Determining the value of the abdominal core health quality collaborative to support regulatory decisions

PURPOSE

The study objective is to document value created by real-world evidence from the Abdominal Core Health Quality Collaborative (ACHQC) for regulatory decisions. The ACHQC is a national effort that generates data on hernia repair techniques and devices.

METHODS

Two retrospective cohort evaluations compared cost and time of ACHQC analyses to traditional postmarket studies. The first analysis was based on 25 reports submitted to the European Medicines Agency of 20 mesh products for post-market surveillance. A second analysis supported label expansion submitted to the Food and Drug Administration, Center for Devices and Radiological Health for a robotic-assisted surgery device to include ventral hernia repair. Estimated costs of counterfactual studies, defined as studies that might have been done if the registry had not been available, were derived from a model described in the literature. Return on investment, percentage of cost savings, and time savings were calculated.

RESULTS

45,010 patients contributed to the two analyses. The cost and time differences between individual 25 ACHQC analyses (41,112 patients) and traditional studies ranged from $1.3 to $2.2 million and from 3 to 4.8 years, both favoring use of the ACHQC. In the second label expansion analysis (3,898 patients), the estimated return on investment ranged from 11 to 461% with time savings of 5.1 years favoring use of the ACHQC.

CONCLUSIONS

Compared to traditional postmarket studies, use of ACHQC data can result in cost and time savings when used for appropriate regulatory decisions in light of key assumptions.

Preoperative optimization in hernia surgery: are we really helping or are we just stalling?

BACKGROUND

Managing patients with abdominal wall hernias and multiple comorbidities can be challenging because these patients are at increased risk for postoperative complications. Preoperative optimization has been used to identify and intervene upon modifiable risk factors to improve hernia repair outcomes, however, waiting to achieve optimization may cause unnecessary delays.

METHODS

We describe our approach to preoperative optimization in hernia and we review the current evidence for preoperative optimization.

CONCLUSION

Modifying risk factors before undergoing elective hernia repair can improve the overall health of patients with multiple comorbidities. However, when considering the hernia-specific data, prolonging waiting times for patients to achieve full optimization is not justified. Surgeons should take a nuanced approach to balance achieving patient optimization without unnecessarily delaying surgical care.

Analysis of retromuscular drain output and postoperative outcomes for heavyweight versus mediumweight polypropylene mesh following open ventral hernia repair

PURPOSE

Heavyweight polypropylene (HWPP) mesh is thought to increase inflammatory response and delay tissue integration compared to mediumweight (MWPP). Reactive fluid volume (i.e., drain output) may be a reasonable surrogate for integration. We hypothesized that daily drain output is higher with HWPP compared to MWPP in open retromuscular ventral hernia repair (VHR).

METHODS

This is a post-hoc analysis of a multicenter, randomized clinical trial conducted March 2017-April 2019 comparing MWPP and HWPP for VHR. Retromuscular drain output in milliliters was measured at 24-h intervals up to postoperative day seven. Univariate analyses compared differences in daily drain output and time to drain removal. Multivariable analyses compared total drain output and wound morbidity within 30 days and hernia recurrence at 1 year.

RESULTS

288 patients were included; 140 (48.6%) HWPP and 148 (51.4%) MWPP. Daily drain output for days 1-3 was higher for HWPP vs. MWPP (total volume: 837.8 mL vs. 656.5 mL) (p < 0.001), but similar on days 4-7 (p > 0.05). Median drain removal time was 5 days for both groups. Total drain output was not predictive of 30-day wound morbidity (p > 0.05) or hernia recurrence at 1 year (OR 1, p = 0.29).

CONCLUSION

While HWPP mesh initially had higher drain outputs, it rapidly returned to levels similar to MWPP by postoperative day three and there was no difference in clinical outcomes. We believe that drains placed around HWPP mesh can be managed similarly to MWPP mesh.

Outcomes of posterior component separation with transversus abdominis release for repair of abdominally based breast reconstruction donor site hernias

PURPOSE

Abdominally based autologous breast reconstruction (ABABR) is common after mastectomy, but carries a risk of complex abdominal wall hernias. We report experience with posterior component separation (PCS) and transversus abdominis release (TAR) with permanent synthetic mesh repair of ABABR-related hernias.

METHODS

Patients at Cleveland Clinic Foundation and Penn State Health were identified retrospectively. Outcomes included postoperative complications, hernia recurrence, and patient-reported outcomes (PROs): Hernia Recurrence Inventory, HerQLes Summary Score, Patient-Reported Outcome Measurement Information System (PROMIS) Pain Intensity 3a Survey, and the Decision Regret Scale (DRS).

RESULTS

Forty patients underwent PCS/TAR repair of hernias resulting from pedicled (35%), free (5%), muscle-sparing TRAMs (15%), and DIEPs (28%) from August 2014 to March 2021. Following PCS, 30-day complications included superficial surgical site infection (13%), seroma (8%), and superficial wound breakdown (5%). Five patients (20%) developed clinical hernia recurrence. At a minimum of 1 year, 17 (63%) reported a bulge, 12 (44%) reported pain, median HerQLes Quality Of Life Scores improved from 33 to 63/100 (p value < 0.01), PROMIS 3a Pain Intensity Scores improved from 52 to 38 (p value < 0.05), and DRS scores were consistent with low regret (20/100).

CONCLUSION

ABABR-related hernias are complex and technically challenging due to missing abdominal wall components and denervation injury. After repair with PCS/TAR, patients had high rates of recurrence and bulge, but reported improved quality of life and pain and low regret. Surgeons should set realistic expectations regarding postoperative bulge and risk of hernia recurrence.

Outcomes of complex abdominal wall reconstruction in patients with connective tissue disorders: a single center experience

INTRODUCTION

Individuals diagnosed with connective tissue disorders (CTD) are known to be predisposed to incisional hernia formation. However, there is a scarcity of data on outcomes for these patients undergoing hernia repair. We sought to describe our outcomes in performing abdominal wall reconstructions in these complex patients.

METHODS

Adult patients with CTD undergoing open, elective, posterior component separation with permanent synthetic mesh at our institution from January 2018 to October 2022 were queried from a prospectively collected database in the Abdominal Core Health Quality Collaborative. We evaluated 30-day wound morbidity, perioperative complications, long-term hernia recurrence, and patient-reported quality of life.

RESULTS

Twelve patients were identified. Connective tissue disorders included Marfan's n = 7 (58.3%), Loeys-Dietz syndrome n = 2 (16.7%), Systemic Lupus Erythematosus n = 2 (16.7%), and Scleroderma n = 1 (8.3%). Prior incisions included three midline laparotomies and nine thoracoabdominal, mean hernia width measured 14 cm, and 9 were recurrent hernias. Surgical site occurrences (SSOs) were observed in 25% of cases, and 16.7% necessitated procedural intervention. All twelve patients were available for long-term follow-up, with a mean of 34 (12-62) months. There were no instances of reoperation or mesh excision related to the TAR procedure. One patient developed a recurrence after having his mesh violated for repair of a new visceral aneurysm. Mean HerQLes scores at 1 year were 70 and 89 at ≥ 2 years; Mean scaled PROMIS scores were 30.7 at 1 year and 36.3 at ≥ 2 years.

CONCLUSION

Ventral hernia repair with TAR is feasible in patients with connective tissue disorder and can be a suitable alternative in patients with large complex hernias.

Cannabis smoking and abdominal wall reconstruction outcomes: a propensity score-matched analysis

PURPOSE

Despite increasing use of cannabis, literature on perioperative effects is lagging. We compared active cannabis-smokers versus non-smokers and postoperative wound morbidity and reoperations following open abdominal wall reconstruction (AWR).

METHODS

Patients who underwent open, clean, AWR with transversus abdominis release and retromuscular synthetic mesh placement at our institution between January 2014 and May 2022 were identified using the Abdominal Core Health Quality Collaborative database. Active cannabis-smokers were 1:3 propensity matched to non-smokers based on demographics and comorbidities. Wound complications, 30 day morbidity, pain (PROMIS 3a-Pain Intensity), and hernia-specific quality of life (HerQles) were compared.

RESULTS

Seventy-two cannabis-smokers were matched to 216 non-smokers. SSO (18% vs 17% p = 0.86), SSI (11.1% vs 9.3%, p = 0.65), SSOPI (12% vs 12%, p = 0.92), and all postoperative complications (46% vs 43%, p = 0.63) were similar between cannabis-smokers and non-smokers. Reoperations were more common in the cannabis-smoker group (8.3% vs 2.8%, p = 0.041), driven by major wound complications (6.9% vs 3.2%, p = 0.004). No mesh excisions occurred. HerQles scores were similar at baseline (22 [11, 41] vs 35 [14, 55], p = 0.06), and were worse for cannabis-smokers compared to non-smokers at 30 days (30 [12, 50] vs 38 [20, 67], p = 0.032), but not significantly different at 1 year postoperatively (72 [53, 90] vs 78 [57, 92], p = 0.39). Pain scores were worse for cannabis-smokers compared to non-smokers at 30 days postoperatively (52 [46, 58] vs 49 [44, 54], p = 0.01), but there were no differences at 6 months or 1 year postoperatively (p > 0.05 for all).

CONCLUSION

Cannabis smokers will likely experience similar complication rates after clean, open AWR, but should be counseled that despite similar wound complication rates, the severity of their wound complications may be greater than non-smokers.

The impact of comorbidities on postoperative outcomes of ventral hernia repair: the patients' perspective

INTRODUCTION

Ventral hernia repair (VHR) outcomes can be adversely affected by modifiable patient co-morbidities, such as diabetes, obesity, and smoking. Although this concept is well accepted among surgeons, the extent to which patients understand the significance of their co-morbidities is unknown, and a few studies have sought to determine patient perspectives regarding the impact of their modifiable co-morbidities on their post-operative outcomes. We attempted to determine how accurately patients predict their surgical outcomes after VHR compared to a surgical risk calculator while considering their modifiable co-morbidities.

METHODS

This is a prospective, single-center, survey-based study evaluating patients' perceptions of how their modifiable risk factors affect outcomes after elective ventral hernia repair. Pre-operatively, after surgeon counseling, patients predicted the percentage of impact that they believed their modifiable co-morbidities (diabetes, obesity, and smoking) had on 30-day surgical site infections (SSI) and hospital readmissions. Their predictions were compared to the Outcomes Reporting App for CLinicians and Patient Engagement (ORACLE) surgical risk calculator. Results were analyzed using demographic information.

RESULTS

222 surveys were administered and 157 were included in the analysis after excluding for incomplete data. 21% had diabetes, 85% were either overweight with body mass index (BMI) 25-29.9 or obese (BMI ≥ 30), and 22% were smokers. The overall mean SSI rate was 10.8%, SSOPI rate was 12.7%, and 30-day readmission rate was 10.2%. ORACLE predictions correlated with observed SSI rates (OR 1.31, 95% CI 1.12-1.54, p < 0.001), but patient predictions did not (OR 1.00, 95% CI 0.98-1.03, p = 0.868). The correlation between patient predictions and ORACLE calculations was weak ([Formula: see text] = 0.17). Patient predictions were on average 10.1 ± 18.0% different than ORACLE, and 65% overestimated their SSI probability. Similarly, ORACLE predictions correlated with observed 30-day readmission rates (OR 1.10, 95% CI 1.00-1.21, p = 0.0459), but patient predictions did not (OR 1.00, 95% CI 0.975-1.03, p = 0.784). The correlation between patient predictions and ORACLE calculations for readmissions was weak ([Formula: see text] = 0.27). Patient predictions were on average 2.4 ± 14.6% different than ORACLE, and 56% underestimated their readmission probability. Additionally, a substantial proportion of the cohort believed that they had a 0% risk of SSI (28%) and a 0% risk of readmission (43%). Education, income and healthcare employment did not affect the accuracy of patient predictions.

CONCLUSIONS

Despite surgeon counseling, patients do not accurately estimate their risks after VHR when compared to ORACLE. Most patients overestimate their SSI risk and underestimate their 30-day readmission risk. Furthermore, several patients believed that they had a 0% risk of SSI and readmission. These findings persisted regardless of level of education, income level, or healthcare employment. Additional attention should be directed toward setting expectations prior to surgery and using applications such as ORACLE to assist in this process.

Psychological disorders in patients with chronic postoperative inguinal pain

PURPOSE

Chronic postoperative inguinal pain (CPIP), a complication of inguinal hernia repair, may negatively affect mental health. The rates of psychological disorders in patients with CPIP are unknown. We aimed to describe the prevalence of psychological disorders coinciding with CPIP.

METHODS

A retrospective chart review was performed of all patients seen at the Cleveland Clinic Center for Abdominal Core Health's inter-disciplinary Chronic Groin Pain Clinic. This clinic is unique in that all patients are evaluated by a surgeon, a sonographer and radiologist, and a behavioral medicine psychologist. Patient psychological history and treatment, Depression Anxiety and Stress Scale (DASS) scores, pain catastrophizing, and trauma or abuse history were captured.

RESULTS

From January 2018 to January 2022, 61 patients were evaluated and included in the study. Psychological treatment had been provided to 37 (61%) patients (present: 16 (27%), past: 21 (35%)). The most common psychological disorders represented were depression (N = 13, 22%), anxiety (N = 10, 17%), and post-traumatic stress disorder (N = 5, 8%). DASS scores indicated that 20 (33%) patients were reporting symptoms of depression and 16 (27%) patients were reporting symptoms of anxiety. Of the 40 patients assessed for pain catastrophizing, 28 (70%) reported rumination, 9 (23%) reported magnification, and 23 (58%) reported feelings of helplessness. A childhood history of emotional or physical abuse was reported by 11 (18%) patients.

CONCLUSION

An inter-disciplinary groin pain clinic has revealed that patients with CPIP frequently have pre-existing complex psychosocial issues. A multi-specialty approach to CPIP may improve preoperative assessments and identify patients who may benefit from further psychological evaluation and treatment.

Comparing anterior gastropexy to no anterior gastropexy for paraesophageal hernia repair: a study protocol for a randomized control trial

BACKGROUND

More than half of patients undergoing paraesophageal hernia repair (PEHR) will have radiographic hernia recurrence at 5 years after surgery. Gastropexy is a relatively low-risk intervention that may decrease recurrence rates, but it has not been studied in a prospective manner. Our study aims to evaluate the effect of anterior gastropexy on recurrence rates after PEHR, compared to no anterior gastropexy.

METHODS

This is a two-armed, single-blinded, registry-based, randomized controlled trial comparing anterior gastropexy to no anterior gastropexy in PEHR. Adult patients (≥18 years) with a symptomatic paraesophageal hernia measuring at least 5 cm in height on computed tomography, upper gastrointestinal series, or endoscopy undergoing elective minimally invasive repair are eligible for recruitment. Patients will be blinded to their arm of the trial. All patients will undergo laparoscopic or robotic PEHR, where some operative techniques (crural closure techniques and fundoplication use or avoidance) are left to the discretion of the operating surgeon. During the operation, after closure of the diaphragmatic crura, participants are randomized to receive either no anterior gastropexy (control arm) or anterior gastropexy (treatment arm). Two hundred forty participants will be recruited and followed for 1 year after surgery. The primary outcome is radiographic PEH recurrence at 1 year. Secondary outcomes are symptoms of gastroesophageal reflux disease, dysphagia, odynophagia, gas bloat, regurgitation, chest pain, abdominal pain, nausea, vomiting, postprandial pain, cardiovascular, and pulmonary symptoms as well as patient satisfaction in the immediate postoperative period and at 1-year follow-up. Outcome assessors will be blinded to the patients' intervention.

DISCUSSION

This randomized controlled trial will examine the effect of anterior gastropexy on radiographic PEH recurrence and patient-reported outcomes. Anterior gastropexy has a theoretical benefit of decreasing PEH recurrence; however, this has not been proven beyond a suggestion of effectiveness in retrospective series. If anterior gastropexy reduces recurrence rates, it would likely become a routine component of surgical PEH management. If it does not reduce PEH recurrence, it will likely be abandoned.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04007952 . Registered on July 5, 2019.

Short-term outcomes and healthcare resource utilization following incisional hernia repair with synthetic mesh in patients with Crohn's disease

PURPOSE

While the use of synthetic mesh for incisional hernia repair reduces recurrence rates, little evidence exists regarding the impact of this practice on the disease burden of a Crohn's patient. We aimed to describe the post-operative outcomes and healthcare resource utilization following incisional hernia repair with synthetic mesh in patients with Crohn's disease.

METHODS

A retrospective review of adult patients with Crohn's disease who underwent elective open incisional hernia repair with extra-peritoneal synthetic mesh from 2014 to 2018 at a single large academic hospital with surgeons specializing in hernia repair was conducted. Primary outcomes included 30-day post-operative complications and long-term rates of fistula formation and hernia recurrence. The secondary outcome compared healthcare resource utilization during a standardized fourteen-month period before and after hernia repair.

RESULTS

Among the 40 patients included, six (15%) required readmission, 4 (10%) developed a surgical site occurrence, 3 (7.5%) developed a surgical site infection, and one (2.5%) required reoperation within the first 30 days. The overall median follow-up time was 42 months (IQR = 33-56), during which time one (2.5%) patient developed an enterocutaneous fistula and eight (20%) experienced hernia recurrence. Healthcare resource utilization remained unchanged or decreased across every category following repair.

CONCLUSION

The use of extra-peritoneal synthetic mesh during incisional hernia repair in patients with Crohn's disease was not associated with a prohibitively high rate of post-operative complications or an increase in healthcare resource utilization to suggest worsening disease during the first 4 years after repair. Future studies exploring the long-term outcomes of this technique are needed.

Understanding the benefits of botulinum toxin A: retrospective analysis of the Abdominal Core Health Quality Collaborative

This was a retrospective analysis of a prospectively maintained database that objectively evaluated the benefit of preoperative chemical component separation with botulinum toxin A in complex hernia repairs.

Continued evaluation.

Management of ventral hernia defect during enterocutaneous fistula takedown: practice patterns and short-term outcomes from the Abdominal Core Health Quality Collaborative

BACKGROUND

An enterocutaneous fistula (ECF) with an associated large hernia defect poses a significant challenge for the reconstructive surgeon. We aim to describe operative details and 30-day outcomes of elective hernia repair with an ECF when performed by surgeons participating in the Abdominal Core Health Quality Collaborative (ACHQC).

STUDY DESIGN

Patients undergoing concomitant hernia and ECF elective repair were identified within the ACHQC. Outcomes of interest were operative details and 30-day rates of surgical site infections (SSI), surgical site occurrences requiring procedural intervention (SSOPI), medical complications, and mortality.

RESULTS

170 patients were identified (mean age 60 years, 52.4% females, mean BMI 32.3 kg/m²). 106 patients (62%) had small-bowel ECFs, mostly managed with resection without diversion. 30 patients (18%) had colonic ECFs, which were managed with resection without diversion (14%) or resection with diversion (6%). 100 (59%) had a prior mesh in place, which was removed in 90% of patients. Hernias measured 14 cm ± 7 in width, and 68 (40%) had a myofascial release performed (41 TARs). Mesh was placed in 115 cases (68%), 72% as a sublay, and more frequently of biologic (44%) or permanent synthetic (34%) material. 30-day SSI was 18% (37% superficial, 40% deep), and 30-day SSOPI was 21%. 19 patients (11%) were re-operated: 8 (8%) due to a wound complication and 4 (2%) due to a missed enterotomy. Two infected meshes were removed, one biologic and one synthetic.

CONCLUSIONS

Surgeons participating in the ACHQC predominantly resect ECFs and repair the associated hernias with sublay mesh with or without a myofascial release. Morbidity remains high, most closely related to wound complications, as such, concomitant definitive repairs should be entertained with caution.

Intraperitonealversusretromuscular mesh placement for open incisional hernias: an analysis of the Americas Hernia Society Quality Collaborative

Background

Incisional hernia repair with mesh improves long-term outcomes, but the ideal mesh position remains unclear. This study compared intraperitoneal versus retromuscular or preperitoneal sublay (RPS) mesh positions for open incisional hernia repairs.

Methods

All patients who had elective open incisional hernia repairs were identified retrospectively in the Americas Hernia Society Quality Collaborative database. The primary outcome was the rate of 30-day surgical-site infection (SSI). Other outcomes of interest included 30-day surgical-site occurrences requiring procedural intervention (SSOPI), hernia-related quality-of-life survey (HerQLes) scores and long-term recurrence. A logistic model was used to generate propensity scores for mesh position using several clinically relevant co-variables. Regression models adjusting for propensity score and baseline characteristics were developed to assess the effect of mesh placement.

Results

A total of 4211 patients were included in the study population: 587 had intraperitoneal mesh and 3624 had RPS mesh. Analysis with propensity score adjustment provided no evidence for differences in SSOPI (odds ratio (OR) 0·79, 95 per cent c.i. 0·49 to 1·26) and SSI (OR 0·91, 0·50 to 1·67) rates or HerQLes scores at 30 days (OR 1·20, 0·79 to 1·82), or recurrence rates (hazard ratio 1·28, 0·90 to 1·82).

Conclusion

Mesh position had no effect on short- or long-term outcomes, including SSOPI and SSI rates, HerQLes scores and long-term recurrence rates.

Open retromuscular versus laparoscopic ventral hernia repair for medium-sized defects: where is the value?

PURPOSE

There is increasing emphasis on value in health care, defined as quality over cost required to deliver care. We analyzed outcomes and costs of repairing medium-sized ventral hernias to identify whether an open retromuscular or laparoscopic intraperitoneal onlay approach would provide superior value to the patient and healthcare system.

METHODS

A retrospective analysis of prospectively collected data from the Americas Hernia Society Quality Collaborative was performed for patients undergoing clean, elective repair of ventral hernias between 4 and 8 cm in width at our institution between 4/2013 and 12/2016 for whom at least 1-year follow-up was available. Recurrence rates, wound complications, length of stay, patient-reported outcomes, and perioperative costs were compared.

RESULTS

One hundred and eighty-six patients met criteria (105 open, 81 laparoscopic) with 93.5% having ≥ 2-year follow-up. Patients undergoing laparoscopic repair had higher BMI, lower ASA classification, slightly lower prevalence of recurrent hernias and less prior mesh utilization, and slightly smaller hernias. Length of stay was shorter in the laparoscopic group (median 1 vs. 3 days, p < 0.001), without increased readmissions. Recurrence rates, wound complications, and patient-reported outcomes were similar. Laparoscopic repair had higher up-front surgical costs, yet equivalent total perioperative costs.

CONCLUSION

Both laparoscopic and open approaches for elective repair of medium-sized ventral hernias offer similar clinical outcomes, patient-reported outcomes, and total perioperative costs. Laparoscopic repair appears to offer superior value based on a significantly reduced postoperative length of stay.

Outcomes of transversus abdominis release in non-elective incisional hernia repair: a retrospective review of the Americas Hernia Society Quality Collaborative (AHSQC)

PURPOSE

Elective repair of large incisional hernias using posterior component separation with transversus abdominis release (TAR) has acceptable wound morbidity and long-term recurrence rates. The outcomes of using this reconstructive technique in the non-elective setting remains unknown. We aim to report 30-day outcomes of TAR in non-elective settings.

METHODS

All patients undergoing open TAR in non-elective settings were identified within the Americas Hernia Society Quality Collaborative (AHSQC). A retrospective review was conducted and outcomes of interest were 30-day Surgical Site Infections (SSI), Surgical Site Occurrences (SSO), SSOs requiring procedural intervention (SSOPI), medical complications, and unplanned readmissions and reoperations.

RESULTS

Fifty-nine patients met inclusion criteria. Mean BMI was 36.6 ± 8.9 kg/m² and mean hernia width was 14.4 ± 7.2 cm. Forty (67.8%) were recurrent hernias. Pain (88%) and bowel obstruction (79.7%) were the most frequent indications for surgery. Surgical field was classified as clean in 69.5% of cases, with an 88% use of permanent synthetic mesh and fascial closure achieved in 93.2% of cases. There were 15 (25.4%) total wound events, 8 (13.6%) were SSIs. There were 8 (13.6%) SSOPIs, 6 of which were wound opening, 1 wound debridement, and 1 percutaneous drainage. At least one wound or medical complication was reported for 37% of the patients. There were no mortalities.

CONCLUSION

Not surprisingly, TAR in the non-elective setting is associated with increased wound morbidity requiring procedural interventions and reoperations compared to what has previously been reported for elective cases. The long-term consequences of this wound morbidity with regard to hernia recurrence are as of yet unknown.

A call for standardization of wound events reporting following ventral hernia repair

INTRODUCTION

Postoperative wound events following ventral hernia repair are an important outcome measure. While efforts have been made by hernia surgeons to identify and address risk factors for postoperative wound events following VHR, the definition of these events lacks standardization. Therefore, the purpose of our study was to detail the variability of wound event definitions in recent ventral hernia literature and to propose standardized definitions for postoperative wound events following VHR.

METHODS

The top 50 cited ventral hernia, peer-reviewed publications from 1995 through 2015 were identified using the search engine Google Scholar. The definition of wound event used and the incidence of postoperative wound events was recorded for each article. The number of articles that used a standardized definition for surgical site infection (SSI), surgical site occurrence (SSO), or surgical site occurrence requiring procedural intervention (SSOPI) was also identified.

RESULTS

Of the 50 papers evaluated, only nine (18%) used a standardized definition for SSI, SSO, or SSOPI. The papers that used standardized definitions had a smaller variability in the incidence of wound events when compared to one another and their reported rates were more consistent with recently published ventral hernia repair literature.

CONCLUSION

Postoperative wound events following VHR are intimately associated with patient quality of life and long-term hernia repair durability. Standardization of the definition of postoperative wound events to include SSI, SSO, and SSOPI following VHR will improve the ability of hernia surgeons to make evidence-based decisions regarding the management of ventral hernias.

Outcome of Intensive Care in Patients with the Acquired Immunodeficiency Syndrome

The prognosis of patients who become critically ill due to complications of the acquired immunodeficiency syndrome (AIDS) is generally believed to be poor, but no detailed studies have substantiated this impression. We performed a retrospective analysis of patients with AIDS admitted to the Medical Special Care Unit (MSCU) at Mount Sinai Medical Center in New York over a 42-month period. Of 910 patients admitted to the MSCU, 35 (4% ) had AIDS. An additional patient admitted to the pediatric intensive care unit was included in the analysis.

Respiratory failure occurred in 31 patients (86% ) and was the most common problem necessitating admission. Twenty-five of these patients (69% ) had Pneumocystis carinii pneumonia. All 31 patients with respiratory failure required endotracheal intubation and mechanical ventilation, and 27 (87%) died during the same hospitalization. Pneumothorax requiring tube thoracostomy occurred in 6 of 31 patients receiving mechanical ventilatory support. Among the 4 mechanically ventilated survivors, only 2 patients remain alive. Intensive care unit intervention in patients with AIDS and respiratory failure is associated with a poor outcome and probably does not alter the ultimate course in most cases.

Prepulse inhibition of the acoustic startle reflex vs. auditory brainstem response for hearing assessment

The high prevalence of noise-induced and age-related hearing loss in the general population has warranted the use of animal models to study the etiology of these pathologies. Quick and accurate auditory threshold determination is a prerequisite for experimental manipulations targeting hearing loss in animal models. The standard auditory brainstem response (ABR) measurement is fairly quick and translational across species, but is limited by the need for anesthesia and a lack of perceptual assessment. The goal of this study was to develop a new method of hearing assessment utilizing prepulse inhibition (PPI) of the acoustic startle reflex, a commonly used tool that measures detection thresholds in awake animals, and can be performed on multiple animals simultaneously. We found that in control mice PPI audiometric functions are similar to both ABR and traditional operant conditioning audiograms. The hearing thresholds assessed with PPI audiometry in sound exposed mice were also similar to those detected by ABR thresholds one day after exposure. However, three months after exposure PPI threshold shifts were still evident at and near the frequency of exposure whereas ABR thresholds recovered to the pre-exposed level. In contrast, PPI audiometry and ABR wave one amplitudes detected similar losses. PPI audiometry provides a high throughput automated behavioral screening tool of hearing in awake animals. Overall, PPI audiometry and ABR assessments of the auditory system are robust techniques with distinct advantages and limitations, which when combined, can provide ample information about the functionality of the auditory system.

Cystic Lung Diseases: Algorithmic Approach

Cysts are commonly seen on CT scans of the lungs, and diagnosis can be challenging. Clinical and radiographic features combined with a multidisciplinary approach may help differentiate among various disease entities, allowing correct diagnosis. It is important to distinguish cysts from cavities because they each have distinct etiologies and associated clinical disorders. Conditions such as emphysema, and cystic bronchiectasis may also mimic cystic disease. A simplified classification of cysts is proposed. Cysts can occur in greater profusion in the subpleural areas, when they typically represent paraseptal emphysema, bullae, or honeycombing. Cysts that are present in the lung parenchyma but away from subpleural areas may be present without any other abnormalities on high-resolution CT scans. These are further categorized into solitary or multifocal/diffuse cysts. Solitary cysts may be incidentally discovered and may be an age related phenomenon or may be a remnant of prior trauma or infection. Multifocal/diffuse cysts can occur with lymphoid interstitial pneumonia, Birt-Hogg-Dubé syndrome, tracheobronchial papillomatosis, or primary and metastatic cancers. Multifocal/diffuse cysts may be associated with nodules (lymphoid interstitial pneumonia, light-chain deposition disease, amyloidosis, and Langerhans cell histiocytosis) or with ground-glass opacities (Pneumocystis jirovecii pneumonia and desquamative interstitial pneumonia). Using the results of the high-resolution CT scans as a starting point, and incorporating the patient's clinical history, physical examination, and laboratory findings, is likely to narrow the differential diagnosis of cystic lesions considerably.

Establishing Pulmonary and Critical Care Medicine in China: 2016 Report on Implementation and Government Recognition: Joint Statement of the Chinese Association of Chest Physicians and the American College of Chest Physicians

This article provides an update on progress toward establishing pulmonary and critical care medicine (PCCM) fellowship training as one of the first four subspecialties to be recognized and supported by the Chinese government. Designed and implemented throughout 2013 and 2014 by a collaborative effort of the Chinese Thoracic Society (CTS) and the American College of Chest Physicians (CHEST), 12 leading Chinese hospitals enrolled a total of 64 fellows into standardized PCCM training programs with common curricula, educational activities, and assessment measures. Supplemental educational materials, online assessment tools, and institutional site visits designed to evaluate and provide feedback on the programs' progress are being provided by CHEST. As a result of this initial progress, the Chinese government, through the Chinese Medical Doctor's Association, endorsed the concept of subspecialty fellowship training in China, with PCCM as one of the four pilot subspecialties to be operationalized nationwide in 2016, followed by implementation across other subspecialties by 2020. This article also reflects on the achievements of the training sites and the challenges they face and outlines plans to enhance and expand PCCM training and practice in China.

Review article: applying pharmacokinetics to optimise dosing of anti-TNF biologics in acute severe ulcerative colitis

BACKGROUND

Acute severe ulcerative colitis (ASUC), the most aggressive presentation of ulcerative colitis (UC), occurs in 15% of adults and children with UC. First line therapy with intravenous corticosteroids is ineffective in half of adults and one-third of children. Therapeutic monoclonal antibodies against TNF (anti-TNF therapy) are emerging as a common treatment for ASUC due to their similar efficacy to calcineurin inhibitors and more favourable adverse effect profile.

AIM

To comprehensively review the evidence for anti-TNF therapy for ASUC in children and adults with regard to outcomes and pharmacokinetics.

METHODS

PubMed and recent conference proceedings were searched using the terms 'ulcerative colitis', 'acute severe ulcerative colitis', 'anti-TNF', 'pharmacokinetics' and the generic names of specific anti-TNF agents.

RESULTS

Outcomes after anti-TNF therapy for ASUC remain suboptimal with about one half of children and adults undergoing colectomy. While several randomised controlled trials have demonstrated the efficacy of anti-TNF therapy for ambulatory patients with moderate to severely active UC, patients in these studies were less ill than those with ASUC. Patients with ASUC may exhibit more rapid clearance of anti-TNF biologics due to pharmacokinetic mechanisms influenced by disease severity.

CONCLUSIONS

Conventional weight-based dosing effective in patients with moderately to severely active UC, may not be equally effective in those with acute severe ulcerative colitis. Personalised anti-TNF dosing strategies, which integrate patient factors and early measures of pharmacokinetics and response, hold promise for ensuring sustained drug exposure and maximising early mucosal healing in patients with acute severe ulcerative colitis.

Posterior component separation with transversus abdominis release successfully addresses recurrent ventral hernias following anterior component separation

PURPOSE

Anterior component separation (ACS) with external oblique release for ventral hernia repair has a recurrence rate up to 32%. Hernia recurrence after prior ACS represents a complex surgical challenge. In this context, we report our experience utilizing posterior component separation with transversus abdominis muscle release (PCS/TAR) and retromuscular mesh reinforcement.

METHODS

Patients with a history of recurrent hernia following ACS repaired with PCS/TAR were retrospectively identified from prospective databases collected at two large academic institutions. Patient demographics, hernia characteristics (using CT scan) and outcomes were evaluated.

RESULTS

Twenty-nine patients with a history of ACS developed 22 (76%) midline, 3 (10%) lateral and 4 (14%) concomitant recurrences. Contamination was present in 11 (38%) of cases. All were repaired utilizing a PCS/TAR with retromuscular mesh placement (83% synthetic, 17% biologic) and fascial closure. Wound morbidity consisted of 13 (45%) surgical site occurrences including 8 (28%) surgical site infections. Five (17%) patients required 90-day readmission, and two (7%) were related to wound morbidity. One organ space infection with frank spillage of stool resulted in the only instance of mesh excision. This case also represents the only instance of recurrence (3%) with a mean follow-up of 11 (range 3-36) months.

CONCLUSION

Patients with a history of an ACS who develop a recurrence represent a challenging clinical scenario with limited options for surgical repair. A PCS/TAR hernia repair achieves acceptable outcomes and may in fact be the best approach available.

Electronic cigarettes. A position statement of the forum of international respiratory societies

BACKGROUND

Awareness and usage of electronic cigarettes has exponentially increased during the last few years, especially among young people and women in some countries. The rapid acceptance of electronic cigarettes may be attributed in part to the perception created by marketing and the popular press that they are safer than combustible cigarettes.

GOALS

To alert and advise policy makers about electronic cigarettes and their potential hazards.

METHODS

Using The Union's position paper on electronic cigarettes as the starting template, the document was written using an iterative process. Portions of the manuscript have been taken directly from the position papers of participating societies.

RESULTS

Because electronic cigarettes generate less tar and carcinogens than combustible cigarettes, use of electronic cigarettes may reduce disease caused by those components. However, the health risks of electronic cigarettes have not been adequately studied. Studies looking at whether electronic cigarettes can aid smoking cessation have had inconsistent results. Moreover, the availability of electronic cigarettes may have an overall adverse health impact by increasing initiation and reducing cessation of combustible nicotine delivery products.

CONCLUSIONS

The health and safety claims regarding electronic nicotine delivery devices should be subject to evidentiary review. The potential benefits of electronic cigarettes to an individual smoker should be weighed against potential harm to the population of increased social acceptability of smoking and use of nicotine, the latter of which has addictive power and untoward effects. As a precaution, electronic nicotine delivery devices should be restricted or banned until more information about their safety is available. If they are allowed, they should be closely regulated as medicines or tobacco products.

Establishing pulmonary and critical care medicine as a subspecialty in China: joint statement of the Chinese thoracic society and the American college of chest physicians

This commentary heralds the recognition in China of a new subspecialty, Pulmonary and Critical Care Medicine, and the first national fellowship training pathway in any medical specialty. Because of striking environmental health-care similarities that existed in the United States, the Chinese medical community decided to model the specialty after that in the United States. Because of its expertise in educating pulmonary and critical care physicians in the United States, the American College of Chest Physicians was chosen by the Chinese Thoracic Society, with the approval of the Chinese government, to help with the transformation of this new specialty. A work group representing the two societies is collaborating to reorganize ICUs within a select group of large teaching hospitals in China and to introduce standardized and rigorous training in pulmonary and critical care medicine as a national program.

History of methicillin-resistant Staphylococcus aureus (MRSA) surgical site infection may not be a contraindication to ventral hernia repair with synthetic mesh: a preliminary report

PURPOSE

A history of methicillin-resistant Staphylococcus aureus (MRSA) surgical site infection presents a significant surgical dilemma as to the risk of subsequent mesh infection, even if no active infection is present. We investigated the outcomes of ventral hernia repair with synthetic mesh in patients with prior MRSA surgical site infections (SSIs).

METHODS

All patients with a clean wound but prior MRSA SSI undergoing open ventral hernia repair with mesh by a single surgeon over a 3-year period were reviewed for the development of any major (need for readmission, operative debridement, or mesh removal) or minor SSI. All patients received peri-operative intravenous vancomycin and prolonged suppressive oral trimethoprim/sulfamethoxazole or doxycycline.

RESULTS

Ten patients (male = 7, female = 3) with clean wounds and a history of MRSA SSI underwent open ventral hernia repair with retrorectus synthetic mesh placement. Mean follow-up was 13.5 ± 3.3 months. Overall, two patients (20 %) developed SSIs (minor = 2, major = 0). Both SSIs were successfully managed with therapeutic oral antibiotics and local wound care without need for surgical debridement or mesh removal. There have been no hernia recurrences in any of the patients.

CONCLUSIONS

Preliminary results suggest that history of MRSA infection may not be a contraindication to the use of synthetic mesh for ventral hernia repair. Macroporous lightweight meshes, combined with use of prolonged suppressive antibiotics and sublay retromuscular mesh placement that provides complete tissue coverage, should be further investigated as an acceptable prosthetic choice when planning a complex ventral hernia repair in the setting of prior MRSA SSI.

Bacterial clearance of biologic grafts used in hernia repair: an experimental study

BACKGROUND

Biologic grafts used in ventral hernia repair are derived from various sources and undergo different post-tissue-harvesting processing, handling, and sterilization techniques. It is unclear how these various characteristics impact graft response in the setting of contamination. We evaluated four materials in an infected hernia repair animal model using fluorescence imaging and quantitative culture studies.

METHODS

One hundred seven rats underwent creation of a chronic hernia. They were then repaired with one synthetic polyester control material (n = 12) and four different biologic grafts (n = 24 per material). Biologic grafts evaluated included Surgisis (porcine small intestinal submucosa), Permacol (crosslinked porcine dermis), Xenmatrix (noncrosslinked porcine dermis), and Strattice (noncrosslinked porcine dermis). Half of the repairs in each group were inoculated with Staphylococcus aureus at 10(4) CFU/ml and survived for 30 days without systemic antibiotics. Animals then underwent fluorescence imaging and quantitative bacterial studies.

RESULTS

All clean repairs remained sterile. Rates of bacterial clearance were as follows: polyester synthetic 0%, Surgisis 58%, Permacol 67%, Xenmatrix 75%, and Strattice 92% (P=0.003). Quantitative bacterial counts had a similar trend in bacterial clearance: polyester synthetic 1×10(6) CFU/g, Surgisis 4.3×10(5) CFU/g, Permacol 1.7×10(3) CFU/g, Xenmatrix 46 CFU/g, and Strattice 31 CFU/g (P=0.001). Fluorescence imaging was unable to detect low bacterial fluorescence counts observed on bacterial studies.

CONCLUSION

Biologic grafts, in comparison to synthetic material, are able to clear a Staphylococcus aureus contamination; however, they are able to do so at different rates. Bacterial clearance correlated to the level of residual bacterial burden observed in our study. Post-tissue-harvesting processing, handling, and sterilization techniques may contribute to this observed difference in ability to clear bacteria.

The cost of assuming the life history of a host: acoustic startle in the parasitoid fly Ormia ochracea

In the obligatory reproductive dependence of a parasite on its host, the parasite must trade the benefit of 'outsourcing' functions like reproduction for the risk of assuming hazards associated with the host. In the present study, we report behavioral adaptations of a parasitic fly, Ormia ochracea, that resemble those of its cricket hosts. Ormia females home in on the male cricket's songs and deposit larvae, which burrow into the cricket, feed and emerge to pupate. Because male crickets call at night, gravid female Ormia in search of hosts are subject to bat predation, in much the same way as female crickets are when responding to male song. We show that Ormia has evolved the same evasive behavior as have crickets: an acoustic startle response to bat-like ultrasound that manifests clearly only during flight. Furthermore, like crickets, Ormia has a sharp response boundary between the frequencies of song and bat cries, resembling categorical perception first described in the context of human speech.

Pulmonary arterial hypertension in human immunodeficiency virus infection

Because of the improvement in survival rates of human immunodeficiency virus (HIV)-infected patients after the introduction of combined antiretroviral therapy, pulmonary arterial hypertension (PAH) has become an important cause of morbidity. As the awareness of PAH has increased, it is more likely that this condition will be diagnosed more frequently and earlier in the course of the disease and HIV infection. The etiopathogenesis is not clear; no evidence of direct infection of the pulmonary vascular tree has been found and the current evidence seems to favor a role of dysregulated cytokine response to HIV infection. The pathological changes of plexiform arteriopathy are indistinguishable from the pathological changes of idiopathic pulmonary arterial hypertension (IPAH). Dyspnea is the most common presenting symptom. Echocardiography, though always not accurate in diagnosing PAH and estimating its severity, remains the main screening tool. Right heart catheterization is the gold standard investigation for diagnosis. New therapies like prostanoids, endothelin receptor antagonists, and phosphodiesterase inhibitors have improved the outcome of patients with HIV-associated PAH. However, the overall prognosis of HIV-infected patients who develop PAH still remains poor.

Multisociety task force recommendations of competencies in Pulmonary and Critical Care Medicine

RATIONALE

Numerous accrediting organizations are calling for competency-based medical education that would help define specific specialties and serve as a foundation for ongoing assessment throughout a practitioner's career. Pulmonary Medicine and Critical Care Medicine are two distinct subspecialties, yet many individual physicians have expertise in both because of overlapping content. Establishing specific competencies for these subspecialties identifies educational goals for trainees and guides practitioners through their lifelong learning.

OBJECTIVES

To define specific competencies for graduates of fellowships in Pulmonary Medicine and Internal Medicine-based Critical Care.

METHODS

A Task Force composed of representatives from key stakeholder societies convened to identify and define specific competencies for both disciplines. Beginning with a detailed list of existing competencies from diverse sources, the Task Force categorized each item into one of six core competency headings. Each individual item was reviewed by committee members individually, in group meetings, and conference calls. Nominal group methods were used for most items to retain the views and opinions of the minority perspective. Controversial items underwent additional whole group discussions with iterative modified-Delphi techniques. Consensus was ultimately determined by a simple majority vote.

MEASUREMENTS AND MAIN RESULTS

The Task Force identified and defined 327 specific competencies for Internal Medicine-based Critical Care and 276 for Pulmonary Medicine, each with a designation as either: (1) relevant, but competency is not essential or (2) competency essential to the specialty.

CONCLUSIONS

Specific competencies in Pulmonary and Critical Care Medicine can be identified and defined using a multisociety collaborative approach. These recommendations serve as a starting point and set the stage for future modification to facilitate maximum quality of care as the specialties evolve.

Laparoscopic component separation in the single-stage treatment of infected abdominal wall prosthetic removal

BACKGROUND

The ideal surgical treatment for complicated ventral hernias remains elusive. Traditional component separation provides local advancement of native tissue for tension-free closure without prosthetic materials. This technique requires an extensive subcutaneous dissection, with the division of perforating vessels predisposing to skin flap necrosis and complicated wound infections. The laparoscopic separation of components provides a minimally invasive alternative to open techniques, while eliminating the potential space and subsequent complications of large skin flaps. We report our initial experience with a minimally invasive component separation with early postoperative outcomes.

METHODS

We retrospectively reviewed the medical records of all patients who underwent a minimally invasive component separation for abdominal wall reconstruction during the resection of an infected prosthetic. Pertinent details included baseline demographics, reason for contamination, operative technique and details, postoperative morbidity, mortality, and recurrence rates.

RESULTS

Between August 2006 and January 2007, seven patients were identified who underwent a laparoscopic component separation. There were four males and three females, with a mean age of 54 years (range 34-84), mean American Society of Anesthesiologist (ASA) score of 3.2 (range 3-4), and mean body mass index (BMI) of 37 kg/m2 (range 30-45). The reason for contamination included exposed non-healing mesh (6) and contaminated fluid collection around the mesh (1). Residual defect size following the removal of all prosthetics was 338 cm2 (range 187-450). The mean operative time was 185 min (range 155-220). Laparoscopic component separation enabled tension-free primary fascial reapproximation in all patients. Three postoperative complications occurred, including superficial surgical site infection (1), respiratory failure (1), and hematoma (1). There was no mortality in this series. During an average follow-up period of 4.5 months, no recurrences were identified.

CONCLUSIONS

This study shows that a minimally invasive component separation is feasible and can result in minimal postoperative wound morbidity in these complex patients. Long-term follow-up is necessary to evaluate the outcomes with respect to recurrence rates.

A reliable method for monitoring intraabdominal pressure during natural orifice translumenal endoscopic surgery

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES) provides surgical access to the peritoneal cavity without skin incisions. The NOTES procedure requires pneumoperitoneum for visualization and manipulation of abdominal organs, similar to laparoscopy. Accurate measurement of the pneumoperitoneum pressure is essential to avoid potentially deleterious effects of intraabdominal compartment syndrome. A reliable method for monitoring pneumoperitoneum pressures during NOTES has not been identified. This study evaluated several methods of monitoring intraabdominal pressures with a standard gastroscope during NOTES.

METHODS

Four female pigs (25 kg) were sedated, and a single-channel gastroscope was passed transgastrically into the peritoneal cavity. Pneumoperitoneum was achieved via a pressure insufflator through a percutaneous, intraperitoneal 14-gauge catheter. Three other pressures were recorded via separate catheters. First, a 14-gauge percutaneous catheter passed intraperitoneally measured true intraabdominal pressure. Second, a 14-gauge tube attached to the endoscope was used to measure endoscope tip pressure. The third pressure transducer was connected directly to the accessory channel of the endoscope. The abdomen was insufflated to a range of pressures (10-30 mmHg), and simultaneous pressures were recorded from all three pressure sensors.

RESULTS

Pressure correlation curves were developed for all animals across all intraperitoneal pressures (mean error, -4.25 to -1 mmHg). Endoscope tip pressures correlated with biopsy channel pressures (R2 = 0.99). Biopsy channel and endoscope tip pressures fit a least-squares linear model to predict actual intraabdominal pressure (R = 0.99 for both). Both scope tip and biopsy channel port pressures were strongly correlative with true intraabdominal pressures (R2 = 0.98 and R2 = 0.99, respectively).

CONCLUSION

This study demonstrates that monitoring pressure through an endoscope is reliable and predictive of true intraabdominal pressure. Gastroscope pressure monitoring is a useful adjunct to NOTES. Future NOTES procedures should incorporate continuous intraabdominal pressure monitoring to avoid the potentially deleterious effects of pneumoperitoneum during NOTES. This can be achieved by the integration of pressure-monitoring capabilities into gastroscopes.

Diaphragm pacing with natural orifice transluminal endoscopic surgery: potential for difficult-to-wean intensive care unit patients

BACKGROUND

Up to 50% of the patients in the intensive care unit (ICU) require mechanical ventilation, with 20% requiring the use of a ventilator for more than 7 days. More than 40% of this time is spent weaning the patient from mechanical ventilation. Failure to wean from mechanical ventilation can in part be attributable to rapid onset of diaphragm atrophy, barotrauma, posterior lobe atelectasis, and impaired hemodynamics, which are normally improved by maintaining a more natural negative chest pressure. The authors have previously shown that laparoscopic implantation of a diaphragm pacing system benefits selected patients. They now propose that an acute ventilator assist with interventional neurostimulation of the diaphragm in the ICU is feasible and could facilitate the weaning of ICU patients from mechanical ventilation. Natural orifice transluminal endoscopic surgery (NOTES) has the potential to expand the benefits of the diaphragm pacing system to this acute patient population by allowing it to be performed at the bedside similarly to insertion of the common gastrostomy tube. This study evaluates the feasibility of this approach in a porcine model.

METHODS

Pigs were anesthetized, and peritoneal access with the flexible endoscope was obtained using a guidewire, needle knife cautery, and balloon dilation. The diaphragm was mapped using a novel endoscopic electrostimulation catheter to locate the motor point (where stimulation provides complete contraction of the diaphragm). An intramuscular electrode then was placed at the motor point with a percutaneous needle. The gastrotomy was managed with a gastrostomy tube.

RESULTS

Four pigs were studied, and the endoscopic mapping instrument was able to map the diaphragm to identify the motor point. In one animal, a percutaneous electrode was placed into the motor point under transgastric endoscopic visualization, and the diaphragm could be paced in conjunction with mechanical ventilation.

CONCLUSIONS

These animal studies demonstrate the feasibility of transgastric mapping of the diaphragm and implantation of a percutaneous electrode for therapeutic diaphragmatic stimulation.

The single-staged approach to the surgical management of abdominal wall hernias in contaminated fields

INTRODUCTION

The surgical treatment of large ventral hernias with accompanying contamination is challenging. We have reviewed our institution's experience with single-staged repair of complex ventral hernias in the setting of contamination.

METHODS

We retrospectively reviewed the medical records of all patients who underwent ventral hernia repairs in the setting of a contaminated field. Pertinent details included baseline demographics, reason for contamination, operative technique and details, postoperative morbidity, mortality and recurrence rates.

RESULTS

Between December 1999 and January 2006, 19 patients were identified with ventral hernia repairs performed in contaminated fields. There were 6 males and 13 females with a mean age of 61 years (40-82), ASA 3.2 (2-4), and BMI of 34 kg/m(2) (20-65). Fourteen patients had prior mesh: prolene (9), composix (3), goretex (1), and alloderm (1). Reasons for contamination included: mesh infection (14), enterocutaneous fistula (7), concomitant bowel resection (8), chronic non-healing wound (2), and necrotizing fasciitis (1). Operative approaches included primary repair (3), component separation without reinforcement (2), and with prosthetic reinforcement (9). In five patients the fascia could not be reapproximated in the midline and the defect was bridged with surgisis (1), Marlex (1), lightweight polypropylene (1) placed in the retrorectus space, and alloderm (2). Mean operative time was 260 min (90-600). Twelve postoperative complications occurred in nine (47%) patients and included wound infection (6), respiratory failure (1), ileus (2), postoperative hemorrhage (1), renal failure (1), and atrial fibrillation (1). One patient died in this series. During routine follow-up two recurrences were identified by physical exam.

CONCLUSIONS

This study shows that single-stage treatment of ventral hernias in contaminated fields can be accomplished with a low recurrence rate and acceptable morbidity in these extremely challenging patients.

Laparoscopic retroperitoneal repair of a right-sided Bochdalek hernia

Bochdalek hernias are rare congenital diaphragmatic defects. We report a case of a 50-year-old male with chronic shortness of breath who was diagnosed with a right-sided Bochdalek hernia. This hernia was repaired using a laparoscopic retroperitoneal approach.

Critical care of immunocompromised patients: human immunodeficiency virus

OBJECTIVE

To describe critical illnesses that occur commonly in patients with human immunodeficiency virus (HIV) infection.

METHODS

We reviewed and summarized the literature on critical illness in HIV infection using a computerized MEDLINE search.

SUMMARY

In the last 10 yrs, our perception of HIV infection and acquired immune deficiency syndrome (AIDS) has changed from an almost uniformly fatal disease into a manageable chronic illness. Even patients with advanced immunosuppression may have prolonged survival, although usually with exacerbations and remissions, complicated by therapy-related toxicity and medical and psychiatric co-morbidity. The prevalence of opportunistic infections and the mortality have decreased considerably since early in the epidemic. The most common reason for intensive care unit admission in patients with AIDS is respiratory failure, but they are less likely to be admitted for Pneumocystis pneumonia and other HIV-associated opportunistic infections. HIV-infected persons are more likely to receive intensive care unit care for complications of end-stage liver disease and sepsis. Hepatitis C has emerged as a common cause of morbidity and mortality in patients with HIV infection. In addition, some develop life-threatening complications from antiretroviral drug toxicity and the immune reconstitution inflammatory syndrome.

Evaluation of a controlled-energy-dissipation orthosis for tremor suppression

The purpose of this study was to assess the effectiveness of the CEDO 1, a prototype Controlled Energy-Dissipating Orthosis for persons disabled by pathological intention tremor. Conventional neurological practice is generally unsuccessful in restoring independent upper extremity function to persons with debilitating tremors. The CEDO 1 was built to determine whether an alternative approach to tremor management, namely the application of velocity-dependent resistive loads to tremorous limbs, is a feasible means of attenuating intention tremor without degrading purposeful movement. The CEDO 1 mounts to a wheelchair or table, permits the three degrees of freedom needed for 'table-top' activities, and generates resistive loads by means of computer-controlled magnetic particle brakes whose torques are transmitted to the user's forearm via a stiff low-inertia linkage. In this investigation, five tremor-disabled and five able-bodied subjects were given computer-mediated pursuit tracking tasks in two degrees of freedom to verify that damping loads applied by the CEDO 1 do selectively attenuate upperextremity intention tremor. Experiments were also done to determine the range of damping loads needed in a tremor-suppressing orthosis and whether non-linear (velocity-squared) loads offer any advantages over linear (viscous) loads. Subjectively, all disabled subjects offered positive remarks on the effect of damping. Objectively, data from four of the five disabled subjects, processed using spectral analysis techniques, demonstrated that linear and non-linear damping loads can selectively reduce subjects' tremors by statistically significant amounts (P values <0.001). These results have allowed design specifications for tremor-suppressing orthoses to be refined, and planning for the CEDO 2 -a functionally improved version of the CEDO 1-is underway.