Obesity is one of the greatest challenges to health in the twenty-first century. According to data from the International Association for the Study of Obesity (IASO), Germany ranks first in the prevalence of obesity for both genders (1). The Federal Office of Statistics revealed that in 2011, 67.1% of men and 53% of women were overweight (2).

Laparoscopic Roux-en-Y-Gastric Bypass (RYGB) was introduced in Germany in the mid-1990s. The long-term durability of RYGB has been shown in different studies. The effects of long-term follow-up over a period of more than 10 years and long-term outcomes after RYGB have recently been published (3). Due to the high BMI of patients in Germany and the high prevalence of comorbidities, the use of RYGB has rapidly increased in Germany in recent years.

In Germany, a stapled anastomosis is more common than the hand sutured anastomosis of the gastrojejunal junction (GJA). In the literature, anastomotic leak rates reach 5.1% with linear staplers and up to 6.6% with circular devices (4).

This study investigated the outcomes with regard on weight loss and amelioration on comorbidities for patients undergoing RYGB with linear or circular staples based on an analysis of data from the German Bariatric Surgery Registry (GBSR). The primary goal of the study was to compare the short-term follow-up rates for the different techniques of gastrojejunal anastomosis in RYGB.

Since January 1 2005, data from a quality assurance study of the surgical treatment of obesity in Germany have been registered prospectively in an online database at the Institute of Quality Assurance in Surgical Medicine of the Otto-von-Guericke University Magdeburg (5, 6). This study evaluates the outcomes of RYGB as a primary operation for data collected between 2005 and 2010. The data studied include patient’s demographics, surgical parameters, complications, and mortality following RYGB for circular versus linear anastomosis with respect to the incidence of leakage, short-term morbidity, and mortality. The results are compared with other findings in the literature.

The paper analyzed data of GBSR without any selection criteria for the patients to several stapling techniques for gastrojejunal anastomosis or hand-sewn anastomosis. Decision depends on the experience of the different centers in Germany.

To ascertain completeness of data entry, participation in the study is a pre-requisite to an institution’s certification as a center for bariatric surgery, and reported case numbers are verified against hospitals’ clinical and billing documentation. The anonymized data are provided to the institutions and serves a center’s quality control in regards to surgical indication, complication rates, outcome, and follow-up in comparison with other centers. To optimize quality and integrity of registry data (e.g., minimize missing data and ensure adherence to eligibility criteria), statistical plausibility checks are employed and regular random audits are conducted by the study director.

The study period ranged from January 1 2005 to December 31 2010 and 96 centers participated. Patients who underwent a primary bariatric procedure were included in a descriptive statistical analysis performed by an independent statistics consulting firm (StatConsult, Magdeburg, Germany).

The study was conducted according to the Recommendations of the Declaration of Helsinki for Biomedical Research and the Guidelines and Standards of the Institutional Review Boards. All patients provided informed consent prior to entering the study.

Statistical analysis was performed by StatConsult GmbH using the SAS^® 9.2 software program. The descriptive statistical analysis was specified by presentation of absolute and relative frequencies for categorical data and mean, standard deviation, minimum and maximum values for continuous variables. The median was presented for continuous variables with high variation. For further verification of differences between groups in categorical data, the χ² test was used or the Fisher’s exact test was applied for rare events. Continuous variables were compared between two groups using a two sample t-test. Multivariable analysis of several influence parameters in parallel for a dependent binary variable was performed using logistic regression. P-values were determined for two-sided tests, with a value of p < 0.05 indicating a statistically significant difference. All tests were deliberately carried out to the full level of significance.

There were 5115 RYGBs performed as a primary approach between 2005 and 2010. In relation to gender distribution, there were 3993 female patients and 1122 male patients. In 2734 (53.6%) patients, the GJA was performed with linear staplers, and in 1587 (31.1%) patients, circular staplers were used. Seven hundred eighty-three patients were operated using the hand-sewn technique. For 11 patients, no valid statement could be made.

Since January 1, 2005, primary and revisional bariatric procedures have been recorded within the framework of a quality assurance study of the surgical treatment of obesity by the Institute for Quality Assurance in Surgical Medicine at the Otto-von-Guericke University Magdeburg with the aim of improving the quality of care (5, 6).

Roux-en-Y-Gastric Bypass is one of the most frequently performed bariatric operations worldwide. For RYGB complications, a leak at the GJA is the most critical aspect to judge the integrity of the anastomosis. The presence of bleeding, marginal ulceration, or anastomotic strictures are of secondary importance.

During a median follow-up of 13 months (range 19–2090 days), the mean BMI loss for patients with linear GJA was 14.74 kg/m². For patients with circular-stapled GJA, the mean BMI loss was 15.10 kg/m². The difference is not statistically significant. These data are similar to the published data form a controlled randomized study by an Austrian group (7). Similar to the literature, both groups reach the BMI nadir 2 years after surgery. Meta-analysis data did not indicate a significant difference between the two techniques concerning the excess weight loss (8). Patients with hand-sewn GJA had a mean BMI reduction of 13.69 kg/m², which is significantly lower than for patients with linear or circular-stapled GJA (p < 0.05).

The data from the GBSR on the surgical treatment of RYGB have not shown any significant differences in the leakage and stricture rates of gastrojejunal anastomosis when comparing linear versus circular techniques according to data published from the meta-analysis (7, 9).

Using linear or circular stapler devices does not significantly influence weight loss postoperatively or alter the amelioration of sleep apnea and hypertension comorbidities. For patients with diabetes mellitus type II, we found a better amelioration rate in linear anastomosis, which is in contrast to meta-analysis. However, the bias of our study is the higher prevalence of comorbidities and the higher BMI in patients with circular-stapled anastomosis and the missing randomization of our patients (8).

Further examinations are necessary to investigate the long-term effect of complete remission of diabetes mellitus type II and hypertension.

The bias and limitations of the GBSR include the evaluated center effect, the high BMI, the incidence of comorbidities of patients in Germany, and the lack of data on duration and treatment of comorbidities and their influence on amelioration. Further studies are necessary to evaluate the complication rates of different stapler devices and assess the impact on amelioration of comorbidities and their long-term effects.

The German Nationwide Survey on Bariatric Surgery is supported by the Ministry of Research and Education Germany (BMBF) grant number 01GI1124. The responsible investigator is Christine Elisabeth Stroh. Christine Elisabeth Stroh, Grigorij Nesterov, Rudolf Weiner, Frank Benedix, Christian Knoll, Matthias Pross, and Thomas Manger confirm that there are no links to firms whose products are mentioned in the article or to firms marketing a competing product. The topic is presented in an independent manner, and the information outlined is product neutral. The following firms support the GBSR without any relation to their products: Johnson & Johnson MEDICAL GmbH, Ethicon Endo-Surgery Deutschland, Norderstedt. Covidien Deutschland GmbH Neustadt/Donau.