Short-term outcomes after open versus robot-assisted repair of ventral hernias: a nationwide database study

PURPOSE

The robotic platform is widely implemented; however, evidence evaluating outcomes of robotic ventral hernia repair is still lacking. The aim of the study was to evaluate the short-term outcomes after open and robot-assisted repair of primary ventral and incisional hernias.

METHODS

Nationwide register-based cohort study with data from the Danish Ventral Hernia Database and the National Danish Patients Registry was from January 1, 2017 to August 22, 2022. Robot-assisted ventral hernia repairs were propensity score matched 1:3 with open repairs according to the confounding variables defect size, Charlson comorbidity index score, and age. Logistic regression analyses were performed for factors associated with length of stay > 2 days, readmission, and reoperation within 90 days.

RESULTS

A total of 528 and 1521 patients underwent robot-assisted and open repair, respectively. The mean length of hospital stay in days was 0.5 versus 2.1 for robot-assisted and open approach, respectively (P < 0.001) and open approach was correlated with risk of length of stay > 2 days (OR 23.25, CI 13.80-39.17, P < 0.001). The incidence of readmission within 90 days of discharge was significantly lower after robot-assisted repair compared to open approach (6.2% vs. 12.1%, P < 0.001). Open approach was independently associated with increased risk of readmission (OR 21.43, CI 13.28-39.17, P = 0.005, P < 0.001).

CONCLUSION

Robot-assisted ventral hernia repair is safe and feasible and associated with shorter length of stay and decreased risk of readmission compared with open ventral hernia repair.

Enhanced recovery after robotic ventral hernia repair: factors associated with overnight stay in hospital

PURPOSE

Enhanced recovery after surgery (ERAS) protocols lead to reduced post-operative stay and improved outcomes after most types of abdominal surgery. Little is known about the optimal post-operative protocol after robotic ventral hernia repair (RVHR), including the potential limits of outpatient surgery. We report the results of an ERAS protocol after RVHR aiming to identify factors associated with overnight stay in hospital, as well as patient-reported pain levels in the immediate post-operative period.

METHODS

This was a prospective cohort study of consecutive patients undergoing RVHR. Patients were included in a prospective database, registering patient characteristics, operative details, pain and fatigue during the first 3 post-operative days and pre- and 30-day post-operative hernia-related quality of life, using the EuraHS questionnaire.

RESULTS

A total of 109 patients were included, of which 66 (61%) underwent incisional hernia repair. The most performed procedure was TARUP (robotic transabdominal retromuscular umbilical prosthetic hernia repair) (60.6%) followed by bilateral roboTAR (robotic transversus abdominis release) (19.3%). The mean horizontal fascial defect was 4.8 cm, and the mean duration of surgery was 141 min. In total, 78 (71.6%) patients were discharged on the day of surgery, and factors associated with overnight stay were increasing fascial defect area, longer duration of surgery, and transverse abdominis release. There was no association between post-operative pain and overnight hospital stay. The mean EuraHS score decreased significantly from 38.4 to 6.4 (P < 0.001).

CONCLUSION

An ERAS protocol after RVHR was associated with a high rate of outpatient procedures with low patient-reported pain levels.

Even minor alteration of plasma creatinine after open abdominal surgery is associated with 30-day mortality: A single-centre cohort study

PURPOSE

Postoperative acute kidney injury is common and associated with increased length of hospital stay, costs and mortality. The impact from postoperative subclinical changes in plasma concentration of creatinine (p-creatinine) on postoperative mortality has received less attention. In this study, the association between the postoperative change of p-creatinine and all-cause mortality was investigated.

METHODS

A single-centre register-based, retrospective study was conducted including patients ≥60 years undergoing open abdominal surgery from 2000 to 2013. Postoperative p-creatinine change was analysed for association with 30-day mortality following adjustment for age, gender, surgical setting and surgical procedure. Main findings A total of 3,460 patients were included in the study of whom 67.6% underwent emergency surgery. The 30-day mortality rate was 18.3%, and a given 10μmol/L daily postoperative increase in p-creatinine was associated with an increased mortality risk with an odds ratio (OR) of 2.67 (95% CI; 2.28-3.14, P<0.001). In patients undergoing emergency surgery, a daily 10μmol/L increase in p-creatinine increased the risk for a fatal outcome a 2.39 OR (CI 95%; 2.05-2.78), P<0.001). In patients undergoing elective surgery, a similar increase in p-creatinine increased risk of postoperative death with a 28.85 OR (CI 95%; 10.25-81.19).

CONCLUSION

Even a minor postoperative p-creatinine increase following open abdominal surgery below the criteria for acute kidney injury was associated with increased 30-day mortality in patients aged 60 years or above.

Skin closure following abdominal wall reconstruction: three-layer skin suture versus staples

Skin closure following abdominal wall reconstruction (AWR) has received little attention, even though these patients have demonstrated insufficient wound healing. This study assessed the postoperative wound-related complications and patient-reported outcomes after skin closure using single- or triple layer closure following AWR. This was a retrospective study at a University Hospital from 2016 to 2018. Patients were grouped into a single-layer cohort (SLC) and a triple-layer cohort (TLC). Skin incisions closed with either technique were compared. Postoperative complications were registered from chart review (SLC: n = 48, TLC: n = 40). Patient reported-outcomes were assessed through the Patient Scar Assessment Questionnaire (PSAQ) and the Hernia Related Quality of Life survey. A total of 51 patients were included (SLC: n = 26, TLC: n = 25). There was no difference in wound complications after single- or triple-layer skin closure; seroma (SLC: 16.7% vs. TLC: 15%, p = 1.00), surgical site infection (SLC: 4.2% vs. TLC: 7.5%, p = .834), hematoma (SLC: 6.2% vs. TLC: 2.5%, p = .744) and wound rupture (SLC: 2.1% vs. TLC: 2.5%, p = 1.00). Patients who had incisions closed using single-layer closure were more satisfied; PSAQ satisfaction with scar symptoms (SLC: 6.7 points (IQR 0.0-18.3) vs. TLC: 26.7 points (IQR 0.0-33.3), p = .039) and scar aesthetics (SLC 25.9 points (IQR 18.5-33.3) vs. TLC: 37.0 (IQR 29.6-44.4), p = .013). There was no difference in 30-day wound complications after either skin closure technique. The results favoured the single-layer closure technique regarding the cosmetic outcome.Abbreviations: AWR: abdominal wall reconstruction; SLC: single-layer cohort; TLC: triple-layer cohort; PSAQ: patient scar assessment questionnaire; IH: incisional hernia; QOL: quality of life; BMI: body mass index; HerQLes: hernia-related quality of life; ASA: American Society of Anesthesiologists; SSO: surgical site occurence; SSI: surgical site infection; LOS: length of stay; RCT: randomized controlled trial.

Physical activity recommendations pre and post abdominal wall reconstruction: a scoping review of the evidence

PURPOSE

There are no universally agreed guidelines regarding which types of physical activity are safe and/or recommended in the perioperative period for patients undergoing ventral hernia repair or abdominal wall reconstruction (AWR). This study is intended to identify and summarise the literature on this topic.

METHODS

Database searches of PubMed, CINAHL, Allied & Complementary medicine database, PEDro and Web of Science were performed followed by a snowballing search using two papers identified by the database search and four hand-selected papers of the authors' choosing. Inclusion-cohort studies, randomized controlled trials, prospective or retrospective. Studies concerning complex incisional hernia repairs and AWRs including a "prehabilitation" and/or "rehabilitation" program targeting the abdominal wall muscles in which the interventions were of a physical exercise nature. RoB2 and Robins-I were used to assess risk of bias. Prospero CRD42021236745. No external funding. Data from the included studies were extracted using a table based on the Cochrane Consumers and Communication Review Group's data extraction template.

RESULTS

The database search yielded 5423 records. After screening two titles were selected for inclusion in our study. The snowballing search identified 49 records. After screening one title was selected for inclusion in our study. Three total papers were included-two randomised studies and one cohort study (combined 423 patients). All three studies subjected their patients to varying types of physical activity preoperatively, one study also prescribed these activities postoperatively. The outcomes differed between the studies therefore meta-analysis was impossible-two studies measured hernia recurrence, one measured peak torque. All three studies showed improved outcomes in their study groups compared to controls however significant methodological flaws and confounding factors existed in all three studies. No adverse events were reported.

CONCLUSIONS

The literature supporting the advice given to patients regarding recommended physical activity levels in the perioperative period for AWR patients is sparse. Further research is urgently required on this subject.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Umbilical hernia repair in patients with cirrhosis: systematic review of mortality and complications

BACKGROUND

Umbilical hernia is a common and potential serious condition in patients with cirrhosis. This systematic review evaluated the risks associated with emergency and elective hernia repair in patients with cirrhosis.

METHODS

Systematic review of clinical trials identified through manual and electronic searches in several databases (last update November 2021). The primary random-effects meta-analyses evaluated mortality in patients with or without cirrhosis or following emergency versus elective repair. The quality of the evidence was assessed using GRADE and Newcastle Ottawa Scale.

RESULTS

Thirteen prospective and 10 retrospective studies including a total of 3229 patients were included. The evidence was graded as very low quality for all outcomes (mortality and postoperative complications within 90 days). In total 191 patients (6%) died after undergoing umbilical hernia repair. Patients with cirrhosis were more than eight times as likely to die after surgery compared with patients without cirrhosis [OR = 8.50, 95% CI (1.91-37.86)] corresponding to 69 more deaths/1000 patients. Among patients with cirrhosis, mortality was higher after emergency versus elective repair [OR = 2.67, 95% CI (1.87-3.97)] corresponding to 52 more deaths/1000 patients. Postoperative complications were more common in patients with cirrhosis compared with patients without cirrhosis.

CONCLUSION

Patients with cirrhosis undergoing emergency umbilical hernia repair have a considerably increased risk of death and severe complications. Accordingly, additional evidence is needed to evaluate methods that would allow elective umbilical hernia repair in patients with cirrhosis.

Visceral obesity is a predictor of surgical site occurrence and hernia recurrence after open abdominal wall reconstruction

PURPOSE

High body mass index (BMI) increases the risk of postoperative complications and hernia recurrence after abdominal wall reconstruction (AWR). However, BMI does not provide specific information on the mass and distribution of adipose tissue. We hypothesized that visceral fat volume (VFV) was a better predictor than BMI for recurrence after AWR.

METHODS

We included all patients undergoing AWR at our institution from November 2010 to December 2016. Data were collected from a prospective database and all patients were summoned for follow-up. VFV was calculated from preoperative CT. The primary and secondary outcomes were hernia recurrence and 30-day postoperative surgical site occurrences (SSO), respectively.

RESULTS

We included a total of 154 patients. At follow-up, 42 (27.3%) patients had developed recurrence. The recurrence rate was significantly higher in patients with a VFV higher than the mean compared to a VFV lower than the mean, P = 0.004. After multivariable Cox-regression, VFV remained significantly predictive of recurrence (HR 1.09 per 0.5 L increase of VFV, P = 0.018). In contrary, BMI was not associated with hernia recurrence. There was no significant difference in the rate of SSO between patients with a VFV above and below the mean. A multivariable logistic regression model showed that VFV was significantly associated with development of SSO (OR 1.12 per 0.5 L increase, P = 0.009).

CONCLUSION

VFV was significantly associated with recurrence and SSOs after AWR. This study suggests VFV as a risk assessment tool for patients undergoing AWR.

Reporting guideline for interventional trials of primary and incisional ventral hernia repair

BACKGROUND

Primary and incisional ventral hernia trials collect unstandardized inconsistent data, limiting data interpretation and comparison. This study aimed to create two minimum data sets for primary and incisional ventral hernia interventional trials to standardize data collection and improve trial comparison. To support these data sets, standardized patient-reported outcome measures and trial methodology criteria were created.

METHODS

To construct these data sets, nominal group technique methodology was employed, involving 15 internationally recognized abdominal wall surgeons and two patient representatives. Initially a maximum data set was created from previous systematic and panellist reviews. Thereafter, three stages of voting took place: stage 1, selection of the number of variables for data set inclusion; stage 2, selection of variables to be included; and stage 3, selection of variable definitions and detection methods. A steering committee interpreted and analysed the data.

RESULTS

The maximum data set contained 245 variables. The three stages of voting commenced in October 2019 and had been completed by July 2020. The final primary ventral hernia data set included 32 variables, the incisional ventral hernia data set included 40 variables, the patient-reported outcome measures tool contained 25 questions, and 40 methodological criteria were chosen. The best known variable definitions were selected for accurate variable description. CT was selected as the optimal preoperative descriptor of hernia morphology. Standardized follow-up at 30 days, 1 year, and 5 years was selected.

CONCLUSION

These minimum data sets, patient-reported outcome measures, and methodological criteria have allowed creation of a manual for investigators aiming to undertake primary ventral hernia or incisional ventral hernia interventional trials. Adopting these data sets will improve trial methods and comparisons.

Causes of prolonged hospitalization after open incisional hernia repair: an observational single-center retrospective study of a prospective database

PURPOSE

Enhanced recovery after surgery (ERAS) is a well-known approach to optimize the recovery after surgery. Little is known about specific causes of prolonged hospitalization despite enhanced recovery after open incisional hernia repair (OIHR). The purpose of this study was to identify the causes of continued hospitalization on each of the first 5 postoperative days (PODs) after OIHR.

METHODS

This was a retrospective study of consecutive patients undergoing open AWR at a regional academic hernia center from 2008 to 2018. Patient charts were evaluated using predefined potential causes of continued hospitalization on each of the first five PODs.

RESULTS

A total of 388 patients (mean age 60.9 years, 54.6% male, mean BMI 27.9 kg/m²) were included in the study. Mesh placement was either preperitoneal/intraperitoneal (20%) or retromuscular (80%) and 61% of the patients had an epidural catheter. The median length of stay (LOS) in the cohort was four [IQR 2-6] days. On PODs 4 and 5, causes of continued hospital stay were absent bowel function (2% on POD 4, 1% on POD 5), pain (7% on POD 3, 2% on POD 4), lack of mobilization (1% on POD 4, 1% on POD 5), and other causes (urinary retention, high drain output, and complications to the surgery).

CONCLUSION

Causes for prolonged hospitalization after OIHR were possibly reducible. Future efforts to improve the ERAS regime and reduce LOS after OIHR should focus on pain treatment- and prevention, alternatives to epidural treatment, and well-defined, evidence-based discharge criteria.

Abdominal wound dehiscence is dangerous: a nationwide study of 14,169 patients undergoing elective open resection for colonic cancer

PURPOSE

The potential impact of abdominal wound dehiscence on long-term survival after elective abdominal surgery is largely unknown. The aim of this study was to examine the impact of abdominal wound dehiscence on survival and incisional hernia repair after elective, open colonic cancer resection.

METHODS

This was a nationwide cohort study based on merged data from Danish national registries, comprising patients subjected to elective, open resection for colonic cancer between May 1, 2001 and January 1, 2016. Multivariable Cox Regression analysis and propensity score matching was applied to adjust for confounding. The associations of abdominal wound dehiscence with 90-day mortality and subsequent incisional hernia repair were also examined.

RESULTS

A total of 14,169 patients were included in the cohort, of which 549 (3.9%) developed abdominal wound dehiscence. The 5-year survival was significantly decreased in patients with abdominal wound dehiscence (42.4%, 95% CI 38.1-46.7 vs. 53.4%, 52.6-54.3, P < 0.001), which was confirmed in the multivariable analysis (HR 1.22, CI 1.06-1.39, P = 0.004). Abdominal wound dehiscence was significantly associated with increased risk of 90-day mortality (OR 1.60, CI 1.12-2.27, P = 0.009) as well as subsequent incisional hernia repair (HR 1.80, CI 1.07-3.01, P = 0.026).

CONCLUSIONS

Abdominal wound dehiscence was significantly associated with decreased survival. Fascial closure after open colonic cancer resection should be given high priority to improve the long-term survival.

Increased risk of postoperative complications with retromuscular mesh placement in emergency incisional hernia repair: A nationwide register-based cohort study

INTRODUCTION

Incisional hernia is common after abdominal surgery. Watchful waiting carries the risk of incarceration and a need for emergency intervention. The aim of this study was to examine the risk of postoperative complications after emergency versus elective incisional hernia repair.

METHODS

Patients above 18 years of age undergoing open incisional hernia repair in Denmark in 2017-2018 were identified in the Danish Ventral Hernia Database. Patients were grouped according to elective or emergency hernia repair. The primary outcome was postoperative complications requiring operative intervention within 90 days, and the secondary outcome was postoperative length of stay.

RESULTS

We included 1050 patients, of whom 882 were admitted for elective and 168 for emergency operation. Patients undergoing emergency repair were older (64.7 years vs 59.2 years, p < 0.001), more often smokers (25.8% vs 13.6%, p = 0.003), and more often had a Charlson comorbidity score ⩾2 (26.8% vs 19.2%, p = 0.005) compared to patients undergoing elective repair. In a multivariate regression analysis, emergency compared to elective operation (OR = 2.71, 95% CI = 1.4-5.25, p = 0.003) and retromuscular compared to onlay mesh placement (OR = 2.14, 95% CI = 1.08-4.24, p = 0.013) were factors significantly associated with increased risk of postoperative complications. In a subgroup analysis including only emergency repairs, risk of complications after retromuscular mesh placement was even higher (OR = 10.12, 95% CI = 1.81-56.68, p = 0.008).

CONCLUSION

Emergency incisional hernia repair was associated with increased risk of postoperative complications and this risk was accentuated with retromuscular mesh placement. The use of retromuscular mesh in the emergency setting should be avoided, and the abdominal wall could either be closed by sutures or additional onlay mesh.

Should simultaneous stoma closure and incisional hernia repair be avoided?

PURPOSE

Patients scheduled for stoma closure may also have an incisional hernia. Studies have reported acceptable outcomes after contaminated ventral hernia repair, but whether stoma closure and incisional hernia repair should be performed as a combined procedure is unknown. This study examined combined stoma closure and incisional hernia repair compared with incisional hernia repair only.

METHODS

This was a nationwide propensity-score matched study. Patients who underwent elective incisional hernia repair from 2007-2017 were identified in the Danish Hernia Database. All patients who underwent concurrent stoma closure were matched 1:3 with patients who underwent incisional hernia repair only. The primary outcome was reoperation for hernia recurrence, whereas secondary outcomes included anastomotic leakage, length of hospital stay, and 30-day reoperation and readmission rates.

RESULTS

In total, 516 patients were included. The risk of reoperation for recurrence was increased after concurrent stoma closure compared with incisional hernia repair only (hazard ratio 1.69, 95% confidence interval 1.01-2.82, p = 0.044). Seven (5.4%) patients who underwent incisional hernia repair concurrent to stoma closure were reoperated for anastomotic leakage. Length of hospital stay and reoperation rates within 30 days were increased after concurrent stoma closure compared with incisional hernia repair only (median 8 versus 3 days, p < 0.001 and 29.5% versus 18.6%, p = 0.013), whereas there was no difference in 30-day readmission rates (p = 0.251).

CONCLUSIONS

Stoma closure and incisional hernia repair should be performed as a dual-stage procedure to decrease the risk of hernia recurrence.

Variation in training requirements within general surgery: comparison of 23 countries

Background

Many differences exist in postgraduate surgical training programmes worldwide. The aim of this study was to provide an overview of the training requirements in general surgery across 23 different countries.

Methods

A collaborator affiliated with each country collected data from the country's official training body website, where possible. The information collected included: management, teaching, academic and operative competencies, mandatory courses, years of postgraduate training (inclusive of intern years), working‐hours regulations, selection process into training and formal examination.

Results

Countries included were Australia, Belgium, Canada, Colombia, Denmark, Germany, Greece, Guatemala, India, Ireland, Italy, Kuwait, the Netherlands, New Zealand, Russia, Saudi Arabia, South Africa, South Korea, Sweden, Switzerland, UK, USA and Zambia. Frameworks for defining the outcomes of surgical training have been defined nationally in some countries, with some similarities to those in the UK and Ireland. However, some training programmes remain heterogeneous with regional variation, including those in many European countries. Some countries outline minimum operative case requirement (range 60–1600), mandatory courses, or operative, academic or management competencies. The length of postgraduate training ranges from 4 to 10 years. The maximum hours worked per week ranges from 38 to 88 h, but with no limit in some countries.

Conclusion

Countries have specific and often differing requirements of their medical profession. Equivalence in training is granted on political agreements, not healthcare need or competencies acquired during training.

Mesh versus suture in elective repair of umbilical hernia: systematic review and meta-analysis

BACKGROUND

Mesh repair of umbilical hernia has been associated with a reduced recurrence rate compared with suture closure, but potentially at the expense of increased postoperative complications and chronic pain. The objective of this systematic review and meta-analysis was to examine the outcomes after elective open mesh and suture repair for umbilical hernia in adults.

METHODS

A literature search was conducted to identify studies presenting original data on elective open mesh and suture repair of umbilical hernia. The primary outcome was hernia recurrence. Secondary outcomes included surgical-site infection (SSI), seroma, haematoma and chronic pain. Meta-analyses were undertaken.

RESULTS

The search resulted in 5353 hits and led to 14 studies being included (6 RCTs and 8 observational studies) describing a total of 2361 patients. Compared with suture, mesh repair was associated with a lower risk of recurrence (risk ratio (RR) 0·48, 95 per cent c.i. 0·30 to 0·77), with number needed to treat 19 (95 per cent c.i. 14 to 31). Mesh repair was associated with a higher risk of seroma (RR 2·37, 1·45 to 3·87), with number needed to harm 30 (17 to 86). There was no significant difference in the risk of SSI, haematoma or chronic pain.

CONCLUSION

The use of mesh in elective repair of umbilical hernia reduced the risk of recurrence compared with suture closure without altering the risk of chronic pain.

Incisional hernia repair in women of childbearing age: A nationwide propensity-score matched study

BACKGROUND & AIMS

Although incisional hernia repair in women of childbearing age is not rare, hernia disease in this group of patients is sparsely documented. The aim of this study was to examine long-term clinical results after incisional hernia repair in women of childbearing age.

MATERIAL AND METHODS

This nationwide cohort study examined incisional hernia repair from 2007 to 2013 in women of childbearing age, registered prospectively in the Danish Ventral Hernia Database. All women with a subsequent pregnancy were included, and a 1:3 propensity-score matched group of women with an incisional hernia repair without a subsequent pregnancy. A prospective follow-up was conducted, including a validated questionnaire. The primary outcome was recurrence, and the secondary outcome was chronic pain from the operated site.

RESULTS

In total, 124 (70.5%) women responded, 47 and 77 women with and without a subsequent pregnancy, respectively. The 5-year cumulative incidence of recurrence was 41.0% (95% confidence interval 32.0%-49.9%). After adjustment for potential confounders, subsequent pregnancy was independently associated with recurrence (hazard ratio 1.83, 95% confidence interval 1.02-3.29, p = 0.044). Twenty-six (21.0%) women reported chronic pain (moderate, n = 21; severe, n = 5) with no difference between women with and without a subsequent pregnancy. Hernia recurrence, higher body mass index, and smoking were associated with chronic pain.

CONCLUSION

Pregnancy following incisional hernia repair was associated with an increased risk of recurrence, but not with chronic pain.

Evaluation of predicted patellofemoral joint kinematics with a moving-axis joint model

The main objectives of this study were to expand the moving-axis joint model concept to the patellofemoral joint and evaluate the patellar motion against experimental patellofemoral kinematics. The experimental data was obtained through 2D-to-3D bone reconstruction of EOS images and segmented MRI data utilizing an iterative closest point optimization technique. Six knee model variations were developed using the AnyBody Modeling System and subject-specific bone geometries. These models consisted of various combinations of tibiofemoral (hinge, moving-axis, and interpolated) and patellofemoral (hinge and moving-axis) joint types. The newly introduced interpolated tibiofemoral joint is calibrated from the five EOS quasi-static lunge positions. The patellofemoral axis of the hinge model was defined by performing surface fits to the patellofemoral contact area; and the moving-axis model was defined based upon the position of the patellofemoral joint at 0° and 90° tibiofemoral-flexion. In between these angles, the patellofemoral axis moved linearly as a function of tibiofemoral-flexion, while outside these angles, the axis remained fixed. When using a moving-axis tibiofemoral joint, a hinge patellofemoral joint offers (-5.12 ± 1.23 mm, 5.81 ± 0.97 mm, 14.98 ± 2.30°, -4.35 ± 1.95°) mean differences (compared to EOS) while a moving-axis patellofemoral model provides (-2.69 ± 1.04 mm, 1.13 ± 0.80 mm, 12.63 ± 2.03°, 1.74 ± 1.46°) in terms of lateral-shift, superior translation, patellofemoral-flexion, and patellar-rotation, respectively. Furthermore, the model predictive capabilities increased as a direct result of adding more calibrated positions to the tibiofemoral model (hinge-1, moving-axis-2, and interpolated-5). Overall, a novel subject-specific moving-axis patellofemoral model has been established; that produces realistic patellar motion and is computationally fast enough for clinical applications.

Short-term safety of preoperative administration of botulinum toxin A for the treatment of large ventral hernia with loss of domain

PURPOSE

Preoperative intramuscular-administered botulinum toxin A (BTA) in the lateral abdominal muscles prior to abdominal wall reconstruction has been reported to produce a flaccid paralysis and improve the primary closure rate of large ventral hernias with loss of domain. Complications to this treatment remain sparsely described. The aim of the current study was to report safety and short-term outcome of abdominal wall reconstruction aided by BTA administration.

METHODS

This was a retrospective two-center study including all patients undergoing abdominal wall reconstruction for ventral hernia aided by preoperative BTA administration to the lateral abdominal muscles. Data were retrieved from patient charts and included preoperative demographic and perioperative information as well as postoperative 30-day complications and readmissions.

RESULTS

A total of 37 patients underwent BTA administration prior to hernia repair. The mean age and body mass index were 59.5 (SD 10.1) years and 31.1 (SD 5.2) kg/m². The BTA injections were administered mean 31.6 days (SD 10.0) prior to the hernia repair. One (2.7%) patient reported pain as a complication immediately after the BTA administration. Subsequent to the hernia repair, six (16.2%) patients were readmitted within 30 days. Nine patients (24.3%) had wound complications and medical complications occurred in seven (18.9%) patients.

CONCLUSIONS

We found early preoperative administration of BTA a safe adjunct to large ventral hernia repair, without adverse events related to the administration preoperative. Future studies should further highlight the efficacy of preoperative BTA for reconstruction of otherwise untreatable hernias.

Nationwide population-based cohort study to assess risk of surgery for adhesive small bowel obstruction following open or laparoscopic rectal cancer resection

Background

Laparoscopic surgery has been reported to reduce the formation of adhesions following colorectal surgery. The aim of this nationwide cohort study was to investigate the risk of surgery for adhesive small bowel obstruction (SBO) following open and laparoscopic rectal cancer resection.

Methods

Patients undergoing rectal cancer resection between 2005 and 2013 were identified in the Danish Colorectal Cancer Group database. The primary outcome of surgery for adhesive SBO was identified in the Danish National Patient Registry. The risk of surgery for adhesive SBO was estimated as the cumulative incidence proportion, treating death as a competing risk. Cox proportional hazards regression analysis with multivariable adjustment was used to compute hazard ratios (HRs). The secondary outcome was 30‐day mortality after surgery for adhesive SBO.

Results

Of 7657 patients, 340 (4·4 per cent) underwent surgery for adhesive SBO. The 5‐year risk of surgery for adhesive SBO was 4·5 per cent among 4472 patients undergoing open resection and 3·0 per cent among 3185 patients having a laparoscopic resection. Laparoscopic rectal resection was associated with a lower risk of subsequent operation for adhesive SBO (adjusted HR 0·65, 95 per cent c.i. 0·50 to 0·86; P = 0·002). The adjusted HR of mortality after adhesive SBO was 0·84 (0·37 to 1·91; P = 0·671) comparing patients with previous laparoscopic and open resection.

Conclusion

Laparoscopic rectal cancer resection was associated with a decreased risk of surgery for adhesive SBO. There was a substantial difference in 30‐day mortality after surgery for adhesive SBO based on the surgical approach used at the time of rectal resection.

Primary ventral or groin hernia in pregnancy: a cohort study of 20,714 women

BACKGROUND

Prevalence, management, and risk of emergency operation for primary ventral or groin hernia in pregnancy are unknown. The objective of this study was to estimate the prevalences of primary ventral or groin hernia in pregnancy and the potential risks for elective and emergency repair.

METHODS

This single-institutional retrospective study included all pregnant women attending one or more prenatal consultations at Hvidovre Hospital, Denmark, during a 3-year period. Patients' medical records were electronically retrieved. A free-text search algorithm and subsequent manual review was conducted to identify patients registered with a primary ventral or groin hernia in pregnancy. Follow-up was conducted by review of medical record notes within the Capital Region of Denmark supplemented with structured telephone interviews on indication.

RESULTS

In total, 20,714 pregnant women were included in the study cohort. Seventeen (0.08%) and 25 (0.12%) women were registered with a primary ventral and groin hernia, respectively. None underwent elective or emergency repair in pregnancy, and all had uncomplicated childbirth. In 10 women, the groin bulge disappeared spontaneously after delivery. During postpartum follow-up of median 4.4 years (range 0.2-6.0 years), five (0.02%) and four (0.02%) underwent elective primary ventral and groin hernia repair, respectively.

CONCLUSION

Primary ventral or groin hernia seems rare in pregnancy, and the incidence of emergency repair is extremely low. Watchful waiting strategy is recommended during pregnancy in women suspected for a primary ventral or groin hernia.

Enhanced recovery after giant ventral hernia repair

PURPOSE

Giant ventral hernia repair is associated with a high risk of postoperative morbidity and prolonged length of stay (LOS). Enhanced recovery (ERAS) measures have proved to lead to decreased morbidity and LOS after various surgical procedures, but never after giant hernia repair. The current study prospectively examined the results of implementation of an ERAS pathway including high-dose preoperative glucocorticoid, and compared the outcome with patients previously treated according to standard care (SC).

METHODS

Consecutive patients who underwent giant ventral hernia repair were included. Pain, nausea and fatigue were registered prospectively in all patients treated according to ERAS, as well as continuous measurement of transcutaneous capillary oxygen saturation. Postoperative morbidity and LOS were compared between patients treated according to ERAS and a historic group treated with SC.

RESULTS

A total of 32 patients were included. Postoperative LOS was decreased after the introduction of the ERAS pathway compared with SC (median 3.0 vs. 5.5 days, P = 0.003). Scores of pain, nausea and fatigue were low, while mean oxygen saturation during the first three postoperative days was 0.92. There were no differences when comparing readmission (5 vs. 2, P = 0.394), postoperative complications (7 vs. 4, P = 0. 458), or reoperation (5 vs. 1, P = 0.172) in ERAS versus controls.

CONCLUSIONS

The current study suggests that an ERAS pathway including preoperative high-dose glucocorticoid may lead to low scores of pain, fatigue and nausea after giant ventral hernia repair with reduced LOS compared with patients treated according to SC.

Abdominal wall hernia and pregnancy: a systematic review

PURPOSE

There is no consensus as to the treatment strategy for abdominal wall hernias in fertile women. This study was undertaken to review the current literature on treatment of abdominal wall hernias in fertile women before or during pregnancy.

METHODS

A literature search was undertaken in PubMed and Embase in combination with a cross-reference search of eligible papers.

RESULTS

We included 31 papers of which 23 were case reports. In fertile women undergoing sutured or mesh repair, pain was described in a few patients during the last trimester of a subsequent pregnancy. Emergency surgery of incarcerated hernias in pregnant women, as well as combined hernia repair and cesarean section appears as safe procedures. No major complications were reported following hernia repair before or during pregnancy. The combined procedure of elective cesarean section and abdominal wall hernia repair was reported in 102 patients without major complications.

CONCLUSIONS

The literature on abdominal wall hernia and pregnancy is sparse. Abdominal wall hernia repair with suture or mesh may cause pain in the last trimester of a subsequent pregnancy. Hernia repair in conjunction with cesarean section appear as the optimal treatment of a pregnant patient with a symptomatic abdominal wall hernia.

Pelvic floor reconstruction with a biological mesh after extralevator abdominoperineal excision leads to few perineal hernias and acceptable wound complication rates with minor movement limitations: single-centre experience including clinical examination and interview

AIM

The aim of the study was to describe long-term subjective and objective results of pelvic floor reconstruction using an absorbable biological mesh after extralevator abdominoperineal excision (ELAPE) for low rectal cancer.

METHOD

Records of 53 patients who had an ELAPE with reconstruction of the pelvic floor with a Permacol® mesh between August 2007 and August 2011 were reviewed. Thirty-one of the patients were called for interview and clinical examination.

RESULTS

Three (6%) patients developed perineal hernia, 11 had fistulae (nine of which were treated successfully), four patients had a perineal abscess and four patients had superficial wound infections. Removal of the mesh was necessary in one case, while another patient needed implantation of a new mesh. In 13 of the 31 interviewed patients, long-term pain was present, but resolved after a median of 8 months (3-56). No major sitting or movement disabilities were encountered. Three-year survival was 82%, and no local recurrences were found.

CONCLUSION

Pelvic floor reconstruction with a biological mesh is a feasible solution when performing ELAPE for low rectal cancer, although long-term pain is a frequent complication.

Surgical complications and graft survival in pediatric kidney transplant recipients treated with a steroid-free protocol: experiences from a Danish university hospital

BACKGROUND

The outcome of pediatric kidney transplantation depends on several factors, among these are the complications, which occur in relation to the surgical procedure. In this study, we present our experience with pediatric kidney transplantation in a steroid-free immunosuppression regimen, from a surgical point of view.

METHODS

Patient charts of pediatric kidney transplantations in the period 1998-2011 were reviewed. Surgical complications, acute rejection, and patient and graft survivals were recorded.

RESULTS

Sixty-one renal transplantations were performed in 58 patients. Thirty patients (49.1%) experienced a surgical complication, of which 11 (18%) required an explorative laparotomy. Overall the five-year Kaplan-Meier patient survival rate was 96.2% and the graft survival rate was 88.6%. Nine patients (14.7%) had an acute rejection episode within the first year after transplantation. No correlation was observed between surgical complications and acute rejection episodes or graft loss.

CONCLUSIONS

This study indicated a high incidence of surgical complications among pediatric kidney transplantations when using a steroid-free immunosuppression regimen. Despite this, we observed high overall patient and graft survival, supporting the trend toward steroids avoidance in pediatric kidney transplantation.

Lay and expert perceptions of zoonotic risks: understanding conflicting perspectives in the light of moral theory

As in many other areas, there is a divide between lay and expert perceptions of risk within the food sector, and this can lead to disagreement over priorities in food risk management. The risk perception literature tends to stress that the parties involved in this disagreement have different concepts of risk and hence are bound more or less to talk at cross-purposes. This paper suggests an alternative analysis: In the light of moral theory, the conflicting perspectives can be understood as a genuine moral conflict. When this conflict is conceptualised, a rational dialogue becomes possible. The paper reports a series of qualitative interviews with lay people and experts on zoonotic food risks. The interviews are used to reconstruct the values underlying some of the dominant perspectives. The conflict between these stylised perspectives is then analysed with the help of moral theory. Finally, some consequences for risk communication are made clear.

Disruption of neutrophil migration in a conditional transgenic model: evidence for CXCR2 desensitization in vivo

We developed transgenic mice conditionally expressing the neutrophil chemoattracting chemokine KC and the beta-galactosidase gene in multiple tissues. In these transgenic mice, doxycycline treatment induced a strong up-regulation in the expression of KC in several tissues, including heart, liver, kidney, skin, and skeletal muscle. Expression of KC within these tissues led to a rapid and substantial increase in the serum levels of KC (serum KC levels were higher than 200 ng/ml 24 h after treatment). Accordingly, beta-galactosidase expression was also detected after injection of doxycycline and was highest in skeletal muscle, pancreas, and liver. Surprisingly, despite expression of KC in multiple tissues, no neutrophil infiltration was observed in any of the tissues examined, including skin. Doxycycline treatment of nontransgenic mice grafted with transgenic skin caused dense neutrophilic infiltration of the grafts, but not the surrounding host skin, indicating that the KC produced in transgenic tissues was biologically active. In separate experiments, neutrophil migration toward a localized source of recombinant KC was impaired in animals overexpressing KC but was normal in response to other neutrophil chemoattractants. Analysis of transgenic neutrophils revealed that high concentrations of KC in transgenic blood had no influence on L-selectin cell surface expression but caused desensitization of the receptor for KC, CXCR2. These results confirm the neutrophil chemoattractant properties of KC and provide a mechanistic explanation for the paradoxical lack of leukocyte infiltration observed in the presence of elevated concentrations of this chemokine.

Enhanced fluorescence resonance energy transfer between spectral variants of green fluorescent protein through zinc-site engineering

Although spectral variants of GFP should in theory be suited for fluorescence resonance energy transfer (FRET) and therefore suited for studies of protein-protein interactions, the unfavorable location of the fluorophore 15 A deep inside the GFP molecule has especially impaired this application. Here, metal-ion site engineering around the dimerization interface known from the X-ray structure of GFP is applied to the cyan and the yellow spectral variant of GFP to stabilize the heterodimeric form of these molecules and thereby increase FRET signaling. The FRET signal, determined as the ratio between the maximal emission for the yellow variant, 530 nm, and the cyan variant, 475 nm, during excitation of the cyan variant at 433 nm was increased up to 8-10-fold in the presence of 10(-4) M ZnCl2 by engineering of two symmetric metal-ion sites being either bidentate or tridentate. A similar increase in FRET signaling was however obtained in a pair of molecules in which a single bidentate metal-ion site was generated by introducing a zinc-binding residue in each of the two spectral variants of GFP and therefore creating an obligate heterodimeric pair. It is concluded that FRET signaling between spectral variants of GFP can be increased by stabilizing dimer formation and especially by favoring heterodimer formation in this case performed by metal-ion site engineering.

Kinetics for hybridization of peptide nucleic acids (PNA) with DNA and RNA studied with the BIAcore technique

The binding of a mixed-sequence pentadecamer PNA (peptide nucleic acid) containing all four nucleobases to the fully complementary as well as various singly mismatched RNA and DNA oligonucleotides has been systematically investigated using thermal denaturation and BIAcore surface-interaction techniques. The rate constants for association (k(a)) and dissociation (k(d)) of the duplex formation as well as the thermal stability (melting temperature, T(m)) of the duplexes have been determined. Upon binding to PNA tethered via a biotin-linker to streptavidin at the dextran/gold surface, DNA and RNA sequences containing single mismatches at various positions in the center resulted in increased dissociation and decreased association rate constants. T(m) values for PNA x RNA duplexes are on average 4 degrees C higher than for PNA x DNA duplexes and follow quantitatively the same variation with mismatches as do the PNA x DNA duplexes. Also a faster k(a) and a slower k(d) are found for PNA x RNA duplexes compared to the PNA x DNA duplexes. An overall fair correlation between T(m), k(a), and k(d) is found for a series of PNA x DNA and PNA x RNA duplexes although the determination of k(a) seemed to be prone to artifacts of the method and was not considered capable of providing absolute values representing the association rate constant in bulk solution.

[Image transmission between hospitals. Technical and clinical testing of the equipment for digital image transmission between hospitals via the ordinary telephone network]

A standard PC-based equipment--"Multiview Photophone"--for two-way image conference between hospitals by means of digital images transmitted through ordinary telephone lines was tested. The technical and visual quality of scanned and transmitted pictures proved to be satisfactory, and ease of handling the equipment and transmission times were acceptable. The clinical test was made by image conferences between a neurological department in a general hospital and a neurosurgical department in a university hospital. CT-scans concerning 39 patients in a prospective series, for whom specialist advice from the neurosurgical department was found necessary, were transmitted. Four of nine acute patients were saved an "unnecessary" transferral to the neurosurgical department. The 30 elective patients were all found to benefit from the two-way conferences, since the decision time was reduced and the quality of information given to the patients and their relatives was improved.

Bacillus subtilis transcription regulator, Spo0A, decreases alkaline phosphatase levels induced by phosphate starvation

Alkaline phosphatase (APase) is induced as a culture enters stationary phase because of limiting phosphate. The results presented here show that expression of APase is regulated both negatively and positively. PhoP, a homolog of a family of bacterial transcription factors, and PhoR, a homolog of bacterial histidine protein kinases, are required for induction of APases when phosphate becomes limiting. The induction period lasts 2 to 3 h, after which the rate of APase accumulation is decreased. Mutant strains defective in the Spo0A transcription factor failed to decrease APase production. The consequent hyperinduction of APase in a spo0A strain was dependent on phoP and phoR. spo0B and spo0F strains also overexpressed APase, suggesting that phosphorylated Spo0A is required for repression of APase. An abrB mutant allele in the presence of the mutant spo0A allele in these strains did not significantly change the APase hyperinduction phenotype, demonstrating that Spo0A repression of abrB expression is not the mechanism by which Spo0A-P regulates APase expression. Our previous report that spo0A mutants do not express APases is in conflict with the present data. We show here that the previously used mutants and a number of commonly used spo0 strains, all of which have an APase deficiency phenotype, contain a previously unrecognized mutation in phoR.

Protoplast transformation of Bacillus licheniformis MC14

A protoplast transformation system has been developed for Bacillus licheniformis MC14. Optimum regeneration conditions were achieved by raising the incubation temperature of the regeneration plates to 46 degrees C. Regenerated transformed colonies could be isolated in 3 to 5 d under these conditions. Plasmids introduced by this method were stably maintained by B. licheniformis MC14 and could be recovered and used to transform Bacillus subtilis.

Role of delayed gastric emptying in the pathogenesis of cysteamine-induced duodenal ulcer in the rat

Cysteamine is a potent duodenal ulcerogen in rats. It has been demonstrated to inhibit gastric empyting, whose role in ulcer formation is unknown. In the present study the effect of cysteamine on gastric motility and emptying rate in rats was studied by direct fluoroscopic observation. The delayed gastric empyting was due to a pronounced relaxation of the stomach and a complete blocking of gastric peristalsis. These effects have their maximum within the first 4 h after administration of cysteamine. Thereafter peristalsis and gastric empyting slowly return. In controls contrast medium administered intragastrically was completely discharged from the stomach within 30 min. After cysteamine the first small amounts of contrast medium were discharged into the duodenum after 4 h, and contrast medium remained in the stomach for at least 12 h after administration. The size of the stomach reached a maximum after 3 h and approached normal values again after 12 h. Because of complete gastric retention the acid gastric secretions provoked by cysteamine probably accumulate in the stomach during the first 4 h after cysteamine administration, and because of the absence of peristalsis they are not mixed with gastric contents. After 4 h this pool of undiluted gastric secretions gradually is emptied into the duodenum, where the mucosal resistance is reduced by inhibition of the secretory activity of Brunner's glands, and ulceration rapidly develops. The time relationship is supported by histopathologic findings and measurements of gastric acid secretions after cysteamine. Vagotomy augmented the inhibitory effect of cysteamine on gastric motility. The relaxation was even more pronounced, and contrast medium was not discharged from the stomach within 24 h. In these rats cysteamine induced ulcerations in the stomach.

Inhibition of Escherichia coli by thioglycerol

Thioglycerol inhibits the growth of various Escherichia coli strains and other microorganisms, both gram positive and gram negative. The susceptibility of organisms varies. The bactericidal action of this substance is not continuous and stops after an initial burst. At subbactericidal concentrations synthesis of ribonucleic acid is the most strongly affected. This is not due to interference with nucleoside biosynthesis or to direct inhibition of ribonucleic acid polymerase by thioglycerol.