Preoperative CT imaging as a tool to predict incisional hernia outcomes following abdominal wall reconstruction: A retrospective cohort analysis.

INTRODUCTION: Ventral wall hernia often causes significant morbidity and requires complex abdominal wall reconstruction (AWR). This study aims to determine whether subcutaneous abdominal fat thickness (AFT) measured with preoperative CT scans could predict postoperative outcomes in patients undergoing AWR. METHODS: A retrospective cohort study was conducted on all patients who underwent AWR at our institution between 2009 and 2021, with a minimum follow-up of 12 months. Using preoperative CT scans, AFT was measured at the xiphoid process, umbilicus, and pubic tubercle, as well as the hernia dimensions. Demographic, operative, and surgical outcome data were also collected and analyzed using statistical tests. RESULTS: The results showed that 9 of 101 patients (8.9%) experienced hernia recurrence. Smoking was associated with an increased risk of hernia recurrence (p < 0.001) with a predictive odds ratio (OR) of 18.27 (p = 0.041). Increased AFT at the xiphoid (p = 0.005), umbilicus (p < 0.001), and pubic tubercle (p < 0.001) were also associated with hernia recurrence and risk of infection. Only AFT at the pubic tubercle reached significance in the regression model predicting recurrence (OR=1.10; p = 0.030) and infection (OR=1.04; p = 0.021). A cut-off value of 67 mm was associated with a positive predictive value of 42.14% (sensitivity of 67% and specificity of 91%). Hernia defect area was not associated with risk of recurrence or infection. CONCLUSIONS: Smoking and increased AFT at the pubic tubercle are significant predictive factors for recurrence and infection in patients undergoing AWR, and preoperative optimization should focus on reducing these factors.

Predictors of acute incisional hernia incarceration at initial hernia diagnosis on computed tomography.

BACKGROUND: Acute incisional hernia incarceration is associated with high morbidity and mortality yet there is little evidence to guide which patients will benefit most from prophylactic repair. We explored baseline computed tomography (CT) characteristics associated with incarceration. METHODS: A case-control study design was utilized to explore adults (≥18 years) diagnosed with an incisional hernia between 2010 and 2017 at a single institution with a 1-year minimum follow-up. Computed tomography imaging at the time of initial hernia diagnosis was examined. Following propensity score matching for baseline characteristics, multivariable logistic regression was performed to identify independent predictors associated with acute incarceration. RESULTS: A total of 532 patients (27.26% male, mean 61.55 years) were examined, of whom 238 experienced an acute incarceration. Between two well-matched cohorts with and without incarceration, the presence of small bowel in the hernia sac (odds ratio [OR], 7.50; 95% confidence interval [CI], 3.35-16.38), increasing sac height (OR, 1.34; 95% CI, 1.10-1.64), more acute hernia angle (OR, 0.98 per degree; 95% CI, 0.97-0.99), decreased fascial defect width (OR, 0.68; 95% CI, 0.58-0.81), and greater outer abdominal fat (OR, 1.28; 95% CI, 1.02-1.60) were associated with acute incarceration. Using threshold analysis, a hernia angle of <91 degrees and a sac height of >3.25 cm were associated with increased incarceration risk. CONCLUSION: Computed tomography features present at the time of hernia diagnosis provide insight into later acute incarceration risk. Improved understanding of acute incisional hernia incarceration can guide selection for prophylactic repair and thereby may mitigate the excess morbidity associated with incarceration. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level III.

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.

CT-measured hernia parameters can predict component separation: a cross-sectional study from China.

PURPOSE: Currently, there are no reliable preoperative methods for predicting component separation (CS) during incisional hernia repair. By quantitatively measuring preoperative computed tomography (CT) imaging, we aimed to assess the value of hernia defect size, abdominal wall muscle quality, and hernia volume in predicting CS. METHODS: The data of 102 patients who underwent open Rives-Stoppa retro-muscular mesh repair for midline incisional hernia between January 2019 and March 2022 were retrospectively analyzed. The patients were divided into two groups: ''CS group'' patients who required CS to attempt fascial closure, and ''non-CS'' group patients who required only Rives-Stoppa retro-muscular release to achieve fascial closure. Hernia defect width, hernia defect angle, rectus width, abdominal wall muscle area and CT attenuation, hernia volume (HV), and abdominal cavity volume (ACV) were measured on CT images. The rectus width to defect width ratio (RDR), HV/ACV, and HV/peritoneal volume (PV; i.e., HV + ACV) were calculated. Differences between the indices of the two groups were compared. Logistic regression models were applied to analyze the relationships between the above CT parameters and CS. Receiver operator characteristic (ROC) curves were generated to evaluate the potential utility of CT parameters in predicting CS. RESULTS: Of the102 patients, 69 were in the non-CS group and 33 were in the CS group. Compared with the non-CS group, hernia defect width (P < 0.001), hernia defect angle (P < 0.001), and hernia volume (P < 0.001) were larger in the CS group, while RDR (P < 0.001) was smaller. The abdominal wall muscle area in the CS group was slightly greater than that in the non-CS group (P = 0.046), and there was no significant difference in the CT attenuation of the abdominal wall muscle between the two groups (P = 0.089). Multivariate logistic regression identified hernia defect width (OR 1.815, 95% CI 1.428-2.308, P < 0.001), RDR (OR 0.018, 95% CI 0.003-0.106, P < 0.001), hernia defect angle (OR 1.077, 95% CI 1.042-1.114, P < 0.001), hernia volume (OR 1.002, 95% CI 1.001-1.003, P < 0.001), and CT attenuation of abdominal wall muscle (OR 0.962, 95% CI 0.927-0.998, P = 0.037) as independent predictors of CS. Hernia defect width was the best predictor for CS, with a cut-off point of 9.2 cm and an area under the curve (AUC) of 0.890. The AUCs of RDR, hernia defect angle, hernia volume, and abdominal wall muscle CT attenuation were 0.843, 0.812, 0.747, and 0.572, respectively. CONCLUSION: Quantitative CT measurements are of great value for preoperative prediction of CS. Hernia defect size, hernia volume, and the CT attenuation of abdominal wall muscle are all preoperative predictive indicators of CS.

Radiological incidence of donor-site incisional hernia and parastomal hernia after vertical rectus abdominus myocutaneous flap-based reconstruction following colorectal surgery.

AIM: A vertical rectus abdominis myocutaneous (VRAM) flap is commonly used to reconstruct perineal defects for low rectal and anal cancer. The incidence of midline incisional hernias after VRAM reconstruction varies from 3.6% when detected clinically to 50% when detected radiologically. The aim of this study is to accurately determine the radiological incidence of donor-site incisional and parastomal hernia following VRAM reconstruction. METHOD: This was a retrospective cohort study of patients undergoing colorectal surgery requiring VRAM reconstruction over 10 years. Data were collected on patient demographics, indication for surgery and surgical procedure, including details of any hernia repair. Images from surveillance CTs were reviewed for the presence and size of midline incisional and/or parastomal hernias. Parastomal hernias were classified based on the European Hernia Society (EHS) classification. RESULTS: One hundred and seventy three patients were included in the analysis. The median age was 67 years (range 29-88 years) and the median length of follow-up was 49 months (interquartile range 24.3-71.0 months). The cumulative incidence of donor-site incisional hernia after VRAM at 1, 2 and 5 years was 15.1%, 25.4% and 29.1%, respectively. The cumulative incidence for PSH at 1, 2 and 5 years was 33.1%, 46.6% and 53.3%, respectively (95% CI 45.4%-60.5%). CONCLUSION: Most patients who develop donor-site incisional hernia and parastomal herniation following VRAM tend to do so within the first 2 years. Although the use of CT imaging improves the diagnosis of donor-site incisional and parastomal hernias, the clinical significance of this is unknown.

Intramuscular Adipose Tissue Content as a Predictor of Incisional Hernia after Hepatic Resection.

BACKGROUND: Incisional hernia (IH) is a common surgical complication, with an incidence of 6-31% following major abdominal surgery. This study aimed to investigate the impact of intramuscular adipose tissue content (IMAC) on the incidence of IH in patients who underwent hepatic resection. METHODS: Data of 205 patients who underwent open hepatic resection between 2007 and 2019 at Ehime University Hospital were retrospectively analyzed. Patient characteristics, perioperative findings, and body composition were compared between patients with IH and those without IH. The quantity and quality of skeletal muscle, calculated as skeletal muscle index and IMAC, were evaluated using preoperative computerized tomography images. RESULTS: Forty (19.5%) patients were diagnosed with IH. The cumulative incidence rates were 15.6% at 1 year and 19.6% at 3 years. On univariate analysis, body mass index, areas of subcutaneous and visceral fat, and IMAC were significantly higher in the IH group than in the non-IH group (p = 0.0023, 0.0070, 0.0047, and 0.0080, respectively). No significant difference in skeletal muscle index was found between the groups (p = 0.3548). The incidence of diabetes mellitus, intraoperative transfusion, and postoperative wound infection was significantly higher in the IH group than in the non-IH group (p = 0.0361, 0.0078, and 0.0299, respectively). On multivariate analysis, a high IMAC and wound infection were independent risk factors for IH (adjusted odds ratio, 2.83 and 4.52, respectively; p = 0.0152 and 0.0164, respectively). CONCLUSION: IMAC can predict the incidence of IH in patients undergoing hepatic resection.

Visceral obesity as a risk factor of incisional hernia after single-port laparoscopic gynecologic surgery.

OBJECTIVE: We aimed to evaluate associations between abdominal fat distribution (AFD) parameters and incisional hernia (IH) in patients who underwent transumbilical single-port laparoscopic surgery (SPLS) for gynecological disease. METHODS: Medical records of 2116 patients who underwent SPLS for gynecological disease at Daejeon St. Mary's Hospital between March 2014 and February 2021 were reviewed. Among 21 (1.0%) patients who developed IH requiring surgical treatment after SPLS, 18 had preoperative abdominopelvic computed tomography (CT) images. As a control group, we randomly selected 72 patients who did not develop IH and who had undergone preoperative abdominopelvic CT scan, matched to test patients by type of surgery. Total fat area (TFA), visceral fat area (VFA), subcutaneous fat area (SFA), visceral-to-subcutaneous fat ratio (VSR), and waist circumference (WC) were measured at the level of the third lumbar vertebral body on the preoperative abdominopelvic CT images, using National Institutes of Health (NIH) ImageJ version 1.53 k. RESULTS: Receiver operating curve analysis showed that VFA has the highest predictive value for IH among AFD parameters (AUC = 0.749, 95% CI 0.630-0.869, p < 0.001). Univariate analysis showed that age, BMI, hypertension, dyslipidemia, TFA, VFA, VSR and WC were significant factors for IH. In multivariate analysis, only high VFA was identified as an independent risk factor for IH (HR 6.18, 95% CI 1.13-33.87, p = 0.04), whereas BMI, TFA, SFA, VSR, and WC failed to show statistical significance. CONCLUSION: We could find high VFA as an independent risk factor of IH in patients who underwent SPLS for gynecologic disease.

INCISIONAL HERNIA AFTER BARIATRIC SURGERY: ONLY THE PHYSICAL EXAMINATION IS ENOUGH?

BACKGROUND: Incisional hernia is characterized by a bulging of the abdominal wall caused by the prolapse of intracavitary structures, such as a segment of the small intestine, through the trocar orifice. Ultrasonography and physical examination are used in the diagnosis of incisional hernia. AIMS: This study aimed to evaluate the difference between physical examination and abdominal ultrasonography at the diagnosis of incisional hernia in patients who underwent laparoscopic bariatric surgery. METHODS: A total of 123 patients who underwent Roux-en-Y gastric bypass type bariatric surgery performed by laparoscopy were analyzed for the presence or absence of hernia by physical and ultrasonography examination at each trocar incision site. RESULTS: In our results, a total of 7 hernias were detected by physical examination, while ultrasonography detected a total of 56 hernias in at least one of the incision sites. Lin's concordance analysis showed that the tests are not concordant. The association between body mass index and hernia detection (p=0.04 for physical examination and p=0.052 for ultrasonography) was observed. Ultrasonography detected more incisional hernias in 10-mm or larger trocars than in 5-mm trocars (p<0.0001, p<0.05). No differences were noted among the trocar types that were used. CONCLUSIONS: Abdominal ultrasonography showed to have a higher accuracy than physical examination, resulting in a substantial increase in incisional hernia detection at the trocar sites.

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.

Validation of a simple technique of volumetric analysis of complex incisional hernias without 3D CT scan reconstruction.

PURPOSE: Volumetric analysis is being increasingly utilized in the preoperative evaluation of complex incisional hernias. Three-dimensional (3D) reconstruction of abdominal computed tomography (CT) scan has been used to obtain surface area (SA) and volume (Vol.) measurements, while others have used simple mathematical formulas to obtain SA and Vol. estimates without 3D reconstruction. Our objective was to assess the correlation of SA and Vol. measurements and estimates of complex incisional hernias. METHODS: We conducted a retrospective agreement study of adults who underwent abdominal wall reconstruction from 2007 to 2018. Demographics, hernia characteristics, and operative data were collected from the medical record. SA and Vol. measurements were obtained after 3D CT reconstruction. Linear CT variables were obtained independently by two surgeons and SA and Vol. estimates were calculated. Because both surgeons reported similar results, only lead author values are reported in the abstract. We used Pearson's correlation coefficient (r) to assess inter-rater agreement and the agreement between SA and Vol. measurements and estimates. RESULTS: A total of 108 patients were eligible for analysis. The mean age was 57 ± 11 years and 53 (49%) were female. 42 (39%) hernias were recurrent, 10 (9%) patients had a stoma, and 9 (8%) had a history of open abdomen. The mean defect width was 11 ± 4 cm and mean defect surface area (DSA) was 150 ± 95 cm2. Inter-rater agreement of SA and Vol. estimates was high (r ≥ 0.80). There was high correlation between SA and Vol. measurements and estimates for DSA, hernia sac volume (HSV), abdominal cavity volume (ACV), and HSV/ACV ratio (r = 0.81, 0.89, 0.94 and 0.91, respectively). CONCLUSION: SA and Vol. estimates demonstrated high level of agreement with SA and Vol. measurements using 3D reconstruction. SA and Vol. estimates can be obtained using simple mathematical formulas using easily obtained linear variables negating the need for the time and effort consuming 3D reconstruction.

Recurrent complex incisional hernia repair by enhanced-view totally extraperitoneal (eTEP) technique.

OBJECTIVE: Treatment of large recurrent abdominal wall hernias remains a surgical challenge. The enhanced-view totally extraperitoneal (eTEP) approach is an emerging technique used to treat hernias with minimally invasive procedure. This article illustrates a step-by-step eTEP approach, used in a complex recurrent hernia repair. PATIENTS AND METHODS: A 56-years-old male had a previous epigastric hernia repair with an intraperitoneal onlay mesh (IPOM) technique in 2018. Six months later, he presented a recurrent epigastric protrusion and a new painful ombilical hernia, objectified on the CT-scan. RESULTS: Four suprapubic trocars were used to dissect the preperitoneal space below the arcuate line and the retromuscular spaces on both sides. On the mid-line, posterior fascia was divided and both hernia sacs were fully dissected. Both anterior and posterior sheats were closed with self-locking non-absorbable threads before placing a Polypropylene self-gripping mesh. The follow-up was uneventful, and the patient was discharged on day 2. CONCLUSIONS: This case report illustrates that eTEP technique can be used safely and effectively to treat complex recurrent ventral hernias even with a mesh already in place. The potential advantages of the eTEP procedure are multiple, such as improving mobility and esthetic results, reducing pain and shorting hospital length of stay.

The role of radiological classification of parastomal hernia as a predictor of the need for surgical hernia repair: a retrospective cohort study.

PURPOSE: Parastomal hernia (PSH) is a frequent complication of stoma creation during colorectal surgery. Radiological classification systems have been proposed for PSH but are primarily used for research. Our objective was to determine if PSH radiological classification at diagnosis could predict the need for surgical repair during follow-up. METHODS: In this retrospective cohort study, we reviewed 705 postoperative CT scans from 154 patients with permanent stoma creation from 2015 to 2018. Patients were included for analysis if a primary PSH was diagnosed on any exam. PSH were classified according to the European Hernia Society (EHS) and Moreno-Matias (MM) classification systems. RESULTS: The incidence of radiological PSH was 41% (63/154) after a median radiological follow-up of 19.2 months (interquartile range, 10.9-32.9). Surgical repair was required in 17 of 62 patients with a primary PSH. There was no significant correlation between PSH classification and surgical hernia repair for either the EHS (p = 0.56) or MM classification systems (p = 0.35) in a univariate analysis. However, in a multivariate analysis, the type of PSH according to the EHS classification was significantly correlated with PSH repair during follow-up (p = 0.02). Type III PSH were associated with a lower incidence of surgical hernia repair as compared with type I, with a hazard ratio (HR) of 0.01 (95% CI, <0.00-0.20). A similar correlation was not seen using the MM classification (p = 0.10). CONCLUSION: EHS classification of PSH was significant correlated with the need for surgical repair during short-term follow-up. Prospective studies are required to establish a potential role in patient care.

Biomechanics applied to incisional hernia repair - Considering the critical and the gained resistance towards impacts related to pressure.

BACKGROUND: Incisional hernia repair is burdened with recurrence, pain and disability. The repair is usually carried out with a textile mesh fixed between the layers of the abdominal wall. METHODS: We developed a bench test with low cyclic loading. The test uses dynamic intermittent strain resembling coughs. We applied preoperative computed tomography of the abdomen at rest and during Valsalva's maneuver to the individual patient to analyze tissue elasticity. FINDINGS: The mesh, its placements and overlap, the type and distribution of fixation elements, the elasticity of the tissue of the individual and the closure of the abdominal defect-all aspects influence the reconstruction necessary. Each influence can be attributed to a relative numerical quantity which can be summed up into a characterizing value. The elasticity of the tissues within the abdominal wall of the individual patient can be assessed with low-dose computed tomography of the abdomen with Valsalva's maneuver. We established a procedure to integrate the results into a surgical concept. We demonstrate potential computer algorithms using non-rigid b-spline registration and artificial intelligence to further improve the evaluation process. INTERPRETATION: The bench test yields relative values for the characterization of hernia, mesh and fixation. It can be applied to patient care using established procedures. The clinical application in the first ninety-six patients shows no recurrences and reduced pain levels after one year. The concept has been spread to other surgical groups with the same results in another fifty patients. Future efforts will make the abdominal wall reconstruction more predictable.

Reoperation with laparoscopic mesh repair for recurrent lumbar hernia due to iliac crest bone harvest.

Previous reports have described laparoscopic mesh repair for lumbar hernia due to iliac crest bone harvest, but there have been no reports of reoperation with laparoscopic mesh repair for recurrent cases after laparoscopic mesh repair. Here, we describe the case of a 72-year-old Japanese woman with lumbar hernia recurrence 6 years after laparoscopic mesh repair for lumbar hernia due to iliac crest bone harvest. We performed a successful reoperation with laparoscopic mesh repair. Laparoscopic surgery should be considered to elucidate the mechanism of recurrence, previous mesh position, and the area that must be covered to prevent recurrence again.

Laparoscopy-assisted repair with Ventralex ST Hernia Patch for a small subcostal hernia: A case report.

A 55-year-old woman with a history of right hepatic lobectomy via a Benz incision presented for evaluation of a new abdominal bulge in the right upper quadrant. We diagnosed an incisional hernia, but because we could neither reduce the hernia contents nor locate the orifice, we performed a laparoscopic evaluation. Laparoscopy revealed subcostal herniation of the greater omentum via a 2-cm defect on the caudal side of the right ribs, which we repaired using a Ventralex ST Hernia Patch. Laparoscopic placement of this mesh with straps allowed for reliable deployment, fixation, and confirmation of defect closure, including the cranial aspect-often a major challenge in subcostal hernia repair.

Clinical and Radiologic Predictors of Parastomal Hernia Development After End Colostomy.

OBJECTIVE. Parastomal hernia (PSH) is a common complication that can occur after end colostomy and may result in considerable morbidity. To select the best candidates for prophylactic measures, knowledge of preoperative PSH predictors is important. This study aimed to determine the value of clinical parameters, preoperative CT-based body metrics, and size of the abdominal wall defect created during end colostomy and measured at postoperative CT for predicting PSH development. MATERIALS AND METHODS. Sixty-five patients who underwent permanent end colostomy with at least 1 year of follow-up were included. On preoperative CT, waist circumference, abdominal wall and psoas muscle indexes, rectus abdominis muscle diameter and diastasis, intra- and extraabdominal fat mass, and presence of other hernias were assessed. On postoperative CT, size of the abdominal wall defect and the presence of PSH were determined. To identify independent predictors of PSH development, univariate analysis with the Kaplan-Meier method and multivariate Cox regression analysis were performed. RESULTS. PSH developed after surgery in 30 patients (46%). Three independent risk factors were identified: chronic obstructive pulmonary disease (COPD) as a comorbidity (hazard ratio [HR], 6.4; 95% CI, 1.9-22.0; p = 0.003), operation time longer than 395 minutes (HR, 3.9; 95% CI, 1.5-10.0; p = 0.005), and maximum aperture diameter of more than 34 mm (HR, 5.2; 95% CI, 2.1-12.7; p < 0.001). PSH developed in all nine patients with a maximum abdominal wall defect diameter of more than 50 mm at the ostomy site. CONCLUSION. COPD, longer operation time, and larger abdominal wall defect at the colostomy site can predict PSH development. Intraoperative creation of an abdominal wall ostomy opening that is more than 34 mm in diameter should be avoided.

Atrophic change of the abdominal rectus muscle significantly influences the onset of parastomal hernias beyond existing risk factors after end colostomy.

PURPOSE: To investigate optimal risk factors, including atrophy of the abdominal rectus muscle (ARM) for postoperative parastomal hernia (PH) in patients who underwent end colostomy at left lower quadrant. METHODS: This single-institution retrospective study included 91 patients who underwent end colostomy between April 2004 and December 2015. The surgical and long-term outcomes among patients with or without PH were collected and compared. RESULTS: Altogether, 22 (24.2%) patients had a PH including 15 (68.2%) patients with a simultaneous incisional hernia. Univariate analysis showed that older patients (71 ± 11.9 vs. 64 ± 12.2 years, p = 0.03) and those with higher body mass index (BMI) (23.8 ± 3.8 vs. 20.9 ± 3.3 kg/m2, p < 0.001) had a statistically significant relation with having PHs. Relative atrophy of left abdominal rectus muscle was more frequently found in patients with PH (ratio of left side/right side; caudal level and medial side: 0.66 vs. 0.92, p < 0.01, caudal level and lateral side: 0.95 vs. 1.03, p = 0.04). Multivariate analysis revealed that BMI > 25 kg/m2 [odds ratio (OR) 9.05, 95% confidence interval (CI) 2.06-39.76, p = 0.003] and atrophy of the left lower medial portion of the abdominal rectus muscle (OR 12.85, 95% CI 2.49-66.39, p = 0.002) were independent risk factors for PHs. Neither the laparoscopic approach nor the extraperitoneal route of the colostomy was proven to correlate with a lower rate of PHs. CONCLUSIONS: High BMI and atrophic change of ARM were significantly associated with PH development. Surgical techniques for prevention of atrophic change of ARM are expected to reduce the incidence of PHs.

Computed Tomography Verified Prevalence of Incisional Hernia 1 Year Postoperatively after Colorectal Cancer Resection.

BACKGROUND AND OBJECTIVE: Incisional hernia is a frequent negative outcome after open and minimal invasive surgery of colorectal cancer. This study aimed to determine computed tomography-verified incisional hernia prevalence 1-year post colorectal cancer surgical resection in patients sutured with standardized small stich 4:1 technique, identify risk factors for incisional hernia and assess to what extent incisional hernia required surgical correction. METHODS: All patients subjected to resectional colorectal cancer surgery during 2012-2016 at Skåne University Hospital were identified in the Swedish Colorectal Cancer Registry. The 1-year follow-up computed tomography was re-evaluated to establish the presence of incisional hernia. Clinical data were collected from Swedish Colorectal Cancer Registry and the patients' medical charts were reviewed. Non-parametric tests and binary logistic regression analysis were used for statistical analysis. RESULTS: In total, 1744 tumors were identified resulting in 1231 patients meeting the inclusion criteria. In total, 25.9% (n = 319) had incisional hernia at the 1-year follow-up computed tomography and 13.2% (n = 162) of the colorectal cancer resections were minimal invasive surgery, and there was non-significant incisional hernia prevalence difference between open and minimal invasive surgery. However, for converted and non-converted minimal invasive surgery, the incisional hernia frequencies were 43.9% (n = 18) and 24.1% (n = 39), respectively (p = 0.012). Significant risk factors for incisional hernia were body mass index, wound rupture, and procedure time. During the follow-up time, 14.1% (n = 45) needed incisional hernia corrective surgery. CONCLUSIONS: Incisional hernia after colorectal cancer surgery is common despite standardized small stich 4:1 closure, but few incisional hernias are surgically corrected. Incisional hernia is equally frequent after open surgery and minimal invasive surgery. However, the risk of incisional hernia is considerably higher after minimal invasive surgery conversion.

Incidence and risk factors for trocar-site incisional hernia detected by clinical and ultrasound examination: a prospective observational study.

BACKGROUND: Trocar site incisional hernia (TSIH) is the most frequent complication associated with laparoscopic surgery. Few studies currently describe its incidence or risk factors. The aim of this report is to determine the real incidence of TSIH and to identify risk factors. METHODS: A cross-sectional prospective study was performed including consecutive patients who underwent a laparoscopic procedure during a 4 months period. All the patients were assessed both clinically (TSIHc) and by an ultrasonographic examination (TSIHu). The main variable studied was the incidence of TSIH. A multivariate analysis was performed to identify risk factors. RESULTS: 76 patients were included. 27.6% of patients were clinically diagnosed as having TSIH (TSIHc) but only 23.7% of those cases were radiologically confirmed (TSIHu). In the logistic regression analysis, age > 70 years (OR 3.462 CI 1.14-10.515, p = 0.028) and body mass index (BMI) ≥ 30 kg/m2 (OR 3.313 CI 1.037-10.588, p = 0.043) were identified as risk factors for TSIH. The size of the trocar also showed statistically significant differences (p < 0.001). Mean follow-up time was 34 months. CONCLUSIONS: TSIH is under-diagnosed due to the lack of related symptomatology and the inadequacy of the postoperative follow-up period. We detected discrepancies between the clinical and ultrasonographic examinations. TSIHu should be considered as the gold standard for the diagnosis of TSIH. Risk factors such as age, BMI and size of the trocar were confirmed. Patients should be followed-up for a minimum of 2 years. Trial registration The study has been retrospectively registered in Clinicaltrials.gov on June 4, 2020 under registration number: NCT04410744.