Necrotizing soft tissue infections

Necrotizing soft tissue infections (NSTI) represent a spectrum of diseases characterized by extensive rapidly progressive necrosis that may involve the skin, subcutaneous tissues, fascia or muscle. Their progress is extremely fast, leading often to sepsis and septic shock that ends up in multiple organ failure with abrupt and high mortality. A variety of classification systems have been developed based on parameters such as anatomic location of the disease or microbiology. There are a number of factors that predispose to the spread of these soft tissue infections, such as delays in recognition, immune suppression, diabetes mellitus and advanced age. The use of broad‐spectrum antibiotics tends to mask the severity of the underlying infection, modulates the clinical presentation, and even delays hospital admission. The most important factor affecting outcome in NSTI is early diagnosis and aggressive radical surgical treatment. The medical records of 13 patients who had been treated for NSTI from 1996 to 2005 were reviewed, retrospectively. There were eight men (61.5%) and five (38.5%) women. Mean age was 56 years (range 27–73). Seven cases of infection involved the perineal region (54%), two the lower limb, one the upper limb and three the abdominal wall/trunk. The most common associated comorbidity was diabetes mellitus in five patients (38.5%). A single organism was identified in two (15%) and multiple organisms in 11 (85%) patients. Necrotizing aponeurositis Type I was the most common of the polymicrobial necrotizing infections. Overall survival was 85%, and the mean hospital stay for survivors was 35 days (range 17–92).     

Factors associated with cardiac rhythm disturbances in the early post-pneumonectomy period: a study on 259 pneumonectomies.

OBJECTIVE: To identify predisposing factors associated with cardiac rhythm disturbances during the early post-pneumonectomy period (first 7 postoperative days). MATERIALS AND METHODS: During the study period (1995-1999), 259 pneumonectomies were performed for malignant (244 cases) or benign disease (15 cases). Postoperative monitoring of patients included continuous arterial pressure - rhythm monitoring and pulse oximetry. Cardiac rhythm disturbances during the intensive care unit stay were detected on the monitor screen and recorded with a 12-lead electrocardiogram. Cardiac rhythm disturbances associated with electrolytes or fluid balance abnormality, mediastinal deviation or surgical postoperative complications were excluded from the study. Age of patients, preexisting cardiac disease, side of pneumonectomy, intrapericardial procedures, stage of the malignant disease, expected postoperative FEV(1)<1200 ml, intraoperative transfusions of packed red cells, elevated right heart pressures, low postoperative serum magnesium levels and long operative times were considered as predisposing factors for the development of post-pneumonectomy cardiac rhythm disturbances. Statistical analysis has been made using logistic regression analysis, Student t-test and chi-square test. RESULTS: Cardiac rhythm disturbances were detected in 49 patients (18.91%). Atrial fibrillation/flutter (31 cases), supraventricular tachycardia (14 cases), and premature ventricular contractions (four cases) were the observed rhythm disturbances. Right pneumonectomy versus left pneumonectomy (P<0.0001) and intrapericardial pneumonectomy versus standard pneumonectomy (P<0.0001) were identified as strong predisposing factors for the establishment of post-pneumonectomy cardiac rhythm disturbances. Patients who established post-pneumonectomy cardiac rhythm disturbances had significantly higher (P=0.024) right ventricular systolic pressure (42.50+/-15.50 mmHg) when compared with patients who had postoperative sinus rhythm (29.07+/-7.71 mmHg) and had also longer operative times than patients who did not develop rhythm disturbances (P=0.015). Mortality rate in patients who developed post-pneumonectomy rhythm disturbances was 20.40%. CONCLUSIONS: Cardiac rhythm disturbances observed early after pneumonectomy are mainly of supraventricular origin, complicating right and intrapericardial pneumonectomies, patients with elevated right heart pressures and long operative times, and are associated with high mortality rates.     

Zentrale Gallengangskarzinome

Surgical resection provides the only chance of cure for patients suffering from hilar cholangiocarcinoma. Due to the central anatomic localization within the liver hilum, established guidelines of oncologic surgery are difficult to apply. Resection of the hilar bifurcation alone or in combination with limited hepatic resection can be performed with low morbidity and low mortality but shows a high rate of local tumor recurrence. Usually, extended resection is required to achieve adequate safety margins. Right trisectionectomy complies best with the basic rules of oncologic surgery while allowing the maximum safety margin. The 5-year survival rates reported after right trisectionectomy range between 20% and 40% and reach 59% in selected patients. The increasing experience with living donor transplantation and recent advances in neoadjuvant tumor therapy may lead to renewed discussion of liver transplantation in hilar cholangiocarcinoma.     

Sentinel Bleeding After Pancreaticoduodenectomy: A Disregarded Sign

Introduction Delayed massive hemorrhage induced by pancreatic fistula after pancreaticoduodenectomy is a rare but life-threatening complication. The purpose of this study was to analyze the clinical course of patients with late hemorrhage, with or without sentinel bleeding, to better define treatment options in the future. Material and Methods From April 1998 to December 2006, 189 pancreaticoduodenectomies were performed. Eleven patients, including two patients referred from other hospitals, were treated with delayed massive hemorrhage occurring 5 days or more after pancreaticoduodenectomy. Sentinel bleeding was defined as minor blood loss via surgical drains or the gastrointestinal tract with an asymptomatic interval until development of hemorrhagic shock. The clinical data of patients with bleeding episodes were analyzed retrospectively. Results Eight of the 11 patients had sentinel bleeding, and seven of them had it at least 6 h before acute deterioration. Seven out of 11 patients died, five out of eight with sentinel bleeding. No differences could be detected between patients with or without sentinel bleeding before delayed massive hemorrhage. The only difference found was that non-surviving patients were significantly older than surviving patients. Delayed massive hemorrhage is a common cause of death after pancreaticoduodenostomy complicated by pancreatic fistula formation. The observation of sentinel bleeding should lead to emergency angiography and dependent from the result to emergency relaparotomy to increase the likelihood of survival.     

Physics-Driven CFD Modeling of Complex Anatomical Cardiovascular Flows—A TCPC Case Study

Recent developments in medical image acquisition combined with the latest advancements in numerical methods for solving the Navier-Stokes equations have created unprecedented opportunities for developing simple and reliable computational fluid dynamics (CFD) tools for meeting patient-specific surgical planning objectives. However, for CFD to reach its full potential and gain the trust and confidence of medical practitioners, physics-driven numerical modeling is required. This study reports on the experience gained from an ongoing integrated CFD modeling effort aimed at developing an advanced numerical simulation tool capable of accurately predicting flow characteristics in an anatomically correct total cavopulmonary connection (TCPC). An anatomical intra-atrial TCPC model is reconstructed from a stack of magnetic resonance (MR) images acquired in vivo. An exact replica of the computational geometry was built using transparent rapid prototyping. Following the same approach as in earlier studies on idealized models, flow structures, pressure drops, and energy losses were assessed both numerically and experimentally, then compared. Numerical studies were performed with both a first-order accurate commercial software and a recently developed, second-order accurate, in-house flow solver. The commercial CFD model could, with reasonable accuracy, capture global flow quantities of interest such as control volume power losses and pressure drops and time-averaged flow patterns. However, for steady inflow conditions, both flow visualization experiments and particle image velocimetry (PIV) measurements revealed unsteady, complex, and highly 3D flow structures, which could not be captured by this numerical model with the available computational resources and additional modeling efforts that are described. Preliminary time-accurate computations with the in-house flow solver were shown to capture for the first time these complex flow features and yielded solutions in good agreement with the experimental observations. Flow fields obtained were similar for the studied total cardiac output range (1–3 l/min); however hydrodynamic power loss increased dramatically with increasing cardiac output, suggesting significant energy demand at exercise conditions. The simulation of cardiovascular flows poses a formidable challenge to even the most advanced CFD tools currently available. A successful prediction requires a two-pronged, physics-based approach, which integrates high-resolution CFD tools and high-resolution laboratory measurements.     

Radiofrequency Catheter Ablation of Posteroseptal Accessory Pathways–Results of a Step-by-Step Ablation Approach

Introduction: Transcatheter radiofrequency ablation of posteroseptal accessory pathways (AP) is challenging. A number of different interventional approaches have been suggested by different groups. The selection of the initial approach is crucial in order to reduce radiation exposure and the number of unsuccessful lesions applied. We present our ablation technique as guided by a simplified electrocardiographic analysis of the delta wave polarity and the electrophysiologic mapping results. Methods and Results: Out of 35 manifest APs encountered in the right (n=17) or the left posteroseptum (n=18) in 35 patients, 34 were successfully ablated. Despite their left sided location, 7 of the 18 left sided APs were ablated after switching from an initial arterial to a venous approach looking for an appropriate target site in the right posteroseptal space or within the coronary sinus network. The other 11 left sided APs were ablated in the mitral ring, on 2 occasions, on their atrial aspect through a retrograde transmitral approach. On the contrary, 16 of the 17 right sided APs were successfully ablated exclusively through a venous approach. Fourteen of these were ablated in the right posteroseptum, in 2 cases, only after reaching their ventricular aspect. Two right sided APs were interrupted in the coronary sinus os and the middle cardiac vein respectively. Conclusion: It appears that even though the electrocardiographic and electrophysiologic location of the AP in the posteroseptal space helps select the appropriate initial approach, it does not always guarantee a successful ablation procedure in the expected site of the corresponding atrioventricular ring. Not uncommonly, it will be necessary to look after intermediate target sites within the coronary sinus to improve the overall ablation success rate.     

Postbiopsy intramural hematoma of the duodenum in an adult with Noonan's syndrome

Intramural duodenal hematoma is a rare complication of endoscopic biopsy. It is usually seen in children with growth failure and in patients with bleeding disorders or who are anticoagulated. It is frequently associated with acute pancreatitis. We present a case of an adult patient with Noonan's syndrome who developed postbiopsy intraduodenal hematoma. Abdominal ultrasound and computed tomography scan established the diagnosis. Conservative treatment was successful. According to a brief review of the literature, patients with Noonan's syndrome may develop hematoma after sampling of the duodenum because they present all the main predisposing factors. Additionally, pulmonic valve stenosis may be another predisposing factor, but this may warrant further investigation.     

A comparative study of postendoscopic sphincterotomy complications with various types of electrosurgical current in patients with choledocholithiasis

BACKGROUND: Whether the type of electrosurgical current used for endoscopic sphincterotomy influences the frequency of postsphincterotomy complications is unknown. METHODS: One hundred eighty-six patients with choledocholithiasis were prospectively randomized to undergo endoscopic sphincterotomy with pure cutting current (n = 62, Group A), blended current (n = 62, Group B), or pure cutting initially followed by blended current (n = 62, Group C). Serum concentrations of amylase and lipase were evaluated in all patients 12 and 24 hours after sphincterotomy. Clinical pancreatitis was classified as mild, moderate, or severe. Postsphincterotomy bleeding was defined as a decrease in hematocrit of greater than 5%. RESULTS: Serum concentrations of amylase and lipase were greater in Groups B and C at 12 and 24 hours after the procedure, as compared with Group A. Clinical mild pancreatitis occurred in 2 patients in Group A (3.2%), 8 in Group B (12.9%), and in 8 in Group C (12.9%). The differences were statistically significant for Group A compared with either Group B or Group C (p = 0.048). Postsphincterotomy bleeding occurred in 3 patients (1.6%), one in each group. CONCLUSION: The use of pure cutting electrosurgical current during endoscopic sphincterotomy in patients with choledocholithiasis is associated with a lesser degree of pancreatic enzyme elevation and lower frequency of pancreatitis, whereas bleeding is not increased compared with blended current. Changing from pure cutting to blended current after the first 3 to 5 mm of the incision is associated with an increased rate of complications compared to the use of pure cutting current for the entire sphincterotomy.