The Role of Surgical Expertise and Surgical Access in Retroperitoneal Sarcoma Resection - A Retrospective Study.

Background: Retroperitoneal sarcoma (RPS) is a rare disease often requiring multi-visceral and wide margin resections for which a resection in a sarcoma center is advised. Midline incision seems to be the access of choice. However, up to now there is no evidence for the best surgical access. This study aimed to analyze the oncological outcome according to the surgical expertise and also the incision used for the resection. Methods: All patients treated for RPS between 2007 and 2018 at the Department of Visceral Surgery and Medicine of the University Hospital Bern and receiving a RPS resection in curative intent were included. Patient- and treatment specific factors as well as local recurrence-free, disease-free and overall survival were analyzed in correlation to the hospital type where the resection occurred. Results: Thirty-five patients were treated for RPS at our center. The majority received their primary RPS resection at a sarcoma center (SC = 23) the rest of the resection were performed in a non-sarcoma center (non-SC = 12). Median tumor size was 24 cm. Resections were performed via a midline laparotomy (ML = 31) or flank incision (FI = 4). All patients with a primary FI (n = 4) were operated in a non-SC (p = 0.003). No patient operated at a non-SC received a multivisceral resection (p = 0.004). Incomplete resection (R2) was observed more often when resection was done in a non-SC (p = 0.013). Resection at a non-SC was significantly associated with worse recurrence-free survival and disease-free survival after R0/1 resection (2 vs 17 months; Log Rank p-value = 0.02 respectively 2 vs 15 months; Log Rank p-value < 0.001). Conclusions: Resection at a non-SC is associated with more incomplete resection and worse outcome in RPS surgery. Inadequate access, such as FI, may prevent complete resection and multivisceral resection if indicated and demonstrates the importance of surgical expertise in the outcome of RPS resection.

The Combination of APRI and ALBI Facilitates Preoperative Risk Stratification for Patients Undergoing Liver Surgery After Neoadjuvant Chemotherapy.

BACKGROUND: Neoadjuvant chemotherapy (NeoCTx) is performed for most patients with colorectal cancer liver metastases (CRCLM). However, chemotherapy-associated liver injury (CALI) has been associated with poor postoperative outcome. To date, however, no clinically applicable and noninvasive tool exists to assess CALI before liver resection. METHODS: Routine blood parameters were assessed in 339 patients before and after completion of NeoCTx and before surgery. The study assessed the prognostic potential of the aspartate aminotransferase (AST)-to-platelet ratio index (APRI), the albumin-bilirubin grade (ALBI), and their combinations. Furthermore, an independent multi-center validation cohort (n = 161) was included to confirm the findings concerning the prediction of postoperative outcome. RESULTS: Higher ALBI, APRI, and APRI + ALBI were found in patients with postoperative morbidity (P = 0.001, P = 0.064, P = 0.001, respectively), liver dysfunction (LD) (P = 0.009, P = 0.012, P < 0.001), or mortality (P = 0.037, P = 0.045, P = 0.016), and APRI + ALBI had the highest predictive potential for LD (area under the curve [AUC], 0.695). An increase in APRI + ALBI was observed during NeoCTx (P < 0.001). Patients with longer periods between NeoCTx and surgery showed a greater decrease in APRI + ALBI (P = 0.006) and a trend for decreased CALI at surgery. A cutoff for APRI + ALBI at - 2.46 before surgery was found to identify patients with CALI (P = 0.002) and patients at risk for a prolonged hospital stay (P = 0.001), intensive care (P < 0.001), morbidity (P < 0.001), LD (P < 0.001), and mortality (P = 0.021). Importantly, the study was able to confirm the predictive potential of APRI + ALBI for postoperative LD and mortality in a multicenter validation cohort. CONCLUSION: Determination of APRI + ALBI before surgery enables identification of high-risk patients for liver resection. The combined score seems to dynamically reflect CALI. Thus, APRI + ALBI could be a clinically relevant tool for optimizing timing of surgery in CRCLM patients after NeoCTx.

Surgical treatment strategies for hepatic alveolar echinococcosis.

Alveolar echinococcosis is a severe and rare helminthic disease with increasing incidence in endemic regions. Herein, available evidence on curative surgical and potential palliative approaches was reviewed. Such strategies have to be applied in the context of available resources in different health-care systems. Complete resection followed by adjuvant therapy remains the only curative treatment available. Curative surgery is performed by open or laparoscopic approach depending on the extent of the disease and the experience of the surgical team. Palliative resections are typically not indicated, because the availability of endoscopic treatments of biliary complications and long-term benzimidazoles represent efficient alternatives to surgery. Liver transplantation as an alternative to palliative surgery has not been shown to be superior to long-term conservative therapy. Immunosuppressive therapy might additionally contribute to fatal disease recurrence after transplantation.

Elevated incidence of alveolar echinococcosis in immunocompromised patients.

INTRODUCTION: Recent experimental data has revealed that the course of alveolar echinococcosis (AE) depends on adaptive immunity. For this study, we aimed to analyze the incidence and outcome of AE in immunocompromised humans. MATERIAL AND METHODS: Retrospective analysis of 131 patients with a median age of 54 years treated for AE between 1971 and 2017 at a Swiss tertiary referral Centre. Fifty-two percent were females and 65 patients (50%) were diagnosed incidentally. Fourteen patients (16%) were operated on laparoscopically. Overall, median follow-up was 48 months. RESULTS: New diagnoses have increased fourfold in immunocompetent and tenfold in immunocompromised patients in the past decade (p ≤ 0.005). Forty-one patients (31.3%) had co-existing or previous immunosuppressive conditions including 16 malignancies (36%), 11 auto-immune diseases or immunosuppressive therapies (31%), 5 infectious diseases (11%), 4 chronic asthma conditions (9%), 2 previous transplantations (4%) and 4 other immunocompromising conditions (9%). Serum levels of anti-Em18, -Em2 and -EgHF antibodies were neither associated with immunocompetence at diagnosis nor during follow-up, but significantly decreased after treatment with benzimidazole (n = 43) or surgery (n = 88) in all patients. Adjuvant therapy for ≥1 year (p = 0.007) with benzimidazole and resection status (R0) (p = 0.002) were both correlated with recurrence-free survival. Survival at 5 and 10 years after surgery was 97% and 94%, respectively, and after conservative treatment 91% and 73%, respectively. Curative surgery (p = 0.014) and immunocompetence (p = 0.048) correlated significantly with overall survival. CONCLUSION: The incidence of human AE has increased over the last 2 decades with surgical interventions resulting in excellent outcomes. We have observed an association of immunosuppressive conditions with both incidence and survival of AE eventually justifying the implementation of a screening program for patients at risk in endemic regions.

Externalized Percutaneous Stent Versus Internal Double J Stent: Short- and Long-term Complications After Kidney Transplantation.

BACKGROUND: In patients undergoing kidney transplantation, ureteral stents are an established technique to reduce major urologic complications such as leakage and stenosis of the ureter. However, the best technique for ureteral stenting remains unclear. The aim of this study was to compare the outcome of percutaneous ureteral stents (PS) with internal double J stents (JJS) after kidney transplantation. METHODS: All patients undergoing kidney transplantation between 2005 and 2014 were retrospectively analyzed. After excluding patients <18 years old, patients without stenting, and patients who underwent multiorgan transplantation, a total of 308 patients were included in the study. Two consecutive cohorts of patients were compared. In the cohort transplanted between 2005 and 2010, stenting was routinely performed using PS (216 patients), and in the second cohort, those transplanted after 2011, stenting was routinely performed using JJS (92 patients). For ureteric anastomosis, the Lich-Grégoir technique was used in all patients. RESULTS: There was no statistical difference in postoperative urinary tract infections (P = .239) between the 2 cohorts. In patients with PS, the incidence of major urologic complications (11.6% vs 3.3%; P = .018), vesicoureteral reflux (14.3% vs 2.2%; P < .001), and urologic reinterventions (14.4% vs 5.4%; P = .031) was significantly higher when compared with JJS patients. Multivariable logistic regression revealed increased incidence of major urologic complications (odds ratio [OR] 3.66, 95% confidence interval [CI] 1.07-12.55, P = .039) and vesicoureteral reflux (OR 5.29, 95% CI 1.21-23.10, P = .027) in patients with PS compared with JJS. CONCLUSION: Stenting of ureterovesical anastomosis using JJS is associated with reduced complications compared with PS after kidney transplantation.

Mesh-augmented versus direct abdominal closure in patients undergoing open abdomen treatment.

BACKGROUND: Open abdomen (OA) may be required in patients with abdominal trauma, sepsis or compartment syndrome. Vacuum-assisted wound closure and mesh-mediated fascial traction (VAWCM) is a widely used approach for temporary abdominal closure to close the abdominal wall. However, this method is associated with a high incidence of re-operations in short term and late sequelae such as incisional hernia. The current study aims to compare the results of surgical strategies of OA with versus without permanent mesh augmentation. METHODS: Patients with OA treatment undergoing vacuum-assisted wound closure and an intraperitoneal onlay mesh (VAC-IPOM) implantation were compared to VAWCM with direct fascial closure which represents the current standard of care. Outcomes of patients from two tertiary referral centers that performed the different strategies for abdominal closure after OA treatment were compared in univariate and multivariate regression analysis. RESULTS: A total of 139 patients were included in the study. Of these, 50 (36.0%) patients underwent VAC-IPOM and 89 (64.0%) patients VAWCM. VAC-IPOM was associated with reduced re-operations (adjusted incidence risk ratio 0.48 per 10-person days; CI 95% = 0.39-0.58, p < 0.001), reduced duration of stay on intensive care unit (ICU) [adjusted hazard ratio (aHR) 0.53; CI 95% = 0.36-0.79, p = 0.002] and reduced hospital stay (aHR 0.61; CI 95% = 0.040-0.94; p = 0.024). In-hospital mortality [22.5 vs 18.0%, risk difference - 4.5; confidence interval (CI) 95% = - 18.2 to 9.3; p = 0.665] and the incidence of intestinal fistula (18.0 vs 22.0%, risk difference 4.0; CI 95% = -10.0 to 18.0; p = 0.656) did not differ between the two groups. In Kaplan-Meier analysis, hernia-free survival was significantly increased after VAC-IPOM (p = 0.041). CONCLUSIONS: In patients undergoing OA treatment, intraperitoneal mesh augmentation is associated with a significantly decreased number of re-operations, duration of hospital and ICU stay and incidence of incisional hernias when compared to VAWCM.

[The Psychometric Properties of the Abdominal Surgery Impact Scale]. / Übersetzung und Testung der Abdominal Surgery Impact Scale.

Background: Assessment of quality of life immediately after abdominal surgery is critical; however, potent tools that provide timely information about patient health are required in order to assess and improve postoperative quality of care. Interestingly, such assessment scales for early postoperative quality of life do not exist in German. The aim of this pilot study was to translate the English version of the "Abdominal Surgery Impact Scale" (ASIS) into German and to empirically test the German version. Methods: After the standardized translation, 30 German-speaking patients who had undergone visceral surgery (laparotomy) were recruited at the ward of the Bern University Hospital Visceral Surgery and Medicine. The internal consistency of the translated instrument (ASIS-D) was assessed on the third postoperative day; reliability, retest-reliability and construct validity were also assessed on the fifth postoperative day. Results: ASIS-D faithfully represented the content of the original version. Cronbach's α overall was 0.85 and for the 6 subscales 0.45-0.88. The overall score of retest-reliability was 0.57** and the construct validity was confirmed. Conclusion: The ASIS-D was shown to be reliable and valid even if other investigations are necessary. It provides specific insights into special postoperative symptoms such as wound pain and postoperative quality of sleep. After further tests, it might be suitable not only for capturing the short-term postal-surgical quality of life, but possibly also for evaluating nursing interventions.

Impact of case-relevant and case-irrelevant communication within the surgical team on surgical-site infection.

BACKGROUND: Surgical-site infections (SSIs) are the most common complications after surgery. An influence from talking and distractions during surgery on patient outcomes has been suggested, but there is limited evidence. The aim of this prospective observational study was to assess the relationship between intraoperative communication within the surgical team and SSI, and between intraoperative distractions and SSI. METHODS: This prospective observational study included patients undergoing elective, open abdominal procedures. For each procedure, intraoperative case-relevant and case-irrelevant communication, and intraoperative distractions were observed continuously on site. The influence of communication and distractions on SSI after surgery was assessed using logistic regressions, adjusting for risk factors. RESULTS: A total of 167 observed procedures were analysed; their mean(s.d.) duration was 4·6(2·1) h. A total of 24 SSIs (14·4 per cent) were diagnosed. Case-relevant communication during the procedure was independently associated with a reduced incidence of organ/space SSI (propensity score-adjusted odds ratio 0·86, 95 per cent c.i. 0·77 to 0·97; P = 0·014). Case-irrelevant communication during the closing phase of the procedure was independently associated with increased incidence of incisional SSI (propensity score-adjusted odds ratio 1·29, 1·08 to 1·55; P = 0·006). Distractions had no association with SSI. CONCLUSION: More case-relevant communication was associated with fewer organ/space SSIs, and more case-irrelevant communication during wound closure was associated with incisional SSI.

Impact of team familiarity in the operating room on surgical complications.

BACKGROUND: The quality of surgical performance depends on the technical skills of the surgical team as well as on non-technical skills, including teamwork. The present study evaluated the impact of familiarity among members of the surgical team on morbidity in patients undergoing elective open abdominal surgery. METHODS: A retrospective analysis was performed to compare the surgical outcomes of patients who underwent major abdominal operations between the first month (period I) and the last month (period II) of a 6-month period of continuous teamwork (stable dyads of one senior and one junior surgeon formed every 6 months). Of 117 patients, 59 and 58 patients underwent operations during period I and period II, respectively, between January 2010 and June 2012. Team performance was assessed via questionnaire by specialized work psychologists; in addition, intraoperative sound levels were measured. RESULTS: The incidence of overall complications was significantly higher in period I than in period II (54.2 vs. 34.5 %; P = 0.041). Postoperative complications grade <3 were significantly more frequently diagnosed in patients who had operations during period I (39.0 vs. 15.5 %; P = 0.007), whereas no between-group differences in grade ≥3 complications were found (15.3 vs. 19.0 %; P = 0.807). Concentration scores from senior surgeons were significantly higher in period II than in period I (P = 0.033). Sound levels during the middle third part of the operations were significantly higher in period I (median above the baseline 8.85 dB [range 4.5-11.3 dB] vs. 7.17 dB [5.24-9.43 dB]; P < 0.001). CONCLUSIONS: Team familiarity improves team performance and reduces morbidity in patients undergoing abdominal surgery.

[Recurrence after hernia surgery: complication or natural course?]. / Rezidiv nach Hernienplastik: Komplikation oder natürlicher Verlauf?

Recurrence after hernia surgery remains a relevant measure of surgical quality. In order to correctly assess the recurrence rate the surgeon needs to distinguish clinical relevant recurrence, clinically irrelevant recurrence and pseudo-recurrence. Current surgical techniques for inguinal hernia repair using mesh are associated with a low rate of recurrence. Thus, recurrence after inguinal hernia surgery is seen as a surgical complication. Conversely, the recurrence rate for large incisional hernias remains above 10 % and in rare cases a recurrence might represent the natural course. Recurrent hernia can depend on the indication, choice of operation and surgical technique. Therefore, postoperative hernia recurrence probably does not represent the natural course but rather a surgical complication that needs to be prevented by an optimized surgical technique.

Time- and temperature-dependent migration studies of Irganox 1076 from plastics into foods and food simulants.

The study provides an exhaustive set of migration data for octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1076) from low-density polyethylene (LDPE) in several food matrices. Irganox 1076 was used as a model migrant because it represents one of the typical substances used as an antioxidant in food packaging polymers. Kinetic (time-dependent) migration studies of Irganox 1076 were performed for selected foodstuffs chosen with different physical-chemical properties and in relation to the actual European food consumption market. The effect of fat content and of the temperature of storage on the migration from plastic packaging was evaluated. The results show that migration increased with fat content and storage temperature. All data obtained from real foods were also compared with data obtained from simulants tested in the same conditions. In all studied cases, the kinetics in simulants were higher than those in foodstuffs. The work provides data valuable for the extension of the validation of migration model developed on simulants to foodstuffs themselves.

Adverse effect of noise in the operating theatre on surgical-site infection.

BACKGROUND: The aim of this pilot study was to evaluate the noise level in an operating theatre as a possible surrogate marker for intraoperative behaviour, and to detect any correlation between sound level and subsequent surgical-site infection (SSI). METHODS: The sound level was measured during 35 elective open abdominal procedures. The noise intensity was registered digitally in decibels (dB) every second. A standard questionnaire was used to evaluate the behaviour of the surgical team during the operation. The primary outcome parameter was the SSI rate within 30 days of surgery. RESULTS: The overall rate of SSI was six of 35 (17 per cent). Demographic parameters and duration of operation were not significantly different between patients with, or without SSI. The median sound level (43·5 (range 26·0-60·0) versus 25·0 (25·0-60·0) dB; P = 0·040) and median level above baseline (10·7 (0·6-33·3) versus 0·6 (0·5-10·8); P = 0·001) were significantly higher for patients who developed a SSI. The sound level was at least 4 dB above the median in 22·5 per cent of the peaks in patients with SSI compared with 10·7 per cent in those without (P = 0·029). Talking about non-surgery-related topics was associated with a significantly higher sound level (P = 0·024). CONCLUSION: Intraoperative noise volume was associated with SSI. This may be due to a lack of concentration, or a stressful environment, and may therefore represent a surrogate parameter by which to assess the behaviour of a surgical team.

Prevention of perioperative thromboembolism in patients with atrial fibrillation.

BACKGROUND: The aim of this retrospective study was to review the safety and efficacy of two regimens for the prophylaxis of perioperative thromboembolism in patients with atrial fibrillation. METHODS: From a database of 14 801 procedures, atrial fibrillation occurred in 1.9 per cent of patients. Those not on oral anticoagulation (n = 146) received low molecular weight heparin (LMWH) before and after surgery (nadroparine 40 units per kg). Patients on oral anticoagulation before surgery (n = 136) received intravenous unfractionated heparin (UFH) after surgery at a dose adequate to maintain the thrombin time at a therapeutic level. RESULTS: The incidence of perioperative arterial or venous thromboembolism was independent of pre-existing risk factors and occurred in 4.6 per cent of patients, without significant difference between the two regimens (P = 0.780). Logistic regression revealed that thromboembolism was significantly associated with increased perioperative mortality (odds ratio 9.5, (95 per cent confidence interval 2.5 to 35.8); P = 0.001). The rate of postoperative bleeding was 4.8 per cent in patients who had LMWH and 17.6 per cent in those who had UFH (P < 0.001). CONCLUSION: Postoperative anticoagulation with therapeutic UFH in patients with atrial fibrillation was associated with an increased rate of bleeding without reducing the risk of thromboembolism.

Analysis of stapling versus endoloops in appendiceal stump closure.

BACKGROUND: The effectiveness of various appendiceal stump closure methods has not been evaluated systematically. The aim of this study was to compare the morbidity of stump closure by stapling or use of endoloops. METHODS: A non-concurrent cohort study of prospectively acquired data was performed. The primary outcome variable was the rate of intra-abdominal surgical-site infection. Secondary outcome measures were complications, duration of intervention, hospital stay, rate of readmission to hospital and the difference in direct costs of the operation. RESULTS: Staples were used in 60.5 per cent and endoloops in 39.5 per cent of 6486 patients operated on for suspected appendicitis between January 1995 and December 2003. Among 4489 patients with acute appendicitis the rate of intra-abdominal surgical-site infection was 0.7 per cent in the stapler group and 1.7 per cent in the endoloop group (P = 0.004). The rate of readmission to hospital was 0.9 and 2.1 per cent respectively (P = 0.001). CONCLUSION: Application of a stapler for transection and closure of the appendiceal stump in patients with acute appendicitis lowered the risk of postoperative intra-abdominal surgical-site infection and the need for readmission to hospital.

Laparoscopic ventral hernia repair is safe and cost effective.

BACKGROUND: Ventral hernia repair is increasingly performed by laparoscopic means since the introduction of dual-layer meshes. This study aimed to compare the early complications and cost effectiveness of open hernia repair with those associated with laparoscopic repair. METHODS: Open ventral hernia repair was performed for 92 consecutive patients using a Vypro mesh, followed by laparoscopic repair for 49 consecutive patients using a Parietene composite mesh. RESULTS: The rate of surgical-site infections was significantly higher with open ventral hernia repair (13 vs 1; p = 0.03). The median length of hospital stay was significantly shorter with laparoscopic surgery (7 vs 6 days; p = 0.02). For laparoscopic repair, the direct operative costs were higher (2,314 vs 2,853 euros; p = 0.03), and the overall hospital costs were lower (9,787 vs 7,654 euros; p = 0.02). CONCLUSIONS: Laparoscopic ventral hernia repair leads to fewer surgical-site infections and a shorter hospital stay than open repair. Despite increased operative costs, overall hospital costs are lowered by laparoscopic ventral hernia repair.

[Practical aspects and current perspectives of liver transplantation for the general practitioner]. / Lebertransplantation--Perspektiven und praktische Aspekte 2005.

Orthotopic liver transplantation (OLT) has become the method of choice for many forms of endstage liver disease and is generally associated with a good long-term outcome. Morbidity and mortality for this routine procedure have become acceptable provided the procedure is carried out with a correct and timely indication. It is important for the general practitioner to recognize the various early clinical signs of liver failure and portal hypertension in due course in order to reach a comprehensive planning of all necessary medical steps ahead. The most frequent indications for OLT such as chronic hepatitis C related cirrhosis, cholostatic forms of liver disease, limited liver tumours and metabolic disorders (haemochromatosis) are discussed in detail and major practical problems that a general practitioner might encounter in the follow-up of patients with OLT are highlighted in this review.

Local and remote ischemia-reperfusion injury is mitigated in mice overexpressing human C1 inhibitor.

Activation of the classical complement pathway is crucially involved in complement-mediated endothelial cell damage in ischemia-reperfusion injury. C1 inhibitor is the only known physiological inhibitor of classical complement pathway activation. Transgenic mice overexpressing human C1 inhibitor were used in a surgical lower torso and a liver ischemia-reperfusion model. Organ-specific endothelial disruption was determined by 125I-tagged albumin extravasation. In the lower torso ischemia-reperfusion model, transgenic mice overexpressing the C1 inhibitor were protected in the muscle and the lungs from endothelial cell damage. In the liver ischemia-reperfusion model, endothelial cell integrity was preserved in transgenic animals in the liver, the gut and the lungs. Our data indicate that inhibiting complement activation by a transgenic approach is effective in protection against ischemia-reperfusion injury.

Laparoscopic appendectomy using endoloops: a prospective, randomized clinical trial.

BACKGROUND: Inadequate closure of the appendix stump can lead to abscess formation or peritonitis. This prospective randomized clinical trial was performed to evaluate the number of endoloops needed in laparoscopic appendectomy. METHODS: A total of 208 patients were randomized in two groups: 109 in group 1 using one and 99 in group 2 using two proximal endoloops. The groups were compared in terms of intra- and postoperative complications. RESULTS: Postoperative complications were found in five patients (4.6%) in group 1, consisting of intraabdominal abscesses (three patients), pulmonary embolism (one patient), and persisting port-site pain (one patient). In group 2, postoperative complications were found in five patients (5.1%), consisting of intraabdominal abscesses (four patients) and prolonged percutaneous drainage (one patient). There was no significant difference between the two groups. DISCUSSION: In acute appendicitis, a minimal inflamed appendix base can be safely divided using one endoloop.

Laparoscopic subtotal cholecystectomy for severe cholecystitis.

BACKGROUND: In severe cholecystitis, laparoscopic cholecystectomy can be technically difficult, and is associated with an increased rate of procedure conversions and common bile duct lesions. METHODS: We investigated the safety and complications of laparoscopic subtotal cholecystectomy for severe cholecystitis in a medium- to long-term follow-up evaluation. Laparoscopic cholecystectomy was performed in 345 patients during a period of 64 months. In 46 of the patients (13.3%), a subtotal cholecystectomy was performed. The results were compared with data on laparoscopic cholecystectomy from 16,130 patients in 84 surgical institutes in Switzerland, collected prospectively by the Swiss Association for Laparoscopic and Thoracoscopic Surgery (SALTS). RESULTS: The median operating time was 93 min (range, 50-140) min. The overall rate of procedure conversions in acute cholecystitis was lowered significantly from 23.2% (SALTS) to 9.7%. There was no bile duct lesion, as compared with the rate of 0.8% in the SALTS data. In follow-up evaluations, fluid collections in 16 patients (35%) and residual gallstones in 6 patients (13%) were of no clinical relevance. CONCLUSIONS: Laparoscopic subtotal cholecystectomy for acute cholecystitis offers a simple and safe solution that prevents bile duct injuries and decreases the rate of conversion in anatomically difficult situations.

Transit time flow measurement: experimental validation and comparison of three different systems.

BACKGROUND: Bloodflow measurements are of major clinical importance for quality control in vascular surgery. They allow detection of low-flow situations which may influence outcome adversely. The purpose of the present study was to validate three different flow systems for measuring absolute blood flow. METHODS: Measurements were performed in an experimental flow model using arteries and veins and blood or saline at two different temperatures. As a reference method true flow was measured by volume sampling. RESULTS: Correlation coefficients between transit time flow and true flow measurements ranged between 0.71 and 0.92. Systematic overestimation and underestimation of transit time flow were observed, but after second-order correction all correlations were excellent, ranging from 0.93 to 0.95 irrespective of flow medium and temperature. CONCLUSIONS: Transit time flow measurements are exact and reproducible. Second-order correction yields good accuracy and high precision, with minimal differences among the three systems evaluated.