BMC Surgery - Latest Articles

To whom do the results of the multicenter, randomized, controlled INSECT trial (ISRCTN 24023541) apply? - Assessment of external validity

Lars Fischer — 2012-02-08T00:00:00Z

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. Background: 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. Methods: 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. Results: 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. Conclusions: Results of the INSECT trial are applicable to a broad spectrum of patients treated at different hospital levels.

Gentamicin supplemented polyvinylidenfluoride mesh materials enhance tissue integration due to a transcriptionally reduced MMP-2 protein expression

Marcel Binnebosel — 2012-01-13T00:00:00Z

Background: A beneficial effect of gentamicin supplemented mesh material on tissue integration is known. To further elucidate the interaction of collagen and MMP-2 in chronic foreign body reaction and to determine the significance of the MMP-2-specific regulatory element (RE-1) that is known to mediate 80% of the MMP-2 promoter activity, the spatial and temporal transcriptional regulation of the MMP-2 gene was analyzed at the cellular level. Methods: A PVDF mesh material was surface modified by plasma-induced graft polymerization of acrylic acid (PVDF+PAAc). Three different gentamicin concentrations were bound to the provided active sites of the grafted mesh surfaces (2, 5 and 8 ug/mg). 75 male transgenic MMP-2/LacZ mice harbouring the LacZ reporter gene under control of MMP-2 regulatory sequence -1241/+423, excluding the RE-1 were randomized to five groups. Bilateral of the abdominal midline one of the five different meshes was implanted subcutaneously in each animal. MMP-2 gene transcription (anti-beta-galactosidase staining) and MMP-2 protein expression (anti-MMP-2 staining) were analyzed semiquantitatively by immunohistochemistry 7, 21 and 90 days after mesh implantation. The collagen type I/III ratio was analyzed by cross polarization microscopy to determine the quality of mesh integration. Results: The perifilamentary beta-galactosidase expression as well as the collagen type I/III ratio increased up to the 90th day for all mesh modifications, whereas no significant changes could be observed for MMP-2 protein expression between days 21 and 90. Both the 5 and 8 ug/mg gentamicin group showed significantly reduced levels of beta-galactosidase expression and MMP-2 positive stained cells when compared to the PVDF group on day 7, 21 and 90 respectively (5 ug/mg: p < 0.05 each; 8 ug/mg: p < 0.05 each). Though the type I/III collagen ratio increased over time for all mesh modifications significant differences to the PVDF mesh were only detected for the 8 ug/mg group at all 3 time points (p < 0.05 each). Conclusions: Our current data indicate that lack of RE-1 is correlated with increased mesh induced MMP-2-gene expression for coated as well as for non-coated mesh materials. Gentamicin coating reduced MMP-2 transcription and protein expression. For the 8 ug/mg group this effect is associated with an increased type I/III collagen ratio. These findings suggest that gentamicin is beneficial for tissue integration after mesh implantation, which possibly is mediated via RE-1.

Failure of available scoring systems to predict ongoing infection in patients with abdominal sepsis after their initial emergency laparotomy

Oddeke van Ruler — 2011-12-23T00:00:00Z

Background: To examine commonly used scoring systems, designed to predict overall outcome in critically ill patients, for their ability to select patients with an abdominal sepsis that have ongoing infection needing relaparotomy. Methods: Data from a RCT comparing two surgical strategies was used. The study population consisted of 221 patients at risk for ongoing abdominal infection. The following scoring systems were evaluated with logistic regression analysis for their ability to select patients requiring a relaparotomy: APACHE-II score, SAPS-II, Mannheim Peritonitis Index (MPI), MODS, SOFA score, and the acute part of the APACHE-II score (APS). Results: The proportion of patients requiring a relaparotomy was 32% (71/221). Only 2 scores had a discriminatory ability in identifying patients with ongoing infection needing relaparotomy above chance: the APS on day 1 (AUC 0.61; 95%CI 0.52-0.69) and the SOFA score on day 2 (AUC 0.60; 95%CI 0.52-0.69). However, to correctly identify 90% of all patients needing a relaparotomy would require such a low cut-off value that around 80% of all patients identified by these scoring systems would have negative findings at relaparotomy. Conclusions: None of the widely-used scoring systems to predict overall outcome in critically ill patients are of clinical value for the identification of patients with ongoing infection needing relaparotomy. There is a need to develop more specific tools to assist physicians in their daily monitoring and selection of these patients after the initial emergency laparotomy.Trial registration numberISRCTN: ISRCTN 51729393

Bovine pericardium retail preserved in glutaraldehyde and used as a vascular patch

Wladimir Saporito — 2011-12-22T00:00:00Z

Background: In this study we evaluated the performance of bovine pericardium preserved in glutaraldehyde used as a vascular patch. Methods: Fourteen young pigs, six females and eight males, weighting 10.3 - 18.4 kg were used in our study. We implanted three remnants in each pig, two in the abdominal aorta and one was juxtaposed to the peritoneum. The smooth face (SF) and rough face (RF) of each remnant were implanted turned to the vessel inner portion and one remnant was juxtaposed to the peritoneum. The animals were sacrificed in 4.5 - 8 months after surgery (75 - 109 kg). The remnants were assessed for aorta wall, fibroses formation in inner apposition and calcification related to the face turned to the vessel inner portion. Results: The rough face showed a lower dilatation level compared to the face implanted in adjacent aorta. There was no difference between intensity and/or incidence of graft calcification when the superficies were compared. The bovine pericardium preserved in glutaraldehyde did not show alterations in its structure when implanted with different faces turned to the inner portion of vessel. Conclusion: When turned to the inner portion of the vessel, the rough face of the remnant presented a lower dilatation in relation to the adjacent aorta and a better quality of endothelium layer and did not show a difference between intensity and/or incidence of graft calcification.

Tension of knotted surgical sutures shows tissue specific rapid loss in a rodent model

Christian Klink — 2011-12-21T00:00:00Z

Background: Every surgical suture compresses the enclosed tissue with a tension that depends from the knotting force and the resistance of the tissue. The aim of this study was to identify the dynamic change of applied suture tension with regard to the tissue specific cutting reaction. Methods: In rabbits we placed single polypropylene sutures (3/0) in skin, muscle, liver, stomach and small intestine. Six measurements for each single organ were determined by tension sensors for 60 minutes. We collected tissue specimens to analyse the connective tissue stability by measuring the collagen/protein content. Results: We identified three phases in the process of suture loosening. The initial rapid loss of the first phase lasts only one minute. It can be regarded as cutting through damage of the tissue. The percentage of lost tension is closely related to the collagen content of the tissue (r = -0.424; p = 0.016). The second phase is characterized by a slower decrease of suture tension, reflecting a tissue specific plastic deformation. Phase 3 is characterized by a plateau representing the remaining structural stability of the tissue. The ratio of remaining tension to initial tension of phase 1 is closely related to the collagen content of the tissue (r = 0.392; p = 0.026). Conclusions: Knotted non-elastic monofilament sutures rapidly loose tension. The initial phase of high tension may be narrowed by reduction of the surgeons' initial force of the sutures' elasticity to those of the tissue. Further studies have to confirm, whether reduced tissue compression and less local damage permits improved wound healing.

Laparoscopic versus open peritoneal dialysis catheter insertion, LOCI-trial: a study protocol.

Sander Hagen — 2011-12-20T00:00:00Z

Background: Peritoneal dialysis (PD) is an effective treatment for end-stage renal disease. It allows patients more freedom to perform daily activities compared to haemodialysis. Key to successful PD is the presence of a well-functioning dialysis catheter. Several complications, such as in- and outflow obstruction, peritonitis, exit-site infections, leakage and migration, can lead to catheter removal and loss of peritoneal access. Currently, different surgical techniques are in practice for PD-catheter placement. The type of insertion technique used may greatly influence the occurrence of complications. In the literature, up to 35% catheter failure has been described when using the open technique and only 13% for the laparoscopic technique. However, a well-designed randomized controlled trial is lacking.Methods/DesignThe LOCI-trial is a multi-center randomized controlled, single-blind trial (pilot). The study compares the laparoscopic with the open technique for PD catheter insertion. The primary objective is to determine the optimum placement technique in order to minimize the incidence of catheter malfunction at 6 weeks postoperatively. Secondary objectives are to determine the best approach to optimize catheter function and to study the quality of life at 6 months postoperatively comparing the two operative techniques.DiscussionThis study will generate evidence on any benefits of laparoscopic versus open PD catheter insertion.Trial registrationDutch Trial Register NTR2878

The CARTS study: Chemoradiation therapy for rectal cancer in the distal rectum followed by organ-sparing transanal endoscopic microsurgery

Guus Bokkerink — 2011-12-15T00:00:00Z

Background The CARTS study is a multicenter feasibility study, investigating the role of rectum saving surgery for distal rectal cancer.Methods/Design Patients with a clinical T1-3 N0 M0 rectal adenocarcinoma below 10 cm from the anal verge will receive neoadjuvant chemoradiation therapy (25 fractions of 2 Gy with concurrent capecitabine). Transanal Endoscopic Microsurgery (TEM) will be performed 8 - 10 weeks after the end of the preoperative treatment depending on the clinical response.Primary objective is to determine the number of patients with a (near) complete pathological response after chemoradiation therapy and TEM. Secondary objectives are the local recurrence rate and quality of life after this combined therapeutic modality. A three-step analysis will be performed after 20, 33 and 55 patients to ensure the feasibility of this treatment protocol.DiscussionThe CARTS-study is one of the first prospective multicentre trials to investigate the role of a rectum saving treatment modality using chemoradiation therapy and local excision. The CARTS study is registered at clinicaltrials.gov (NCT01273051)

Laparoscopic gastric pouch and remnant resection: a novel approach to refractory anastomotic ulcers after Roux-en-Y Gastric Bypass: Case report

Daniel Steinemann — 2011-12-02T00:00:00Z

Background: Anastomotic or marginal ulcers occur in 0.6 to 16% of patients after laparoscopic Roux-en-Y-Gastric Bypass. Initial therapy aims at eliminating known risk factors including smoking, Helicobacter pylori infection, use of non-steroidal anti-inflammatory drugs and inhibition of gastric acid secretion. While this approach is successful in 68 to 88% of the cases, up to one third of patients need a subsequent surgical revision. However, marginal ulcers still recur in up to 10% of cases after revisional surgery, thus constituting a serious challenge for bariatric surgeons.Case presentationWe herein report a case of an insidious marginal ulcer refractory to both medical therapy with high-dosed proton pump inhibitors and sucralfate as well as surgical therapy consisting of the lengthening of a short alimentary limb and later resection of the gastroenterostomy and construction of a new tension-free anastomosis. Only after gastrectomy by laparoscopic en-bloc resection of the gastrojejunostomy, the gastric pouch and resection of the gastric remnant with reconstruction by esophagojejunostomy the patient remained free of symptoms. Conclusion: By laparoscopic resection of the entire gastric pouch and the gastric remnant the risk to leave a suboptimally vascularised or even ischemic pouch in situ was avoided. The esophagojejunostomy was then created in healthy, good vascularised tissue. In our case this novel approach was effective in the management of a refractory anastomotic ulcer and might represent a rescue option when simple revision of the gastrojejunostomy fails.

Acute effects of remote ischemic preconditioning on cutaneous microcirculation - a controlled prospective cohort study

Robert Kraemer — 2011-11-23T00:00:00Z

Background: Therapeutic strategies aiming to reduce ischemia/reperfusion injury by conditioning tissue tolerance against ischemia appear attractive not only from a scientific perspective, but also in clinics. Although previous studies indicate that remote ischemic intermittent preconditioning (RIPC) is a systemic phenomenon, only a few studies have focused on the elucidation of its mechanisms of action especially in the clinical setting. Therefore, the aim of this study is to evaluate the acute microcirculatory effects of remote ischemic preconditioning on a distinct cutaneous location at the lower extremity which is typically used as a harvesting site for free flap reconstructive surgery in a human in-vivo setting. Methods: Microcirculatory data of 27 healthy subjects (25 males, age 24 ± 4 years, BMI 23.3) were evaluated continuously at the anterolateral aspect of the left thigh during RIPC using combined Laser-Doppler and photospectrometry (Oxygen-to-see, Lea Medizintechnik, Germany). After baseline microcirculatory measurement, remote ischemia was induced using a tourniquet on the contralateral upper arm for three cycles of 5 min. Results: After RIPC, tissue oxygen saturation and capillary blood flow increased up to 29% and 35% during the third reperfusion phase versus baseline measurement, respectively (both p = 0.001). Postcapillary venous filling pressure decreased statistically significant by 16% during second reperfusion phase (p = 0.028). Conclusion: Remote intermittent ischemic preconditioning affects cutaneous tissue oxygen saturation, arterial capillary blood flow and postcapillary venous filling pressure at a remote cutaneous location of the lower extremity. To what extent remote preconditioning might ameliorate reperfusion injury in soft tissue trauma or free flap transplantation further clinical trials have to evaluate.Trial registrationClinicalTrials.gov: NCT01235286

Auto-aggressive metallic mercury injection around the knee joint: a case report

Joerg Friesenbichler — 2011-11-17T00:00:00Z

Background: Accidental or intentional subcutaneous and/or intramuscular injection of metallic mercury is an uncommon form of poisoning. Although it does not carry the same risk as mercury vapour inhalation, it may cause destructive early and late reactions.Case PresentationHerein we present the case of a 29-year-old male patient who developed an obsessive-compulsive disorder causing auto-aggressive behaviour with injection of elemental mercury and several other foreign bodies into the soft tissues around the left knee about 15 years before initial presentation. For clinical examination X-rays and a CT-scan of the affected area were performed. Furthermore, blood was taken to determine the mercury concentration in the blood, which showed a concentration 17-fold higher than recommended. As a consequence, the mercury depots and several foreign bodies were resected marginally. Conclusion: Blood levels of mercury will decrease rapidly following surgery, especially in combination with chelating therapy. In case of subcutaneous and intramuscular injection of metallic mercury we recommend marginal or wide excision of all contaminated tissue to prevent migration of mercury and chronic inflammation. Nevertheless, prolonged clinical and biochemical monitoring should be performed for several years to screen for chronic intoxication.