Preliminary study of responses in mussel (Mytilus edilus) exposed to bisphenol A, diallyl phthalate and tetrabromodiphenyl ether.

Environmental pollutants with hormonal activity including bisphenol, diallyl phtalate and tetrabromodiphenyl ether, have the potential to alter gonadal development and reproduction in aquatic wildlife. Little is known about the biological impact of environmentally relevant concentrations in mussels. To investigate some aspects of their potential estrogenic action, mussels were continuously exposed during 3 weeks. Gonadal development and vitellogenin like protein levels were examined. Bisphenol (50 microg/l) induced the expression of phospho-proteins in females and spawning in both sexes. Diallyl phthalate and tetrabromodiphenyl ether decreased phospho-protein levels in both sexes and induced spawning in males. Moreover, severe damaging effects on ovarian follicles and ovocytes were observed in both bisphenol A- and tetrabromodiphenyl ether-exposed female mussels.

Lectin-binding to hemocytes of Mytilus edulis.

Lectin receptors for WGA, Ricinus 60, Ricinus 120, and for the agglutinin from the albumin gland of Helix pomatia were detected on the surface of Mytilus hemocytes by an agglutination assay. When hemocyte monolayers on slides were incubated with these lectins, strong rosette formation was obtained after addition of human erythrocytes. The lowest lectin concentration which caused formation of rosettes was determined to be 5 micrograms/ml of WGA or of Helix agglutinin, and 20 micrograms/ml of Ricinus 60 or 40 micrograms/ml of Ricinus 120, respectively. In contrast to these results, no binding of indicator cells to Mytilus hemocytes occurred with various other lectins, including Con A.

New biosensors for environmental analysis.

Environmental analysis requires fast and reliable measurement results. Biosensors, which facilitate integral monitoring as well as single substance analysis, achieve high sensitivities in a minimum of measuring time. Four new on-line biosensors, which cover a wide range of environmentally relevant substances, are introduced: A water-quality monitoring bacteria electrode, whose gradual development is described as an example, a heavy-metal screening urease inhibition sensor, a genotoxic potential as well as a immunotoxic potential indicating sensor. Future prospects are given.

Laparoscopic thermal ablation of hepatic neuroendocrine tumor metastases.

BACKGROUND: Neuroendocrine tumor metastases to the liver are generally slow growing, but patients suffer from hormone hypersecretion despite aggressive multimodality therapy. A minimally invasive method of tumor ablation affords symptomatic improvement with minimal morbidity. METHODS: Radiofrequency electrical energy is delivered to tissues via a 4-prong catheter resulting in tissue heating to 60 to 70 degrees C and cell death. Porcine studies were conducted to define appropriate parameters for energy delivery and then applied to patients using laparoscopic techniques. RESULTS: In the porcine model 3.5 to 4 cm lesions were reproducibly created in 15 minutes using 30 to 50 W of power. The ablation process was monitored via temperature feedback from thermocouples in the catheter tips and by a hyperechoic blush noted on ultrasonography. Laparoscopic thermal ablation of 13 tumors in six patients with carcinoid (two patients), gastrinoma, insulinoma, nonsecreting islet cell cancer, or medullary thyroid cancer was performed. There were no intraoperative complications, and all patients were discharged the next day. Successful ablation was confirmed by spiral-computed tomography and by symptomatic improvement in patients with secreting tumors. CONCLUSIONS: Laparoscopic thermal ablation of hepatic tumors is a novel, minimally invasive method of providing effective cytoreduction of neuroendocrine tumors metastatic to the liver.

Effectiveness of water exercise on postural mobility in the well elderly: an experimental study on balance enhancement.

BACKGROUND: The fear of falling may cause elderly people to limit their movement. As movement errors are known to facilitate the acquisition of motor skills, the elderly may inadvertently cause the loss of postural skills by constraining their movements, and hence avoid potential movement errors. It was hypothesized that by having elderly individuals exercise in a risk-free environment-water was utilized in this experiment-their postural capabilities would improve. METHODS: Four groups of elderly subjects (80 +/- 5.8 years old) were placed into four groups: Water Exercisers; Land Exercisers; Water Sitters; and Land Sitters. Each group met twice per week for 45 minutes for 5 weeks of simple exercises or socializing in the designated medium. The distance each individual could reach (Functional Reach, FR) was measured at the end of each week. RESULTS: Initially, each group was at risk (FR < 10 inches) for falling Statistical testing showed that the Water Exercisers (WE) increased their FR almost every week; the Land Exercisers (LE) increased only during the first week; and the Water Sitters (WS) and Land Sitters (LS) did not increase at all. The FRs after 5 weeks were 13.4 +/- 1.6 (WE), 11.3 +/- 1.5 (LE), 9.6 +/- 1.3 (WS), and 9.3 +/- 0.71 (LS) inches for each group, respectively. CONCLUSIONS: The data showed that the postural capabilities in these elderly people, as measured by the FR, were enhanced by the production of movement errors that was facilitated in a water environment (in the case of the Water groups) or the initiation of a novel exercise program (Land Exercisers). Alternative explanations, and implication of these results, are discussed.

Laparoscopic hepatic artery infusion pump placement.

Patients with metastatic colorectal cancer limited to the liver are candidates for regional chemotherapy with implantable hepatic artery infusion (HAI) pumps. The poor prognosis of these patients, and the requirement of a laparotomy for placement, has deterred many oncologists from referral for HAI pump implantation. Minimally invasive surgical techniques are particularly well suited for the task of HAI pump placement in patients who may not tolerate the additional physiologic stress of a major surgical intervention. Advances in laparoscopic techniques allow pumps to be implanted safely and effectively, replicating the well-described tenets of open pump placement. The principal steps of the operation include a thorough laparoscopic evaluation to exclude extrahepatic disease, complete vascular isolation of the hepatic and gastroduodenal arteries, ligation of aberrant hepatic vessels, secure cannulation of the gastroduodenal artery, and confirmation of complete hepatic perfusion without extrahepatic perfusion. We describe the procedure and briefly review our clinical experience. We believe that the benefits typically derived from minimally invasive approaches (less pain, fewer perioperative complications, shorter hospitalization, faster recovery, and potentially less immune suppression) will be seen in these patients as well. If so, a completely laparoscopic approach to regional treatment of the liver may extend survival and improve the quality of life of patients whose prognosis is poor regardless of treatment. Controlled trials will be required to evaluate the added value of a laparoscopic approach to the placement of the hepatic artery pump.

Effect of an esophageal bougie on the incidence of dysphagia following nissen fundoplication: a prospective, blinded, randomized clinical trial.

HYPOTHESIS: Based on retrospective, uncontrolled studies, it has been claimed that Nissen fundoplication should be performed over an esophageal bougie to minimize postoperative dysphagia. We hypothesized that a surgeon experienced in laparoscopic fundoplication will have similar rates of postoperative dysphagia whether or not an esophageal bougie is used. DESIGN: A patient and observer blinded, randomized, prospective clinical trial to assess the effect of intraoperative bougie use. SETTING: A tertiary care teaching hospital that is a regional referral source for complex laparoscopic foregut surgical procedures. PATIENTS: Three hundred thirty-six consecutive patients referred for laparoscopic fundoplication between March 1, 1996, and July 31, 1998, were evaluated for eligibility based on inclusion criteria and, if applicable, were offered randomization for fundoplication with or without a 56F bougie. One hundred seventy-one patients were enrolled in this study. INTERVENTIONS: All patients underwent laparoscopic Nissen fundoplication, 81 with a bougie (hereafter referred to as the bougie group) and 90 without a bougie (hereafter referred to as the no bougie group). MAIN OUTCOME MEASURES: Dysphagia severity and frequency were assessed by a blinded observer using a standardized scoring system. Incidence of complications related to the use or absence of a bougie, operative times, and postsurgical recovery was also assessed. RESULTS: The mean operating time was 148 minutes (range, 65-295 minutes). The overall operative morbidity was 9% (7. 4% in the bougie group and 11% in the no bougie group, P=.41). One esophageal injury (1.2%) occurred in the bougie group. The 30-day mortality was 0. Long-term dysphagia assessment was completed in 90% of patients, with a mean follow-up of 11 months. Overall, long-term postoperative dysphagia was present in 13 patients (17%) in the bougie group and 24 patients(31%) in the no bougie group (P=.047). Severe dysphagia occurred in 5% of patients in the bougie group and 14% in the no bougie group. CONCLUSION: This study confirms the dogma that use of a large-caliber stent during the creation of a fundoplication decreases the long-term incidence of dysphagia; albeit at the risk of injury from the introduction of a bougie.

Monitoring freshwater sediments.

The objectives of the SENSPOL Expert Meeting on 'Monitoring Freshwater Sediments' held in Antwerp, Belgium, 12-13 September, 2001, were firstly to identify and define problems and secondly to develop a realistic strategy to solve these problems. Both of the stakeholder groups (governmental authorities and the dredging industry) present at the workshop participated in detailed discussions to elucidate the role of sensors in the field of sediments and sediment/water interfaces. The 19 invited experts were agreed that in situ monitoring systems are needed to monitor freshwater sediments. New recognised tools for sediment monitoring would help industry to meet the governmental sediment quality criteria and to handle the data concerning historic river contamination and geological background data. The need to monitor by effect-related studies together with chemical monitoring was stressed. The main focus for development of new sensor tools should be for on site determination of certain priority pollutants where there would be advantage over existing methods or where no suitable method exists, and to monitor biological effects (alarm systems and effect-related on site tests). Sensing technologies would also be useful to monitor bioavailability in sediments in situ to provide information for risk assessment. In addition, they could be of use to monitor bioremediation in situ. A useful role was forseen in dredging sediments, for in situ sediment screening and to guide treatment of dredged material. The new sensing tools presented, included determination of metal concentrations in sediments using the diffuse gradients in thin films (DGT) technique (Lancaster University, UK), an analytical protocol for determination of metal speciation in sediments (Universitat Autonoma de Barcelona, Spain), microbiotests for determination of sediment toxicity (University of Ghent, Belgium), a portable whole cell sensors device for heavy metal bioavailability (VITO, Belgium) and a microfabricated sensor array system for Pb concentration profile measurement in the microM range at the liquid-solid interface (University of Geneva, Switzerland).

Liver resection using total vascular exclusion, scalpel division of the parenchyma, and a simple compression technique for hemostasis and biliary control.

Recent improvements in perioperative morbidity and long-term outcome following liver surgery have led surgeons to attempt larger and more technically challenging liver resections. Total vascular exclusion (TVE) of the liver during resection has been proposed as a technique that will facilitate these difficult resections while minimizing blood loss. Total vascular exclusion is performed by obtaining complete isolation of the vascular pedicle of the liver. Once the hepatic vein is clamped, rapid resections may be performed with a loss of only the blood volume contained within the liver itself. Safe performance of total vascular exclusion of the liver requires a thorough understanding of hepatic anatomy, patient selection criteria, and the physiologic changes incurred by hepatic exclusion and subsequent ischemia and reperfusion. The following report discusses these issues, gives a detailed description of the steps involved in obtaining safe total vascular exclusion, and presents a technique using rapid parenchymal excision with a scalpel and capsular compression to obtain hemostasis and prevent bile leaks. We briefly discuss our experience with 144 consecutive resections in which this technique was used.

A decision analysis of the optimal initial approach to achalasia: laparoscopic Heller myotomy with partial fundoplication, thoracoscopic Heller myotomy, pneumatic dilatation, or botulinum toxin injection.

In the absence of randomized controlled trials that directly compare all of the modern methods of managing achalasia, decision analysis may help determine the optimal treatment strategy. Four strategies for the initial management of achalasia were compared using the following decision model: (1) laparoscopic Heller myotomy and partial fundoplication; (2) pneumatic dilatation; (3) botulinum toxin injection; and (4) thoracoscopic Heller myotomy. Probabilities of clinical events and utilities of health states were estimated using review of the medical literature and patient interviews. A recursive decision tree (Markov model) was used to simulate all the important outcomes of each initial treatment option, allowing for complications, relapses over time, and transitions between strategies when appropriate. After 10 years, laparoscopic Heller myotomy with partial fundoplication was associated with the longest quality-adjusted survival (quality-adjusted life years [QALY] = 7.41). The difference between this strategy and either pneumatic dilatation or botulinum toxin injection was small. Thoracoscopic Heller myotomy was associated with the poorest quality-adjusted survival (QALY = 7.15). Pneumatic dilatation was the favored strategy when the effectiveness of laparoscopic surgery at relieving dysphagia was less than 89.7%, the operative mortality risk was greater than 0.7%, or the probability of reflux after pneumatic dilatation was less than 19%. In a decision model, laparoscopic Heller myotomy with partial fundoplication is at least as effective as endoscopic approaches for managing achalasia symptoms. However, the differences are small enough that patient preferences and local expertise should be taken into consideration when tailoring a treatment plan for an individual patient.

Clinical short-term results of radiofrequency ablation in primary and secondary liver tumors.

BACKGROUND: Radiofrequency ablation (RFA) is emerging as a new therapeutic method for management of solid tumors. We report here our experience in the use of this technique for management of primary and secondary unresectable liver cancers. METHODS: Thirty-five patients with liver cancers were considered not suitable for curative resection at presentation: 8 with primary hepatocellular carcinoma ([HCC] 6 HCC and 2 fibrolamellar); 27 with metastatic liver cancer (17 colorectal carcinoma and 10 others). They were treated either with radiofrequency heat ablation (Radionics Europe N.V., Wettdren, Belgium) alone percutaneously and/or intraoperatively or in conjunction with surgical resections. The quality of RFA was based on the subjective feeling of whether the tumor was completely destroyed or not. The effectiveness of RFA was assessed according to clinical findings, radiographic images, and tumor markers at follow-up. RESULTS: In 8 primary liver cases, 4 patients with a high level of alpha fetoprotein (AFP) benefited from the RFA with a 83.3% to 99.7% reduction of AFP. One with fibrolamellar hepatocellular carcinoma died 2 months after an incomplete percutaneous RFA from recurrence. The rest all had stable disease at the time of follow-up (mean 10.4 months). In patients with colorectal liver metastases, there were 4 deaths: 1 patient died postoperatively on the 30th day from a severe chest infection having shown a considerable reduction of carcinoembryonic antigen level (CEA, 8 versus 36 microg/L); 3 died from local and systemic disease, 1 at 12 months and 2 at 1 month, having had an incomplete RFA. The others had stable disease at follow-up (mean 7.6 months). Five patients underwent liver resections successfully with the application of RFA for residual lesions in the remaining contralateral lobe. In 10 patients with other liver tumors, 7 patients had stable disease at follow-up (mean 13.4 months); 1 patient had evidence of local and systemic recurrence 10 months after surgical resections with the intraoperative RFA and 2 patients died of systemic recurrence of disease 3 and 6 months after RFA alone. Two patients had liver resections in conjunction with the intraoperative RFA. The mean follow-up in our series was 8.5 months. CONCLUSION: Radiofrequency heat ablation is useful as a primary treatment for unresectable liver cancers. The procedure can be used to treat the small residual tumor load in the contralateral lobe following liver resection in those considered unresectable at the first presentation. This new therapeutic strategy seems to increase surgical resectability in patients judged unresectable.

Incidence of cancer of the pancreas, extrahepatic bile duct and ampulla of Vater in the United States, before and after the introduction of laparoscopic cholecystectomy.

BACKGROUND: Some epidemiologic studies have identified cholecystectomy as a risk factor for pancreatic and biliary cancer. METHODS: We compared the incidence of cancers of the pancreas, extrahepatic bile duct and ampulla of Vater before and after the widespread adoption of laparoscopic cholecystectomy in the United States in 1991, when the use of cholecystectomy increased dramatically. RESULTS: Compared with 1980 to 1991, there was no increase in the incidence of cancer of the pancreas (adjusted incidence rate ratio [IRR] 0.97, 95% confidence interval [CI] 0.94 to 0.99) or extrahepatic bile duct (IRR 0.80, 95% CI 0.74 to 0.87) during 1992 to 1996. There was a small increase in the incidence of ampullary cancer (IRR 1.14, 95% CI 1.03 to 1.26). CONCLUSIONS: We did not find clear evidence of a short-term increase in the incidence of cancers of the pancreas, bile duct, and ampulla of Vater, that was attributable to the increased use of cholecystectomy.

Quality of life before and after laparoscopic Heller myotomy for achalasia.

BACKGROUND: Because the surgical treatment of achalasia is directed at the palliation of chronic symptoms, it is important to assess how surgery affects patients' health-related quality of life (HRQL). METHODS: We evaluated upper gastrointestinal symptoms, satisfaction, and HRQL in 19 patients with achalasia before and after undergoing a laparoscopic Heller myotomy and partial fundoplication. HRQL was assessed using the Medical Outcomes Study 36-item short form health survey (SF-36). RESULTS: The mean age of the patients was 40 years (range 16 to 74), and 58% were men. After a median follow-up of 21 months (range 2 to 35), 12 of 16 patients were satisfied with the results of their surgery. Liquid and solid dysphagia scores were improved after surgery, and the prevalence of heartburn symptoms did not change. Although all the health concepts measured by the SF-36 instrument showed some improvement, statistically significant increases (on a 0 to 100 scale) were detected in physical functioning (11.1, P = 0.02), role-physical (25.0, P = 0.05), bodily pain (12.2, P = 0.01), vitality (13.7, P = 0.02), and social functioning (18.4, P = 0.02). CONCLUSIONS: Most aspects of HRQL improve after a laparoscopic Heller myotomy and partial fundoplication for achalasia.

A miniaturized Ames mutagenicity assay employing bioluminescent strains of Salmonella typhimurium.

Increased awareness of the role of environmental factors in carcinogenesis has led to an emphasis on preventing or minimizing exposure to genotoxicants. This is presently promoting the development of simple, rapid, cost-effective mutagenicity screening assays. We have developed a test system based on the well-known Salmonella mutagenicity assay. The lux genes, which permit cells to emit light through bioluminescence, were introduced into Salmonella typhimurium strain TA98. These bacteria were exposed for 48 h to chemicals or complex mixtures in 48-well microplates containing an appropriate liquid medium. Cells were subsequently centrifuged and resuspended in buffer. The final postexposure revertant biomass was then estimated using a microluminometer. Replication trials confirmed methodological reproducibility. Clear dose-response relationships were obtained with the direct frameshift mutagens 4NQO and 2NF. Mutagenicity threshold effect concentrations found for these compounds were comparable to those reported in the literature. Industrial effluents and environmental extracts (effluents, suspended solids) were also tested and results compared well with those of the SOS Chromotest. While further validation of this new adaptation of the Ames test will be required, it appears at this time that it could be well suited for routine screening of xenobiotics and environmental samples.

A mathematical model for preoperative planning of radiofrequency ablation of hepatic tumors.

BACKGROUND: Radiofrequency ablation (RFA) is rapidly evolving as an effective minimally invasive technique for the treatment of small and unresectable liver tumors. A potential cause of treatment failure is the inability to determine the optimum number of overlapping ablations needed to completely destroy tumors larger than the size of a single ablation. To clarify this relationship, we performed a mathematical evaluation that enables us to accurately estimate the number of ablations needed to completely ablate larger tumors. METHODS: This estimation is based on the assumptions that complete ablation of the surface of a target tumor, including its blood supply, would completely destroy the tumor and that the tumor and ablations produced are perfectly spherical. The smallest possible number of partially overlapping ablations that would completely cover the surface of the target tumor is the same as the number of faces on a regular polyhedron that has a circumscribing diameter equal to or greater than the diameter of the target sphere. RESULTS: This mathematical analysis shows that for a 5-cm ablation device, tumors with diameters ranging between 3.01 and 3.30 cm will require at least four ablations. Tumors between 3.31 and 4.12 cm require six overlapping ablations, and tumors between 4.13 and 6.23 cm require 12 overlapping ablations. The number of ablations needed for larger tumors and for 3-, 4-, 6-, and 7-cm ablation devices are also determined. CONCLUSION: The smallest number of ablations required to completely ablate a spherical target tumor larger than the size of the ablation sphere increases dramatically as tumor size increases. Because this model is geometrically optimized, even a small change in the position of the ablation spheres with respect to the target sphere can leave potentially unablated tumor and thus result in treatment failure.

Laparoscopic antireflux surgery in the elderly.

BACKGROUND: Laparoscopic antireflux surgery is frequently denied to older patients with gastroesophageal reflux disease (GERD) because of a perceived higher operative complication rate, a decreased impact of the intervention on quality of life, and decreased cost effectiveness. This study compares disease severity, surgical outcomes, and impact on quality of life between elderly and young patients with GERD. METHODS: Patients were selected from a prospectively maintained database of 1100 patients who underwent various laparoscopic esophageal procedures at our institution. Only patients having chronic intractable GERD and a minimum 6 months' follow-up were included in the study. Thirty elderly patients with a mean age of 71.2 years (SD +/- 5.6) were compared with a group of 30 younger patients (mean age, 43.9 +/- 12.8 years). Comparisons were made between subjective and objective outcomes, operative results, and health-related quality of life (HQRL) scores using SF-36 instruments. RESULTS: The preoperative symptom assessment scores presenting frequency of symptoms on a 0-4 scale), and preoperative pH and manometry data were comparable in the two groups. Elderly patients had significantly higher ASA (American Society of Anesthesiologists) scores. Each group demonstrated a significant improvement in the postoperative symptom assessment scores and the esophageal functional studies (p<0.05). However, no significant differences were found in terms of postoperative complications, postoperative hospital stay, postoperative symptom scores, Demeester scores, or the HRQL data. CONCLUSION: Laparoscopic antireflux surgery in elderly patients improves acid reflux and appears to be safe and effective as measured by postoperative testing in elderly and young patients.

Transthoracic hepatic radiofrequency ablation.

BACKGROUND: Radiofrequency ablation (RFA) is an alternative for the treatment of unresectable hepatic tumors. Tumors beneath the diaphragmatic dome may be difficult to access by laparoscopy. In these cases, a transthoracic transdiaphragmatic approach for delivering RFA can be used. METHODS: Three patients with hepatic metastatic disease were treated using a transthoracic transdiaphragmatic approach to deliver RFA therapy for tumors in liver segments 7 and 8. The patients underwent thoracoscopy. The tumors were identified using transdiaphragmatic ultrasound, and transthoracic transdiaphragmatic RFA (TTRFA) was performed. RESULTS: In three patients, TTRFA was successfully used to ablate five lesions. There were no perioperative complications, blood loss was minimal,and postoperative hospital stays ranged from 2 to 8 days. There were no recurrences during a follow-up period of 4 to 20 months. CONCLUSIONS: TTRFA is a viable alternative for hepatic tumors located beneath the dome of the diaphragm that are difficult to access by laparoscopy.

Preoperative determinants of an esophageal lengthening procedure in laparoscopic antireflux surgery.

BACKGROUND: In a minority of patients undergoing antireflux surgery, an esophageal lengthening procedure is required to reduce the gastroesophageal junction (GEJ) below the esophageal hiatus. We evaluated risk factors associated with an irreducible GEJ to identify clinical features that were predictive of the need for a Collis gastroplasty in patients undergoing laparoscopic antireflux surgery. METHODS: Patients who required a Collis gastroplasty during a laparoscopic antireflux procedure (defined as the inability to reduce the GEJ > 2.5 cm below the esophageal hiatus despite extensive mobilization of the mediastinal esophagus) were compared to a random sample of patients who did not have a Collis gastroplasty. Predictors of the need for an esophageal lengthening procedure were identified using logistic regression modeling. Risks were expressed as odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Twenty patients who had a Collis gastroplasty were compared to 133 patients who had adequate esophageal length. The presence of a stricture (OR 3.0; 95% CI 1.0, 9.7), paraesophageal hernia (OR 3.5; 95% CI 1.3, 9.6), Barrett's esophagus (OR 3.7, 95% CI 1.3, 10.7), and re-do antireflux surgery (OR 6.4; 95% CI 2.0, 20.7) were associated with the need for gastroplasty. Patients with none of these factors were extremely unlikely to require a gastroplasty (OR 0.08; 95% CI 0.02, 0.34). CONCLUSION: Patients undergoing laparoscopic antireflux surgery who are at high risk of needing an esophageal lengthening procedure can be easily identified preoperatively using simple clinical characteristics.

Outcomes of laparoscopic herniorrhaphy without fixation of mesh to the abdominal wall.

BACKGROUND: Recently there has been interest in performing laparoscopic herniorrhaphies without the use of staples or tacks to fix the mesh. Although mesh fixation has been linked to an increased incidence of nerve injury and involves increased operative costs, many surgeons feel that fixation is necessary to reduce the risk of hernia recurrence. This study evaluates the outcomes of laparoscopic herniorrhapies performed with and without mesh fixation at our institution. METHODS: We retrospectively evaluated our last 172 laparoscopic herniorrhaphies, which span a period of conversion from staple fixation to nonfixation of total extraperitoneal herniorrhaphies using systematic chart review and follow-up self-administered questionnaires. The outcomes assessed were the incidences of postoperative neuralgia and hernia recurrence. Adjustment for important prognostic factors was achieved using Cox regression for estimating the risk of recurrence, and multiple logistic regression for estimating the risk of neuropathic complications. RESULTS: Of 172 laparoscopic herniorrhaphies performed in 129 patients since July 1993, 105 were accomplished without mesh fixation, and 67 were performed with fixation of mesh to the abdominal wall. There were no significant differences in demographics between the two groups. A trend toward a higher incidence of neuropathic complications was observed in the mesh-fixation group (risk ratio [RR], 2.2; 95% CI, 0.5-10). A nonsignificant increased risk of hernia recurrence with fixation of mesh was observed (4.2 vs 1.6 per 100 hernia-years at risk; RR, 2.3; 95% CI, 0.4-13.10), but this finding may be associated with a selection bias with regard to giant hernia defects. CONCLUSIONS: Our data suggest that mesh fixation to the abdominal wall may be avoided in total extraperitoneal repairs without increasing the risk of hernia recurrence and neuropathic complications. The increased risk of recurrence observed with mesh fixation possibly results from selection bias. Large randomized controlled studies are needed to determine whether mesh fixation is truly related to neuropathic complications and the incidence of recurrence.

Laparoscopic radiofrequency ablation and hepatic artery infusion pump placement in the evolving treatment of colorectal hepatic metastases.

BACKGROUND: Laparoscopic radiofrequency ablation (LRFA) and laparoscopic hepatic artery infusion pump (LHAIP) placement are new treatment options for patients with colorectal liver metastases. This study investigates the selection criteria, safety, efficacy, and preliminary outcomes of patients treated with LRFA and LHAIP placement. METHODS: Fourty five patients with colorectal metastases confined to the liver, 37 of whom had failed systemic chemotherapy, were treated with LRFA and/or LHAIP between September 1996 and December 2001. Treatment selection was individualized, based on each patient's general health, liver function, and tumor size, number, location, and distribution. RESULTS: Twenty patients (44%) had LRFA alone, 10 (22%) had LHAIP placement alone, and 15 (33%) patients had combined LRFA and LHAIP therapy. The LRFA group had a significantly shorter mean operative time and blood loss (p <0.05), but hospital stays were similar when compared to patients receiving LRFA + LHAIP or LHAIP alone. Tumor characteristics were worse in both LHAIP groups, with a higher incidence of tumors >or=4 cm, major vascular involvement, diffuse tumor pattern, bilobar distribution, and involvement of more than three segments. During a mean follow-up period of 11.5 +/- 7.8 months (range, 1-38), the actuarial survival was 70%, 67%, and 50% for LRFA, LRFA + LHAIP, and LHAIP, respectively. LHAIP only patients had the shortest estimated mean survival time of the three groups by Kaplan-Meier survival curves (p = 0.001). CONCLUSION: LRFA and/or LHAIP placement are safe and feasible treatment options for the treatment of colorectal hepatic metastases. The choice of treatment for patients should be based primarily on tumor characteristics. Long-term studies, which will elucidate the role of these evolving treatments, are now under way.