Decision analysis model of incisional hernia after open abdominal surgery

Background The incidence rate of incisional hernias after open surgery has been reported to be higher than that of port site hernias after laparoscopic surgery. No studies have compared the costs for the health care system in treating those two types of hernia. Methods A systematic review was conducted to obtain the baseline data, and a decision analysis model was created to simulate the occurrence and recurrence of incisional and port site hernias. Results The overall risk of having incisional hernias was eight-times higher than that of having port site hernias (7.4% vs 0.9%). A cost savings of ￡93 per patient can be generated for the health care system in the UK. Similar results were obtained for Germany, Italy and France. Conclusions The additional treatment costs for incisional hernia should be taken into account when the costs of a surgery performed by open approach are compared with by laparoscopy.     

Clinical risk management in anaesthesia

Contin Educ Anaesth Crit     

Low-molecular weight heparin for deep vein thrombosis prophylaxis in hospitalized medical patients: results from a cost-effectiveness analysis.

Multiple options exist for the prevention of deep vein thrombosis (DVT) in medical inpatients. We sought to determine the cost-effectiveness of low-molecular-weight heparin (LMWH) relative to unfractionated heparin (UFH) for DVT prevention in this setting. We conducted a cost-effectiveness analysis from the perspective of a third-party payer employing a decision model and literature-based estimates for inputs. In the base-case analysis, LMWH had little impact on the rate of DVT. Despite higher acquisition costs, however, LMWHs resulted in net savings. Routine use of LMWH saves approximately US$89 per patient. The lower rate of heparin-induced thrombocytopenia (HIT) with LMWH accounted for this differential. Univariate sensitivity analysis revealed the model was moderately sensitive to the odds ratio of HIT with LMWH and the cost of HIT. Multivariate sensitivity analysis confirmed the LMWH approach dominated financially. 'Worst-case' scenario modeling, where LMWH actually increased the risk for DVT, had little effect on the rate of HIT, and was substantially more costly than UFH, still demonstrated that LMWHs were economically superior. Monte-Carlo simulation indicated the 95% confidence interval around the estimate for savings with LMWH ranged from US$7 to US$373. We conclude that, despite their higher cost, LMWHs for thromboprophylaxis in medical patients result in savings.     

Emphysematous pyelonephritis successfully treated with laparoscopic nephrectomy

Emphysematous pyelonephritis is a severe life-threatening infection which continues to carry significant morbidity and mortality. We present a case recently managed at our institution by laparoscopic nephrectomy. The patient survived, and in comparison to some of the more conventionally managed patients in the literature, made an extremely speedy recovery. We would advocate this option to be seriously considered when patients are suitable and appropriately trained surgeons are available.     

Linear and angular measurements of computer-generated models: are they accurate, valid, and reliable?

INTRODUCTION: Traditional advanced imaging modalities such as CT and MRI are limited in their ability to perform accurate linear distance and angular measurements regardless of anatomical orientation. The construction of 3D models has been used to perform anthropometric analyses as well as in the reconstruction of rapid prototypes. We hypothesized that such measurements would be precise to within 2 mm or 2 degrees of measurements performed with a coordinate measurement machine (CMM). We also hypothesized that there would be a high degree of interobserver reliability with these measurements. MATERIALS AND METHODS: Multiple aluminum screws were implanted in various positions in three foam pelvises which were subsequently scanned by CT and rendered as 3D models using a commercially available software package (Mimics). Linear and angular measurements were performed using a CMM machine, the software package, and a dial caliper or goniometer. The deviation of the measurements from the CMM data was compared using ANOVA. The interobserver reliability of both the manual and computer-generated measurements was calculated. RESULTS: The mean difference between the CMM distances and those measured manually and with the software was 2.12 +/- 1.20 mm and 1.57 +/- 1.05 mm, respectively. The mean difference between the CMM angular measurements and the angular measurements performed manually and with the software was 4.07 +/- 4.70 degrees and 1.62 +/- 1.32 degrees, respectively. In all cases, the manual measurements were significantly less accurate (p < 0.0001) and there was a high degree of interobserver reliability. CONCLUSIONS: Computer-generated measurements taken from three-dimensionally reconstructed models are more accurate than manual measurements and are within 2 mm and 2 degrees of measurements performed with a CMM. These measurements have high interobserver reliability.     

Comparison of survival by allocation to medical therapy, surgery, or heart transplantation for ischemic advanced heart failure.

BACKGROUND: To ascertain survival of ischemic advanced heart failure patients by treatment allocation, we examined the outcome of transplant assessment patients allocated to medical therapy, high-risk conventional surgery, or transplantation. METHODS: Patients were identified from the Papworth transplant database and excluded if primary etiology was not ischemic. Grouping was undertaken according to treatment allocation at initial assessment, and analysis was performed by intention to treat. Survival was computed from the time of assessment and Cox regression used to stratify patients according risk with the Heart Failure Survival Score. RESULTS: From May 1993 to September 2001, a total of 755 patients were admitted for transplant assessment, with 348 (46.1%) identified as having heart failure of ischemic origin. Variables required for calculation of the Heart Failure Survival Score was available in 273 patients (78.4%), and 20 patients (7.3%) were lost to follow-up. Of the remaining 253 patients, 89 (35.2%) were allocated to medical therapy, 32 (12.6%) to surgery, and 132 (52.2%) to transplantation. The relative risk (95% confidence limit) of death compared with medical therapy was 0.62 (0.28, 1.40) for surgery and 0.38 (0.24, 0.61) for transplantation in medium- to high-risk patients. For low-risk patients, the relative risks for death compared with medical therapy were 1.87 (0.63, 5.60) for surgery and 1.97 (0.79, 4.96) for transplantation. CONCLUSIONS: Transplantation improved survival of medium- and high-risk patients compared with medical therapy. In the low-risk group, this was not evident. However, repeated assessment of risk is required because the hazard for death rises steadily after the third year in these patients.     

Relation of serum albumin concentration to death rate in nursing home men

Serum albumin was measured in 126 men (average age 70.6; range 40 to 96) of a Veterans Administration Nursing Home, and was correlated with other items in an extensive clinical data base, including death or survival during the year after the analysis. The reason for institutionalization was chronic neurologic disease or other disabling physical condition in 63 men (group A), and psychiatric disorder in 63 men (group B). In group A, the proportions of men with albumin less than 3.5, 3.5-4.0, and greater than 4.0 g/dl were 6%, 37%, and 57%, respectively. In this group, the serum albumin level was significantly (p less than 0.05) correlated with death rate, hemoglobin, hematocrit, serum cholesterol, and serum lactic dehydrogenase. The death rate in group A during the year after the albumin analysis was 25%. For the patients with albumin level less than 3.5, 3.5-4.0, and greater than 4.0 g/dl, the death rates were 50%, 43%, and 11% respectively (p less than 0.01 for comparison of the former two groups with the latter). The subgroup with albumin 3.5-4.0 g/dl represented only 37% of the men in group A, but accounted for 63% of the group's deaths. In group B, serum albumin level was not significantly correlated with any other clinical variable. Death rate during the year after the albumin analysis was only 2% in group B, and did not correlate with the albumin level. These data indicate that, in nonpsychiatric Nursing Home men, the desirable level for the serum albumin concentration is higher than 3.5 g/dl.