Difference In Leak Rate Research Articles

FP7.13 - Is There A Difference In Anastomotic Leak Rates Requiring Re-Operation Following Emergency Right Hemicolectomy Between Colorectal And Non-Colorectal Surgeons?

Abstract Aim Right sided colonic cancers can often obstruct and present as an emergency. The decision to perform an anastomosis following the right hemicolectomy resection is often multifactorial. This study explores whether there are differences in leak rates between colorectal and non-colorectal surgeons in the context of emergency right hemicolectomy operations performed for malignancy. Methods A retrospective study was conducted at a 3-site Trust in South-East England between 2017 and 2022. Theatre and Infoflex Cancer records were used to obtain patients who had undergone an open right hemicolectomy for malignancy and their operating surgeon. Discharge summaries and clinic letters were then used to ascertain return to theatre for an anastomotic leak. Results There were 281 patients who had undergone an emergency right hemicolectomy in this time interval. There was a 152:129 female:male ratio. 17 out of 37 patients had an anastomosis undertaken by an Upper Gastrointestinal Surgeon. 2 out of the 17 (12%) had an anastomotic leak. 129 out of 244 had an anastomosis undertaken by a Colorectal Surgeon. 17 of the 129 (13%) had an anastomotic leak. There was no significant difference between the leak rates between colorectal and non-colorectal surgeons (p=0.888). Conclusion The study shows that there is no statistical difference in right hemicolectomy anastomotic leak rates between colorectal and non-colorectal surgeons in the emergency setting.

Six-year analysis of 30-day post-operative leaks for primary sleeve gastrectomy: a MBSAQIP database study.

Sleeve gastrectomy is the most performed bariatric surgery. Post-operative gastric sleeve leaks, although rare, are dreaded complications. This study aims to perform an updated investigation of the factors associated with sleeve leaks. This retrospective cohort study analyzed 692,554 cases from the MBSAQIP database (2016-2021) with CPT code 43,775 for primary sleeve gastrectomy. We excluded emergency operations, conversions/revisions, endoscopic interventions, patient with prior foregut surgery, and open operations. Multivariate logistic regression analysis (STATA version 15) was performed to identify factors associated with sleeve gastrectomy leaks. Out of 692,554 patients, 600,910 (86.77%) patients underwent laparoscopic sleeve gastrectomy, and 91,644 (13.23%) patients underwent robotic sleeve gastrectomy. 1179 (0.17%) developed leaks within 30days; 177(0.19%) were in the robotic group and 1002 (0.17%) in the laparoscopic group with no significant difference in leak rates between two groups on multivariate analysis. Black patients had lower odds of having leaks as compared to white patients (Odds Ratio (OR): 0.68 (0.56-0.82); p < 0.01). Hispanic patients had lower odds of having leak as compared to non-Hispanics. Factors associated with higher leak odds (p < 0.05) included hypertension, GERD, smoking, immunosuppression, increased operating time, and albumin < 3.5g/dl. Higher odds of leaks were observed in years 2016-2019 vs 2020-2021 (OR: 1.44 (1.25-1.65), p < 0.01). Higher odds of leak in operations with general surgeons compared to bariatric surgeons was found (OR: 1.46 (1.04-2.02), p = 0.02); observed only on robotic group on subgroup analysis (OR: 2.2 (1.2-4.2), p = 0.02). Staple line reinforcement, oversewing, and performance of leak test showed no differences in leak rate. Bougie size and distance from pylorus were not associated with changes in leak rate. This study provides updated insights into the factors associated with sleeve leaks, reinforcing information gained from prior studies. A higher association of leak among general surgeons could represent a learning curve for new robotic general surgeons. The overall decreasing trend for gastric sleeve leak is encouraging and may be a sign of improved techniques.

Frequency of Leaks from Conical Centrifuge Tubes.

Threaded conical centrifuge tubes are ubiquitous in biological laboratories and are frequently used for the storage/transport of potentially biohazardous samples. However, limited data are available on how frequently and from where these tubes leak. These data are valuable for laboratory biorisk management and to inform future studies on risks arising from the routine use of laboratory consumables. The frequency of leaks from threaded conical centrifuge tubes was tested using a Glo Germ solution as a tracer. Conical tubes (15 and 50 mL) from several brands were filled, inverted, and placed on their side on the benchtop. After 1 h, the presence or absence of leaks on the benchtop surface, tube threads, and exterior was recorded. We observed that liquid leaked out of tubes that were apparently properly threaded in 2% of 15 mL tubes (confidence interval [95% CI] 1.4-2.6) and 1.4% of 50 mL tubes (95% CI 0.2-1.5). After opening, liquid was found on the threads on the outside of the tube in 20% of 15 mL tubes (95% CI 10-31) and 14% of 50 mL tubes (95% CI 1-28). We did not find sufficient evidence that differences in leak rates among brands were practically significant. The fact that leaks were not uncommonly observed from conical centrifuge tubes suggests that mitigations for any hazard posed by a leak should be a component of every biorisk management strategy for protocols involving the manipulation of hazardous substances in these tubes. Further research should be conducted on other activities that could cause tubes to leak (such as centrifugation or vortexing) and should be completed to understand the risks associated with this consumable. Research into the costs and benefits of mitigating the risk of leaks from conical tubes is recommended.

Oral Antibiotic Bowel Preparation Prior to Urgent Colectomy Reduces Odds of Organ Space Surgical Site Infections: a NSQIP Propensity-Score Matched Study

BackgroundPreoperative administration of oral antibiotic bowel preparation (OABP) alone has been shown to reduce infectious outcomes in patients undergoing elective colectomy. However, it remains unclear if these benefits extend to the emergency setting. This is a retrospective, propensity-score matched study comparing 30-day perioperative morbidity between those who received OABP alone versus no preparation prior to urgent colectomy. MethodsUsing the American College of Surgeons National Surgical Quality Improvement Program database, adults undergoing urgent colectomy from 2012 to 2019 were included. Those who were clinically obstructed or who received mechanical bowel preparation were excluded. Outcomes of interest included: surgical site infection (SSI), leak, ileus, and major morbidity. ResultsOf 24,559 patients meeting inclusion criteria, 878 (3.6%) received OABP prior to urgent colectomy. Prior to matching, those receiving no preparation were more likely to have higher ASA class, diabetes, hypertension, preoperative sepsis, open procedures, and a dirty wound classification. After matching, 1756 patients, remained with 878 in each arm. Preoperative characteristics were balanced on univariate analysis. Postoperatively, patients receiving OABP experienced decreased organ space SSI (11.2% vs. 15.5%, p = 0.009) and ileus (30.3% vs. 35.3%, p = 0.029), with no difference in leak rates (3.3% vs 3.3%, p = 1.000) or NSQIP major morbidity (47.4% vs. 49.9%, p = 0.316). On multivariate logistic regression, including propensity score, the reduction in organ space SSI associated with OABP persisted (OR 0.684, 95% CI 0.516–0.903). ConclusionOABP prior to select urgent colectomies was associated with fewer organ space SSIs and may be considered when feasible.

3. Assessment of in vitro dural repair techniques with a hydrostatic pressure device

<h3>BACKGROUND CONTEXT</h3> Incidental durotomies are a relatively infrequent occurrence during lumbar spine surgery and are generally benign, without significant adverse consequences. Treatment with direct repair, with or without augmentation, is generally very effective and further cerebrospinal fluid (CSF) leak is uncommon. The strength and stability of a dural repair is dependent on several factors, including patient age, quality of dural tissue, the size and location of the durotomy, and the manner in which the repair is performed. There is limited in vitro evidence comparing the strength of different dural repair techniques and the resulting likelihood of recurrent CSF leak. <h3>PURPOSE</h3> To compare the strength and stability of various dural repair techniques in an in vitro human cadaveric durotomy model. <h3>STUDY DESIGN/SETTING</h3> An in vitro testing device was created to apply controlled, hydrostatic pressure to evaluate the integrity of a surgically-created durotomy. <h3>PATIENT SAMPLE</h3> Sixteen human cadaveric specimens. <h3>OUTCOME MEASURES</h3> The hydrostatic pressure required to cause a leak at the site of the dural repair. <h3>METHODS</h3> Complete human cadavers were placed in the prone position and the dura in the thoracic and lumbar spines was exposed through a midline incision and subsequent laminectomies. The dura was clamped 8 cm proximal and distal to the level of the durotomy and clamped with reliable, water-tight plastic rings. A 16-gauge plastic catheter was introduced into the lateral aspect of the dura and sutured in a water-tight fashion to serve as the source for instilling saline into the dura. The catheter was attached to a hydrostatic pressure measuring column to assess the intradural pressure. Linear durotomies of either 1 cm or 6 cm in length were made with a 15 blade in both the thoracic and lumbar spines of each cadaver. A dural repair was performed with either a 6-0 prolene or 2-0 silk suture. Repair technique were either multiple, simple interrupted sutures or a simple running repair with knots at the respective margins of the durotomy. An analysis of variant analysis (ANOVA) was employed to assess differences in leak rates with respect to applied hydrostatic pressure. <h3>RESULTS</h3> Eight repair groups (thoracic vs lumbar / 6-0 prolene vs 2-0 silk / running vs multiple interrupted) were studied for each of the 1 cm and 6 cm durotomies. There were no significant differences noted in the frequency or extent of spinal fluid leak at different hydrostatic pressures with respect to either suture type employed or suture technique performed. There was a slight difference in the mean applied hydrostatic pressure applied to create a fluid leak in the 6 cm durotomy (16 cm H2O) compared to the 1 cm durotomy (12 cm H2O) but this did not reach statistical significance. <h3>CONCLUSIONS</h3> In this in vitro study of the integrity of the repair of experimentally created durotomies, no significant difference was noted with respect to different suture type or technique of repair. Larger durotomies had a slight, not significant trend for recurrent leak at lower applied hydrostatic pressures. In general, expansion of the repaired dura with controlled delivery of intrathecal fluid, simulating an in vivo, intraoperative Valsalva maneuver, did not reveal significant differences in varying repair types. While this in vitro study does not directly replicate an in vivo scenario, the results do reinforce the necessity of a meticulous water tight suture repair to adequately treat incidental durotomies and thus avoid the troublesome consequences of a recurrent CSF leak. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Reconstruction and Cerebrospinal Fluid Leaks in Endoscopic Endonasal Approach for the Management of Clival Chordomas-A Systematic Review.

The success of the endoscopic endonasal approach (EEA) to surgically manage clival chordomas (CC) relies on robust repair methods to reduce complications, such as cerebrospinal fluid (CSF) leaks. Our study aims to evaluate the existing literature to assess reconstructive techniques utilised and post-operative CSF leak rates in this cohort. A systematic review and analysis was performed of all published data related to CC patients managed with an EEA. A total of 24 articles were included, representing 363 patients and 396 procedures. A variety of reconstruction methods were used with 95.9% of studies using an intracranial repair graft, 70.8% using a nasoseptal flap (NSF), 62.5% using glue/haemostat, 58.3% using nasal packs and 75.0% employing multi-layered reconstruction. Post-operative CSF leak rate was 10.1%. The leak rate was less in subgroups where a NSF was used (9.4%) although this was not statistically significant (p = 0.273). There were no differences in leak rates when glue/haemostat (p = 0.139) or nasal packs (p = 0.550) were used. Our review is the most up-to-date synthesis of the existing literature surrounding the EEA to CCs assessing reconstruction and post-operative CSF leaks. It demonstrates most authors employ a multi-layered reconstruction method. The lack of statistical significance observed for CSF leaks in subgroups is likely due to a variety of cofounding surgeon and patient factors. Higher quality prospective randomised multi-centric studies, with reporting of specific repair techniques will enable future systematic reviews to provide a more accurate consensus regarding optimal methods of reconstruction in this field.

Timing and outcome of right- vs left-sided colonic anastomotic leaks: Is there a difference?

BackgroundAnastomotic leaks (AL) contribute to postoperative mortality, prolonged hospitalization, and increased health care costs. While left-sided AL (LAL) are well described in the literature, there is a paucity of studies on outcomes and management of right-sided AL (RAL). This study aimed to compare the timing of RAL versus LAL, and the variable diagnosis, management and outcomes of RAL versus LAL. We hypothesized that the timing of RAL may be later compared to LAL and may result in worse overall outcomes. MethodsPatients who underwent curative intent surgery for neoplastic disease from January 1995 to December 2015 were included. Patients that underwent an anastomosis below the peritoneal reflection, neoadjuvant treatment, fecal diversion, previous colectomy/anastomosis, multiple anastomoses, and patients with inflammatory bowel disease or hereditary colorectal cancer syndromes were excluded. Patient demographics, neoplastic data, operative data, time to AL, methods utilized for diagnosis of AL, and management of AL were collected. The primary endpoint was timing of AL, and secondary endpoints were management and outcome based on RAL versus LAL. RAL and LAL were analyzed and compared using Chi-squared and categorical variables were expressed as number (percentage) and continuous variables expressed as median (interquartile range). ResultsA total of 2223 patients underwent oncologic resection for colonic neoplasia (1457 right sided and 766 left sided anastomoses). 67% of patients were male and median age was 69 years (range, 34–91). There were 48 total AL events (2.16%): 26 RAL (1.78%) and 22 LAL (2.87%). There was no statistical difference in leak rates between RAL and LAL and no difference in time to diagnosis or management (Table 1). RAL had significantly decreased operative time (p = 0.016), decreased intraoperative blood loss (p = 0.002), and increased diagnosis by CT/plain radiograph (p = 0.04). All patients that underwent surgery for leak had some form of fecal diversion performed. Morbidity and mortality were comparable between groups (p = 0.70; p = 1.0). ConclusionsThis study found overall very low AL rates with comparable timing of RAL and LAL, and no difference in management or outcome of RAL vs. LAL. These findings are informative for patient and surgeon expectations before and after surgery and when AL is suspected.

TP6.2.23 Does using intraoperative Tisseel reduce the leak rate in Cardio-Oesophagectomy: A single centre retrospective audit of anastomotic and chyle leaks

Abstract Aims Anastomotic leak and chylothorax are serious complications of cardio-oesophagectomy. The application of a tissue sealant to the anastomosis and ligated thoracic duct could be beneficial in protecting against leaks. We aimed to determine if using Tisseel, a fibrin-based tissue sealant, had any impact on anastomotic or chyle leak rates following cardio-oesophagectomy. Methods All elective cardio-oesophagectomys performed in a tertiary upper GI centre between 01/01/2013 and 01/01/2018 were identified. Patient records were retrospectively analysed to assess basic demographics; whether Tisseel was used; whether anastomotic or chyle leak occurred and if so whether this was managed conservatively or surgically. Results 245 records were available, Tisseel was used in 151 cases (61.6%). Patient demographics were similar between the Tisseel and no Tisseel groups (82.7% vs 77.7% male, mean age 66 vs 65 years). There was no significant difference in anastomotic leak (4.0% vs 7.4%, p = 0.24) or chyle leak (6.6% vs 4.3%, p = 0.44) rates. For patients who had an anastomotic leak there was a significantly lower rate of re-thoracotomy when Tisseel was used (16.7% vs 85.7%, p = 0.021). There was no significant difference in re-thoracotomy rates for chyle leak (40% vs 100%, p = 0.085). Conclusion Our data does not show any significant difference in leak rates when Tisseel is used. However, it does show that Tisseel use is associated with lower rate of re-thoracotomy in patients with anastomotic leak. This could possibly be due to smaller contained leaks. Further work is needed to determine the true benefit of Tisseel use in cardio-oesophagectomy.

Outcomes of 350 Robotic-assisted Esophagectomies at a High-volume Cancer Center: A Contemporary Propensity-score Matched Analysis.

To evaluate perioperative and oncologic outcomes in our RAMIE cohort and compare outcomes with contemporary OE controls. RAMIE has emerged as an alternative to traditional open or laparoscopic approaches. Described in all esophagectomy techniques, rapid adoption has been attributed to both enhanced visualization and technical dexterity. We retrospectively reviewed patients who underwent RAMIE for malignancy. Patient characteristics, perioperative outcomes, and survival were evaluated. For perioperative and oncologic outcome comparison, contemporary OE controls were propensity-score matched from NSQIP and NCDB databases. We identified 350 patients who underwent RAMIE between 2010 and 2019. Median body mass index was 27.4, 32% demonstrated a Charlson Comorbidity Index >4. Nodal disease was identified in 50% of patients and 74% received neoadjuvant chemoradiotherapy. Mean operative time and blood loss were 425 minutes and 232 mL, respectively. Anastomotic leak occurred in 16% of patients, 2% required reoperation. Median LOS was 9 days, and 30-day mortality was 3%. A median of 21 nodes were dissected with 96% achieving an R0 resection. Median survival was 67.4 months. 222 RAMIE were matched 1:1 to the NSQIP OE control. RAMIE demonstrated decreased LOS (9 vs 10 days, P = 0.010) and reoperative rates (2.3 vs 12.2%, P = 0.001), longer operative time (427 vs 311 minutes, P = 0.001), and increased rate of pulmonary embolism (5.4% vs 0.9%, P = 0.007) in comparison to NSQIP cohort. There was no difference in leak rate or mortality. Three hundred forty-three RAMIE were matched to OE cohort from NCDB with no difference in median overall survival (63 vs 53 months; P = 0.130). In this largest reported institutional series, we demonstrate that RAMIE can be performed safely with excellent oncologic outcomes and decreased hospital stay when compared to the open approach.

A prospective trial of intraoperative tissue oxygenation measurement and its association with anastomotic leak rate after Ivor Lewis esophagectomy.

BackgroundAnastomotic leak following Ivor Lewis esophagectomy is associated with increased morbidity/mortality and decreased survival. Tissue oxygenation at the anastomotic site may influence anastomotic leak. Methods for establishing tissue oxygenation at the anastomotic site are lacking.MethodsOver a 2-year study period, 185 Ivor Lewis esophagectomies were performed. Study participants underwent measurement of gastric conduit tissue oxygenation at the planned anastomotic site using the wireless pulse oximetry device. Associations between anastomotic leaks or strictures and tissue oxygenation levels were analyzed using Wilcoxon rank sum test or Fisher’s exact test.ResultsAmong study participants (n=114), median gastric conduit tissue oxygenation level was 92% (range, 62–100%). There were 8 (7.0%) anastomotic leaks and 3 (2.6%) strictures. Analysis of tissue oxygenation as a continuous variable showed no difference in median tissue oxygenation in patients with and without leaks (98% and 92%; P=0.2) and stricture formation (89% and 92%; P=0.6). Analysis of tissue oxygenation as a dichotomous variable found no difference in anastomotic leak rates [7.5% (n=93) in >80% vs. 0% (n=20) in ≤80%; P=0.3]. There were no significant differences in leak rates in concurrent study nonparticipants.ConclusionsNo significant association was observed between intraoperative tissue oxygenation at the anastomotic site and subsequent anastomotic leak or stricture formation among patients undergoing Ivor Lewis esophagectomy.

Effect of thoracic versus cervical anastomosis on anastomotic leak among patients who undergo esophagectomy after neoadjuvant chemoradiation

ObjectiveTo assess the rate and effect of anastomotic leak among patients who undergo esophagectomy with either thoracic or cervical anastomosis after neoadjuvant chemoradiation. MethodsWe conducted a retrospective cohort study using data from the National Surgical Quality Improvement Program Esophagectomy Data File. We included adult patients who underwent esophagectomy for esophageal cancer (2016-2017) after neoadjuvant chemoradiation. We used inverse probability of treatment weighted regression adjustment to compare 30-day anastomotic leak and mortality rates among patients with cervical or thoracic anastomoses. We accounted for confounding due to patient-, surgeon-, and procedure-related variables. ResultsOf the 908 patients who met inclusion criteria, 528 (58%) had a thoracic anastomosis and 119 (13%) experienced anastomotic leak. There was no statistically significant difference in leak rate for patients who underwent thoracic (12%) compared with cervical anastomoses (14%) in the inverse probability of treatment weighted regression adjustment analysis (P = .09). Although overall 30-day mortality was low (2.3%), it was significantly higher among patients who had an anastomotic leak (8.4% vs 1.4%; P < .01). Among patients with a leak, there was no significant difference in length of stay, mortality, or type of required intervention for patients with cervical versus thoracic anastomoses. ConclusionsAnastomosis type does not affect leak rates or mortality after esophagectomy in patients who have undergone neoadjuvant chemoradiation. Patient risk factors and surgeon experience should determine the ideal surgical approach for each patient.

Analysis of the impact of EEA stapler size on risk of anastomotic complications in colorectal anastomosis: does size matter?

Colorectal anastomotic complications are dreaded and dramatically affect outcomes. Causes are multifactorial, with the size of the end-to-end anastomosis (EEA) stapler a modifiable factor and potential target for risk reduction. Our goal was to examine the impact of the EEA stapler size on the risk of anastomotic complications in left-sided colorectal resections. A prospective divisional database was reviewed for consecutive elective left-sided resections with a colorectal anastomosis using an EEA stapler from January 2013 May 2018 inclusive. Patients were stratified into 25-29mm or 30-33mm cohorts. Patient and disease demographics, operative variables, and postoperative outcomes were evaluated. The main outcome measures were the rate and factors associated with anastomotic complications. Four hundred seventy-three cases were evaluated, 185 ( 39.1%) were in the 25-29mm group and 288 (60.9%) in the 30-33mm group. Patients were comparable in demographics and operative variables. More males were anastomosed with the 30-33mm than with the 25-29mm stapler (57.6% vs 28.6%, p < 0.01). Significantly more patients developed an anastomotic stricture with the 25-29mm than with the 30-33mm staplers (7.1% vs. 2.1%; p = 0.007). There was no significant difference in leak rates or reoperation/interventions between groups. On logistic regression, neither gender, operative indication nor approach were associated with anastomotic leak, readmission, or reoperation/intervention. Stapler size remained significantly associated with stricture (p = 0.032). The 25-29mm EEA staplers were associated with an increased rate of anastomotic stricture compared to 30-33mm staplers in left-sided colorectal anastomoses. As stapler size is a simple process measure that is easily modifyable, this is a potential target for improving anastomotic complication rates. Further controlled trials may help assess the impact of stapler size on improving patient and quality outcomes.

Wound leakage rates of ex vivo uniplanar versus biplanar phacoemulsification clear corneal incisions in dogs.

The purpose of this study was to compare the leakage rates of perilimbal uniplanar and biplanar clear corneal incisions in dogs when subjected to increased intraocular pressure (IOP) both from within the eye and via external pressure. Uniplanar clear corneal incisions were created in eight freshly enucleated canine eyes using a 3.2mm straight slit knife while 8 fellow eyes received a biplanar clear corneal incision consisting of an approximately 300μm deep groove followed by a 3.2mm straight slit knife entry into the anterior chamber. Both wounds were reapposed using three simple interrupted 8-0 polyglactin 910 sutures. Eyes were cannulated with two 25g needles: One connected to a pressure transducer, and the other connected to a reservoir of isotonic saline. The IOP at which the wound leaked was recorded when the intraocular pressure was increased internally by raising the height of the fluid bag, and again when the cornea was externally compressed. Kaplan-Meier survival curves compared incision types for each method of increasing IOP and were evaluated using Mantel-Cox log-rank analysis. Both wound types resisted leakage at IOP in the physiologically achievable range and no significant differences were observed between clear corneal incisions when pressure was applied externally (P=.353) or was increased from within the globe (P=.615). Ex vivo uniplanar and biplanar clear corneal incisions in dogs are equally strong, with no significant differences in leakage rates when IOP is increased internally or externally.

Reinforcement of intrathoracic oesophago-gastric anastomosis with fibrin sealant (Tisseel®) in oesophagectomy for cancer: A prospective comparative study

PurposeFibrin sealant (Tisseel) is a human protein and thrombin soluble fibrinogen that has been indicated for reinforcement of gastro-intestinal anastomoses to prevent leakage. The objective of this study is to examine the impact of fibrin sealant regarding anastomotic leak, following Ivor-Lewis procedure. MethodsThis is a prospective comparative study on 2-stage oesophagectomy for cancer of the distal oesophagus or oesophagogastric junction. N = 57 individuals were randomly subjected; n = 22 patients to Tisseel in combination to surgical anastomosis versus n = 35 patients to surgical anastomosis alone. The test of probability was assessed through Chi-Square, independent samples paired T-Test and Log-Rank analysis. ResultsOf the 57 cases included, 56 underwent hybrid and 1 open oesophagectomy. In the Tisseel group, n = 5(22.7%) developed anastomotic leak comparing to n = 3(8.6%) of the control group. No statistically significant difference in leak rate was shown between the two groups; the test of probability was rejected. ConclusionsOur results are not supportive of Tisseel tissue sealing property on the intrathoracic oesophago-gastric anastomosis and fibrin sealant's use cannot be justified.

Fresh underground light non-aqueous liquid (LNAPL) pollution source zone monitoring in an outdoor experiment using cross-hole electrical resistivity tomography.

Real-time monitoring of source zone of light non-aqueous liquids (LNAPLs) is important for preventing accidental pollution and taking effective underground pollution remediation measures. As a high-precision monitoring technology, cross-hole electrical resistivity tomography (CHERT) has been widely used to obtain static information regarding underground stratigraphic structures and dynamic information regarding fluid motion. The time-lapse data processing method can be used to obtain pollution zone dynamic change information. Since the leakage rate directly affects the diffusion range of pollution, this study simulated the initial evolution process of LNAPL pollution source regions under two different leakage rates. The time-lapse monitoring of the above process was performed using CHERT. The test results show that CHERT can be used to observe the migration of LNAPLs and the initial evolution of the contaminated area. Differences in leakage rate will result in variation in soil wettability and fluid distribution, which will cause changes in soil resistivity in the corresponding region. The low-saturation LNAPL-contaminated area may exhibit low-resistivity characteristics and is easily overlooked in field investigations. In addition, the degree of contamination in the saturated zone can be quantitatively evaluated by CHERT; however, the pollution range and oil saturation value determined by CHERT are underestimated. The results showed the electrical variation characteristics of the initial evolution process of the fresh pollution source area and provide data that will enable early warnings of LNAPL leakage. This shows that CHERT is a promising tool for monitoring LNAPL pollution source leakage even if further research is needed to fully understand the effect of hydrological processes on electronic signals.

A large single-institution review of tracheoesophageal fistulae with evaluation of the use of transanastomotic feeding tubes

IntroductionTransanastomatic feeding tube (TAT) use in the repair of tracheoesophageal fistulas (TEF) with or without esophageal atresia (EA) and EA with or without TEF allows for earlier enteral feedings, however, may predispose to esophageal stricture. MethodsWe review our institutional experience with esophageal atresia repair over a 15-year period from 2000 to 2015 and report on our observed complication rate with emphasis on the surgical approach and use of TATs. ResultsWe identified 110 TEF repairs. Ninety-six were Type C, 7 were Type A, 4 were Type D, and 3 were Type E (H-Type). TATs were used in 74% of patients. The stricture rate with the TAT approached 56% versus 17% without a TAT (p<0.0005). There was no difference in leak rate (p=0.27). Ninety-four TEF repairs were performed via open thoracotomy, and 16 were initially approached thoracoscopically. Six out of 16 that were started thoracoscopically were completed with the minimally invasive approach. Whether the case was started thoracoscopically, completed thoracoscopically, or performed open made no difference in the rate of stricture or anastomotic leak, but we did observe an increase in musculoskeletal complications in the open thoracotomy group (28% vs. 0). ConclusionOur data suggests that the use of TATs does not protect against anastomotic leak, but may increase stricture rate. Further, the thoracoscopic group showed no difference in the leak or stricture rate and demonstrated less musculoskeletal complications. Confirmation of these findings will require a prospective study. Level of evidenceIII.

Microbial microleakage assessment of class V cavities restored with different materials and techniques: A laboratory study.

The aim of this study was to compare microbial microleakage of class V cavities restored with different materials and techniques using a microbial leakage assessment method. One hundred extracted, caries-free, human maxillary premolars were randomly divided into five groups. Group 1: Resin-modified glass ionomer (RMGI), Group 2: Closed sandwich with flowable composite + nanohybrid composite, Group 3: Nanohybrid composite, Group 4: Closed sandwich with RMGI + nanohybrid composite, and Group 5: Flowable composite + nanohybrid composite that were co-cured together ("snow-plow" technique). A microbial penetration method utilizing Streptococcus mutans as an indicator was tested for leakage assessment. Data were analyzed and the significance level was α =0.05. The log-rank test indicated a statistically significant difference in leakage rates among the five groups (P = 0.008). Mantel-Cox log-rank test indicated statistically significant differences in microleakage rates between Groups 1 and 3 (P = 0.029), between Groups 2 and 5 (P = 0.005), and between Groups 3 and 5 (P = 0.002). With respect to the limitations of an in vitro study, our findings suggest that adding a thin layer of flowable composite or RMGI under nanohybrid composite in class V cavities did not decrease the bacterial leakage rate, whereas use of the "snow-plow" technique caused an increase in the microleakage rate.

Risk factors for cerebrospinal fluid leak in pediatric patients undergoing endoscopic endonasal skull base surgery

ObjectivesTo determine the risk factors associated with cerebrospinal fluid (CSF) leak following endoscopic endonasal surgery (EES) for pediatric skull base lesions. MethodsRetrospective chart review of pediatric patients (ages 1 month to 18 years) treated for skull base lesions with EES from 1999 to 2014. Five pathologies were reviewed: craniopharyngioma, clival chordoma, pituitary adenoma, pituitary carcinoma, and Rathke's cleft cyst. Fisher's exact tests were used to evaluate the different factors to determine which had a statistically higher risk of leading to a post-operative CSF leak. Results55 pediatric patients were identified who underwent 70 EES's for tumor resection. Of the 70 surgeries, 47 surgeries had intraoperative CSF leaks that were repaired at the time of surgery. 11 of 47 (23%) surgeries had post-operative CSF leaks that required secondary operative repair. Clival chordomas had the highest CSF leak rate at 36%. There was no statistical difference in leak rate based on the type of reconstruction, although 28% of cases that used a vascularized flap had a post-operative leak, whereas only 9% of those cases not using a vascularized flap had a leak. Post-operative hydrocephalus and perioperative use of a lumbar drain were not significant risk factors. ConclusionsPediatric patients with an intra-operative CSF leak during EES of the skull base have a high rate of post-operative CSF leaks. Clival chordomas appear to be a particularly high-risk group. The use of vascularized flaps and perioperative lumbar drains did not statistically decrease the rate of post-operative CSF leak.

A multicenter randomized controlled trial comparing pancreatic leaks after TissueLink versus SEAMGUARD after distal pancreatectomy (PLATS) NCT01051856

BackgroundPancreatic leak is common after distal pancreatectomy. This trial sought to compare TissueLink closure of the pancreatic stump to that of SEAMGUARD. MethodsA multicenter, prospective, trial of patients undergoing distal pancreatectomy randomized to either TissueLink or SEAMGUARD. ResultsEnrollment was closed early due to poor accrual. Overall, 67 patients were enrolled, 35 TissueLink and 32 SEAMGUARD. The two groups differed in American Society of Anesthesiologist class and diagnosis at baseline and were relatively balanced otherwise. Overall, 37 of 67 patients (55%) experienced a leak of any grade, 15 (46.9%) in the SEAMGUARD arm and 22 (62.9%) in the TissueLink arm (P = 0.19). The clinically significant leak rate was 17.9%; 22.9% for TissueLink and 12.5% for SEAMGUARD (P = 0.35). There were no statistically significant differences in major or any pancreatic fistula–related morbidity between the two groups. ConclusionsThis is the first multicentered randomized trial evaluating leak rate after distal pancreatectomy between two common transection methods. Although a difference in leak rates was observed, it was not statistically significant and therefore does not provide evidence of the superiority of one technique over the other. Choice should remain based on surgeon comfort, experience, and pancreas characteristics.

Sutureless closure of colonic defects with tissue adhesives: an in vivo study in the rat

BackgroundTissue adhesives (TAs) in gastrointestinal surgery are gradually gaining acceptance. Before implementation as colonic sealants, an evaluation of the sealing capability of a TA when in contact with fecal matter, as in a leaking anastomosis, is needed. In this study, we used clinically available TAs for the sutureless closure of colonic defects evaluating mechanical strength and tissue healing. MethodsA total of 160 rats were divided into 8 groups. Two .5-cm incisions were created, one in the proximal and another in the distal colon. Incisions were sealed with a TA: Histoacryl Flex, Bioglue, Dermabond, Tissucol, Duraseal Xact, gelatin-resorcinol-formaldehyde or Glubran 2. A control group was included in which the colonic defects were not sealed. Follow-up time was 3 or 10 days. Clinical complication rate, bursting pressure, and histopathologic analysis was included. ResultsLeakage rates in the TA groups were highest for Duraseal Xact, Bioglue, and gelatin-resorcinol-formaldehyde at 3 and 10 days. The cyanoacrylates Glubran 2, Histoacryl Flex, and Omnex, and the fibrin glue Tissucol showed the lowest overall clinical complication rates while maintaining the highest bursting pressure at day 10. Histoacryl Flex exhibited significantly higher collagen formation at day 10 than the other TAs. ConclusionsThis experimental model evaluates the protective effect of a TA seal on a leaking colonic defect. We found large differences in leakage rates and inertness of the tested TAs. The cyanoacrylates Histoacryl Flex, Omnex, and Glubran 2 as well as the fibrin glue Tissucol demonstrated the lowest leakage rates and the most inert histopathologic profile while maintaining high mechanical strength.