Mohammed R. Moussavian

Antibiotic coating of abdominal closure sutures and wound infection

BACKGROUND Poor wound healing and the development of infection in incisional wounds continue to be among the most common complications of open abdominal surgery. Various bacteria may contaminate not only the tissue in the operative wound, but also the actual suture material. To prevent the contamination of suture material in surgical wounds, triclosan-coated polyglactin 910 suture materials with antibacterial activity (Vicryl plus) was developed. The aim of this study was to ascertain if the use of Vicryl plus reduced the number of wound infections after midline laparotomy comparing to polydioxanon suture (PDS II). METHODS We performed 2,088 operations in our department between October 2004 and September 2006 via midline incision. In the first time period (TP1), a PDS II loop suture was used. In the second time period (TP2), we used Vicryl plus. All variables were recorded prospectively in a database. The primary outcome was the number of wound infections. Risk factors for poor wound healing were collected prospectively to compare the 2 groups. RESULTS Using a PDS loop suture for abdominal wall closure in TP1, 10.8% of patients with wound infections were detected. The number of patients with wound infections decreased in TP2 using Vicryl plus for abdominal wall closure to 4.9% (P < .001) despite no other changes in protocols of patient care. Other risk factors for the development of site infections were comparable in the 2 groups. CONCLUSION The use of antibiotic-coated loop suture for abdominal wall closure can decrease the number wound infections after abdominal surgery.

Impact of postoperative pancreatic fistula on surgical outcome--the need for a classification-driven risk management.

BackgroundThe International Study Group of Pancreatic Fistula (ISGPF) classification allows comparison of incidence and severity of postoperative pancreatic fistula (POPF). Its post hoc character, however, does not provide a guideline for the treatment of POPF in individual patient. We therefore studied the association of POPF type A-C on secondary surgical morbidity and mortality in patients undergoing pancreatic resection.Patients and methodsBetween 3/2001-12/2007, 483 patients underwent pancreatic resections. POPF were classified according to the ISGPF classification. All patient data were entered in a clinical data management system prospectively.ResultsPatients who developed POPF had significantly more vascular but not other surgical complications than patients without POPF. Patients with POPF A had no vascular or surgical complications. Twenty one of the 29 patients with POPF C had surgical complications (17 vascular complications). Mortality attributed to surgical complications after POPF C was 5/29. A soft pancreatic consistency (OR 8.5; p < 0.008) and a high drain lipase activity on postoperative day 3 (OR 4.4; p = 0,065) were predictors for the development of POPF C.DiscussionPOPF C is associated with vascular complications like erosion bleeding and other surgical complications like delayed gastric emptying or pleural effusions. A soft pancreatic consistency and a high drain lipase activity on postoperative day 3 are early predictors for the development of POPF C.

Surgery of Liver Metastasis in Gynecological Cancer – Indication and Results

Background: Liver surgery for patients with liver metastases from gynecological malignancies, an indicator of advanced cancer disease, has remained unclear in the literature. We therefore analyzed the potential survival benefit of patients with surgically resectable compared to unresectable liver metastases. Patients and Methods: 43 patients who underwent surgery for liver metastases from gynecological cancers were included in our retrospective observational analysis. Overall survival was estimated according to the Kaplan-Meier method and compared with the log-rank test. Results: Primary gynecological tumors were breast (n = 27), ovarian (n = 8), and uterine (n = 8) cancers. Solely exploratory laparotomy was performed in 13 patients who served as controls. Whereas the perioperative mortality was 0%, minor complications occurred in 18.7%. The overall survival of all patients undergoing liver resection was significantly higher (p < 0.05) than that of patients with unresectable metastases. Subgroup analyses showed that particularly patients with respectable liver metastases from breast cancer had a significantly higher (50%) 5-year survival compared to patients with only an exploratory laparotomy. Conclusion: In selected patients, liver resection of metastases from gynecological cancers can achieve a survival benefit similar to that of patients with colorectal cancer metastases.

Multidrug donor preconditioning protects steatotic liver grafts against ischemia-reperfusion injury

BACKGROUND Graft dysfunction of steatotic livers (SL) still remains a major challenge in liver transplantation. Different mechanisms are thought to be involved in the impaired tolerance of SL to ischemia-reperfusion injury. Thus, different pharmacologic strategies may need to be combined to effectively protect SL and to reduce graft dysfunction after transplantation. Therefore, we analyzed the effectiveness of a multidrug donor preconditioning (MDDP) procedure to protect SL from cold ischemia-reperfusion injury. METHODS Liver steatosis was induced by a high-carbohydrate, fat-free diet. A total of 24 Sprague-Dawley rats were divided into 3 groups (n = 8 each), including a control group with nonsteatotic livers (Con), a vehicle-treated SL group (SL-Con), and a SL group undergoing MDDP (SL-MDDP), including pentoxyphylline, glycine, deferoxamine, N-acetylcysteine, erythropoietin, melatonin, and simvastatin. MDDP was applied before liver perfusion with 4°C histidine-tryptophan-ketoglutarate (HTK) solution and organ harvest. After 24 hours of cold storage in HTK, postischemic reperfusion was performed in an isolated liver reperfusion model using 37°C Krebs-Henseleit bicarbonate buffer. RESULTS After 60 minutes of reperfusion, SL showed a significant reduction of bile flow as well as a marked increase of liver enzyme levels and apoptotic cell death compared with Con. This was associated with an increased malondialdehyde formation, interleukin-1 production, and leukocytic tissue infiltration. MDDP completely abolished the inflammatory response and was capable of significantly reducing parenchymal dysfunction and injury. CONCLUSIONS MDDP decreases SL injury after cold storage and reperfusion. The concept of MDDP as a simple and safe preoperative regime, thus may be of interest in clinical use, expanding the donor pool from marginal donors.

Long term follow up for incisional hernia after severe secondary peritonitis—incidence and risk factors

BACKGROUND In patients with secondary peritonitis, infections of the abdominal cavity might render the abdominal wall susceptible to secondary complications such as incisional hernia (IH). METHODS One hundred ninety-eight patients treated for secondary peritonitis underwent midline laparotomy. Ninety-two surviving patients accessible to clinical follow-up were examined for the occurrence of IH, and risk factors at the time of surgery or during follow-up were determined. RESULTS During a median follow-up period of 6 years, 54.3% of the patients developed IHs. A high body mass index, coronary heart disease, intense blood loss, requirement for intraoperative or postoperative transfusions, and small bowel perforation as a source of peritonitis were associated with IH. CONCLUSIONS IH occurs quite frequently after surgery for secondary peritonitis. Preexisting risk factors for IH and intraoperative blood loss or requirement for blood transfusions were correlated with the development of IH. Interestingly, surgical technique was not correlated with the development of IH in this series.

Delayed Gastric Emptying after Pancreaticoduodenectomy: Influence of the Orthotopic Technique of Reconstruction and Intestinal Motilin Receptor Expression

BackgroundDelayed gastric emptying (DGE) is still a common postoperative complication after pancreaticoduodenectomy (PD). Because different reconstruction techniques after PD and the influence of motilin receptor expression are controversially discussed, the present study analyzed the influence of a total orthotopic reconstruction technique on DGE after PD.MethodsData from patients undergoing PD and reconstruction using a total orthotopic technique were reviewed, and correlations between DGE and clinico-pathological variables were analyzed. Motilin receptor expression was measured within the duodenum, jejunum, and terminal ileum.ResultsThree hundred seven patients received orthotopic reconstruction using a single jejunal loop. DGE grade B or C could be observed in 16.6% of the patients. DGE was significantly associated with the severity of a postoperative pancreatic fistula, the need for a reoperation, wound infections, and vascular complications. Furthermore, these parameters correlated significantly with the grade of DGE. The density of motilin receptor expression decreased significantly behind the duodenum in aboral direction.ConclusionsThe orthotopic reconstruction after PD is the shortest distance without resection of a jejunal segment, preserves the greatest length of jejunum and thus the highest density of motilin receptors, and should therefore be recommended to reduce the incidence of DGE after PD.

Hemoglobin induces cytotoxic damage of glycine‐preserved renal tubules

In isolated tubular segments (ITS) of rat kidney cortex, we studied the effect of hemoglobin (Hb) on reoxygenation damage. All tubules were suspended in Ringer’s solution containing 5‐mm glycine and oxygenated for 30 min with 95% O2:5% CO2, followed by a 30‐min period with 95% N2:5% CO2, and final reoxygenation for 60 min. Untreated tubules served as controls. Different concentrations of free Hb and equivalent amounts of intact erythrocytes were added to the incubation medium. Secondly, we added deferoxamine (DFO) to Hb and erythrocytes. Membrane leakage and lipid peroxidation were measured by lactate dehydrogenase and glutamate dehydrogenase and the development of thiobarbituric acid reactive substances. Cell function was quantified by gluconeogenesis and intracellular potassium accumulation. Hb exerted concentration‐dependent cytotoxic effects indicated by significantly increased enzyme leakage rates, lipid peroxidation and a significantly decreased cell function (P < 0.05), in ITS during hypoxia, and subsequent reoxygenation. Moreover, we found that toxicity of both Fe2+ and Fe3+ ions increased with rising concentration. However, Fe2+ showed a higher tissue toxicity than Fe3+. DFO reduced significantly the reoxygenation damage of free Hb and iron ions. Our data clearly demonstrate a pronounced cytotoxic effect of free Hb in ITS, which critically depended on the reduction state of the iron ions.

Split-Liver Procedure and Inflammatory Response: Improvement by Pharmacological Preconditioning

BACKGROUND Final outcome of split-liver (SL) transplantation is impaired due to an increased rate of vascular complications and primary non-function. Herein, we hypothesized that an in situ split-liver procedure induces an inflammatory response and a deterioration of graft quality. We further studied whether graft quality can be improved by pharmacologic preconditioning. MATERIAL AND METHODS SL-procedure was performed in rats. One group (SL-HPP; n = 8) was pretreated according to a defined protocol [Homburg preconditioning protocol (HPP)], including pentoxyphylline, glycine, deferoxamine, N-acetylcysteine, erythropoietin, melatonin, and simvastatin. A second SL group (SL-Con; n = 8) received NaCl. Untreated non-SL served as controls (Sham; n = 8). Cytokines release, leukocyte invasion, endothelial activation and liver morphology were studied directly after liver harvest and after 8 h cold storage. Lung tissue was studied to determine remote injury. RESULTS The SL-procedure induced an increase of TNF-α concentration, intercellular-adhesion-molecule 1 (ICAM-1) expression, leukocytic-tissue infiltration and vacuolization. This was associated with an increased number of apoptotic hepatocytes. HPP reduced TNF-α release, ICAM-1 expression, the number of infiltrated leukocytes, as well as hepatocellular vacuolization and apoptosis. In lung tissue, the SL-procedure caused an increased IL-1 and IL-6 concentration and leukocyte infiltration. CONCLUSIONS HPP was capable of abrogating cytokine-mediated leukocytic response. Pharmacologic preconditioning of liver donors prevents the SL procedure-mediated inflammatory response, resulting in an improved graft quality.

Early Host Tissue Response to Different Types of Vascular Prostheses Coated with Silver Acetate or Vaporized Metallic Silver

OBJECTIVES In vascular surgery, the infection of prosthetic vascular grafts represents a serious life-threatening complication. Due to the increasing resistance of hospital micro-organisms to standard antibiotic therapies, maximum effort should be put in the primary prevention of such infections. For this purpose, grafts may be coated with different antibacterial silver formulations. In the present study the different effects of silver acetate-coating and vaporized metallic silver-coating on the vascularization and perigraft inflammation during the initial phase after implantation of Intergard Silver (IS) and Silver Graft (SG) were compared. METHODS Silver acetate-coated IS and vaporized metallic silver-coated SG were implanted into the dorsal skinfold chamber of C57BL/6 mice (n = 8 per group) to study angiogenesis and leukocyte inflammation at the implantation site by means of repetitive intravital fluorescence microscopy over a 14-day period. At the end of the in vivo experiments, apoptosis and cell proliferation in the newly developed granulation tissue surrounding the implants was analyzed by immunohistochemistry. RESULTS IS exhibited an improved vascularization, resulting in a significantly higher functional capillary density when compared to SG. Moreover, the leukocyte inflammatory response to IS was less pronounced, as indicated by a reduced number of adherent leukocytes in perigraft venules. This was associated with a higher proliferative activity of the granulation tissue incorporating the IS when compared to SG. The numbers of apoptotic cells in the perigraft tissue were low and did not differ between the two groups. CONCLUSION Silver acetate-coated IS exhibits an improved vascularization and reduced perigraft inflammation during the first 14 days after implantation when compared to vaporized metallic silver-coated SG. This may contribute to reducing the risk of early perigraft seroma formation and subsequent infection.

Amiodarone pretreatment of organ donors exerts anti‐oxidative protection but induces excretory dysfunction in liver preservation and reperfusion

The continuous shortage of organs necessitates the use of marginal organs from donors with various diseases, including arrhythmia‐associated cardiac failure. One of the most frequently used anti‐arrhythmic drugs is amiodarone (AM), which is given in particular in emergency situations. Apart from its anti‐arrhythmic actions, AM provides anti‐oxidative properties in cardiomyocytes. Thus, we were interested in whether AM donor pretreatment affects the organ quality and function of livers procured for preservation and transplantation. Donor rats were pretreated with AM (5 mg/kg of body weight) 10 minutes before flush‐out of the liver with a cold (4°C) histidine‐tryptophan‐ketoglutarate solution (n = 8). Livers were then stored for 24 hours at 4°C before ex situ reperfusion with a 37°C Krebs‐Henseleit solution for 60 minutes in a nonrecirculating system. At the end of reperfusion, tissue samples were taken for histology and Western blot analysis. Animals with vehicle only (0.9% NaCl) served as ischemia/reperfusion controls (n = 8). Additionally, livers of untreated animals (n = 8) not subjected to 24 hours of cold ischemia served as sham controls. AM pretreatment effectively attenuated lipid peroxidation, stress protein expression, and apoptotic cell death. This was indicated by an AM‐mediated reduction of malondialdehyde, heme oxygenase‐1, and caspase‐3 activation. However, AM treatment also induced mitochondrial damage and hepatocellular excretory dysfunction, as indicated by a significantly increased glutamate dehydrogenase concentration in the effluate and decreased bile production. In conclusion, AM donor pretreatment exerts anti‐oxidative actions in liver preservation and reperfusion. However, these protective AM actions are counteracted by an induction of mitochondrial damage and hepatocellular dysfunction. Accordingly, AM pretreatment of donors for anti‐arrhythmic therapy should be performed with caution. Liver Transpl 15:763–775, 2009.