The European Hernia Society Prehabilitation Project: a systematic review of patient prehabilitation prior to ventral hernia surgery

BACKGROUND

Ventral hernia repair is one of the most commonly performed surgical procedures worldwide. To reduce the risk of complications, patient prehabilitation has received increasing focus in recent years. To assess prehabilitation measures, this European Hernia Society endorsed project was launched. The aim of this systematic review was to evaluate the current literature on patient prehabilitation prior to ventral hernia repair.

METHODS

The strategies examined were optimization of renal disease, obesity, nutrition, physical exercise, COPD, diabetes and smoking cessation. For each topic, a separate literature search was conducted, allowing for seven different sub-reviews.

RESULTS

A limited amount of well-conducted research studies evaluating prehabilitation prior to ventral hernia surgery was found. The primary findings showed that smoking cessation and weight loss for obese patients led to reduced risks of complications after abdominal wall reconstruction.

CONCLUSION

Prehabilitation prior to ventral hernia repair may be widely used; however, the literature supporting its use is limited. Future studies evaluating the impact of prehabilitation before ventral hernia surgery are warranted.

An evidence map and synthesis review with meta-analysis on the risk of incisional hernia in colorectal surgery with standard closure

PURPOSE

To assess the incidence of incisional hernia (IH) across various type of incisions in colorectal surgery (CS) creating a map of evidence to define research trends, gaps and areas of future interest.

METHODS

Systematic review of PubMed and Scopus from 2010 onwards. Studies included both open (OS) and laparoscopic (LS). The primary outcome was incidence of IH 12 months after index procedure, secondary outcomes were the study features and their influence on reported proportion of IH. Random effects models were used to calculate pooled proportions. Meta-regression models were performed to explore heterogeneity.

RESULTS

Ninetyone studies were included reporting 6473 IH. The pooled proportions of IH for OS were 0.35 (95% CI 0.27-0.44) I² 0% in midline laparotomies and 0.02 (95% CI 0.00-0.07), I² 52% for off-midline. In case of LS the pooled proportion of IH for midline extraction sites were 0.10 (95% CI 0.07-0.16), I² 58% and 0.04 (95% CI 0.03-0.06), I² 86% in case of off-midline. In Port-site IH was 0.02 (95% CI 0.01-0.04), I² 82%, and for single incision surgery (SILS) of 0.06-95% CI 0.02-0.15, I² 81%. In case of stoma reversal sites was 0.20 (95% CI 0.16-0.24).

CONCLUSION

Midline laparotomies and stoma reversal sites are at high risk for IH and should be considered in research of preventive strategies of closure. After laparoscopic approach IH happens mainly by extraction sites incisions specially midline and also represent an important area of analysis.

Classification of acute diverticulitis in the left colon with ultrasonography and computed tomography: value of current severity classification schemes

BACKGROUND AND AIMS

The current management of acute diverticulitis of the left colon (ADLC) requires tests with high prognostic value. This paper analyzes the usefulness of ultrasonography (US) in the initial diagnosis of ADLC and the validity of current classifications schemes for ADLC.

PATIENTS

This retrospective observational study included patients with ADLC scheduled to undergo US or computed tomography (CT) following a clinical algorithm. According to the imaging findings, ADLC was classified as mild, locally complicated, or complicated. We analyzed the efficacy of US in the initial diagnosis and the reasons why CT was used as the first-line technique. We compared the findings with published classifications schemes for ADLC.

RESULTS

A total of 311 patients were diagnosed with acute diverticulitis; 183 had ADLC, classified at imaging as mild in 104, locally complicated in 60, and complicated in 19. The diagnosis was reached by US alone in 98 patients, by CT alone in 77, and by combined US and CT in 8. The main reasons for using CT as the first-line technique were the radiologist's lack of experience in abdominal US and the unavailability of a radiologists on call. Six patients diagnosed by US were reexamined by CT, but the classification changed in only three. None of the published classification schemes included all the imaging findings.

CONCLUSIONS

US should be the first-line imaging technique in patients with suspected ADLC. Various laboratory and imaging findings are useful in establishing the prognosis of ADLC. New schemes to classify the severity of ADLC are necessary to ensure optimal clinical decision making.

[Neuroendocrine carcinomas of the colon and rectum. A unit's experience over six years]

INTRODUCTION

Neuroendocrine tumours of the colon and rectum are infrequent. They are usually undifferentiated, easy to diagnose for the pathologist and are especially aggressive in their clinical behaviour. Prognosis is usually poor and they have a high tendency to metastase early.

MATERIAL AND METHODS

We have reviewed our experience in a Colorectal Unit during a period of six years. Patients with neuroendocrine tumours have been reviewed retrospectively. Carcinoid tumours have not been included in this study.

RESULTS

During this period, 2,155 patients have been operated for colorectal cancer and in five patients a neuroendocrine tumour has been found in the specimen. Mean age was 66 years, three male and two female. One tumour was located in the caecum, two in the rectum and two in the sigmoid colon. Two patients had hepatic metastasis at diagnosis. Surgery was performed in all patients and two patients received adjuvant quimiotherapy. A patient died because of post-operative hepatic insufficiency, another at 2 months and another after one year. Two patients are still alive after eight months follow-up.

CONCLUSIONS

Neuroendocrine tumours appear to be rare in the colon and rectum. Clinical manifestations are not different from standard adenocarcinoma. When these tumours are diagnosed, they have distance disease, as in two of the five cases, related to a poor prognosis for the patient. Surgery is the treatment that can offer a greater chance of survival to these patients.

Removal and environmental exposure of alcohol ethoxylates in US sewage treatment

Alcohol ethoxylates (AE) are a common nonionic surfactant employed in consumer and industrial detergents worldwide. Commercial AE are typically complex mixtures composed of > 100 homologous compounds with varying alkyl chain lengths and varying numbers of ethylene oxide (EO) units. Recent improvements in analytical methodology have enabled accurate measurement of the entire AE mixture in sewage treatment plant (STP) influents and effluents, including alkyl chain lengths from 12 to 18 carbons with a range of ethoxylation from 0 to 18 EO units. These improved analytical methods were used to measure AE concentrations at nine sites representative of sewage treatment processes and geographical locations. These new data will make possible a more accurate assessment of environmental risk for AE in the United States. The results indicate that all AE homologues are effectively removed (> 99%) in the most common treatment types. Individual STP total AE effluent concentrations ranged from a low of 0.92 microg/L for activated sludge to a high of 15.6 microg/L for a trickling filter process. For the purpose of representing a national average distribution, an average-flow-weighted wastewater treatment plant effluent concentration was determined for each AE component. The total-flow-weighted average AE effluent concentration was 3.64 microg/L.

Predicting the sorption of fatty alcohols and alcohol ethoxylates to effluent and receiving water solids

Alcohol ethoxylates (AEs) are an important group of nonionic surfactants. Commercial AEs consist of a mixture of several homologues of varying carbon chain length (Cx) and degree of ethoxylation (EOy). The major disposal route of AE is down the drain to municipal wastewater treatment plants that discharge into receiving surface waters. Sorption of AE homologues onto activated sludge and river water solids is an important factor in assessing exposure of AE in the environment. This study presents the experimental determination of sorption coefficients for a wide array of AE homologues including five alcohols under environmentally relevant conditions and combines these data with literature data to generate a predictive model for the sorption of AEs in the environment. These results demonstrate that sorption can be effectively modeled using a log Kd vs. Cx and EOy predictive equation having the form log Kd = 0.331C - 0.00897EO - 1.126(R2 = 0.64).

Ecotoxicity quantitative structure-activity relationships for alcohol ethoxylate mixtures based on substance-specific toxicity predictions

Traditionally, ecotoxicity quantitative structure-activity relationships (QSARs) for alcohol ethoxylate (AE) surfactants have been developed by assigning the measured ecotoxicity for commercial products to the average structures (alkyl chain length and ethoxylate chain length) of these materials. Acute Daphnia magna toxicity tests for binary mixtures indicate that mixtures are more toxic than the individual AE substances corresponding with their average structures (due to the nonlinear relation of toxicity with structure). Consequently, the ecotoxicity value (expressed as effects concentration) attributed to the average structures that are used to develop the existing QSARs is expected to be too low. A new QSAR technique for complex substances, which interprets the mixture toxicity with regard to the "ethoxymers" distribution (i.e., the individual AE components) rather than the average structure, was developed. This new technique was then applied to develop new AE ecotoxicity QSARs for invertebrates, fish, and mesocosms. Despite the higher complexity, the fit and accuracy of the new QSARs are at least as good as those for the existing QSARs based on the same data set. As expected from typical ethoxymer distributions of commercial AEs, the new QSAR generally predicts less toxicity than the QSARs based on average structure.

A laboratory batch reactor test for assessing nonspeciated volatile organic compound biodegradation in activated sludge

The relative rates of biodegradation and stripping and volatilization of nonspeciated volatile organic compounds (VOCs) in wastewater treated with aerobic activated-sludge processes can be quantified using a newly developed procedure. This method was adapted from the original aerated draft tube reactor test that was developed to measure biodegradation rate constants for specific volatile pollutants of interest. The original batch test has been modified to include solid-phase microextraction (SPME) fibers for sampling in the gas phase. The experimental procedure using SPME fibers does not require specific identification and quantitation of individual pollutants and can be used to evaluate wastewater with multiple VOCs. To illustrate use of this procedure, laboratory experiments were conducted using biomass and wastewater or effluent from three activated-sludge treatment systems. Each experiment consisted of two trials: a stripping-only trial without biomass and a stripping plus biodegradation trial using biomass from the activated-sludge unit of interest. Data from the two trials were used to quantify the rates of biodegradation by difference. The activated-sludge systems tested were a laboratory diffused-air reactor treating refinery wastewater, a full-scale surface aerated reactor treating a petrochemical wastewater, and a full-scale diffused-air reactor treating a variety of industrial effluents. The biodegradation rate constant data from each laboratory batch experiment were used in model calculations to quantify the fraction emitted (fe) and the fraction biodegraded (fbio) for each system. The fe values ranged from a maximum of 0.01 to a maximum of 0.32, whereas fbio values ranged from a minimum of 0.40 to a minimum 0.95. Two of these systems had been previously tested using a more complicated experimental approach, and the current results were in good agreement with previous results. These results indicate that biodegradation rate constant data from this laboratory method can be successfully used to predict the fate of VOCs in field-scale treatment units, and thus could potentially be used for demonstration of compliance with wastewater VOC emission regulations.

Transfers and transformations of zinc in flow-through wetland microcosms

Two microcosm-scale wetlands (570-liter containers) were integratively designed and constructed to investigate transfers and transformations of zinc associated with an aqueous matrix, and to provide future design parameters for pilot-scale constructed wetlands. The fundamental design of these wetland microcosms was based on biogeochemical principles regulating fate and transformations of zinc (pH, redox, etc.). Each wetland consisted of a 45-cm hydrosoil depth inundated with 25 cm of water, and planted with Scirpus californicus. Zinc ( approximately 2 mg/liter) as ZnCl2 was amended to each wetland for 62 days. Individual wetland hydraulic retention times (HRT) were approximately 24 h. Total recoverable zinc was measured daily in microcosm inflow and outflows, and zinc concentrations in hydrosoil and S. californicus tissue were measured pre- and post-treatment. Ceriodaphnia dubia and Pimephales promelas7-day aqueous toxicity tests were performed on wetland inflows and outflows, and Hyalella azteca whole sediment toxicity tests (10-day) were performed pre- and post-treatment. Approximately 75% of total recoverable zinc was transferred from the water column. Toxicity decreased from inflow to outflow based on 7-day C. dubia tests, and survival of H. azteca in hydrosoil was >80%. Data illustrate the ability of integratively designed wetlands to transfer and sequester zinc from the water column while concomitantly decreasing associated toxicity.

Ethylene glycol ethers: an environmental risk assessment

Ethylene glycol ethers and acetates are used as intermediates, solvents, and plasticizers. They primarily enter the environment from manufacturing effluents and emissions and during their use in commercial products. Therefore, an examination of their ultimate fate and toxicity, as well as their potential for exposure, was performed. Overall, these data show that ethylene glycol ethers and acetates are not persistent in the environment, are not bioaccumulative, are generally classified by U.S. Environmental Protection Agency (EPA) procedures as "practically non-toxic" to aquatic organisms based on acute toxicity, and that conservatively calculated exposures are mostly below concentrations of concern for chronic risks to aquatic life.

Design and construction of wetlands for aqueous transfers and transformations of selected metals

Two pilot-scale wetland cells (6.1 x 30.5 m) were integratively designed and constructed to emphasize and enhance transfers and transformations of selected metals (Cu, Pb, and Zn) in an aqueous matrix. A series of preliminary experiments and analyses were conducted to select macrofeatures (hydroperiod, hydrosoil, and vegetation) of the constructed wetland system. These wetland cells were designed to operate in series or parallel with nominal hydraulic retention times of 24-48 hr, respectively. With water at a depth of 30 cm, both wetland cells had hydrosoil (45 cm) planted with Scirpus californicus. After 250 days of wetland operation, average hydrosoil redox potentials in each wetland cell decreased from +90 mV to -165 mV, and average plant height increased from 0.3 to 2.7 m. Aqueous samples were collected over a 4.5-month period at the inflow and outflow sites of the wetland cells. Average inflow concentrations of total recoverable Cu, Pb, and Zn were 22.4, 10.5, and 565.9 micrograms/L, respectively. After a 46-hr HRT, average outflow concentrations of total recoverable Cu, Pb, and Zn were 15, 2.2, and 85.9 micrograms/L, resulting in removals of 33, 79, and 85%, respectively. Initial results suggest that these constructed wetlands can be designed to remove targeted metals in wastewater.

[Application of extracorporeal lithotripsy in intestinal subocclusion caused by a clam shell]

A patient with intestinal obstruction secondary to a foreign body (clam shell) impacted in the ileocecal valve was treated by extracorporeal shock wave lithotripsy. The resolution of ileus without complications was obtained.

Mechanisms responsible for F-actin stabilization after lysis of polymorphonuclear leukocytes

While actin polymerization and depolymerization are both essential for cell movement, few studies have focused on actin depolymerization. In vivo, depolymerization can occur exceedingly rapidly and in a spatially defined manner: the F-actin in the lamellipodia depolymerizes in 30 s after chemoattractant removal (Cassimeris, L., H. McNeill, and S. H. Zigmond. 1990. J. Cell Biol. 110:1067-1075). To begin to understand the regulation of F-actin depolymerization, we have examined F-actin depolymerization in lysates of polymorphonuclear leukocytes (PMNs). Surprisingly, much of the cell F-actin, measured with a TRITC-phalloidin-binding assay, was stable after lysis in a physiological salt buffer (0.15 M KCl): approximately 50% of the F-actin did not depolymerize even after 18 h. This stable F-actin included lamellar F-actin which could still be visualized one hour after lysis by staining with TRITC-phalloidin and by EM. We investigated the basis for this stability. In lysates with cell concentrations greater than 10(7) cells/ml, sufficient globular actin (G-actin) was present to result in a net increase in F-actin. However, the F-actin stability was not solely because of the presence of free G-actin since addition of DNase I to the lysate did not increase the F-actin loss. Nor did it appear to be because of barbed end capping factors since cell lysates provided sites for barbed end polymerization of exogenous added actin. The stable F-actin existed in a macromolecular complex that pelleted at low gravitational forces. Increasing the salt concentration of the lysis buffer decreased the amount of F-actin that pelleted at low gravitational forces and increased the amount of F-actin that depolymerized. Various actin-binding and cross-linking proteins such as tropomyosin, alpha-actinin, and actin-binding protein pelleted with the stable F-actin. In addition, we found that alpha-actinin, a filament cross-linking protein, inhibited the rate of pyrenyl F-actin depolymerization. These results suggested that actin cross-linking proteins may contribute to the stability of cellular actin after lysis. The activity of crosslinkers may be regulated in vivo to allow rapid turnover of lamellipodia F-actin.

Characterization of tetramethylrhodaminyl-phalloidin binding to cellular F-actin

Fluorescent derivatives of phalloidin are widely used to measure filamentous actin (F-actin) levels and to stabilize F-actin. We have characterized the kinetics and affinity of binding of tetramethylrhodaminyl (TRITC)-phalloidin to rabbit skeletal muscle F-actin and to F-actin in lysates of rabbit polymorphonuclear leukocytes (PMNs). We have defined conditions where TRITC-phalloidin can be used to inhibit F-actin depolymerization and to quantify F-actin without prior fixation. By equilibrium measurements, the affinity of TRITC-phalloidin binding to rabbit skeletal muscle F-actin (pyrene labeled) or to PMN lysate F-actin was 1-4 x 10(-7) M. In both cases, the stoichiometry of binding was approximately 1:1. Kinetic measurements of TRITC-phalloidin binding to PMN lysate F-actin resulted in an association rate constant of 420 +/- 120 M-1 sec-1 and a dissociation rate constant of 8.3 +/- 0.9 x 10(-5) sec-1. The affinity calculated from the kinetic measurements (2 +/- 1 x 10(-7) M) agreed well with that obtained by equilibrium measurements. The rate with which 0.6 microM TRITC-phalloidin inhibited 0.1 microM pyrenyl F-actin depolymerization (90% inhibition in 10 sec) was much faster than the rate of binding to pyrenyl F-actin (less than 1% bound in 10 sec), suggesting that phalloidin binds to filament ends more rapidly than to the rest of the filament. We show that TRITC-phalloidin can be used to measure F-actin levels in cell lysates when G-actin is also present (i.e., in cell lysates at high concentrations) if DNase I is included to prevent phalloidin-induced polymerization.

Kinetic analysis of F-actin depolymerization in polymorphonuclear leukocyte lysates indicates that chemoattractant stimulation increases actin filament number without altering the filament length distribution

The rate of filamentous actin (F-actin) depolymerization is proportional to the number of filaments depolarizing and changes in the rate are proportional to changes in filament number. To determine the number and length of actin filaments in polymorphonuclear leukocytes and the change in filament number and length that occurs during the increase in F-actin upon chemoattractant stimulation, the time course of cellular F-actin depolymerization in lysates of control and peptide-stimulated cells was examined. F-actin was quantified by the TRITC-labeled phalloidin staining of pelletable actin. Lysis in 1.2 M KCl and 10 microM DNase I minimized the effects of F-actin binding proteins and G-actin, respectively, on the kinetics of depolymerization. To determine filament number and length from a depolymerization time course, depolymerization kinetics must be limited by the actin monomer dissociation rate. Comparison of time courses of depolymerization in the presence (pointed ends free) or absence (barbed and pointed ends free) of cytochalasin suggested depolymerization occurred from both ends of the filament and that monomer dissociation was rate limiting. Control cells had 1.7 +/- 0.4 x 10(5) filaments with an average length of 0.29 +/- 0.09 microns. Chemo-attractant stimulation for 90 s at room temperature with 0.02 microM N-formylnorleucylleucylphenylalanine caused a twofold increase in F-actin and about a two-fold increase in the total number of actin filaments to 4.0 +/- 0.5 x 10(5) filaments with an average length of 0.27 +/- 0.07 microns. In both cases, most (approximately 80%) of the filaments were quite short (less than or equal to 0.18 micron). The length distributions of actin filaments in stimulated and control cells were similar.