Trends in open abdominal surgery in the United States—Observations from 9,950,759 discharges using the 2009–2013 National Inpatient Sample (NIS) datasets

Missing the Mark: Evaluating the Validity of the Ventral Hernia Screen in Detecting Recurrence

PURPOSE

Hernia recurrence is a primary metric in evaluating the success of ventral hernia repair (VHR). Current screening methods for hernia recurrence, including the validated Ventral Hernia Screening (VHS) questionnaire, have not yet been critically evaluated. The purpose of this study was to evaluate the predictive value of the VHS for hernia recurrence.

METHODS

This is a retrospective cohort study of adult patients who underwent primary VHR utilizing poly-4-hydroxybutyrate mesh at a single-institution from January 2016 to December 2021 who completed at least one VHS during their postoperative follow-up. All patients who screened positive underwent follow-up diagnostic computed tomography or physical examination for confirmation of hernia recurrence. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were assessed for each item and the VHS as a whole.

RESULTS

A total of 68 patients who completed 119 VHS questionnaires were included. The median time to VHS administration was 3.6 years (range .8-6.3 years). The VHS tool had a sensitivity of 40.0%, specificity of 71.1%, PPV of 5.7%, and NPV of 96.4%. Individual items of the VHS also produced poor screening effects, with sensitivities between 20 and 40%, specificities between 79 and 97%, PPVs between 4 and 25%, and NPVs from 95 to 97%.

CONCLUSION

The VHS was a poor positive predictive tool for hernia recurrence, with both a low PPV and sensitivity. Many patients may be unaware of when they truly have hernia recurrence in the long term. More rigorous tools need to be developed to monitor recurrence following VHR.

Economic Analysis of AbClo, a Novel Abdominal Fascia Closure Device, for Patients With an Open Abdomen Following Trauma or Acute Abdominal Surgery

BACKGROUND

Open Abdomen (OA) cases represent a significant surgical and resource challenge. AbClo is a novel non-invasive abdominal fascial closure device that engages lateral components of the abdominal wall muscles to support gradual approximation of the fascia and reduce the fascial gap. The study objective was to assess the economic implications of AbClo compared to negative pressure wound therapy (NPWT) alone on OA management.

METHODS

We conducted a cost-minimization analysis using a decision tree comparing the use of the AbClo device to NPWT alone among patients with midline laparotomy for trauma or acute abdominal surgery who were ineligible for primary fascial closure. The time horizon was limited to the length of the inpatient hospital stay, and costs were considered from the perspective of the US Medicare payer. Clinical effectiveness data for AbClo was obtained from a randomized clinical trial. Cost data was obtained from the published literature. Probabilistic and deterministic sensitivity analyses were performed. The primary outcome was incremental cost.

RESULTS

The mean cumulative costs per patient were $76 582 for those treated with NPWT alone and $70,582 for those in the group treated with the AbClo device. Compared to NPWT alone, AbClo was associated with lower incremental costs of -$6012 (95% CI -$19 449 to +$1996). The probability that AbClo was cost-savings compared to NPWT alone was 94%.

CONCLUSIONS

The use of AbClo is an economically attractive strategy for management of OA in in patients with midline laparotomy for trauma or acute abdominal surgery who were ineligible for primary fascial closure.

Protocol for an independent patient data meta-analysis of prophylactic mesh placement for incisional hernia prevention after abdominal aortic aneurysm surgery: a collaborative European Hernia Society project (I-PREVENT-AAA)

INTRODUCTION

Incisional hernia (IH) is a prevalent and potentially dangerous complication of abdominal surgery, especially in high-risk groups. Mesh reinforcement of the abdominal wall has been studied as a potential intervention to prevent IHs. Randomised controlled trials (RCTs) have demonstrated that prophylactic mesh reinforcement after abdominal surgery, in general, is effective and safe. In patients with abdominal aortic aneurysm (AAA), prophylactic mesh reinforcement after open repair has not yet been recommended in official guidelines, because of relatively small sample sizes in individual trials. Furthermore, the identification of subgroups that benefit most from prophylactic mesh placement requires larger patient numbers. Our primary aim is to evaluate the efficacy and effectiveness of the use of a prophylactic mesh after open AAA surgery to prevent IH by performing an individual patient data meta-analysis (IPDMA). Secondary aims include the evaluation of postoperative complications, pain and quality of life, and the identification of potential subgroups that benefit most from prophylactic mesh reinforcement.

METHODS AND ANALYSIS

We will conduct a systematic review to identify RCTs that study prophylactic mesh placement after open AAA surgery. Cochrane Central Register of Controlled Trials, MEDLINE Ovid, Embase, Web of Science Core Collection and Google Scholar will be searched from the date of inception onwards. RCTs must directly compare primary sutured closure with mesh closure in adult patients who undergo open AAA surgery. Lead authors of eligible studies will be asked to share individual participant data (IPD). The risk of bias (ROB) for each included study will be assessed using the Cochrane ROB tool. An IPDMA will be performed to evaluate the efficacy, with the IH rate as the primary outcome. Any signs of heterogeneity will be evaluated by Forest plots. Time-to-event analyses are performed using Cox regression analysis to evaluate risk factors.

ETHICS AND DISSEMINATION

No new data will be collected in this study. We will adhere to institutional, national and international regulations regarding the secure and confidential sharing of IPD, addressing ethics as indicated. We will disseminate findings via international conferences, open-source publications in peer-reviewed journals and summaries posted online.

PROSPERO REGISTRATION NUMBER

CRD42022347881.

Comparison between the effects of epidural and intravenous patient-controlled analgesia on postoperative disability-free survival in patients undergoing thoracic and abdominal surgery: A post hoc analysis

BACKGROUND

Thoracic epidural analgesia (TEA) and intravenous patient-controlled analgesia (IV-PCA) are widely used to mitigate immediate postoperative pain; however, their effects on long-term disability-free survival are poorly documented. This study aimed to compare the effects of postoperative TEA and IV-PCA on disability-free survival in patients who underwent thoracic or abdominal surgery.

METHODS

This post hoc analysis of a prospective observational study included 845 inpatients aged ≥55 years that underwent elective thoracic and abdominal surgery between 1 April 2016 and 28 December 2018 in a tertiary care hospital. Inverse probability of treatment weighted (IPTW) using stabilized inverse propensity scores was adopted to minimize bias. The primary outcome in this study was disability-free survival, defined as survival with a 12-item World Health Organization Disability Assessment Schedule 2.0 score of <16%, assessed at 3 months and 1 year after surgery.

RESULTS

The final analysis included 601 patients who received TEA and 244 who received IV-PCA. After IPTW, the weighted incidence of disability-free survival at 3 months and 1 year was 60.5% and 61.4% in the TEA group and 78.3% and 66.2% in the IV-PCA group, respectively. The adjusted OR for disability-free survival at 3 months and 1 year was 0.84 (95% confidence interval [CI]: 0.50-1.39) and 1.21 (95% CI: 0.72-2.05), respectively, for the TEA group.

CONCLUSION

No significant differences were observed in the disability-free survival at 3 months and 1 year after elective thoracic and abdominal surgery in patients aged ≥55 years who received TEA or IV-PCA.

SIGNIFICANCE STATEMENT

This study is the first in our setting to document the long-term effects of patient-controlled analgesia. In a post hoc analysis of our prospective cohort study, we show that although differences in chronic postsurgical pain exist at 3 months post-surgery, disability-free survival rates at 1 year do not differ irrespective of the choice of patient-controlled analgesia. The findings of this study highlight the need for shared decision-making between clinicians and patients.

Scoping review: The terminology used to describe major abdominal surgical procedures

BACKGROUND

Major abdominal surgery (MAS) can have a profound impact on the patient but there is currently no consensus as to which surgical procedures constitute MAS. The main objective of this work is to ascertain the terminology used to describe MAS procedures and to apply these findings in order to propose a definition of MAS.

METHODS

The following databases were searched: Ovid MEDLINE (R) ALL, Embase Classic and Embase (via OvidSP), Global Health (via OvidSP), Health Management Information Consortium (via OvidSP), APA PsycInfo (via OvidSP), PubMed and Web of Science. Original research articles, published between 1980 and April 26, 2022 that contained a description of MAS procedure were included in this study. Article screening and data extraction was undertaken independently by 3 authors. Content analysis was performed to identify key terminology used to describe MAS.

RESULTS

Five thousand six hundred and sixty three articles were identified, of which 767 underwent full-text review and 312 were included in the scoping review. Content analysis resulted in 4 main categories: (1) pre-operative factors, (2) intraoperative factors, (3) operation-related factors, (4) post-operative factors. Operation-related factors was the predominant category (1137 references coded). The gastrointestinal resection made the vast majority of the references coded (591).

CONCLUSIONS

Based on these results, the term "major abdominal surgery" should be defined as an intra-peritoneal operation with no primary involvement of the thorax, involving either luminal resection and/or resection of a solid organ associated with the gastrointestinal tract. However, further work is required to verify this definition using real world data.

Optimal computed tomography-based biomarkers for prediction of incisional hernia formation

PURPOSE

Unstructured data are an untapped source for surgical prediction. Modern image analysis and machine learning (ML) can harness unstructured data in medical imaging. Incisional hernia (IH) is a pervasive surgical disease, well-suited for prediction using image analysis. Our objective was to identify optimal biomarkers (OBMs) from preoperative abdominopelvic computed tomography (CT) imaging which are most predictive of IH development.

METHODS

Two hundred and twelve rigorously matched colorectal surgery patients at our institution were included. Preoperative abdominopelvic CT scans were segmented to derive linear, volumetric, intensity-based, and textural features. These features were analyzed to find a small subset of OBMs, which are maximally predictive of IH. Three ML classifiers (Ensemble Boosting, Random Forest, SVM) trained on these OBMs were used for prediction of IH.

RESULTS

Altogether, 279 features were extracted from each CT scan. The most predictive OBMs found were: (1) abdominopelvic visceral adipose tissue (VAT) volume, normalized for height; (2) abdominopelvic skeletal muscle tissue volume, normalized for height; and (3) pelvic VAT volume to pelvic outer aspect of body wall skeletal musculature (OAM) volume ratio. Among ML prediction models, Ensemble Boosting produced the best performance with an AUC of 0.85, accuracy of 0.83, sensitivity of 0.86, and specificity of 0.81.

CONCLUSION

These OBMs suggest increased intra-abdominopelvic volume/pressure as the salient pathophysiologic driver and likely mechanism for IH formation. ML models using these OBMs are highly predictive for IH development. The next generation of surgical prediction will maximize the utility of unstructured data using advanced image analysis and ML.

Optimizing Surgical Wound Care in Obstetrics and Gynecology

Importance

Obstetrics and gynecology (OB/GYN) accounts for at least half of all open abdominal surgeries performed. Rates of surgical wound complications after open procedures in OB/GYN range from 5% to 35%. Therefore, optimizing management of surgical wound complications has the potential to significantly reduce cost and morbidity. However, guidelines addressing best practices for wound care in OB/GYN are limited.

Objective

The objectives of this review are to describe the fundamentals of wound healing and to evaluate available evidence addressing surgical wound care. Based on these data, we provide recommendations for management of extrafascial surgical wound dehiscence after OB/GYN procedures.

Evidence Acquisition

Literature search was performed in PubMed, Medline, OVID, and the Cochrane database. Relevant guidelines, systematic reviews, and original research articles investigating mechanisms of wound healing, types of wound closure, and management of surgical wound complications were reviewed.

Results

Surgical wound complications in OB/GYN are associated with significant cost and morbidity. One of the most common complications is extrafascial dehiscence, which may occur in the setting of hematomas, seromas, or infection. Management includes early debridement and treatment of any underlying infection until healthy granulation tissue is present. For wounds healing by secondary intention, advanced moisture retentive dressings reduce time to healing and are cost-effective when compared with conventional wet-to-dry gauze dressings. Negative pressure wound therapy can be applied to deeper wounds healing by secondary intention. Review of published evidence also supports the use of delayed reclosure to expedite wound healing for select patients.

Conclusions

Optimizing surgical wound care has the potential to reduce the cost and morbidity associated with surgical wound complications in OB/GYN. Advanced moisture retentive dressings should be considered for wounds healing by secondary intention. Data support delayed reclosure for select patients, although further studies are needed.

Preoperative Computed Tomography Morphological Features Indicative of Incisional Hernia Formation After Abdominal Surgery

OBJECTIVE

To investigate key morphometric features identifiable on routine preoperative computed tomography (CT) imaging indicative of incisional hernia (IH) formation following abdominal surgery.

BACKGROUND

IH is a pervasive surgical disease that impacts all surgical disciplines operating in the abdominopelvic region and affecting 13% of patients undergoing abdominal surgery. Despite the significant costs and disability associated with IH, there is an incomplete understanding of the pathophysiology of hernia.

METHODS

A cohort of patients (n=21,501) that underwent colorectal surgery was identified, and clinical data and demographics were extracted, with a primary outcome of IH. Two datasets of case-control matched pairs were created for feature measurement, classification, and testing. Morphometric linear and volumetric measurements were extracted as features from anonymized preoperative abdominopelvic CT scans. Multivariate Pearson testing was performed to assess correlations among features. Each feature's ability to discriminate between classes was evaluated using 2-sided paired t testing. A support vector machine was implemented to determine the predictive accuracy of the features individually and in combination.

RESULTS

Two hundred and twelve patients were analyzed (106 matched pairs). Of 117 features measured, 21 features were capable of discriminating between IH and non-IH patients. These features are categorized into three key pathophysiologic domains: 1) structural widening of the rectus complex, 2) increased visceral volume, 3) atrophy of abdominopelvic skeletal muscle. Individual prediction accuracy ranged from 0.69 to 0.78 for the top 3 features among 117.

CONCLUSIONS

Three morphometric domains identifiable on routine preoperative CT imaging were associated with hernia: widening of the rectus complex, increased visceral volume, and body wall skeletal muscle atrophy. This work highlights an innovative pathophysiologic mechanism for IH formation hallmarked by increased intra-abdominal pressure and compromise of the rectus complex and abdominopelvic skeletal musculature.

Reoperation Through a Prosthetic-Reinforced Abdominal Wall and Its Association With Postoperative Outcomes and Longitudinal Health Care Utilization

Importance

Prosthetic reinforcement of critically sized incisional hernias is necessary to decrease hernia recurrence, but long-term prosthetic-mesh footprint may increase complication risk during subsequent abdominal operations.

Objective

To investigate the association of prior incisional hernia repair with mesh (IHRWM) with postoperative outcomes and health care utilization after common abdominal operations.

Design, Setting, and Participants

This was a population-based, retrospective cohort study of patients undergoing inpatient abdominal surgical procedures during the period of January 2009 to December 2016, with at least 1 year of follow-up within 5 geographically diverse statewide inpatient/ambulatory databases (Florida, Iowa, Nebraska, New York, Utah). History of an abdominal operation was ascertained within the 3-year period preceding the index operation. Patients admitted to the hospital with a history of an abdominal operation (ie, bariatric, cholecystectomy, small- or large-bowel resection, prostatectomy, gynecologic) were identified using the International Classification of Diseases, Ninth Revision and Tenth Revision, Clinical Modification procedure codes. Patients with prior IHRWM were propensity score matched (1:1) to controls both with and without a history of an abdominal surgical procedure based on clinical and operative characteristics. Data analysis was conducted from March 1 to November 27, 2021.

Main Outcomes and Measures

The primary outcome was a composite of adverse postoperative outcomes (surgical and nonsurgical). Secondary outcomes included health care utilization determined by length of hospital stay, hospital charges, and 1-year readmissions. Logistic and Cox regression determined the association of prior IHRWM with the outcomes of interest. Additional subanalyses matched and compared patients with prior IHR without mesh (IHRWOM) to those with a history of an abdominal operation.

Results

Of the 914 105 patients undergoing common abdominal surgical procedures (81 123 bariatric [8.9%], 284 450 small- or large-bowel resection [31.1%], 223 768 cholecystectomy [24.5%], 33 183 prostatectomy [3.6%], and 291 581 gynecologic [31.9%]), all 3517 patients (age group: 46-55 years, 1547 [44.0%]; 2396 majority sex [68.1%]) with prior IHRWM were matched to patients without a history of abdominal surgical procedures. After matching, prior IHRWM was associated with increased overall complications (odds ratio [OR], 1.43; 95% CI, 1.27-1.60), surgical complications (OR, 1.51; 95% CI, 1.34-1.70), length of hospital stay (mean increase of 1.03 days; 95% CI, 0.56-1.49 days; P < .001), index admission charges (predicted mean difference of $11 896.10; 95% CI, $6096.80-$17 695.40; P < .001), and 1-year unplanned readmissions (hazard ratio, 1.14; 95% CI, 1.05-1.25; P = .002). This trend persisted even when comparing matched patients with prior IHRWM to patients with a history of abdominal surgical procedures, and the treatment outcome disappeared when comparing patients with prior IHRWOM to those without a previous abdominal operation.

Conclusions and Relevance

Reoperation through a previously prosthetic-reinforced abdominal wall was associated with increased surgical complications and health care utilization. This risk appeared to be independent of a history of abdominal surgical procedures and was magnified by the presence of a prosthetic-mesh footprint in the abdominal wall.

Current approaches to acute postoperative pain management after major abdominal surgery: a narrative review and future directions

Poorly controlled postoperative pain is associated with increased morbidity, negatively affects quality of life and functional recovery, and is a risk factor for persistent pain and longer-term opioid use. Up to 10% of opioid-naïve patients have persistent opioid use after many types of surgeries. Opioid-related side-effects and the opioid abuse epidemic emphasise the need for alternative, opioid-minimising, multimodal analgesic strategies, including neuraxial (epidural/intrathecal) techniques, truncal nerve blocks, and lidocaine infusions. The preference for minimally invasive surgical techniques has changed anaesthetic and analgesic requirements in abdominal surgery compared with open laparotomy, leading to a decline in popularity of epidural anaesthesia and an increasing interest in intrathecal morphine and truncal nerve blocks. Limited research exists on patient quality of recovery using specific analgesic techniques after intra-abdominal surgery. Poorly controlled postoperative pain after major abdominal surgery should be a research priority as it affects patient-centred short-term and long-term outcomes (including quality of life scores, return to function measurements, disability-free survival) and has broad community health and economic implications.

Negative pressure wound therapy for managing the open abdomen in non-trauma patients

BACKGROUND

Management of the open abdomen is a considerable burden for patients and healthcare professionals. Various temporary abdominal closure techniques have been suggested for managing the open abdomen. In recent years, negative pressure wound therapy (NPWT) has been used in some centres for the treatment of non-trauma patients with an open abdomen; however, its effectiveness is uncertain.

OBJECTIVES

To assess the effects of negative pressure wound therapy (NPWT) on primary fascial closure for managing the open abdomen in non-trauma patients in any care setting.

SEARCH METHODS

In October 2021 we searched the Cochrane Wounds Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL EBSCO Plus. To identify additional studies, we also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses, and health technology reports. There were no restrictions with respect to language, date of publication, or study setting.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that compared NPWT with any other type of temporary abdominal closure (e.g. Bogota bag, Wittmann patch) in non-trauma patients with open abdomen in any care setting. We also included RCTs that compared different types of NPWT systems for managing the open abdomen in non-trauma patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection process, risk of bias assessment, data extraction, and GRADE assessment of the certainty of evidence.

MAIN RESULTS

We included two studies, involving 74 adults with open abdomen associated with various conditions, predominantly severe peritonitis (N = 55). The mean age of the participants was 52.8 years; the mean proportion of women was 39.2%. Both RCTs were carried out in single centres and were at high risk of bias. Negative pressure wound therapy versus Bogota bag We included one study (40 participants) comparing NPWT with Bogota bag. We are uncertain whether NPWT reduces time to primary fascial closure of the abdomen (NPWT: 16.9 days versus Bogota bag: 20.5 days (mean difference (MD) -3.60 days, 95% confidence interval (CI) -8.16 to 0.96); very low-certainty evidence) or adverse events (fistulae formation, NPWT: 10% versus Bogota: 5% (risk ratio (RR) 2.00, 95% CI 0.20 to 20.33); very low-certainty evidence) compared with the Bogota bag. We are also uncertain whether NPWT reduces all-cause mortality (NPWT: 25% versus Bogota bag: 35% (RR 0.71, 95% CI 0.27 to 1.88); very low-certainty evidence) or length of hospital stay compared with the Bogota bag (NPWT mean: 28.5 days versus Bogota bag mean: 27.4 days (MD 1.10 days, 95% CI -13.39 to 15.59); very low-certainty evidence). The study did not report the proportion of participants with successful primary fascial closure of the abdomen, participant health-related quality of life, reoperation rate, wound infection, or pain. Negative pressure wound therapy versus any other type of temporary abdominal closure There were no randomised controlled trials comparing NPWT with any other type of temporary abdominal closure. Comparison of different negative pressure wound therapy devices We included one study (34 participants) comparing different types of NPWT systems (Suprasorb CNP system versus ABThera system). We are uncertain whether the Suprasorb CNP system increases the proportion of participants with successful primary fascial closure of the abdomen compared with the ABThera system (Suprasorb CNP system: 88.2% versus ABThera system: 70.6% (RR 0.80, 95% CI 0.56 to 1.14); very low-certainty evidence). We are also uncertain whether the Suprasorb CNP system reduces adverse events (fistulae formation, Suprasorb CNP system: 0% versus ABThera system: 23.5% (RR 0.11, 95% CI 0.01 to 1.92); very low-certainty evidence), all-cause mortality (Suprasorb CNP system: 5.9% versus ABThera system: 17.6% (RR 0.33, 95% CI 0.04 to 2.89); very low-certainty evidence), or reoperation rate compared with the ABThera system (Suprasorb CNP system: 100% versus ABThera system: 100% (RR 1.00, 95% CI 0.90 to 1.12); very low-certainty evidence). The study did not report the time to primary fascial closure of the abdomen, participant health-related quality of life, length of hospital stay, wound infection, or pain.

AUTHORS' CONCLUSIONS

Based on the available trial data, we are uncertain whether NPWT has any benefit in primary fascial closure of the abdomen, adverse events (fistulae formation), all-cause mortality, or length of hospital stay compared with the Bogota bag. We are also uncertain whether the Suprasorb CNP system has any benefit in primary fascial closure of the abdomen, adverse events, all-cause mortality, or reoperation rate compared with the ABThera system. Further research evaluating these outcomes as well as participant health-related quality of life, wound infection, and pain outcomes is required. We will update this review when data from the large studies that are currently ongoing are available.

Nationwide increase in component separation without concomitant rise in readmissions: A nationwide readmissions database analysis

BACKGROUND

The use of component separation technique (CST) in complex abdominal wall reconstruction (AWR) increases the rate of primary musculofascial closure but can be associated with increased wound complications, which may require readmission. This study examines 3-year trends in readmissions for patients undergoing AWR with or without CST.

METHODS

The Nationwide Readmissions Database was queried for patients undergoing elective AWR from 2016-2018. CST, demographic characteristics, and 90-day complications and readmissions were determined. CST versus non-CST readmissions were compared, including matched subgroups. Standard statistics and logistic regression were used.

RESULTS

Over the 3-year period, 94,784 patients underwent AWR. There was an annual increase in the prevalence of CST: 4.0% in 2016; 6.1% in 2017; 6.7% in 2018 (P < .01), which is a 67.5% upsurge during that time. Most cases (82.3%) occurred at urban teaching hospitals, which had more comorbid patients (P < .01). The yearly 90-day readmission rate did not change: 16.0%, 18.2%, and 16.9% (P = .26). Readmissions were higher for CST patients than non-CST patients (17.1% vs 15.7%), but not in the matched subgroup (17.0% vs 16.4%; P = .41). Most commonly, readmissions were for infection (28.3%); 14.3% of readmitted patients underwent reoperation. Smoking, morbid obesity, diabetes, chronic lung disease, urban-teaching hospital status, and increased length of stay increased the chance of readmission (all P < .05).

CONCLUSION

From 2016 to 2018, the use of CST increased 67.5% nationwide without an increase in readmissions. As we look toward clinical targets to reduce risk of readmission, modifiable health conditions, such as smoking, morbid obesity, and diabetes should be targeted during the prehabilitation process.

Postoperative Work and Activity Restrictions After Abdominal Surgery: A Systematic Review

OBJECTIVE

This systematic review aims to assess what is known about convalescence following abdominal surgery. Through a review of the basic science and clinical literature, we explored the effect of physical activity on the healing fascia and the optimal timing for postoperative activity.

BACKGROUND

Abdominal surgery confers a 30% risk of incisional hernia development. To mitigate this, surgeons often impose postoperative activity restrictions. However, it is unclear whether this is effective or potentially harmful in preventing hernias.

METHODS

We conducted 2 separate systematic reviews using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The first assessed available basic science literature on fascial healing. The second assessed available clinical literature on activity after abdominal surgery.

RESULTS

Seven articles met inclusion criteria for the basic science review and 22 for the clinical studies review. The basic science data demonstrated variability in maximal tensile strength and time for fascial healing, in part due to differences in layer of abdominal wall measured. Some animal studies indicated a positive effect of physical activity on the healing wound. Most clinical studies were qualitative, with only 3 randomized controlled trials on this topic. Variability was reported on clinician recommendations, time to return to activity, and factors that influence return to activity. Interventions designed to shorten convalescence demonstrated improvements only in patient-reported symptoms. None reported an association between activity and complications, such as incisional hernia.

CONCLUSIONS

This systematic review identified gaps in our understanding of what is best for patients recovering from abdominal surgery. Randomized controlled trials are crucial in safely optimizing the recovery period.

Perioperative optimization in complex abdominal wall hernias: Delphi consensus statement

BACKGROUND

The incidence of incisional hernia after major abdominal surgery via a midline laparotomy is 20-41 per cent with short-term follow-up, and over 50 per cent in those surviving an abdominal catastrophe. Abdominal wall reconstruction (AWR) requires complex operations, often involving mesh resection, management of scarred skin, fistula takedown, component separation or flap reconstruction. Patients tend to have more complex conditions, with multiple co-morbidities predisposing them to a vicious cycle of complications and, subsequently, hernia recurrence. Currently there appears to be variance in perioperative practice and minimal guidance globally. The aim of this Delphi consensus was to provide a clear benchmark of care for the preoperative assessment and perioperative optimization of patients undergoing AWR.

METHODS

The Delphi method was used to achieve consensus from invited experts in the field of AWR. Thirty-two hernia surgeons from recognized hernia societies globally took part. The process included two rounds of anonymous web-based voting with response analysis and formal feedback, concluding with a live round of voting followed by discussion at an international conference. Consensus for a strong recommendation was achieved with 80 per cent agreement, and a weak recommendation with 75 per cent agreement.

RESULTS

Consensus was obtained on 52 statements including surgical assessment, preoperative assessment, perioperative optimization, multidisciplinary team and decision-making, and quality-of-life assessment. Forty-six achieved over 80 per cent agreement; 14 statements achieved over 95 per cent agreement.

CONCLUSION

Clear consensus recommendations from a global group of experts in the AWR field are presented in this study. These should be used as a baseline for surgeons and centres managing abdominal wall hernias and performing complex AWR.

Mini fluid chAllenge aNd End-expiratory occlusion test to assess flUid responsiVEness in the opeRating room (MANEUVER study): A multicentre cohort study

BACKGROUND

The fluid challenge response in surgical patients can be predicted by functional haemodynamic tests. Two tests, the mini-fluid challenge (mini-FC) and end-expiratory occlusion test (EEOT), have been assessed in a few small single-centre studies with conflicting results. In general, functional haemodynamic tests have not performed reliably in predicting fluid responsiveness in patients undergoing laparotomy.

OBJECTIVE

This trial is designed to address and compare the reliability of the EEOT and the mini-FC in predicting fluid responsiveness during laparotomy.

DESIGN

Prospective, multicentre study.

SETTING

Three university hospitals in Italy.

PATIENTS

A total of 103 adults patients scheduled for elective laparotomy with invasive arterial monitoring.

INTERVENTIONS

The study protocol evaluated the changes in the stroke volume index (SVI) 20 s (EEOT20) and 30 s (EEOT30) after an expiratory hold and after a mini-FC of 100 ml over 1 min. Fluid responsiveness required an increase in SVI at least 10% following 4 ml kg-1 of Ringer's solution fluid challenge infused over 10 min.

MAIN OUTCOME MEASUREMENTS

Haemodynamic data, including SVI, were obtained from pulse contour analysis. The area under the receiver operating characteristic curves of the tests were compared with assess fluid responsiveness.

RESULTS

Fluid challenge administration induced an increase in SVI at least 10% in 51.5% of patients. The rate of fluid responsiveness was comparable among the three participant centres (P = 0.10). The area under the receiver operating characteristic curves (95% CI) of the changes in SVI after mini-FC was 0.95 (0.88 to 0.98), sensitivity 98.0% (89.5 to 99.6) and specificity 86.8% (75.1 to 93.4) for a cut-off value of 4% of increase in SVI. This was higher than the SVI changes after EEOT20, 0.67 (0.57 to 0.76) and after EEOT30, 0.73 (0.63 to 0.81).

CONCLUSION

In patients undergoing laparotomy the mini-FC reliably predicted fluid responsiveness with high-sensitivity and specificity. The EEOT showed poor discriminative value and cannot be recommended for assessment of fluid responsiveness in this surgical setting.

TRIAL REGISTRATION

NCT03808753.

The incisional hernia epidemic: evaluation of outcomes, recurrence, and expenses using the healthcare cost and utilization project (HCUP) datasets

BACKGROUND

Incisional hernias (IH) following abdominal surgery persist as morbid, costly, and multi-disciplinary surgical challenges. Using longitudinal, multi-state, administrative claims data (HCUP State Inpatient Databases (SID)); (HCUP State Ambulatory Surgery and Services Databases (SASD)), we aimed to characterize the epidemiology, outcomes, recurrence, and costs of IH.

STUDY DESIGN

529,108 patients undergoing abdominal surgery in 2010 across six specialties (colorectal, general/bariatric, hepatobiliary, obstetrics/gynecology, urology, and vascular) were identified within inpatient and ambulatory databases for Florida (FL), Iowa (IA), Nebraska (NE), New York (NY), and Utah (UT). IH repairs, complications, and expenditures were assessed through 2014. Predictive regression modeling was validated using a training set of 1000 bootstrapped repetitions.

RESULTS

16,169 (3.1%) patients developed hernias requiring repair (4.3-year mean follow-up), 3176 (20%) underwent recurrent repair, and 731 (23%) underwent re-recurrent repair. Patients with IH had increased readmissions (6.6 vs. 2.4), morbidity (39 vs. 8% surgical and 22 vs. 7% medical), and costs ($46,000 vs. $25,000) when compared to patients without IH (p < 0.001). IH expenditures totaled $875 million: initial ($687 million), recurrent ($155 million), and re-recurrent hernias ($33 million). IH predominated in colorectal (10%), hepatobiliary (8%), and vascular (5%) procedures. Of 31 significant independent IH risk factors (p < 0.001), obesity, age, smoking, open surgery, and prior surgery were pervasive across surgical specialties.

CONCLUSION

IH represents an unremitting surgical epidemic associated with considerable morbidity, costs, and features consistent with a chronic disease state. We define critical pervasive risk factors (obesity, age, smoking open surgery, and prior surgery) independently associated with IH across surgical disciplines. With failed repairs, subsequent success becomes less likely, increasing morbidity and costs-underscoring the critical importance of optimal treatment and prevention.

Prevention of adhesions post-abdominal surgery: Assessing the safety and efficacy of Chitogel with Deferiprone in a rat model

Introduction

Adhesions are often considered to be an inevitable consequence of abdominal and pelvic surgery, jeopardizing the medium and long-term success of these procedures. Numerous strategies have been tested to reduce adhesion formation, however, to date, no surgical or medical therapeutic approaches have been successful in its prevention. This study demonstrates the safety and efficacy of Chitogel with Deferiprone and/or antibacterial Gallium Protoporphyrin in different concentrations in preventing adhesion formation after abdominal surgery.

Materials and methods

112 adult (8–10 week old) male Wistar albino rats were subjected to midline laparotomy and caecal abrasion, with 48 rats having an additional enterotomy and suturing. Kaolin (0.005g/ml) was applied to further accelerate adhesion formation. The abrasion model rats were randomized to receive saline, Chitogel, or Chitogel plus Deferiprone (5, 10 or 20 mM), together with Gallium Protoporphyrin (250μg/mL). The abrasion with enterotomy rats were randomised to receive saline, Chitogel or Chitogel with Deferiprone (1 or 5 mM). At day 21, rats were euthanised, and adhesions graded macroscopically and microscopically; the tensile strength of the repaired caecum was determined by an investigator blinded to the treatment groups.

Results

Chitogel with Deferiprone 5 mM significantly reduced adhesion formation (p<0.01) when pathologically assessed in a rat abrasion model. Chitogel with Deferiprone 5 mM and 1 mM also significantly reduced adhesions (p<0.05) after abrasion with enterotomy. Def-Chitogel 1mM treatment did not weaken the enterotomy site with treated sites having significantly better tensile strength compared to control saline treated enterotomy rats.

Conclusions

Chitogel with Deferiprone 1 mM constitutes an effective preventative anti-adhesion barrier after abdominal surgery in a rat model. Moreover, this therapeutic combination of agents is safe and does not weaken the healing of the sutured enterotomy site.

National health disparities in incisional hernia repair outcomes: An analysis of the Healthcare Cost and Utilization Project National Inpatient Sample (HCUP-NIS) 2012-2014

BACKGROUND

Incisional hernias represent an acquired defect from failed healing of an abdominal facial incision and are therefore distinct from primary hernias. While literature regarding incisional hernia incidence, risk factors, and treatment are abundant, no study has examined national health disparities specific to incisional hernia repair. The objective of this study was to analyze national health disparities unique to surgical incisional hernia repair procedures.

METHODS

Patient data queried from the Healthcare Cost and Utilization Project National Inpatient Sample from 2012 to 2014 using International Classification of Diseases 9th revision procedure codes for incisional hernia repair were used to generate univariate and multivariate models including demographics, socioeconomic factors, admission status, and hospital characteristics. Primary outcomes were nonelective admission status, in-hospital mortality, surgical complications, and extended duration of stay.

RESULTS

We estimated that 89,258 incisional hernia repair procedures occurred annually from 2012 to 2014, incurring $6.3 billion in hospital charges. By multivariate analysis, multiple risk factors contribute to significantly increased odds of nonelective repair. These include age over 65, female sex, non-White race, nonprivate insurance, obesity, and increased Charlson comorbidity index. Nonelective incisional hernia repair was strongly correlated with worse outcomes including in-hospital mortality (odds ratio [95% confidence interval] 3.01 [2.51, 3.61]), postoperative complications (odds ratio 1.2 [1.14, 1.25]), and extended duration of stay (odds ratio 2.96 [2.81, 3.12]). After controlling for admission status, other disparities persisted including extended duration of stay for Black individuals (odds ratio 1.21 (1.12, 1.31]).

CONCLUSION

Providers should be aware of these significant health disparities in incisional hernia repair status and outcomes especially for elderly, non-White, nonprivate insurance, and obese/comorbid patients. Management strategies that increase access to elective repair and that prevent incisional hernia should be expanded to address these disparities.

Prrx1 Fibroblasts Represent a Pro-fibrotic Lineage in the Mouse Ventral Dermis

Fibroblast heterogeneity has been shown within the unwounded mouse dorsal dermis, with fibroblast subpopulations being identified according to anatomical location and embryonic lineage. Using lineage tracing, we demonstrate that paired related homeobox 1 (Prrx1)-expressing fibroblasts are responsible for acute and chronic fibroses in the ventral dermis. Single-cell transcriptomics further corroborated the inherent fibrotic characteristics of Prrx1 fibroblasts during wound repair. In summary, we identify and characterize a fibroblast subpopulation in the mouse ventral dermis with intrinsic scar-forming potential.

Poly-4-hydroxybutyrate (Phasix™) mesh onlay in complex abdominal wall repair

BACKGROUND

Poly-4-hydroxybutyric acid (P4HB, Phasix™) is a biosynthetic polymer that degrades by hydrolysis that can be woven into a mesh for use in soft tissue reinforcement. Herein, we describe our initial experience performing complex abdominal wall repair (CAWR) utilizing component separation and P4HB mesh as onlay reinforcement.

METHODS

All patients undergoing CAWR between June 2014 and May 2017 were followed prospectively for postoperative outcomes. Only those patients who underwent components separation with primary repair of the fascial edges followed by onlay of P4HB mesh were included in this study.

RESULTS

105 patients (52 male, 53 female; mean age 59.2 years, range 22-84) met inclusion criteria. Mean BMI was 29.1 (range 16-48); 52% patients had prior attempted hernia repair, most with multiple medical comorbidities (71% of patients with ASA 3 or greater). 30% of cases were not clean at the time of repair (CDC class 2 or greater). Median follow-up was 36 months (range 9-63). Eighteen patients (17%) developed a hernia recurrence ranging from 2 to 36 months postoperatively. Five (5%) patients developed a localized superficial infection treated with antibiotics, three (2.8%) required re-operation for non-healing wounds, and six (6%) patients developed seroma.

CONCLUSIONS

These data demonstrate a relatively low rate of hernia recurrence, seroma, and other common complications of CAWR in a highly morbid patient population. Importantly, the rate of mesh infection was low and no patients required complete mesh removal, even when placed into a contaminated or infected surgical field.

A Novel Rat Model to Test Intra-Abdominal Anti-adhesive Therapy

Background: Adhesion formation after abdominal surgery is considered almost inevitable and a major cause of morbidity. Novel treatments have been proposed, however there is a lack of suitable small animal models for pre-clinical evaluation, mainly due to inconsistency in adhesion formation in positive control animals. Here, we propose a new rat model of abdominal adhesions using Kaolin as the adhesion-inducing agent at an optimized dosage for testing newer agents in respect to their anti-adhesive property.

Materials and Methods: Twenty-five adult (8–10 week old) male Wistar albino rats underwent midline laparotomy and caecal abrasion and were randomized to receive topical applications of normal saline or different concentrations and volumes of a Kaolin-based formulation. At day 14 rats were humanely killed, and adhesions graded macroscopically by an investigator blinded to the treatment groups, using pre-determined adhesion scores and microscopically using histopathology.

Results: Kaolin at 0.005 g/mL caused consistent adhesions without compromising rat viability. At higher doses significant morbidity and mortality was observed in the animals treated.

Conclusions: Kaolin induced adhesion in a rat abdominal surgery model is reliable and can be safely used to test the efficacy of novel anti-adhesive formulations to prevent intra-abdominal adhesions.

Soft tissue mobilization techniques in treating chronic abdominal scar tissue: A quasi-experimental single subject design

INTRODUCTION

Roughly 17 million abdominal surgeries are performed annually in the U.S. Up to 17% of those may be readmitted for adhesion related problems. This study evaluated the effectiveness of soft tissue mobilization (STM) techniques at improving chronic pain, mobility restrictions and functional deficits following complex abdominal surgery.

METHODS

Subjects Two females aged 51 and 65.

DESIGN

Single subject quasi-experimental A-B-A.

INTERVENTION

Four 30-min treatment sessions of abdominal tissue mobilizations. Outcome measures Pain pressure threshold (PPT) and average scar mobility (ASM), Numeric Pain Rating Scale (NPRS), and the Oswestry Disability Index (ODI).

RESULTS

Subject 1 ASM and PPT of the abdomen improved significantly and exceeded the established standard error of measurement (SEM). PPT of the scar decreased during the second baseline. This decrease exceeded the SEM for PPT but was not statistically significant. The changes in NPRS did not reach the minimal clinically important difference (MCID). Subject 2 abdominal PPT and ASM showed statistically significant improvements that exceeded their SEMs. Scar PPT showed improvement during the repeat baseline, however, this reached neither statistical significance nor the SEM.

CONCLUSIONS

Scar mobility and abdominal PPT improved both statistically and clinically in both subjects after only 4 sessions of STM. Scar pain measured by NPRS and PPT did not show significant improvement. This study demonstrated that STM can be an effective way to treat chronic abdominal scars by increasing scar mobility and reducing abdominal sensitivity to pressure. It is non-invasive, and is a less costly alternative to laparoscopic adhesiolysis.

A nationwide evaluation of robotic ventral hernia surgery

BACKGROUND

The purpose of this study was to examine outcomes of robotic ventral hernia repair(RVHR) versus laparoscopic ventral hernia repair(LVHR).

METHODS

The Nationwide Inpatient Sample was queried from October 2008 to December 2013 for ventral hernia repairs. Demographics, morbidity, mortality, and charges were compared between RVHR and LVHR.

RESULTS

From 2008-2013, 149,622 ventral hernia surgeries were identified; 117,028 open, 32,243 laparoscopic, and 351 robotic. Open repairs were excluded. RVHR rose annually with 2013 containing 47.9% of all RVHRs. RVHR patients were more likely to be older and have more chronic conditions. There was no difference between length of stay. Pneumonia rates were higher with RVHR; however, after controlling for confounding variables, there was no difference in pneumonia rates. Mortality and other major complications were similar. Total charges were increased for RVHR in univariate and multivariate analysis. RVHR was more common in teaching hospitals and wealthier zip codes.

CONCLUSION

RVHR demonstrates comparable safety to the laparoscopic technique, with increased charges and increased volume in urban teaching hospitals and patients from areas of higher median income.

Development of a Clinically Actionable Incisional Hernia Risk Model after Colectomy Using the Healthcare Cost and Utilization Project

BACKGROUND

Incisional hernia remains a persistent and burdensome complication after colectomy. Through individualized risk-assessment and prediction models, we aimed to improve preoperative risk counseling for patients undergoing colectomy; identify modifiable preoperative risk factors; and encourage the use of evidence-based risk-prediction instruments in the clinical setting.

STUDY DESIGN

A retrospective review of the Healthcare Cost and Utilization Project data was conducted for all patients undergoing either open or laparoscopic colectomy as identified through the state inpatient databases of California, Florida, and New York in 2009. Incidence of incisional hernia repair was collected from both the state inpatient databases and the state ambulatory surgery and services databases in the 3 states between index surgery and 2011. Hernia risk was calculated with multivariable hierarchical logistic regression modeling and validated using bootstrapping techniques. Exclusion criteria included concurrent hernia, metastasis, mortality, and age younger than 18 years. Inflation-adjusted expenditure estimates were calculated.

RESULTS

Overall, 30,741 patients underwent colectomy, one-third of these procedures performed laparoscopically. Incisional hernia repair was performed in 2,563 patients (8.3%) (27-month follow-up). Fourteen significant risk factors were identified, including open surgery (odds ratio = 1.49; p < 0.0001), obesity (odds ratio = 1.49; p < 0.0001), and alcohol abuse (odds ratio = 1.39; p = 0.010). Extreme-risk patients experienced the highest incidence of incisional hernia (19.8%) vs low-risk patients (3.9%) (C-statistic = 0.67).

CONCLUSIONS

We present a clinically actionable model of incisional hernia using all-payer claims after colectomy. The data presented can structure preoperative risk counseling, identify modifiable patient-specific risk factors, and advance the field of risk prediction using claims data.