAAC study [7.3%; 95% CI = (3.9; 13.1%)] experienced wound infection or burst abdomen until the day of discharge as compared to 16 [11.3%; 95% CI = (6.6; 17.8%)] patients in the INSECT control group (p = 0.31). The length of postoperative hospital stay was comparable in both study groups. One year after surgery, incisional hernias were observed in 21 ISSAAC patients (14.0%) in contrast to 30 hernias (21.3%) in the INSECT control group.
The ultra-long-term absorbable, elastic monofilament suture material MonoMax® is safe and efficient for abdominal wall closure.
Laparotomy; Abdominal hernia; Fascia; Suture materials; Humans
The pp-Whipple procedure requires extensive preparation. The conventional preparation technique is done with scissors for dissection and ligatures, and with clips and sutures for hemostasis. This procedure is very time-consuming and requires numerous changes of instruments. The LigaSure™ device allows dissection and hemostasis for preparation with one instrument. Up to now there has been no comparison of the two techniques with regard to operating time and the patients' outcome. It is still unclear which technique has the optimal benefit/risk ratio for the patient.
A single-center, randomized, single-blinded, controlled superiority trial to compare two different techniques for dissection in a pp-Whipple procedure. 102 patients will be included and randomized pre-operatively. All patients aged 18 years or older scheduled for primary elective pp-Whipple procedure who signed the informed consent will be included. The primary endpoint is the operating time of the randomized technique. Control Intervention: Conventional dissection technique; experimental intervention: LigaSureTM dissection technique. Duration of study: Approximately 15 months; follow up time: 3 years. The trial is registered at German ClinicalTrials Register (DRKS00000166).
Colorectal cancer is the second most common tumor in developed countries, with a lifetime prevalence of 5%. About one third of these tumors are located in the rectum. Surgery in terms of low anterior resection with mesorectal excision is the central element in the treatment of rectal cancer being the only option for definite cure. Creating a protective diverting stoma prevents complications like anastomotic failure and meanwhile is the standard procedure. Bowel obstruction is one of the main and the clinically and economically most relevant complication following closure of loop ileostomy. The best surgical technique for closure of loop ileostomy has not been defined yet.
A study protocol was developed on the basis of the only randomized controlled mono-center trial to solve clinical equipoise concerning the optimal surgical technique for closure of loop ileostomy after low anterior resection due to rectal cancer.
The HASTA trial is a multi-center pragmatic randomized controlled surgical trial with two parallel groups to compare hand-suture versus stapling for closure of loop ileostomy. It will include 334 randomized patients undergoing closure of loop ileostomy after low anterior resection with protective ileostomy due to rectal cancer in approximately 20 centers consisting of German hospitals of all level of health care. The primary endpoint is the rate of bowel obstruction within 30 days after ileostomy closure. In addition, a set of surgical and general variables including quality of life will be analyzed with a follow-up of 12 months. An investigators meeting with a practical session will help to minimize performance bias and enforce protocol adherence. Centers are monitored centrally as well as on-site before and during recruitment phase to assure inclusion, treatment and follow up according to the protocol.
Aim of the HASTA trial is to evaluate the efficacy of hand-suture versus stapling for closure of loop ileostomy in patients with rectal cancer.
German Clinical Trial Register Number: DRKS00000040
Radiotherapy exerts part of its antineoplastic effect by generating oxidative stress, therefore genetic variation in
oxidative stress-related enzymes may influence survival of rectal
cancer patients. We hypothesized that genetic polymorphisms
associated with higher amounts of reactive oxygen species (ROS)
that exaggerate cytotoxic activity could improve survival after
radiotherapy. We followed 114 rectal cancer patients who received
radiotherapy for an average of 42.5 months. Associations between
genotypes (GSTP1, GSTM1,
MnSOD, MPO and
eNOS) and overall survival were assessed using
Kaplan-Meier curves and Cox proportional hazards regression. As
hypothesized, patients carrying low ROS producing
eNOS Glu298Asp asparagine allele showed an
increased hazard of death compared to homozygous carriers of the
glutamine allele (hazard ratio (HR): 2.10, 95% confidence
interval (CI): 1.01–4.38). However, carriers of low ROS
producing MPO G463A A allele had a decreased
hazard of death compared to patients homozygous for the G allele
(HR: 0.44, 95% CI: 0.21–0.93) although patients
homozygous for the A allele had a slightly increased hazard (HR:
1.12, 95% CI: 0.25–5.08). This explorative study
provides first results and highlights the need for further, larger
studies to investigate association between genetic variation in
oxidative stress genes and survival of rectal cancer patients who
Concomitant treatment in addition to intervention may influence the primary outcome, especially in complex interventions such as surgical trials. Evidence-based standards for perioperative care after distal pancreatectomy, however, have been rarely defined. This study's objective was therefore to identify and analyse the current basis of evidence for perioperative management in distal pancreatectomy.
A standardised questionnaire was sent to 23 European centres recruiting patients for a randomized controlled trial (RCT) on open distal pancreatectomy that would compare suture versus stapler closure of the pancreatic remnant (DISPACT trial, ISRCTN 18452029). Perioperative strategies (e.g., bowel preparation, pain management, administration of antibiotics, abdominal incision, drainages, nasogastric tubes, somatostatin, mobilisation and feeding regimens) were assessed. Moreover, a systematic literature search in the Medline database was performed and retrieved meta-analyses and RCTs were reviewed.
All 23 centres returned the questionnaire. Consensus for thoracic epidural catheters (TECs), pain treatment and transverse incisions was found, as well as strong consensus for the placement of intra-abdominal drainages and perioperative single-shot antibiotics. Also, there was consensus that bowel preparation, somatostatin application, postoperative nasogastric tubes and intravenous feeding might not be beneficial. The literature search identified 16 meta-analyses and 19 RCTs demonstrating that bowel preparation, somatostatin therapy and nasogastric tubes can be omitted. Early mobilisation, feeding and TECs seem to be beneficial for patients. The value of drainages remains unclear.
Most perioperative standards within the centres participating in the DISPACT trial are in accordance with current available evidence. The need for drainages requires further investigation.
Clinical trial registration: ISRCTN 18452029
Chronic pancreatitis is an inflammatory disease which is characterized by an irreversible conversion of pancreatic parenchyma to fibrous tissue. Beside obstructive jaundice and pseudocyst formation, about half of the patients need surgical intervention due to untreatable chronic pain during the course of the disease. In most of the patients with chronic pancreatitis, the head of the pancreas is the trigger of the chronic inflammatory process. Therefore, resection of pancreatic head tissue must be the central part of any surgical intervention. However, it is unclear to which extent the surgical procedure must be radical in order to obtain a favourable outcome for the patients.
A single centre randomized controlled, superiority trial to compare two techniques of duodenum preserving pancreatic head resection. Sample size: 65 patients will be included and randomized intraoperatively. Eligibility criteria: All patients with chronic pancreatitis and indication for surgical resection and signed informed consent. Cumulative primary endpoint (hierarchical model): duration of surgical procedure, quality of life after one year, duration of intensive care unit stay, duration of hospital stay. Reference treatment: Resection of the pancreatic head with dissection of the pancreas from the portal vein and transsection of the gland (Beger procedure). Intervention: Partial Resection of the pancreatic head without transsection of the organ and visualization of the portal vein (Berne procedure).
Duration: September 2003-October 2007.
The trial is conducted in compliance with the protocol and in accordance with the moral, ethical, regulatory and scientific principles governing clinical research as set out in the Declaration of Helsinki (1989) and the Good Clinical Practice guideline (GCP). The Center for Clinical Studies of the Department of Surgery Heidelberg is responsible for planning, conducting and final analysis of the trial.
There are two ways to open the abdominal cavity in elective general surgery: vertically or transversely. Various clinical studies and a meta-analysis have postulated that the transverse approach is superior to other approaches as regards complications. However, in a recent survey it was shown that 90 % of all abdominal incisions in visceral surgery are still vertical incisions. This discrepancy between existing recommendations of clinical trials and clinical practice could be explained by the lack of acceptance of these results due to a number of deficits in the study design and analysis, subsequent low internal validity, and therefore limited external generalisability. The objective of this study is to address the issue from the patient's perspective.
This is an intraoperatively randomized controlled observer and patient-blinded two-group parallel equivalence trial. The study setting is the Department of General-, Visceral-, Trauma Surgery and Outpatient Clinic of the University of Heidelberg, Medical School. A total of 172 patients of both genders, aged over 18 years who are scheduled for an elective abdominal operation and are eligible for either a transverse or vertical incision. To show equivalence of the two approaches or the superiority of one of them from the perspective of the patient, a primary endpoint is defined: the pain experienced by the patient (VAS 0–100) on day two after surgery and the amount of analgesic required (piritramide [mg/h]). A confidence interval approach will be used for analysis. A global α-Level of 0.05 and a power of 0.8 is guaranteed, resulting in a size of 86 patients for each group. Secondary endpoints are: time interval to open and close the abdomen, early-onset complications (frequency of burst abdomen, postoperative pulmonary complications, and wound infection) and late complications (frequency of incisional hernias). Different outcome variables will be ranked by patients and surgeons to assess the relevance of possible endpoints from the patients' and surgeons' perspective.
This is a randomized controlled observer and patient-blinded two-group parallel trial to answer the question if the transverse abdominal incision is equivalent to the vertical one due to the described endpoints.
More than 100 surgical approaches to treat rectal prolapse have been described. These can be done through the perineum or transabdominally. Delorme’s procedure is the most frequently used perineal, resection rectopexy the most commonly used abdominal procedure. Recurrences seem more common after perineal compared to abdominal techniques, but the latter may carry a higher risk of peri- and postoperative morbidity and mortality.
DeloRes is a randomized, controlled, observer-blinded multicenter trial with two parallel groups. Patients with a full-thickness rectal prolapse (third degree prolapse), considered eligible for both operative methods are included. The primary outcome is time to recurrence of full-thickness rectal prolapse during the 24 months following primary surgery. Secondary endpoints are time to and incidence of recurrence of full-thickness rectal prolapse during the 5-year follow-up, duration of surgery, morbidity, hospital stay, quality of life, constipation, and fecal incontinence. A meta-analysis was done on the basis of the available data on recurrence rates from 17 publications comprising 1,140 patients. Based on the results of a meta-analysis it is assumed that the recurrence rate after 2 years is 20% for Delorme’s procedure and 5% for resection rectopexy. Considering a rate of lost to follow-up without recurrence of 30% a total of 130 patients (2 x 65 patients) was calculated as an adequate sample size to assure a power of 80% for the confirmatory analysis.
The DeloRes Trial will clarify which procedure results in a smaller recurrence rate but also give information on how morbidity and functional results compare.
German Clinical Trial Number DRKS00000482
Rectal prolapse; Surgery; Delorme’s procedure; Resection rectopexy; Recurrence
The optimal strategy for abdominal wall closure has been an issue of ongoing debate. Available studies do not specifically enroll patients who undergo emergency laparotomy and thus do not consider the distinct biological characteristics of these patients. The present randomized controlled trial evaluates the efficacy and safety of two commonly applied abdominal wall closure strategies in patients undergoing primary emergency midline laparotomy.
The CONTINT trial is a multicenter, open label, randomized controlled trial with a two-group parallel design. Patients undergoing a primary emergency midline laparotomy are enrolled in the trial. The two most commonly applied strategies of abdominal wall closure after midline laparotomy are compared: the continuous, all-layer suture technique using slowly absorbable monofilament material (two Monoplus® loops) and the interrupted suture technique using rapidly absorbable braided material (Vicryl® sutures). The primary endpoint within the CONTINT trial is an incisional hernia within 12 months or a burst abdomen within 30 days after surgery. As reliable data on this primary endpoint is not available for patients undergoing emergency surgery, an adaptive interim analysis will be conducted after the inclusion of 80 patients, allowing early termination of the trial if necessary or modification of design characteristics such as recalculation of sample size.
This is a randomized controlled multicenter trial with a two-group parallel design to assess the efficacy and safety of two commonly applied abdominal wall closure strategies in patients undergoing primary emergency midline laparotomy.
A response to Seiler et al: Interrupted or continuous slowly absorbable sutures for closure of primary elective midline abdominal incisions: a multicenter randomized trial (INSECT: ISRCTN24023541). Ann Surg 2009, 249(4):576-582.
Existing evidence suggests that the transfer of results of randomized controlled trials into clinical practice may be limited. Potential reasons can be attributed to aspects of external validity. The aim of this study is to investigate issues related to the external validity of the INSECT trial.
All participating surgical departments were categorized and the clinical and baseline characteristics of randomized patients were evaluated. In addition, demographic and clinical data of all screened and randomized patients at the Departments of Surgery in Heidelberg and Erlangen were analyzed.
Twenty-five centers enrolled a total of 625 patients. These centers included eight primary, 11 secondary, and six tertiary care centers. The tertiary care centers enrolled the most patients (n = 237, 38%) followed by the primary care centers (n = 199, 32%) and the secondary care centers (n = 189 patients; 30%). The mean number and baseline data of randomized patients did not differ between the three types of care centers (p = 0.09). Overall, the treatment according to protocol was at least 92%. At the Department of Surgery, University of Heidelberg, 307 patients were screened and 60 out of 130 eligible patients were randomized. There were no differences in demographic and clinical baseline data between included and non-included patients. In Erlangen, 351 patients were screened and 57 out of 106 eligible patients randomized.
Results of the INSECT trial are applicable to a broad spectrum of patients treated at different hospital levels.
Wound infection affects a considerable portion of patients after abdominal operations, increasing health care costs and postoperative morbidity and affecting quality of life. Antibacterial coating has been suggested as an effective measure to decrease postoperative wound infections after laparotomies. The INLINE metaanalysis has recently shown the superiority of a slowly absorbable continuous suture for abdominal closure; with PDS plus® such a suture has now been made available with triclosan antibacterial coating.
The PROUD trial is designed as a randomised, controlled, observer, surgeon and patient blinded multicenter superiority trial with two parallel groups and a primary endpoint of wound infection during 30 days after surgery. The intervention group will receive triclosan coated polydioxanone sutures, whereas the control group will receive the standard polydioxanone sutures; abdominal closure will otherwise be standardized in both groups. Statistical analysis is based on intention-to-treat population via binary logistic regression analysis, the total sample size of n = 750 is sufficient to ensure alpha = 5% and power = 80%, an interim analysis will be carried out after data of 375 patients are available.
The PROUD trial will yield robust data to determine the effectiveness of antibacterial coating in one of the standard sutures for abdominal closure and potentially lead to amendment of current guidelines. The exploration of clinically objective parameters as well as quality of life holds immediate relevance for clinical management and the pragmatic trial design ensures high external validity.
The trial protocol has been registered with the German Clinical Trials Register (DRKS00000390).
A recently published systematic review indicated superiority of duodenum-preserving techniques when compared with pancreatoduodenectomy, for the treatment of patients with chronic pancreatitis in the head of the gland. A multicentre randomised trial to confirm these results is needed.
ChroPac aims to investigate differences in quality of life, mortality and morbidity during 24 months after surgery (duodenum-preserving pancreatic head resection versus pancreatoduodenectomy) in patients with chronic pancreatitis of the pancreatic head.
ChroPac is a randomised, controlled, observer and patient blinded multicentre surgical trial with two parallel comparison groups. The primary outcome measure will be the average quality of life during 24 months after surgery. Statistical analysis is based on the intention-to-treat population. Analysis of covariance will be applied for the intervention group comparison adjusting for age, centre and quality of life before surgery. Level of significance is set at 5% (two-sided) and sample size (n = 100 per group) is determined to assure a power of 90%.
The ChroPac trial will explore important outcomes from different perspectives (e.g. surgeon, patient, health care system). Its pragmatic approach promises high external validity allowing a comprehensive evaluation of the surgical strategy for treatment of patients with chronic pancreatitis.
Research on surgical interventions is associated with several methodological and practical challenges of which few, if any, apply only to surgery. However, surgical evaluation is especially demanding because many of these challenges coincide. In this report, the second of three on surgical innovation and evaluation, we discuss obstacles related to the study design of randomised controlled trials and non-randomised studies assessing surgical interventions. We also describe the issues related to the nature of surgical procedures—for example, their complexity, surgeon-related factors, and the range of outcomes. Although difficult, surgical evaluation is achievable and necessary. Solutions tailored to surgical research and a framework for generating evidence on which to base surgical practice are essential.
Development of incisional hernia after open abdominal surgery remains a major cause of post-operative morbidity. The aim of this study was to determine the current practice of surgeons in terms of access to and closure of the abdominal cavity in elective open surgery.
Twelve surgical departments of the INSECT-Trial group documented the following variables for 50 consecutive patients undergoing abdominal surgery: fascial closure techniques, applied suture materials, application of subcutaneous sutures, subcutaneous drains, methods for skin closure. Descriptive analysis was performed and consensus of treatment variables was categorized into four levels: Strong consensus >95%, consensus 75–95%, overall agreement 50–75%, no consensus <50%.
157 out of 599 patients were eligible for analysis (85 (54%) midline, 54 (35%) transverse incisions). After midline incisions the fascia was closed continuously in 55 patients (65%), using slowly absorbable (n = 47, 55%), braided (n = 32, 38%) sutures with a strength of 1 (n = 48, 57%). In the transverse setting the fascia was closed continuously in 39 patients (72%) with slowly absorbable (n = 22, 41%) braided sutures (n = 27, 50%) with a strength of 1 (n = 30, 56%).
In the present evaluation midline incision was the most frequently applied access in elective open abdominal surgery. None of the treatments for abdominal wall closure (except skin closure in the midline group) is performed on a consensus level.
Totally Implantable Access Ports (TIAP) are being extensively used world-wide and can be expected to gain further importance with the introduction of new neoadjuvant and adjuvant treatments in oncology. Two different techniques for the implantation can be selected: A direct puncture of a central vein and the utilization of a Seldinger device or the surgical Venae sectio. It is still unclear which technique has the optimal benefit/risk ratio for the patient.
A single-center, expertise based randomized, controlled superiority trial to compare two different TIAP implantation techniques. 100 patients will be included and randomized pre-operatively. All patients aged 18 years or older scheduled for primary elective implantation of a TIAP under local anesthesia who signed the informed consent will be included. The primary endpoint is the primary success rate of the randomized technique. Control Intervention: Venae Sectio will be employed to insert a TIAP by a surgeon; Experimental intervention: Punction of V. Subclavia will be used to place a TIAP by a radiologist. Duration of study: Approximately 10 months, follow up time: 90 days.
The PORTAS 2 – Trial will be conducted in accordance with the protocol and in compliance with the moral, ethical, and scientific principles governing clinical research as set out in the Declaration of Helsinki (1989) and Good Clinical Practice (GCP). The Center of Clinical Trials at the Department of Surgery, University Hospital Heidelberg is responsible for design and conduct of the trial including randomization and documentation of patients' data. Data management and statistical analysis will be performed by the independent Institute for Medical Biometry and Informatics (IMBI), University of Heidelberg.
The trial is registered at ClinicalTrials.gov (NCT00600444).
Several randomized controlled trials have compared different suture materials and techniques for abdominal wall closure with respect to the incidence of incisional hernias after midline laparotomy and shown that it remains, irrespective of the methods used, considerably high, ranging from 9% to 20%. The development of improved suture materials which would reduce postoperative complications may help to lower its frequency.
This is a historically controlled, single-arm, multi-centre, prospective trial to evaluate the safety of MonoMax® suture material for abdominal wall closure in 150 patients with primary elective midline incisions. INSECT patients who underwent abdominal closure using Monoplus® and PDS® will serve as historical control group. The incidences of wound infections and of burst abdomen are defined as composite primary endpoints. Secondary endpoints are the frequency of incisional hernias within one year after operation and safety. To ensure adequate comparability in surgical performance and recruitment, the 4 largest centres of the INSECT-Trial will participate. After hospital discharge, the investigators will examine the enrolled patients again at 30 days and at 12 ± 1 months after surgery.
This historically controlled, single-arm, multi-centre, prospective ISSAAC trial aims to assess whether the use of an ultra-long-lasting absorbable monofilament suture material is safe and efficient.
Although considered the reference standard for generating valid scientific evidence of a treatment's benefits and harms, the number of Randomised Controlled Trials (RCT) comparing surgical techniques remains low. Much effort has been made in order to overcome methodological issues and improve quality of RCTs in surgery. To the present there has been, however, only little emphasis on development and maintenance of institutions for implementation of adequately designed and conducted surgical RCTs.
Description of the developments in surgical RCT infrastructure in Germany between 2001 and 2006. Cross sectional evaluation of completed and ongoing surgical RCTs within the German Surgical Society and the Clinical Study Centre, Department of Surgery, University of Heidelberg.
Foundation of a national Clinical Trial Centre (CTC) for the organisation of multi-centre RCTs in the surgical setting (Study Center of the German Surgical Society, SDGC). Establishment of a network of CTCs with affiliated Clinical Sites (CSs) to enhance patient recruitment and shorten the duration of RCTs. Since its foundation four surgical RCTs with a total sample size of 1650 patients (1006 of these randomised) have been supervised by the SDGC with 35 CSs involved in patient recruitment. Five further CTCs were set up in 2006. Together with their affiliated CSs a network has been organised providing improved conditions for the conduction of surgical RCTs.
Improvement of infrastructure substantially facilitates integration of RCTs into routine surgical practice. A network of collaborating CTCs and CSs can provide an adequate infrastructure for the conduction of multi-centre RCTs.
Secondary hyperparathyroidism (sHPT) is common in patients with chronic renal failure. Despite the initiation of new therapeutic agents, several patients will require parathyroidectomy (PTX). Total PTX with autotransplantation of parathyroid tissue (TPTX+AT) and subtotal parathyroidectomy (SPTX) are currently considered as standard surgical procedures in the treatment of sHPT. Recurrencerates after TPTX+AT or SPTX are between 10% and 12% (median follow up: 36 months).
Recent retrospective studies demonstrated a lower rate of recurrent sHPT of 0–4% after PTX without autotransplantation and thymectomy (TPTX) with no higher morbidity when compared to the standard procedures. The observed superiority of TPTX is flawed due to different definitions of outcomes, varying follow up periods and different surgical treatment strategies (with and without thymectomy).
Patients with sHPT (intact parathyroid hormone > 10 times above the upper limit of normal) on long term dialysis (>12 months) will be randomized either to TPTX or TPTX+AT and followed for 36 months. Outcome parameters are recurrence rates of sHPT, frequencies of reoperations due to refractory hypoparathyroidism or recurrent/persistent hyperparathyroidism, postoperative morbidity and mortality and quality of life. 50 patients per group will be randomized in order to obtain relevant frequencies of outcome parameters that will form the basis for a large scale confirmatory multicentred randomized controlled trial.
sHPT is a disease with a high incidence in patients with chronic renal failure. Even a small difference in outcomes will be of clinical relevance. To assess sufficient data about the rate of recurrent sHPT after both methods, a multicentred, randomized controlled trial (MRCT) under standardized conditions is mandatory.
Due to the existing uncertainties the calculated number of patients necessary in each treatment arm (n > 4000) makes it impossible to perform this study as a confirmatory trial. Therefore estimates of different outcomes are performed using a pilot MRCT comparing 50 versus 50 randomized patients in order to establish a hypothesis that can be tested thereafter.
If TPTX proves to have a lower rate of recurrent sHPT, no relevant disadvantages and no higher morbidity than TPTX+AT, current surgical practice may be changed.
International Standard Randomized Controlled Trial Number Registration (ISRCTN86202793)
Restorative proctocolectomy is increasingly being performed minimal invasively but a totally laparoscopic technique has not yet been compared to the standard open technique in a randomized study.
This is a two armed, single centre, expertise based, preoperatively randomized, patient blinded study. It is designed as a two-group parallel superiority study. Power calculation revealed 80 patients per group in order to recruit the 65 patients to be analysed for the primary endpoint. The primary objective is to investigate intra-operative blood loss and the need for blood transfusions. We hypothesise that intra-operative blood loss and the need for peri-operative blood transfusions are significantly higher in the conventional group. Additionally a set of surgical and non-surgical parameters related to the operation will be analysed as secondary objectives. These will include operative time, complications, postoperative pain, lung function, postoperative length of hospital stay, a cosmetic score and pre-and postoperative quality of life.
The trial will answer the question whether there is indeed an advantage in the laparoscopic group in regard to blood loss and the need for blood transfusions. Moreover, it will generate data on the safety and potential advantages and disadvantages of the minimally invasive approach.
The closure of the abdomen after median laparotomy is still a matter of debate among surgeons. Further well designed and performed randomised controlled trials determining the optimal method of abdominal fascial closure are needed.
This is a three armed, multi-centre, intra-operatively randomised, controlled, patient blinded trial. Over 20 surgical departments will enrol 600 patients who are planned for an elective primary abdominal operation. The objective of this study is to compare the frequency of abdominal incisional hernias between two continuous suture techniques with different, slowly absorbable monofilament materials and an interrupted suture using an absorbable braided suture material at one year postoperatively.
This trial will answer the question whether the continuous abdominal wall closure with a slowly absorbable material with longitudinal elasticity is superior to the continuous suture with a material lacking elasticity and to interrupted sutures with braided thread.