The SCAR-3 study: 5-year adhesion-related readmission risk following lower abdominal surgical procedures

Ovulation provides excessive coagulation and hepatocyte growth factor signals to cause postoperative intraabdominal adhesions

Postoperative adhesions show a higher occurrence in females aged 16-60, especially after pelvic surgeries. This study explores the role of ovulation in adhesion formation in mice. Ovarian surgery in mice with normal- or super-ovulation led to pronounced adhesions, whereas ovulation-defective Pgr-KO mice showed minimal adhesions. Specifically, exposure to ovulatory follicular fluid (FF) markedly increased the adhesion. The hazardous exposure time window was one day before to 2.5 days after the surgery. Mechanistically, early FF exposure triggered adhesions via the blood coagulation cascade, while later exposure relied on the HGF/cMET signaling pathway. Prophylactic administration of a thrombin inhibitor pre-operatively or a cMET inhibitor postoperatively effectively mitigated FF-induced adhesions, while COX inhibitor treatment exhibited no discernible effect. These findings underscore ovulation as a pivotal factor in the development of pelvic wound adhesions and advocate for targeted preventive strategies such as c-MET inhibition, scheduling surgeries outside the ovulatory period, or employing oral contraceptive measures.

Use of mixed gas pneumoperitoneum during minimally invasive surgery: a systematic review of human and mouse modelled laparoscopic interventions

The formation of pneumoperitoneum involves the process of inflating the peritoneal cavity during laparoscopic and typically uses CO2 as the insufflation gas. This review aims to identify ideal gas mixtures for establishing the pneumoperitoneum with animal and human studies undertaken up to the writing of this review. A systematic search of PubMed, OVID, and clinicaltrials.gov was performed to identify studies on the utilisation of mixed gases in laparoscopic surgery, including non-randomised/randomised trials, animal and human studies, and studies with inflating pressures between 12 and 16 mmHg. ROBINS-I and RoB2 tool was used to assess the risk of bias. A narrative synthesis of results was performed due to the heterogeneity of the studies. 5 studies from the database search and 5 studies from citation search comprising 128 animal subjects and 61 human patients were found. These studies collated results based on adhesion formation (6 studies), pain scores (2 studies) and other outcomes, with results favouring the use of carbon dioxide + 10% nitrous oxide + 4% oxygen. This has shown a significant reduction in adhesion formation, pain scores and inflammation. The use of this gas mixture provides promising results for future practice. Several of the studies available require larger sample sizes to develop a more definitive answer on the effects of different gas mixtures. Furthermore, the number of confounding factors in randomised trials should be reduced so that each component of the current suggested gas mixture can be tested for safety and efficacy.

Diagnostic Efficacy Study Comparing Tzanakis Scoring System With Alvarado Scoring System in Effective Diagnosis of Acute Appendicitis

Objective Among the common causes of abdominal emergencies, acute appendicitis ranks at the top, particularly in the young population. While negative appendectomy is not uncommon, the risk of appendicular perforation is substantial if the diagnosis is missed or delayed. This study evaluated the diagnostic efficacy of the Tzanakis scoring system for acute appendicitis, comparing it with the Alvarado scoring system, considering the histopathological finding as the gold standard. Materials and methods This prospective observational study, conducted in the General Surgery department in a tertiary care hospital in India, included clinically diagnosed acute appendicitis cases posted for open or laparoscopic appendicectomy. Results The mean age for the 60 participants included in the study was 30.97±13.44, and the median was 24.5 yrs. The sensitivity of ultrasonography (USG) in diagnosing histopathological positive acute appendicitis was 89%, and the specificity was 50%. The sensitivity, specificity, positive, and negative predictive values of the Tzanakis score were 87%, 50%, 96%, and 22%, respectively, and those of the Alvarado score were 54%, 75%, 96%, and 10%, respectively. Conclusion The receiver operator characteristic (ROC) curve for the Alvarado and Tzanakis scores showed that the area under the curve (AUC) was greater for the Tzanakis scoring system (0.670) than for the Alvarado scoring system (0.598). Differences between the AUCs were not statistically significant. Although the Tzanakis scoring system is more sensitive than the Alvarado scoring system in diagnosing acute appendicitis, studies with larger samples are needed to show the superiority of this scoring system over the Alvarado scoring system.

Changing patterns and surgical outcomes of small bowel obstruction in the era of minimally invasive surgery for colorectal cancer

INTRODUCTION

This study aimed to investigate whether the incidence, patterns, and surgical outcomes of small bowel obstruction (SBO) have changed in the era of minimally invasive surgery (MIS) for primary colorectal cancer (CRC).

METHODS

Consecutive patients who underwent laparotomy for SBO were divided into MIS and traditional open surgery (TOS) groups based on the previous colorectal cancer operation technique used. The MIS group was selected from 1544 consecutive patients who underwent MIS as a treatment for primary CRCs between 2014 and 2022, while the TOS group was selected from 1604 consecutive patients who underwent TOS as a treatment for primary CRCs between 2004 and 2013. The demographics, clinicopathological features, and surgical outcomes were compared between the two groups.

RESULTS

The SBO incidence in patients who underwent MIS for primary CRC was significantly lower than that in patients who underwent TOS (4.4%, n =68/1544 vs. 9.7%, n =156/1604, P <0.0001). Compared with the TOS group, the MIS group had significantly different ( P <0.0001) SBO patterns: adhesion (48.5 vs. 91.7%), internal herniation (23.5 vs. 2.6%), external herniation (11.8 vs. 1.9%), twisted bowel limbs (4.4 vs. 0.6%), ileal volvulus with pelvic floor adhesion (5.9 vs. 1.9%), and nonspecific external compression (5.9 vs. 1.3%). A subset analysis of patients with adhesive SBO (ASBO) showed that the MIS group tended to ( P <0.0001) have bands or simple adhesions (75.8%), whereas the TOS group predominantly had matted-type adhesions (59.4%). Furthermore, SBO in the MIS group had an acute (<3 months) or early (3-12 months) onset (64.7%), while that in the TOS group ( P <0.0001) had an intermediate or a late onset. When the surgical outcomes of SBO were evaluated, the TOS group had significantly more ( P <0.0001) blood loss and longer operation time; however, no significant difference was observed in the surgical morbidity/mortality (Clavien-Dindo classification ≧3, 11.8 vs. 14.1%, P =0.6367), hospitalization, and readmission rates between the two groups. Postoperative follow-up showed that the estimated 3-year (11.37 vs. 18.8%) and 6-year (25.54 vs. 67.4%) recurrence rates of SBO were significantly lower ( P =0.016) in the MIS group than in the TOS group.

CONCLUSIONS

The wide adoption of MIS to treat primary CRC has led to a lower incidence, altered patterns, and reduced recurrence rates of SBO. Awareness of this new trend will help develop surgical techniques to prevent incomplete restoration of anatomical defects and bowel malalignments specifically associated with MIS for CRC, as well as facilitate timely and appropriate management of SBO complications whenever they occur.

Incidence of adhesive small bowel obstruction after surgery for colorectal cancer in Sweden 2007-2016

AIM

Population-based data on incidence and risk factors of adhesive small bowel obstruction (SBO) are limited. The aims of this study were to assess the risk of SBO and SBO surgery after bowel resection for colorectal cancer (CRC) and to assess whether this risk is modified by minimally invasive surgery (MIS) and radiotherapy in a retrospective national study.

METHODS

CRCBaSe, a nationwide register linkage originating from the Swedish Colorectal Cancer Register, was used to identify Stage I-III CRC patients who underwent resection in 2007-2016, with follow-up throughout 2017. Matched CRC-free comparators (1:6) were included as a reference of SBO and SBO surgery incidence. The association between MIS and preoperative radiotherapy and the incidence rate of SBO was evaluated in adjusted multivariable Cox regression models.

RESULTS

Among 33 632 CRC patients and 198 649 comparators, the 5-year cumulative incidence of SBO and SBO surgery was 7.6% and 2.2% among patients and 0.6% and 0.2% among comparators, with death as a competing risk. In all patients, MIS was associated with a reduced incidence of SBO (hazard ratio [HR] 0.7, 95% CI 0.6-0.8) and SBO surgery (HR 0.5, 95% CI 0.3-0.7). In rectal cancer patients, radiotherapy was associated with an increased incidence of SBO (HR 1.6, 95% CI 1.4-1.8) and SBO surgery (HR 1.7, 95% CI 1.3-2.3).

DISCUSSION

Colorectal cancer surgery is associated with a marked increase in risk of SBO, compared with the general population. The incidence is further increased if open surgery or radiotherapy is performed.

Irritable Bowel Syndrome-Like Symptoms in Quiescent Inflammatory Bowel Disease: A Practical Approach to Diagnosis and Treatment of Organic Causes

BACKGROUND

Despite achieving remission in inflammatory bowel disease (IBD), persistent gastrointestinal symptoms are common in quiescent IBD. While irritable bowel syndrome (IBS) is commonly diagnosed in IBD, IBS-like symptoms of recurrent abdominal pain and altered bowel habits can also be attributed to a wide range of overlapping gastrointestinal (GI) etiologies and systemic disorders with GI manifestations that often do not respond to conventional IBS therapies. Delay in diagnosis of these conditions can lead to ongoing patient suffering, reduced quality of life, repetition of invasive testing, increased healthcare utilization, and potentially unnecessary empirical escalation of IBD-related treatments.

AIMS

This review provides a practical approach for the evaluation and diagnosis of IBS mimickers in IBD. We summarize the definition, pathophysiology, diagnosis and treatment of the potential etiologies causing unexplained GI symptoms.

CONCLUSION

Overlapping conditions can co-exist with IBD and explain IBS-like symptoms. The diagnostic work-up in this population should be individualized and tailored to the predominant symptom pattern, associated clinical signs and symptoms and predisposing conditions that can be obtained from a detailed history and physical examination.

Multifunctional Oxidized Dextran-Metformin as a Tissue-Adhesive Hydrogel to Prevent Postoperative Peritoneal Adhesions in Patients with Metabolic Syndrome

Patients with metabolic syndrome (MetS) undergoing surgery are at high risk of developing peritoneal adhesions and other severe postoperative complications. However, the single shielding function and absence of physiological activity render conventional methods less useful in preventing adhesions in patients with MetS. To address this challenge, a convenient method is introduced for developing a novel tissue-adhesive hydrogel called oxidized dextran-metformin (ODE-ME) via Schiff base linkages. This injectable ODE-ME hydrogel exhibits excellent tissue-adhesive properties and various physiological functions, particularly enhanced antibacterial effects. Furthermore, in vivo experiments demonstrate that the hydrogel can effectively alleviate hyperglycemia, reduce excessive inflammation, and improve fibrinolytic activity in MetS mice, thereby preventing adhesions and promoting incisional healing. The hydrogel concurrently isolates injured tissues and lowers the blood glucose levels immediately after surgery in mice. Therefore, the ODE-ME hydrogel functions as a multifunctional barrier material and has potential for preventing postoperative peritoneal adhesions in patients with MetS in clinical settings.

The Role of Prophylactic and Adjuvant Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in Prevention of Peritoneal Metastases in Advanced Colorectal Cancer

Hyperthermic intraperitoneal chemotherapy (HIPEC) is a locoregional therapy that may be combined with cytoreductive surgery (CRS) to treat patients with colorectal cancer and peritoneal metastases (PM). In recent years, three randomized controlled trials (RCTs) have investigated the role of prophylactic or adjuvant HIPEC in preventing the development of PM in patients with high-risk colorectal cancer: PROPHYLOCHIP and COLOPEC evaluated adjuvant HIPEC, and HIPECT4 studied concurrent HIPEC and CRS. Although PROPHYLOCHIP and COLOPEC were negative trials, a great deal may be learned from their methodology, outcome measures, and patient selection criteria. HIPECT4 is the first RCT to show a clinical benefit of HIPEC in high-risk T4 colorectal cancer, demonstrating improved locoregional disease control with the addition of HIPEC to CRS with no increase in the rate of complications. This review critically examines the strengths and limitations of each major trial and discusses their potential impact on the practice of HIPEC. Several additional ongoing clinical trials also seek to investigate the role of HIPEC in preventing PM in advanced colorectal cancer.

Financial and Inpatient Burden of Adhesion-Related Small Bowel Obstruction: A Systematic Review of the Literature

BACKGROUND

Postoperative adhesions may occur after >90% of laparotomies and is the most common cause of small bowel obstruction (SBO). Despite the high incidence, there is a lack of data related to financial implications of adhesion-related SBO (ASBO). This systematic literature review of in-hospital costs for treatment of ASBO searched PubMed, Scopus and Google Scholar databases according to PRISMA guidelines. Exclusion criteria were reviews, editorials, clinical vignettes, studies of patients <18 years of age, studies with no English full text and studies assessing adhesiolysis for causes other than SBO or that used extrapolations with economic models. Main outcome measures were financial costs per patient and national costs.

RESULTS

Seven studies, published between 1999 and 2016, incorporating a total of 39 573 patients, were identified. Four were undertaken in European countries, one in the USA, 1 in New Zealand and 1 in Nigeria. Overall national costs regarding treatment of patients with ASBO ranged between $3.468 million and $1.77 billion. Median overall cost in the medical management group was $2371.5 ($1814-$2568) vs $12370 ($4914-$25321) in the surgical group. Median length of stay was 4 (3-7) days for patients conservatively treated and 11.5 (8-16.3) days for patients who underwent surgery. Median length of stay of operated patients on was almost triple that of patients conservatively managed.

CONCLUSIONS

Given the major financial implications of ASBO, further initiatives are needed to avoid operations for SBO when clinically appropriate and minimize delays taking patients with high suspicion of complete SBO to the operating room.

Hyperglycaemia and the risk of post-surgical adhesion

Post-surgical adhesions are a major complication leading to organ dysfunctions, pain, intestinal obstruction, and infertility. The incidence of post-surgical adhesion is really high. The factors involved in the pathogenesis of post-surgical fibrosis, are largely unknown, for example why two patients with similar abdominal operation have a different risks of adhesion severity? High secretion of pro-inflammatory cytokines and growth factors, includes tumour necrosis factor α (TNF-α), interleukin 6 (IL6), and transforming growth factor β (TGF-β) by persistent recruitment of immune cells and the inappropriate proliferated fibroblast/mesothelial cells can stimulate signalling pathways particularly TGF-β leads to the up-regulation of some pro-fibrotic genes that impair fibrinolytic activity and promote extracellular matrix (ECM) accumulation. In this review, we focus on the role of diabetes and hyperglycaemia on post-surgical fibrosis, including the molecular mechanisms affected by hyperglycaemia that cause inflammation, oxidative stress, and increase the expression of pro-fibrotic molecules.

Endoscopic small bowel balloon dilations in patients with Crohn's disease: a Danish nationwide cohort study, 1997-2015

OBJECTIVE

Small bowel strictures are a common complication in Crohn's disease. Endoscopic balloon dilation (EBD) is an emerging therapeutic approach that is minimally invasive and helps to preserve the bowel. The aim of this study was to describe the use of EBD in adult Crohn's disease patients with small bowel strictures.

METHODS

This nationwide cohort comprised individuals ≥18 years old, diagnosed with Crohn's disease in Denmark between 1 January 1997 and 31 December 2015, according to the National Patient Registry (NPR).

RESULTS

The cohort consisted of 9737 incident Crohn's disease patients that were followed for a median of 8.2 years [interquartile range (IQR) = 4.1-13.3]. During the observation period, a total of 90 (1%) patients underwent a small bowel-related EBD. After a follow-up period of a median of 3.4 (IQR = 1.8-5.0) years, primary small bowel strictures treated only with one dilation and no subsequent small bowel surgery accounted for 29 (59%) of 49 cases. A median of 7.2 (IQR = 2.4-13.2) months after their first dilation, 13 (27%) of those 49 patients underwent small bowel surgery. Forty-one patients with postsurgical strictures were dilated after a median of 6.5 (IQR = 2.5-10.2) years following small bowel surgery. Postsurgical strictures treated with only one dilation and no further small bowel surgery accounted for 20 (49%) of the 41 cases.

CONCLUSION

The frequency of EBD in this Danish nationwide cohort was low. During a median follow-up of 5 years after EBD, most patients did not require further surgery. This suggests that EBD is an effective treatment and could be offered to more patients with Crohn's disease.

Barrier materials for prevention of surgical adhesions: systematic review

BACKGROUND

Postoperative surgical adhesions constitute a major health burden internationally. A wide range of materials have been evaluated, but despite constructive efforts and the obvious necessity, there remains no specific barrier widely utilized to prevent postoperative adhesion formation. The aim of this study was to highlight and characterize materials used for prevention of postoperative surgical adhesions in both animal and human studies.

METHODS

A systematic review was performed of all original research articles presenting data related to the prevention of postoperative adhesions using a barrier agent. All available observational studies and randomized trials using animal models or human participants were included, with no restrictions related to type of surgery. PubMed and Embase databases were searched using key terms from inception to August 2019. Standardized data collection forms were used to extract details for each study and assess desirable characteristics of each barrier and success in animal and/or human studies.

RESULTS

A total of 185 articles were identified for inclusion in the review, with a total of 67 unique adhesion barrier agents (37 natural and 30 synthetic materials). Desirable barrier characteristics of an ideal barrier were identified on review of the literature. Ten barriers achieved the primary outcome of reducing the incidence of postoperative adhesions in animal studies followed with positive outputs in human participants. A further 48 materials had successful results from animal studies, but with no human study performed to date.

DISCUSSION

Multiple barriers showed promise in animal studies, with several progressing to success, and fulfilment of desirable qualities, in human trials. No barrier is currently utilized commonly worldwide, but potential barriers have been identified to reduce the burden of postoperative adhesions and associated sequelae.

Surgical management of adhesive small bowel obstruction: Is it still mandatory to wait? - An update

Small bowel obstruction syndromes (SBO) represent one of the main causes of emergency admission for surgical abdominal pain. The 2018 Bologna Guidelines (Ten Broek et al. 2018) recommend non-operative management at the outset if there are no signs of severity; surgery is proposed after 72h for the 20-30% of patients who fail medical management. However, these recommendations were based on old studies published at a time when laparoscopic surgery was not commonplace and when diagnostic capabilities (particularly for establishing etiology) were less developed than they are today. Additionally, the advent and development of laparoscopy and enhanced rehabilitation after surgery have led to a decrease in surgical morbidity. These guidelines are therefore now debated and several recent publications have encouraged urgent or semi-urgent surgical management for patients presenting for SBO in order to reduce morbidity, mortality, duration of hospitalization and costs, and to improve the feasibility of therapeutic laparoscopy. Prompt surgical management could also reduce the risk of recurrent small bowel obstructions. This model for early surgical management probably cannot be applied to all patients. It therefore seems important to select those patients at risk for failure of medical treatment and to identify those in whom the probability of successful laparoscopy is high. New radiological tools should allow better selection in the future. At the present time, the indications for early surgery "within 24h" should be emphasized.

Small Bowel Obstruction After Neonatal Repair of Congenital Diaphragmatic Hernia-Incidence and Risk-Factors Identified in a Large Longitudinal Cohort-Study

OBJECTIVE

In patients with a congenital diaphragmatic hernia (CDH), postoperative small bowel obstruction (SBO) is a life-threatening event. Literature reports an incidence of SBO of 20% and an association with patch repair and ECMO treatment. Adhesions develop due to peritoneal damage and underly various biochemical and cellular processes. This longitudinal cohort study is aimed at identifying the incidence of SBO and the risk factors of surgical, pre-, and postoperative treatment.

METHODS

We evaluated all consecutive CDH survivors born between January 2009 and December 2017 participating in our prospective long-term follow-up program with a standardized protocol.

RESULTS

A total of 337 patients were included, with a median follow-up of 4 years. SBO with various underlying causes was observed in 38 patients (11.3%) and significantly more often after open surgery (OS). The majority of SBOs required surgical intervention (92%). Adhesive SBO (ASBO) was detected as the leading cause in 17 of 28 patients, in whom surgical reports were available. Duration of chest tube insertion [odds ratio (OR) 1.22; 95% CI 1.01-1.46, p = 0.04] was identified as an independent predictor for ASBO in multivariate analysis. Beyond the cut-off value of 16 days, the incidence of serous effusion and chylothorax was higher in patients with ASBO (ASBO/non-SBO: 2/10 vs. 3/139 serous effusion, p = 0.04; 2/10 vs. 13/139 chylothorax, p = 0.27). Type of diaphragmatic reconstruction, abdominal wall closure, or ECMO treatment showed no significant association with ASBO. A protective effect of one or more re-operations has been detected (RR 0.16; 95% CI 0.02-1.17; p = 0.049).

CONCLUSION

Thoracoscopic CDH repair significantly lowers the risk of SBO; however, not every patient is suitable for this approach. GoreTex®-patches do not seem to affect the development of ASBO, while median laparotomy might be more favorable than a subcostal incision. Neonates produce more proinflammatory cytokines and have a reduced anti-inflammatory capacity, which may contribute to the higher incidence of ASBO in patients with a longer duration of chest tube insertion, serous effusion, chylothorax, and to the protective effect of re-operations. In the future, novel therapeutic strategies based on a better understanding of the biochemical and cellular processes involved in the pathophysiology of adhesion formation might contribute to a reduction of peritoneal adhesions and their associated morbidity and mortality.

Intraperitoneal microbial contamination drives post-surgical peritoneal adhesions by mesothelial EGFR-signaling

Abdominal surgeries are lifesaving procedures but can be complicated by the formation of peritoneal adhesions, intra-abdominal scars that cause intestinal obstruction, pain, infertility, and significant health costs. Despite this burden, the mechanisms underlying adhesion formation remain unclear and no cure exists. Here, we show that contamination of gut microbes increases post-surgical adhesion formation. Using genetic lineage tracing we show that adhesion myofibroblasts arise from the mesothelium. This transformation is driven by epidermal growth factor receptor (EGFR) signaling. The EGFR ligands amphiregulin and heparin-binding epidermal growth factor, are sufficient to induce these changes. Correspondingly, EGFR inhibition leads to a significant reduction of adhesion formation in mice. Adhesions isolated from human patients are enriched in EGFR positive cells of mesothelial origin and human mesothelium shows an increase of mesothelial EGFR expression during bacterial peritonitis. In conclusion, bacterial contamination drives adhesion formation through mesothelial EGFR signaling. This mechanism may represent a therapeutic target for the prevention of adhesions after intra-abdominal surgery.

Incidence and mortality results of intestinal obstruction in geriatric and adult patients: 10 years retrospective analysis

Objectives

People with ileus is one of the patient groups with the highest admission rates to the emergency departments. In this study, it was aimed to determine the effects of age groups and etiological factors on mortality when evaluated together with gender.

Material and Methods

In our study, patients who were consulted from the Emergency Service to the General Surgery department with a pre-diagno- sis of abdominal pain between 2009 and 2020 were retrospectively screened. Patients hospitalized for ileus were analyzed in terms of age (18-65 years and over 65 years), gender, operation, etiology, incidence, and mortality.

Results

Between 2009 and 2020, 534 (3.03%) of 17.601 patients who received emergency consultation from the general surgery clinic were diagnosed with ileus. While 253 (47.4%) of the patients were operated, 317 (59.4%) patients and 101 (18.9%) patients were diagnosed with brid and malignancy, respectively; and 21 (3.9%) patients died in the complete patient group (Table 1). While the incidence of brid was high in non-operated patients, in operated patients, malignancy and other pathologies was found to be higher (p <0.001) (Table 2). While, in patients 65 years and older, mortality was observed in 10.6% of women and 2.6% of men, it was determined that the mortality rate was higher in women (p= 0.008) (Figure 4).

Conclusion

The mortality rate in patients hospitalized with the diagnosis of mechanical bowel obstruction was found to be statistically significantly higher in female patients aged 65 and over.

Sex differences in non-strangulated postoperative adhesive small bowel obstruction: A retrospective cohort study

BACKGROUND

Adhesive small bowel obstruction (ASBO) is one of the major causes of postoperative morbidity. Non-surgical management is generally applied to non-strangulated ASBO. Several factors have been reported to affect the response to non-surgical management in patients with ASBO. However, the association between sex differences and non-strangulated ASBO remains unclear. This study aimed to elucidate the effect of sex differences in non-strangulated postoperative ASBO.

METHODS

We divided 139 patients with a first episode of non-strangulated postoperative ASBO into two groups: male group (n = 83) and female group (n = 56). Clinical features and prognosis were compared between the two groups.

RESULTS

Female patients had lower proportions of oesophageal/gastric malignancies (P = 0.044) and colorectal malignancies (P = 0.030) and a higher proportion of uterine/ovarian malignancies (P < 0.001) than male patients did. More female patients required surgical management than male patients (P = 0.003) did. Hospital length of stay (LOS) was longer (P = 0.046) in the female group than in the male group. Multiple logistic regression analysis showed that the female sex was associated with an increased risk of the need for surgical management (odds ratio 5.318, P = 0.006). Cox proportional hazards regression analysis revealed that the female sex was positively associated with increased LOS (hazard ratio 0.687, P = 0.045).

CONCLUSION

Female sex was associated with failure of non-surgical management and increased LOS in patients with non-strangulated postoperative ASBO.

Post-Operative Adhesions: A Comprehensive Review of Mechanisms

Post-surgical adhesions are common in almost all surgical areas and are associated with significant rates of morbidity, mortality, and increased healthcare costs, especially when a patient requires repeat operative interventions. Many groups have studied the mechanisms driving post-surgical adhesion formation. Despite continued advancements, we are yet to identify a prevailing mechanism. It is highly likely that post-operative adhesions have a multifactorial etiology. This complex pathophysiology, coupled with our incomplete understanding of the underlying pathways, has resulted in therapeutic options that have failed to demonstrate safety and efficacy on a consistent basis. The translation of findings from basic and preclinical research into robust clinical trials has also remained elusive. Herein, we present and contextualize the latest findings surrounding mechanisms that have been implicated in post-surgical adhesion formation.

Prevention of Post-Operative Adhesions: A Comprehensive Review of Present and Emerging Strategies

Post-operative adhesions affect patients undergoing all types of surgeries. They are associated with serious complications, including higher risk of morbidity and mortality. Given increased hospitalization, longer operative times, and longer length of hospital stay, post-surgical adhesions also pose a great financial burden. Although our knowledge of some of the underlying mechanisms driving adhesion formation has significantly improved over the past two decades, literature has yet to fully explain the pathogenesis and etiology of post-surgical adhesions. As a result, finding an ideal preventative strategy and leveraging appropriate tissue engineering strategies has proven to be difficult. Different products have been developed and enjoyed various levels of success along the translational tissue engineering research spectrum, but their clinical translation has been limited. Herein, we comprehensively review the agents and products that have been developed to mitigate post-operative adhesion formation. We also assess emerging strategies that aid in facilitating precision and personalized medicine to improve outcomes for patients and our healthcare system.

The Potential Association between the Risk of Post-Surgical Adhesion and the Activated Local Angiotensin II Type 1 Receptors: Need for Novel Treatment Strategies

Background

Post-surgical adhesion bands (PSABs) are a common complication after abdominal or pelvic surgeries for different reasons like cancer treatment. Despite improvements in surgical techniques and the administration of drugs or the use of physical barriers, there has only been limited improvement in the frequency of postoperative adhesions. Complications of PSAB are pain, infertility, intestinal obstruction, and increased mortality. The most important molecular mechanisms for the development of PSAB are inflammatory response, oxidative stress, and overexpression of pro-fibrotic molecules such as transforming growth factor β. However, questions remain about the pathogenesis of this problem, for example, the causes for individual differences or why certain tissue sites are more prone to post-surgical adhesions.

Summary

Addressing the pathological causes of PSAB, the potential role of local angiotensin II/angiotensin II type 1 receptors (AngII/AT1R), may help to prevent this problem.

Key Message

The objective of this article was to explore the role of the AngII/AT1R axis potential to induce PSAB and the therapeutic potential of angiotensin receptor blockers in the prevention and treatment of PSAB.

Association Between Statin Use at the Time of Intra-abdominal Surgery and Postoperative Adhesion-Related Complications and Small-Bowel Obstruction

IMPORTANCE

Adhesion-related complications (ARCs), including small-bowel obstruction, are common complications of intra-abdominal surgery. Statins, which have antifibrotic pleiotropic effects, inhibit adhesion formation in murine models but have not been assessed in humans.

OBJECTIVE

To assess whether statin use at the time of intra-abdominal surgery is associated with a reduction in ARCs.

DESIGN, SETTING, AND PARTICIPANTS

These 2 separate retrospective cohort studies (The Health Improvement Network [THIN] and Optum's Clinformatics Data Mart [Optum]) compared adults receiving statins with those not receiving statins at the time of intra-abdominal surgery. Individuals undergoing intra-abdominal surgery from January 1, 1996, to December 31, 2013, in the United Kingdom and from January 1, 2000, to December 31, 2016, in the US were included in the study. Those with obstructive events before surgery or a history of inflammatory bowel disease were excluded. Data analysis was performed from September 1, 2012, to November 24, 2020.

EXPOSURE

The primary exposure was statin use at the time of surgery.

MAIN OUTCOMES AND MEASURES

The primary outcome was ARCs, defined as small-bowel obstruction or need for adhesiolysis, occurring after surgery. Sensitivity analyses included statin use preceding but not concurrent with surgery, fibrate use, and angiotensin-converting enzyme inhibitor use. All analyses were adjusted for age, sex, and conditions associated with microvascular disease, such as hypertension, hyperlipidemia, obesity, and tobacco use; surgical approach and site; and diagnosis of a malignant tumor.

RESULTS

A total of 148 601 individuals met the inclusion criteria for THIN (mean [SD] age, 49.6 [17.7] years; 70.1% female) and 1 188 217 for Optum (mean [SD] age, 48.2 [16.4] years; 72.6% female). A total of 2060 participants (1.4%) experienced an ARC in THIN and 54 136 (4.6%) in Optum. Statin use at the time of surgery was associated with decreased risk of ARCs (THIN: adjusted hazard ratio [HR], 0.81; 95% CI, 0.71-0.92; Optum: adjusted HR, 0.92; 95% CI, 0.90-0.95). Similar associations were appreciated between statins and small-bowel obstruction (THIN: adjusted HR, 0.80; 95% CI, 0.70-0.92; Optum: adjusted HR, 0.88; 95% CI, 0.85-0.91).

CONCLUSIONS AND RELEVANCE

This study's findings suggest that, among individuals in 2 separate cohorts undergoing intra-abdominal surgery, statin use may be associated with a reduced risk of postoperative ARCs. Statins may represent an inexpensive, well-tolerated pharmacologic option for preventing ARCs.

Risk factors for small bowel obstruction after open rectal cancer resection

Background

Small bowel obstruction (SBO) is observed in around 10% of patients with prior open abdominal surgery. Rectal resection causes the highest readmission rates. The aim of this study was to investigate risk factors for readmission for SBO and causes for SBO in patients who needed surgery following rectal cancer surgery.

Methods

A population-based registry with prospectively gathered data on 752 consecutive patients with rectal cancer who underwent open pelvic surgery between January 1996 and January 2017 was used. Univariable and multivariable regression analysis was performed, and the risk of SBO was assessed.

Results

In total, 84 patients (11%) developed SBO after a median follow-up time of 48 months. Of these patients, 57% developed SBO during the 1st year after rectal cancer surgery. Surgery for SBO was performed in 32 patients (4.3%), and the cause of SBO was stoma-related in one-fourth of these patients. In the univariable analysis previous RT and re-laparotomy were found as risk factors for readmission for SBO. Re-laparotomy was an independent risk factor for readmission for SBO (OR 2.824, CI 1.129–7.065, P = 0.026) in the multivariable analysis, but not for surgery for SBO. Rectal resection without anastomoses, splenic flexors mobilization, intraoperative bleeding, operative time were not found as risk factors for SBO.

Conclusions

One-tenth of rectal cancer patients who had open surgery developed SBO, most commonly within the 1st postoperative year. The risk of SBO is greatest in patients with complications after rectal cancer resection that result in a re-laparotomy.

The anti-adhesive effect of anti-VEGF agents in experimental models: A systematic review

Adhesions constitute a major problem in abdominal-pelvic and thoracic surgery with significant impact in the postoperative quality of life and healthcare services utilization. Adhesiogenesis is the result of increased fibrin formation, impaired fibrinolysis, angiogenesis, and fibrosis. Despite the recent advancements, the ideal anti-adhesive agent remains to be determined. To this end, we performed a comprehensive literature search in PubMed, EMBASE, and Scopus databases to identify studies investigating the antiadhesive role of anti-VEGF agents in peritoneal, pleural, and pericardial experimental adhesion models. Fifteen studies were eligible for inclusion with a total population of 602 animals (334 rats, 180 rabbits, and 88 mice). The majority of included studies (11/15) used bevacizumab, while three studies used other anti-VEGF antibodies and one study used an anti-VEGFR-antibody. A rat model was used in nine studies, while rabbit (n = 3) or mouse (n = 3) models were used less frequently. Eleven studies used peritoneal models, three studies used pleural models, and one study used a pericardial model. The scales (n = 12) and interval (Range: 1-42 days) used for the evaluation of adhesions varied between the studies. All studies demonstrated a significant decrease in adhesion scores between the anti-VEGF and control groups up to 42 days postprocedure. VEGF blockade resulted in decreased fibrosis in four out of five studies that used peritoneal models, while the effect on pleural models depended on the pleurodesis agent and was significant between 7 and 28 days. The effect of anti-VEGF agents on anastomosis integrity depends on the dose and the model that is used (inconclusive results).Current data support the anti-adhesive role of Anti-VEGF agents in all three serosal surfaces up to 6 weeks postprocedure. Further studies are needed to confirm the anti-adhesive role of anti-VEGF agents in pleural and pericardial adhesion experimental models and investigate any effect on anastomosis integrity in peritoneal models.

Management of giant presacral schwannoma. Clinical series and literature review

PURPOSE

Presacral schwannomas are rare tumors. Due to their benign nature and slow growth, these tumors are often giant and become difficult to treat. Their removal is a surgical challenge with different strategies reported in the literature. This study presents the consecutives cases of presacral schwannomas operated on in our institution, our surgical strategy and literature review.

METHODS

This retrospective study includes all consecutive patients operated on for a pre-sacral schwannoma in our department between 2006 and 2019, i.e. 6 patients. We report clinical features, pre and post-operative imaging, surgical data and post-operative outcomes.

RESULTS

All patients had symptoms before surgery (constipation, dysuria, radicular or lower back pain) with an average duration of 7.4 months. All patients underwent an MRI and a CT scan before the surgery. Five patients had type III schwannoma according to Klimo classification and one patient had a type II. The average size was 504,9 cm³ (range 53,1-1495,4). All the patients were operated on by an anterior approach in a double team with an mean duration of 246 min. Intraoperative bleeding was less than 500 ml for 4 patients, 2 patients had significant bleeding (2700 and 2900 mL). Excision was total or subtotal in all cases. One patient had an intraoperative complication (air embolism). Follow up at 3 months was excellent with a disappearance of symptoms for all patients except one patient who retained constipation. One patient had a late complication (bowel obstruction due to tissue adhesions). At last follow-up after phone interview, no patient had clinical symptoms that could suggest a recurrence.

CONCLUSION

The anterior approach with a double surgical team is a great option for the treatment of presacral schwannoma. Combined with adequate preoperative imaging and intraoperative stimulation, it reduces the risk of intra and postoperative complications.

Incidence and risk factors of postoperative ileus after hysterectomy for benign indications

PURPOSE

Postoperative ileus (POI) after abdominal surgery is associated with prolonged hospital stay and increased costs. The aim of this study is to investigate the incidence of, risk factors for, and outcomes associated with POI in patients undergoing hysterectomy for benign indications.

METHODS

A retrospective review of 1017 consecutive patients undergoing benign hysterectomy over the period 2012-2017 in a single center was performed. POI was predefined as absence of flatus and defecation for more than 2 days with the presence of one or more of the following symptoms: nausea, vomiting, and abdominal distention. The association between perioperative variables and the risk of POI was evaluated by univariate analysis. Independent risk factors were identified by multivariate logistic regression analysis.

RESULTS

Overall incidence of POI was 9.2%. Incidence of POI did not differ significantly among three different surgical approaches (abdominal hysterectomy, 10.6%; laparoscopic hysterectomy, 7.8%; vaginal hysterectomy, 11.3%; P = 0.279). Independent risk factors of POI identified by multivariate analysis included anesthesia technique (odds ratio [OR] 2.662, 95% interval [CI] 1.533-4.622, P = 0.001), adhesiolysis (odds ratio [OR] 1.818, 95% interval [CI] 1.533-4.622, P = 0.011), duration of operation (odds ratio [OR] 1.005, 95% interval [CI] 0.942-6.190, P = 0.029), previous cancer (odds ratio [OR] 4.789, 95% interval [CI] 1.232-18.626, P = 0.024), and dysmenorrhea (odds ratio [OR] 1.859, 95% interval [CI] 1.182-2.925, P = 0.007).

CONCLUSION

POI is a common complication after hysterectomy. This study identified risk factors of POI specifically for gynecologic patients. Patients exposed to these factors should be monitored closely for the development POI.

Prevention of intra-abdominal adhesions by a hyaluronic acid gel; an experimental study in rats

BACKGROUND

In 80% to 90% of the patients intra-abdominal adhesions occur after abdominal surgery, which can cause small-bowel obstruction, chronic abdominal pain, female infertility and difficulty during reoperation. A novel crosslinked hyaluronic acid gel is evaluated regarding its anti-adhesive capacities in an ischemic button model in rats.

METHOD

51 adult, male Wistar rats from a registered breeder, received eight ischemic buttons each and were treated with hyaluronic acid gel (HA, HyaRegen^©), hyaluronic acid carboxymethylcellulose (HA-CMC, Seprafilm^©) or no anti-adhesive barrier. After 14 days, the animals were sacrificed and adhesions were scored macroscopically. The number of buttons and organs involved in adhesions were recorded. Per animal, one button with adhesions and one without adhesions was explanted for qPCR analysis. Mann-Whitney U, Fisher's exact and Wilcoxon signed rank test were used for data analysis. A p-value of 0.05 was considered significant.

RESULTS

Macroscopic evaluation of adhesion formation did not differ between the groups. The number of organs involved in adhesions in the HA gel group was significantly lower compared to HA-CMC (p = .041) and the control group (p = .012). A significantly, 1.36-fold higher clec10a (p = 0.25), 1.80-fold higher cd163 (p = 0.003) and 5.14-fold higher mmp1 expression (p = 0.028) was found in ischemic buttons with adhesions compared to buttons without adhesions.

CONCLUSION

HA gel application reduces the number of organs involved in adhesions in an ischemic button model, but no overall reduction in adhesion formation was encountered. Macrophage subtype 2 polarization and high mmp1 expression are associated with adhesion formation. Further investigation is needed in the exact pathophysiologic process of adhesion formation and the role of macrophage polarization.

Neutrophil and monocyte kinetics play critical roles in mouse peritoneal adhesion formation

Peritoneal adhesions are pathological fibroses that ensnare organs after abdominal surgery. This dense connective tissue can cause small bowel obstruction, female infertility, and chronic abdominal pain. The pathogenesis of adhesions is a fibrotic response to tissue damage coordinated between mesothelial cells, fibroblasts, and immune cells. We have previously demonstrated that peritoneal adhesions are a consequence of mechanical injury to the mesothelial layer sustained during surgery. Neutrophils are among the first leukocytes involved in the early response to tissue damage. Here, we show that when subjected to mechanical stress, activated mesothelial cells directly recruit neutrophils and monocytes through upregulation of chemokines such as CXCL1 and monocyte chemoattractant protein 1 (MCP-1). We find that neutrophils within the adhesion sites undergo cell death and form neutrophil extracellular traps (NETosis) that contribute to pathogenesis. Conversely, tissue-resident macrophages were profoundly depleted throughout the disease time course. We show that this is distinct from traditional inflammatory kinetics such as after sham surgery or chemically induced peritonitis, and suggest that adhesions result from a primary difference in inflammatory kinetics. We find that transient depletion of circulating neutrophils significantly decreases adhesion burden, and further recruitment of monocytes with thioglycolate or MCP-1 also improves outcomes. Our findings suggest that the combination of neutrophil depletion and monocyte recruitment is sufficient to prevent adhesion formation, thus providing insight for potential clinical interventions.

Outcomes after single-look trauma laparotomy: A large population-based study

BACKGROUND

Outcomes following damage control laparotomy for trauma have been studied in detail. However, outcomes following a single operation, or "single-look trauma laparotomy" (SLTL), have not. We evaluated the association between SLTL and both short-term and long-term outcomes in a large population-based data set.

METHODS

The California Office of Statewide Health Planning and Development patient discharge database was evaluated for calendar years 2007 through 2014. Injured patients with SLTL during their index admission were identified using International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes. Diagnosis and procedure codes were used to identify specific abdominal organ injuries, surgical interventions, and perioperative complications. Subsequent acute care admissions were examined for postoperative complications and related surgical interventions. Clinical characteristics, injuries, surgical interventions, and outcomes were analyzed by mechanism of injury.

RESULTS

There were 2113 patients with SLTL during their index admission; 712 (33.7%) had at least one readmission to an acute care facility. Median time to first readmission was 110 days. Penetrating mechanism was more common than blunt (60.6% vs. 39.4%). Compared to patients with penetrating injury, blunt-injured patients had a significantly higher median Injury Severity Score (9 vs. 18, p < 0.0001) and a significantly higher mortality rate during the index admission (4.1% vs. 27.0%, p < 0.0001). More than 30% of SLTL patients requiring readmission had a surgery-related complication. The most common primary reasons for readmission were bowel obstruction (17.7%), incisional hernia (11.8%), and infection (9.1%). There was no significant association between mechanism of injury and development of surgery-related complications requiring readmission.

CONCLUSIONS

Patients with SLTL had postinjury morbidity and mortality, and more than 30% required readmission. Complication rates for SLTL were comparable to those reported for emergency general surgery procedures. Patients should be educated on signs and symptoms of the most common complications before discharge following SLTL. Further investigation should focus on the factors associated with the development of these complications.

LEVEL OF EVIDENCE

Prognostic and epidemiologic study, level III.

Factors Predicting the Need for Early Surgical Intervention for Small Bowel Obstruction

PURPOSE

Small bowel obstruction (SBO) is a common disease that requires hospitalization. The most common cause of SBO is postoperative adhesion. Delayed timing of operations in patients who need surgical intervention results in mortality or morbidity. A number of studies on SBO have established criteria for emergency surgery. However, few objective clinical parameters are available for screening patients who need a delayed operation. Therefore, we analyzed factors that affect the clinical course of SBO to select appropriate therapeutic plans for reducing the risk of complications in these patients.

METHODS

We investigated the clinical characteristics of patients admitted to the surgery department of our hospital between January 1, 2015, and December 31, 2016, who were diagnosed with SBO. Patients were divided into an operative treatment group (n = 12) and a conservative treatment group (n = 96). We compared clinical characteristics between the 2 groups.

RESULTS

The operative treatment group underwent more operations before SBO than the conservative treatment group (P = 0.007). Initial leukocyte counts (P = 0.004) and C-reactive protein (CRP) levels (P = 0.028) were elevated in the operative group. Body mass index (BMI) was lower in the operative group (P = 0.013).

CONCLUSION

The number of operations before SBO, leukocyte counts, CRP levels, and BMI were useful parameters for selecting patients who needed an urgent operation for SBO.

Identification of candidate biomarkers correlated with pathogenesis of postoperative peritoneal adhesion by using microarray analysis

BACKGROUND

Postoperative peritoneal adhesion (PPA), characterized by abdominal pain, female infertility, and even bowel obstruction after surgery, has always been a major concern. The occurrence and formation of adhesion are from complex biological processes. However, the molecular mechanisms underlying the basis of microarray data profile, followed by peritoneal adhesion formation, are largely unknown.

AIM

To reveal the underlying pathogenesis of PPA at the molecular level.

METHODS

The gene expression profile was retrieved from the Gene Expression Omnibus database for our analysis. We identified a panel of key genes and related pathways involved in adhesion formation using bioinformatics analysis methods. We performed quantitative PCR and western blotting in vivo to validate the results preliminarily.

RESULTS

In total, 446 expressed genes were altered in peritoneal adhesion. We found that several hub genes (e.g., tumor necrosis factor, interleukin 1 beta, interleukin 6, C-X-C motif chemokine ligand 1, C-X-C motif chemokine ligand 2) were marked as significant biomarkers. Functional analysis suggested that these genes were enriched in the Toll-like receptor signaling pathway. According to the Kyoto Encyclopedia of Genes and Genomes pathway and published studies, TLR4, myeloid differentiation primary response protein 88 (MyD88), and nuclear factor kappa B (NF-κB) played essential roles in Toll-like signaling transduction. Here, we obtained a regulatory evidence chain of TLR4/MyD88/NF-κB/inflammatory cytokines/peritoneal adhesion involved in the pathogenesis of postoperative adhesion. The results of the microarray analysis were verified by the animal experiments. These findings may extend our understanding of the molecular mechanisms of PPA.

CONCLUSION

The regulatory evidence chain of TLR4/MyD88/NF-κB/inflammatory cytokines/peritoneal adhesion may play key roles in the pathogenesis of PPA. Future studies are required to validate our findings.

Adhesion-related readmissions after open and laparoscopic surgery: a retrospective cohort study (SCAR update)

BACKGROUND

Adhesions are the most common driver of long-term morbidity after abdominal surgery. Although laparoscopy can reduce adhesion formation, the effect of minimally invasive surgery on long-term adhesion-related morbidity remains unknown. We aimed to assess the impact of laparoscopy on adhesion-related readmissions in a population-based cohort.

METHODS

We did a retrospective cohort study of patients of any age who had abdominal or pelvic surgery done using laparoscopic or open approaches between June 1, 2009, and June 30, 2011, using validated population data from the Scottish National Health Service. All patients who had surgery were followed up until Dec 31, 2017. The primary outcome measure was the incidence of hospital readmissions directly related to adhesions in the laparoscopic and open surgery cohorts at 5 years. Readmissions were categorised as directly related to adhesions, possibly related to adhesions, and readmissions for an operation that was potentially complicated by adhesions. We did subgroup analyses of readmissions by anatomical site of surgery and used Kaplan-Meier analyses to assess differences in survival across subgroups. We used multivariable Cox-regression analysis to determine whether surgical approach was an independent and significant risk factor for adhesion-related readmissions.

FINDINGS

Between June 1, 2009, and June 30, 2011, 72 270 patients had an index abdominal or pelvic surgery, of whom 21 519 (29·8%) had laparoscopic index surgery and 50 751 (70·2%) had open surgery. Of the 72 270 patients who had surgery, 2527 patients (3·5%) were readmitted within 5 years of surgery for disorders directly related to adhesions, 12 687 (17·6%) for disorders possibly related to adhesions, and 9436 (13·1%) for operations potentially complicated by adhesions. Of the 21 519 patients who had laparoscopic surgery, 359 (1·7% [95% CI 1·5-1·9]) were readmitted for disorders directly related to adhesions compared with 2168 (4·3% [4·1-4·5]) of 50 751 patients in the open surgery cohort (p<0·0001). 3443 (16·0% [15·6-16·4]) of 21 519 patients in the laparoscopic surgery cohort were readmitted for disorders possibly related to adhesions compared with 9244 (18·2% [17·8-18·6]) of 50 751 patients in the open surgery cohort (p<0·005). In multivariate analyses, laparoscopy reduced the risk of directly related readmissions by 32% (hazard ratio [HR] 0·68, 95% CI 0·60-0·77), and of possibly related readmissions by 11% (HR 0·89, 0·85-0·94) compared with open surgery. Procedure type, malignancy, sex, and age were also independently associated with risk of adhesion-related readmissions.

INTERPRETATION

Laparoscopic surgery reduces the incidence of adhesion-related readmissions. However, the overall burden of readmissions associated with adhesions remains high. With further increases in the use of laparoscopic surgery expected in the future, the effect at the population level might become larger. Further steps remain necessary to reduce the incidence of adhesion-related postsurgical complications.

FUNDING

Dutch Adhesion Group and Nordic Pharma.

Adhesive small bowel obstruction - an update

Small bowel obstruction (SBO) accounts for 12-16% of emergency surgical admissions and 20% of emergency surgical procedures. Even with the advent of laparoscopic surgery, intra-abdominal adhesions remain a significant cause of SBO, accounting for 65% of cases. History and physical examination are essential to identify signs of bowel ischemia as this indicates a need for urgent surgical exploration. Another critical aspect of evaluation includes establishing the underlying cause for obstruction and distinguishing between adhesive and non-adhesive etiologies as adhesive SBO (ASBO) can be managed non-operatively in 70-90% of patients. A patient with a history of abdominopelvic surgery along with one or more cardinal features of obstruction should be suspected to have ASBO until proven otherwise. Triad of severe pain, pain out of proportion to the clinical findings, and presence of an abdominal scar suggest possible closed-loop obstruction. Computed tomography has higher sensitivity and specificity compared to plain films and is recommended by the Bologna guidelines. Correcting fluid and electrolyte imbalance is an initial crucial step to mitigate severe hypovolemia. Patients should proceed with surgery if symptoms of bowel compromise are present, or if symptoms do not resolve or have worsened. Surgery is indicated in patients with ischemia, strangulation, perforation, peritonitis, or failure of non-operative treatment. With advances in minimal access technology and increasing experience, laparoscopic adhesiolysis is recommended. Mechanical adhesion barriers are an effective measure to prevent adhesion formation.

Outcomes in adhesive small bowel obstruction from a large statewide database: What to expect after nonoperative management

BACKGROUND

Although adhesive small-bowel obstruction (ASBO) is frequently managed nonoperatively, little is known regarding outcomes on readmission following this approach. Using a large population-based dataset, we evaluated risk factors for operative intervention and mortality at readmission in patients with ASBO who were initially managed nonoperatively.

METHODS

The ASBO patients were identified in the California Office of Statewide Health Planning and Development 2007 to 2014 patient discharge database. Patients who were managed operatively at index admission or had an International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code for nonadhesive obstructive small bowel disease were excluded. Associations between risk factors and both operative intervention and death following readmission were evaluated using survival analysis.

RESULTS

Among 15,963 ASBO patients, 3,103 (19.4%) had at least one readmission. The 1,069 (34.5%) who received an operation during their first readmission presented sooner (175 days vs. 316 days, p < 0.001) and were more likely to die during that readmission (5.2% vs. 0.7%, p < 0.001). Operative management at first readmission was associated with younger age, fewer comorbidities, and shorter times to readmission. Patients operatively managed at first readmission had longer times to second readmission compared with nonoperative patients. Stratified analyses using nonoperative patients as the reference over the study period revealed that patients who underwent lysis of adhesions and bowel resection were 5.04 times (95% confidence interval [CI], 2.82-9.00) as likely to die while those who underwent lysis only were 2.09 times (95% CI, 1.14-3.85) as likely to die. Patients with bowel resection only were at an increased risk for subsequent interventions beyond the first readmission (hazard ratio, 1.79; 95% CI, 1.11-2.87).

CONCLUSION

In a large cohort readmitted for ASBO and initially managed nonoperatively, subsequent operative intervention conferred a greater risk of death and a longer time to readmission among survivors. Prospective research is needed to further delineate outcomes associated with initial nonoperative management of ASBO.

LEVEL OF EVIDENCE

Prognostic and epidemiological, level III.

Incidence and risk factors of early postoperative small bowel obstruction in patients undergoing hysterectomy for benign indications

BACKGROUND

Small bowel obstruction (SBO) is a major cause of postoperative mortality and morbidity following abdominal and pelvic surgery, with 225,000-345,000 annual admissions. SBO may be classified based on onset from day of surgery. Early SBO occurs within the first 30 days following surgery, whereas late SBO occurs after the initial 30-day postoperative window. The majority of either type of bowel obstruction is believed to be secondary to intra-abdominal adhesions. Early SBO warrants special attention because of the difficulty in distinguishing between mechanical and nonmechanical obstruction during this period. Whereas conservative management often leads to resolution of nonmechanical obstruction and some partial SBO, surgical management is associated with a higher rate of complications compared to surgery for late SBO because of the presence of hypervascular adhesions in the early postoperative period. The current literature regarding SBO, and early SBO in particular, following hysterectomy is limited. Given that approximately 400,000 hysterectomies are performed annually, understanding the risk factors associated with SBO following these types of surgeries is imperative for improving patient outcomes.

OBJECTIVE

The objective of this study was to evaluate the incidence of and risk factors for early small bowel obstruction (SBO) after hysterectomy for benign indications.

MATERIALS AND METHODS

This was a retrospective cohort study using data from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2014 to 2016. Current Procedural Terminology codes were used to identify patients undergoing hysterectomy for benign indications with or without concomitant colpopexy, lysis of adhesions (LOA), adnexectomy, or appendectomy. Data on patient demographics and clinical and surgical factors were obtained. Patients were then stratified into those with and those without SBO. Pairwise comparison was performed using the Wilcoxon rank-sum test and Fisher exact tests. Multivariable logistic regression was used to identify significant independent predictors of SBO.

RESULTS

Of 47,937 hysterectomies, SBO occurred in 286 patients, at a rate of 5.9 per 1000 hysterectomies. Comparing patients with and without SBO, those with an obstruction were older (49 vs 46 years, P <.001) and were more likely to smoke (21.0% vs 15.8%, P = .02), to have a history of prior abdominal surgery (73.4% vs 65.4%, P = .005), and to have medical comorbidities such as hypertension and dyspnea. Patients experiencing SBO were also more likely to undergo abdominal hysterectomy (72.0% vs 21.2%, P < .001), adhesiolysis (5.2% vs 2.1%, P < .001), appendectomy (1.7% vs 0.5%, P = .02), and cystotomy repair (1.0% vs 0.3%, P = .002). After logistic regression, route of hysterectomy was not a significant risk factor for SBO, whereas wound class ≥3 (adjusted odds ratio [aOR], 5.96; 95% confidence interval [CI], 2.71-12.99) and perioperative transfusion (aOR, 5.01; 95% CI, 3.54-7.13) were the most significant risk factors. Additional risk factors for early SBO included nonwhite race (aOR, 1.84; 95% CI, 1.33-2.48), increasing age (aOR, 1.04; 95% CI, 1.02-1.05), prior abdominal or pelvic surgery (aOR, 1.49; 95% CI, 1.17-2.03), operating times >170 minutes (aOR, 1.90; 95% CI, 1.37-2.58), uterine weight >250 g (aOR, 1.54; 95% CI, 1.11-2.14), lysis of adhesions (aOR, 2.10; 95% CI, 1.23-3.66), and concurrent appendectomy (aOR, 2.64; 95% CI, 1.06-6.65).

CONCLUSION

Early SBO is a rare complication of benign hysterectomy. Although route of hysterectomy was not found to be a significant risk factor for early SBO, variables typically associated with abdominal hysterectomy compared to minimally invasive hysterectomy, including higher wound class, larger uteri, and perioperative transfusion (a marker of intraoperative blood loss), were strongly correlated with subsequent development of early obstruction.

PLGA/PLCA casting and PLGA/PDPA electrospinning bilayer film for prevention of postoperative adhesion

Postoperative adhesion is a common complication and preventing adhesions during or immediately after operation is particularly important. The application of solid barrier materials represents the most successful clinical strategy to prevent postoperative adhesion. However, a simple physical barrier effect might be insufficient in preventing adhesion satisfactorily. Multilayered structures can be designed with an outer layer as the barrier and an inner layer to respond to relative drug release. In this article, bilayer film composed of a PLGA/PLCA casting layer as barrier and PLGA/PDPA electrospinning layer to respond to the release of anti-fibrosis drug l-Phe was designed and synthesized. The adhesion prevention effect of the above PLGA/PLCA/PDPA bilayer film was examined and compared with single PLGA/PLCA casting film and single PLGA/PDPA electrospinning film by applying rabbit sidewall defect-cecum abrasion model. As demonstrated by histological observation and immunohistochemical analysis, the bilayer film was the most effective of the three films in postoperative adhesion prevention in terms of both physical barrier effect and anti-fibrosis effect of the PDPA macromolecular prodrug. Besides anti-fibrosis effect, PDPA could also suppress excess proliferation of vascular endothelial cells and microvessel caused by long-term stimulation of implantation materials to the surrounding tissues. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2030-2039, 2019.

Surgical adhesions in mice are derived from mesothelial cells and can be targeted by antibodies against mesothelial markers

Peritoneal adhesions are fibrous tissues that tether organs to one another or to the peritoneal wall and are a major cause of postsurgical and infectious morbidity. The primary molecular chain of events leading to the initiation of adhesions has been elusive, chiefly due to the lack of an identifiable cell of origin. Using clonal analysis and lineage tracing, we have identified injured surface mesothelium expressing podoplanin (PDPN) and mesothelin (MSLN) as a primary instigator of peritoneal adhesions after surgery in mice. We demonstrate that an anti-MSLN antibody diminished adhesion formation in a mouse model where adhesions were induced by surgical ligation to form ischemic buttons and subsequent surgical abrasion of the peritoneum. RNA sequencing and bioinformatics analyses of mouse mesothelial cells from injured mesothelium revealed aspects of the pathological mechanism of adhesion development and yielded several potential regulators of this process. Specifically, we show that PDPN+MSLN+ mesothelium responded to hypoxia by early up-regulation of hypoxia-inducible factor 1 alpha (HIF1α) that preceded adhesion development. Inhibition of HIF1α with small molecules ameliorated the injury program in damaged mesothelium and was sufficient to diminish adhesion severity in a mouse model. Analyses of human adhesion tissue suggested that similar surface markers and signaling pathways may contribute to surgical adhesions in human patients.

Impact of postcolectomy adhesion-related complications on healthcare utilization

Objective

The objective of this study was to explore adhesion-related complications (ARCs) within 1 year after colectomy.

Methods

Using Truven MarketScan® Commercial and Medicare databases, the first inpatient colectomies during 2009–2013 (index) were identified: left, right, partial, transverse, or total. One-year continuous enrollment was required pre and postindex. Only the first inpatient rehospitalization event was analyzed. ARC was defined as the subset of rehospitalizations with a diagnosis of ileus, small bowel obstruction, or postindex adhesiolysis. ARC and non-ARC events were evaluated descriptively, including time to ARC, length of stay (LOS), and total hospitalization reimbursement (2015 US dollars [2015 USD]). Patient, provider, and procedure factors associated with ARC were explored using logistic regression models.

Results

A total of 64,532 colectomies were identified: left (39.2%), right (34.9%), partial (20.0%), transverse (2.3%), and total (3.6%). Surgical approach was classified as open (60.1%) and laparoscopic (39.9%). All-cause first inpatient readmission incidence within 1 year was 24.7%, and ARC incidence was 5.7% in all patients or 23.2% in all first readmissions. ARC had statistically higher resource utilization compared to non-ARC with respective mean (SD) time to event (130 [102] and 137 [106] days), mean (SD) LOS (7.2 [8.0] and 5.2 [6.8] days), and mean (SD) total reimbursement ($29,802 [$43,037] and $22,476 [$36,130]). ARC risk factors included (OR [95% CI]) resection type (total vs right, 3.78 [3.27–4.36]), left vs right (1.69 [1.53–1.86]), adhesiolysis (2.45 [1.42–4.23]), computerized tomography (1.79 [1.65–1.95]), surgical indication: inflammatory bowel disease vs cancer (1.69 [1.43–1.99]), and multiple abdominal procedures (1.38 [1.29–1.49]). Laparoscopic approach was protective (0.42 [0.39–0.46]).

Conclusion

ARCs were associated with almost one-fourth of all first rehospitalizations within the first year after colectomy and were associated with substantial healthcare utilization. Risk factors included increased index colectomy complexity, while the laparoscopic approach was protective. Future research is needed to better identify high-risk patients and allow for appropriate economic and clinical risk adjustment of outcomes.

Effect of statins on experimental postoperative adhesion: a systematic review and meta-analysis

Adhesion is a significant concern after surgery. Many researchers studied the anti-adhesive effect of statin, of which results were inconsistent. Thus, we purposed to perform a systematic review and meta-analysis to evaluate the effect of statins on postoperative adhesion in an experimental study. A comprehensive search was conducted using MEDLINE, EMBASE, and Google Scholar to identify animal studies that investigated the postoperative anti-adhesive effect of statins applied at the surgical area. Primary outcome measure was gross adhesion score. Secondary outcomes included microscopic adhesion score and tissue plasminogen activator (t-PA) activity. Totally, 298 rats from 9 animal studies (172 rats received statin therapy and 126 rats received placebo or no treatment) were included in the final analysis. The combined results showed that gross and microscopic adhesion scores were significantly lower in the statin group in comparison to the control group (standardized mean difference [SMD] = 1.65, 95% confidence interval [CI]: 1.02 to 2.28, P_chi² < 0.001, I² = 77.9%; SMD = 1.90, 95% CI: 1.10 to 2.79, P_chi² < 0.001, I² = 84.5%, respectively). However, there was no evidence of a difference in t-PA activity (SMD = -3.43, 95% CI: -7.95 to 1.09, P_chi² < 0.001, I² = 95.5%). In conclusion, statins were effective in preventing postoperative adhesion, as assessed based on gross and microscopic adhesion scores in rats.

Adhesion awareness in 2016: An update of the national survey of surgeons

BACKGROUND AND AIMS

Adhesions, that form in 60-80% of all abdominal operations, can cause complications such as chronic abdominal pain, small-bowel obstruction, female infertility, and the need for adhesiolysis in future surgeries. Our 2010 Adhesion Awareness survey demonstrated that despite the huge clinical impact of adhesions; adhesion-related complications were seldom mentioned in the informed consent. Six years later, a follow-up survey was conducted to assess the progress on awareness on adhesion-related complications in the Netherlands.

MATERIAL AND METHODS

The 2010 Adhesion Awareness survey was repeated after a literature update. The knowledge regarding adhesions; the use of anti-adhesive agents and involvement in the informed consent process were assessed. Surgeons and surgical trainees were contacted by e-mail. The data was analysed using a Chi-square or Mann-Whitney U test and corrected for multiple testing.

RESULTS

The response rate was 32.6%, similar to the survey in 2010 (34.4%). 88.1% agreed with the clinical relevance of adhesions, comparable to 2010 (89.8%). The score on the knowledge test was 38.8% (2010: 37.2%). Involvement of adhesion-related complications in the informed consent process increased, although 32.5% almost never mentions adhesions. In 2016, 42.4% reported a correct occurrence of bowel lesions during adhesiolysis, higher than in 2010 (P<0.001).

CONCLUSIONS

The adhesion awareness did not increase in six years, despite the efforts made. However, an increased awareness regarding adhesiolysis related complications was detected. Improvement of knowledge and behavior is essential to narrowing the gap between the impact of adhesions as a major complication of abdominal surgery and the limited adhesion awareness.

The sticky business of adhesion prevention in minimally invasive gynecologic surgery

PURPOSE OF REVIEW

The negative impact of postoperative adhesions has long been recognized, but available options for prevention remain limited. Minimally invasive surgery is associated with decreased adhesion formation due to meticulous dissection with gentile tissue handling, improved hemostasis, and limiting exposure to reactive foreign material; however, there is conflicting evidence on the clinical significance of adhesion-related disease when compared to open surgery. Laparoscopic surgery does not guarantee the prevention of adhesions because longer operative times and high insufflation pressure can promote adhesion formation. Adhesion barriers have been available since the 1980s, but uptake among surgeons remains low and there is no clear evidence that they reduce clinically significant outcomes such as chronic pain or infertility. In this article, we review the ongoing magnitude of adhesion-related complications in gynecologic surgery, currently available interventions and new research toward more effective adhesion prevention.

RECENT FINDINGS

Recent literature provides updated epidemiologic data and estimates of healthcare costs associated with adhesion-related complications. There have been important advances in our understanding of normal peritoneal healing and the pathophysiology of adhesions. Adhesion barriers continue to be tested for safety and effectiveness and new agents have shown promise in clinical studies. Finally, there are many experimental studies of new materials and pharmacologic and biologic prevention agents.

SUMMARY

There is great interest in new adhesion prevention technologies, but new agents are unlikely to be available for clinical use for many years. High-quality effectiveness and outcomes-related research is still needed.

Risk factors associated with longer cecal intubation time: a systematic review and meta-analysis

PURPOSE

Cecal intubation time (CIT) is an indicator for difficult colonoscopy which is associated with patients' unpleasant experience as well as increased risk of complications. Several studies have attempted to identify predictors for prolonged CIT but those studies tended to be small which gave rise to inconsistent and underpowered results. This systematic review and meta-analysis was conducted to summarize all available data.

METHODS

MEDLINE and EMBASE databases were searched through November 2017 for studies that investigated the factors for prolonged CIT. Only factors that were reported by at least three studies were included in the meta-analyses. Pooled mean difference (MD) and 95% confidence interval (CI) were calculated using random effects model. The between-study heterogeneity of effect size was quantified using the Q statistic and I².

RESULTS

A total of nine studies involving 7131 patients were included. A total of six factors were analyzed. Patients with older age (≥ 65 versus < 65), female sex (versus male), low body mass index (BMI) (< 25 versus ≥ 25 kg/m²), and poor bowel preparation (versus fair to good) had significantly longer CIT. The presence of diverticulosis and prior abdominal surgery were not significantly associated with prolonged CIT.

CONCLUSIONS

The current meta-analyses have demonstrated that old age, female sex, low BMI, and poor bowel preparation were the predictors for prolonged CIT.

Do intra-abdominal adhesions cause pain?

Hard to prove

Double-balloon enteroscopy-assisted dilatation avoids surgery for small bowel strictures: A systematic review

AIM

To evaluate the therapeutic role of double-balloon enteroscopy (DBE) in small bowel strictures and to propose a standard approach to small bowel strictures.

METHODS

Systematic review of studies involving DBE in patients with small bowel strictures. Only studies limited to small bowel strictures were included and those with ileo-colonic strictures were excluded.

RESULTS

In total 13 studies were included, in which 310 patients were dilated. The average follow-up time was 31.8 mo per patient. The complication rate was 4.8% per patient and 2.6% per dilatation. Surgery was avoided in 80% of patients. After the first dilatation, 46% were treated with re-dilatation and only 17% required surgery.

CONCLUSION

DBE-assisted dilatation avoids surgery in 80% of patients with small bowel strictures and is safe and effective. We propose a standardized approach to small bowel strictures.

Efficacy of proximal colectomy for surgical management of right-sided first colorectal cancer in Lynch Syndrome mutation carriers

BACKGROUND

This study analyzes the occurrence of colorectal cancer (CRC) in Lynch syndrome (LS) mutation carriers, interval until diagnosis of metachronous CRC, and survival after proximal colectomy (PC) compared with total (TC) and subtotal colectomy (STC) for right-sided first CRC in LS mutation carriers.

METHODS

Sixty-four LS mutation carriers with right-sided first CRC treated with PC or TC + STC were confirmed by clinical records. Bivariate analyses were examined for significance and life tables were generated for risk of metachronous CRC and survival estimates following surgery.

RESULTS

One of 16 (6.3%) mutation carriers treated with TC + STC developed subsequent CRC compared with 13/48 (27%) treated by PC. There was no significant difference in survival estimates between PC compared with TC + STC through 25 years after surgery.

CONCLUSION

Risk of subsequent CRC and survival estimates following PC and TC + STC should be considered in surgical management of right-sided first CRC in LS mutation carriers.