Gender Equality in Diastasis Rectus Abdominis in Chronic Back Pain: A Model of M. Transversus Abdominis Motor Control Impairment.

Introduction: Diastasis rectus abdominis (DRA) is defined as an increased distance between the left and right muscle of the m. rectus abdominis. Pregnancy-related factors are assumed to be dominant factors in the occurrence of DRA. However DRA is not only found in peri-partum women but also in men and nulliparous women with back or pelvic pain. This study provides an inventory of the incidence of DRA in subjects with chronic back and pelvic pain. If DRA is common in both men and women then other factors besides pregnancy, like impaired motor control, should be explored as cause for DRA. Material and Methods: This study was conducted with data from 849 back pain patients. Results from ultrasound assessment of the abdominal wall were combined with anamnestic data on age, gender, medical history and pregnancies (in women). Results: There was no difference in Inter Rectus Distance cranial of the umbilicus (IRD above umbilicus) between men and women. Almost half of all women and men (45% and 43%, respectively) exhibit an increased IRD above umbilicus. The incidence of an increased IRD above umbilicus is twice as high in women below 30 years, compared to men below 30 years old. This difference is not observed for men and women above 30 years old. Discussion: DRA occurs in women during pregnancy and increases with an increasing number of pregnancies. However, this condition does not affect significantly more women than men. Increased IRD above umbilicus already occurs in young men (mean age 30). Over 30 years of age, cranial of the umbilicus there is no difference in IRD between women and men. An alternative etiological mechanism is suggested.

Developing and validating an implantable suture tension sensor.

Introduction: Suture tension has a direct influence on the sutured tissue. For abdominal wall closure, suture tension should be optimal without causing tissue necrosis, which can result in surgical site infection or incisional hernia. The purpose of the present study is to evaluate a device that can measure suture tension in-situ and in real-time. Materials and methods: A cheap, commercially available analog-to-digital converter was used, in conjunction with a force sensing resistor. A sensor probe housing was designed and 3D-printed. In order to test the sensor, a mechanical, computer controlled human abdominal wall model called the AbdoMAN was used. Results: An implantable suture tension sensor was developed, keeping cost-effectiveness in mind. This sensor can translate tension in the suture into a downward force, applied to the force sensing resistor. The sensor's raw readout was characterized using a set of weights, from which a formula correlating the readout to a specific force, was derived. Preliminary validation was successfully performed using the AbdoMANmodel, which showed a progressive rise in suture tension when the intra-abdominal pressure was artificially increased over time. Conclusion: The implantable suture tension sensor appeared to be capable of recording real time changes in suture tension, and the. validation process of this sensor has been initiated. With the information from devices like this, a much better understanding of the issues at play in the development of incisional hernia can be gained.

A preoperative prediction model for anastomotic leakage after rectal cancer resection based on 13.175 patients.

INTRODUCTION: This study aims to develop a robust preoperative prediction model for anastomotic leakage (AL) after surgical resection for rectal cancer, based on established risk factors and with the power of a large prospective nation-wide population-based study cohort. MATERIALS AND METHODS: A development cohort was formed by using the DCRA (Dutch ColoRectal Audit), a mandatory population-based repository of all patients who undergo colorectal cancer resection in the Netherlands. Patients aged 18 years or older were included who underwent surgical resection for rectal cancer with primary anastomosis (with or without deviating ileostomy) between 2011 and 2019. Anastomotic leakage was defined as clinically relevant leakage requiring reintervention. Multivariable logistic regression was used to build a prediction model and cross-validation was used to validate the model. RESULTS: A total of 13.175 patients were included for analysis. AL was diagnosed in 1319 patients (10%). A deviating stoma was constructed in 6853 patients (52%). The following variables were identified as significant risk factors and included in the prediction model: gender, age, BMI, ASA classification, neo-adjuvant (chemo)radiotherapy, cT stage, distance of the tumor from anal verge, and deviating ileostomy. The model had a concordance-index of 0.664, which remained 0.658 after cross-validation. In addition, a nomogram was developed. CONCLUSION: The present study generated a discriminative prediction model based on preoperatively available variables. The proposed score can be used for patient counselling and risk-stratification before undergoing rectal resection for cancer.

Consensus paper on postural dysfunction: recommendations for prevention, diagnosis and therapy.

Good fundamentals of posture and balance are essential for the efficient performance of both simple daily tasks and more complex movement patterns. In particular, postural balance is the ability to keep the body in equilibrium and to regain balance after the shift of body segments: postural control mechanisms of integration of the visual, vestibular and foot afferential channels contribute to this. This document provides recommendations based on scientific evidence, clinical practice, and consensus between experts concerning the prevention, diagnosis, and treatment of postural dysfunction at the three stages of life as the developmental age, adult age, and old age > 65 years and follows the "National Guidelines on Classification and Measuring of Posture and its Dysfunctions" per the Italian Ministry of Health (December 2017). The paper answers four main questions: i) "Which measures can be adopted to prevent postural dysfunctions?" ii) "What can we do in order to make a correct diagnosis of postural dysfunction?" iii) "What are the correct treatment programs for postural dysfunctions?" iv) Which professional competencies and experiences are useful for preventing, diagnosing and treating postural dysfunctions? By the Consensus of the Experts and the scientific evidence, emerge that the approach to postural dysfunctions requires a multidisciplinary and interdisciplinary team. Furthermore, rehabilitation treatment interventions must be specific to the age groups that have been indicated, to consider the integration of the main systems and subsystems of postural control that change with age.

Hernia width explains differences in outcomes between primary and incisional hernias: a prospective cohort study of 9159 patients.

PURPOSE: Data on primary (PH) and incisional hernias (IH) are often pooled, even though several studies have illustrated that these are different entities with worse outcomes for IHs. The aim of this study is to validate previous research comparing PHs and IHs and to examine whether hernia width is an important contributor to the differences between these hernia types. METHODS: A registry-based, prospective cohort study was performed, utilizing the French Hernia Club database. All patients undergoing PH or IH repair between September 8th 2011 and May 22nd 2019 were included. Baseline, hernia and surgical characteristics, and postoperative outcomes were collected. Outcomes were analyzed per width category (≤ 2 cm, 3-4 cm, 5-10 cm and > 10 cm). RESULTS: A total of 9159 patients were included, of whom 4965 (54%) had PH and 4194 (46%) had IH. PHs and IHs differed significantly in 12/15 baseline characteristics, 9/10 hernia and surgical characteristics, and all outcomes. Overall, complications and re-interventions were more common in patients with IH. After correcting for width, the differences between PH and IH were no longer significant, except for medical complications, which were more common after IH repair compared to PH. CONCLUSION: After correcting for hernia width, most outcomes do not significantly differ between PH and IH, indicating that not hernia type, but hernia width is an important factor contributing to the differences between PH and IH.

Differences in biomechanics of abdominal wall closure with and without mesh reinforcement: A study in post mortem human specimens.

INTRODUCTION: Small bites for the closure of the abdominal wall after midline laparotomy result in significantly less incisional hernias in comparison with large bites. However, fundamental knowledge of underlying biomechanical phenomena remains sparse. The objective of this study was to develop a digital image correlation-based method to compare different suturing techniques in terms of strain pattern after closure of a midline laparotomy in a passive model just after the time of surgery. METHODS: A digital image correlation (DIC)-based method was used for the comparison of strain fields on the external surface of the myofascial abdominal wall (skin and subcutaneous fat removed) among six configurations, including an intact linea alba in five post mortem human specimens. The second configuration comprised primary mass closure with small bites (five mm between two consecutive stitches and five mm distance from the incision, 5x5 mm). The third configuration was primary mass closure with large bites (ten mm by ten mm, 10x10 mm). The fourth, fifth and sixth configuration comprised primary mass closure with large bites and the placement of a mesh in onlay position with two different overlaps and the use of glue to simulate the integration of the mesh within the soft tissue. RESULTS: No visible difference was observed between 5x5 and 10x10 mm closure configurations. However, the use of mesh as suture line reinforcement highlighted a stiffer behavior of the midline area for similar intra-abdominal pressure, which was amplified when a larger mesh overlap was used. However, the whole abdominal wall showed quite similar shapes for the various configurations, except for the configuration with mesh reinforcement and the use of glue. CONCLUSION: Mesh reinforcement incited lower opening tension profiles in the midline area of the abdominal wall. following closure of the linea alba in median laparotomy. The next step should be to investigate the impact of mesh location (e.g. retromuscular) and different time points after surgery.

Evaluation of a new suture material (Duramesh™) by measuring suture tension in small and large bites techniques for laparotomy closure in a porcine model.

PURPOSE: After closure of laparotomies, sutures may pull through tissue due to too high intra-abdominal pressure or suture tension, resulting in burst abdomen and incisional hernia. The objective of this study was to measure the suture tension in small and large bites with a new suture material. METHODS: Closure of the linea alba was performed with small bites (i.e., 5 mm between two consecutive stitches and 5 mm distance from the incision) and large bites (i.e., 10 mm × 10 mm) with Duramesh™ size 0 (2 mm) and PDS II 2-0 in 24 experiments on six porcine abdominal walls. The abdominal wall was fixated on an artificial computer-controlled insufflatable abdomen, known as the 'AbdoMan'. A custom-made suture tension sensor was placed in the middle of the incision. RESULTS: The suture tension was significantly lower with the small bites technique and Duramesh™ when compared with large bites (small bites 0.12 N (IQR 0.07-0.19) vs. large bites 0.57 N (IQR 0.23-0.92), p < 0.025). This significant difference was also found in favour of the small bites with PDS II 2-0 (p < 0.038). No macroscopic tissue failure was seen during or after the experiments. CONCLUSION: Closure of the abdominal wall with the small bites technique and Duramesh™ was more efficient in dividing suture tension across the incision when compared to large bites. However, suture tension compared to a conventional suture material was not significantly different, contradicting an advantage of the new suture material in the prevention of burst abdomen and incisional hernia during the acute, postoperative phase.

Use of the Humeral Head as a Reference Point to Prevent Axillary Nerve Damage during Proximal Fixation of Humeral Fractures: An Anatomical and Radiographic Study.

INTRODUCTION: Treatment of proximal humeral fractures with plate osteosynthesis or intramedullary nail fixation in humeral shaft fractures with a proximal locking bolt carries the risk of iatrogenic injury of the axillary nerve. The purpose of this anatomical study is to define a more reliable safe zone to prevent iatrogenic axillary nerve injury using the humeral head instead of the acromion as a (radiographic) reference point during operative treatment. MATERIALS AND METHODS: Anatomical dissection and labeling of the axillary nerve and branches was performed on 10 specially embalmed human specimens. Standard AP and straight lateral radiographs were made. The distances were measured indirectly from the cranial tip of the humerus to the axillary nerve on radiographs. RESULTS: The median distance from the cranial tip of the humerus to the axillary nerve was 52 mm. The mean number of axillary nerve branches was 3. The distances from the cranial tip of the humerus to the nerve (branch) varied from 23 to 78 mm. The median distance from the proximal (anterior) branch was 36 mm, to the second branch 47 mm, 54 mm to the third branch and 73 mm to the fourth branch. The axillary nerve moves along with the humerus in cranial and caudal direction when the subacromial space varies. CONCLUSION: This study shows that the position of the axillary nerve can be better determent using the cranial tip of the humerus as a reference point instead of the acromion. Furthermore, it is unsafe to place the proximal locking bolts in the zone between 24 mm and 78 mm from the cranial tip of the humerus. The greatest chance to cause a lesion of the main branch of the axillary nerve is in the zone between 48 mm and 58 mm caudal from the tip of the humeral head. HOW TO CITE THIS ARTICLE: Theeuwes HP, Potters JW, Bessems JHJM, et al. Use of the Humeral Head as a Reference Point to Prevent Axillary Nerve Damage during Proximal Fixation of Humeral Fractures: An Anatomical and Radiographic Study. Strategies Trauma Limb Reconstr 2020;15(2):63-68.

Long-term follow-up of a multicentre cohort study on laparoscopic peritoneal lavage for perforated diverticulitis.

AIM: Laparoscopic peritoneal lavage has increasingly been investigated as a promising alternative to sigmoidectomy for perforated diverticulitis with purulent peritonitis. Most studies only reported outcomes up to 12 months. Therefore, the objective of this study was to evaluate long-term outcomes of patients treated with laparoscopic lavage. METHODS: Between 2008 and 2010, 38 patients treated with laparoscopic lavage for perforated diverticulitis in 10 Dutch teaching hospitals were included. Long-term follow-up data on patient outcomes, e.g. diverticulitis recurrence, reoperations and readmissions, were collected retrospectively. The characteristics of patients with recurrent diverticulitis or complications requiring surgery or leading to death, categorized as 'overall complicated outcome', were compared with patients who developed no complications or complications not requiring surgery. RESULTS: The median follow-up was 46 months (interquartile range 7-77), during which 17 episodes of recurrent diverticulitis (seven complicated) in 12 patients (32%) occurred. Twelve patients (32%) required additional surgery with a total of 29 procedures. Fifteen patients (39%) had a total of 50 readmissions. Of initially successfully treated patients (n = 31), 12 (31%) had recurrent diverticulitis or other complications. At 90 days, 32 (84%) patients were alive without undergoing a sigmoidectomy. However, seven (22%) of these patients eventually had a sigmoidectomy after 90 days. Diverticulitis-related events occurred up to 6 years after the index procedure. CONCLUSION: Long-term diverticulitis recurrence, re-intervention and readmission rates after laparoscopic lavage were high. A complicated outcome was also seen in patients who had initially been treated successfully with laparoscopic lavage with relevant events occurring up to 6 years after initial surgery.

Pitfalls and clinical recommendations for the primary lumbar hernia based on a systematic review of the literature.

PURPOSE: The lumbar abdominal wall hernia is a rare hernia in which abdominal contents protrude through a defect in the dorsal abdominal wall, which can be of iatrogenic, congenital, or traumatic origin. Two anatomical locations are known: the superior and the inferior lumbar triangle. The aim of this systematic review is to provide a clear overview of the existing literature and make practical clinical recommendations for proper diagnosis and treatment of the primary lumbar hernia. METHODS: The systematic review was conducted according to the PRISMA guidelines. A systematic search in PubMed, MEDLINE, and EMBASE was performed, and all studies reporting on primary lumbar hernias were included. No exclusion based on study design was performed. Data regarding incarceration, recurrence, complications, and surgical management were extracted. RESULTS: Out of 670 eligible articles, 14 were included and additional single case reports were analysed separately. The average quality of the included articles was 4.7 on the MINORS index (0-16). Risk factors are related to increased intra-abdominal pressure. CT scanning should be performed during pre-operative workup. Available evidence favours laparoscopic mesh reinforcement, saving open repair for larger defects. Incarceration was observed in 30.8% of the cases and 2.0% had a recurrence after surgical repair. Hematomas and seromas are common complications, but surgical site infections are relatively rare. CONCLUSION: The high risks of incarceration in lumbar hernias demand a relatively fast elective repair. The use of a mesh is recommended, but the surgical approach should be tailored to individual patient characteristics and risk factors.

Incidence, risk factors and prevention of stoma site incisional hernias: a systematic review and meta-analysis.

AIM: Stoma reversal might lead to a stoma site incisional hernia. Recently, prophylactic mesh reinforcement of the stoma site has gained increased attention, supporting the need for accurate data on the incidence of and risk factors for stoma site incisional hernia and to identify high-risk patients. The aim of this study was to assess incidence, risk factors and prevention of stoma site incisional hernias. METHOD: Embase, MEDLINE, Web of Science, Cochrane and Google Scholar databases were searched. Studies reporting the incidence of stoma site incisional hernia after stoma reversal were included. Study quality was assessed with the Newcastle-Ottawa Scale and Cochrane risk of bias tool. Data on incidence, risk factors and prophylactic mesh reinforcement were extracted. RESULTS: Of 1440 articles found, 33 studies comprising 4679 reversals were included. The overall incidence of incisional hernia was 6.5% [range 0%-38%, median follow-up 27.5 (17.54-36) months]. Eleven studies assessed stoma site incisional hernia as the primary end-point, showing an incidence of 17.7% [range 1.7%-36.1%, median follow-up 28 (15.25-51.70) months]. Body mass index, diabetes and surgery for malignant disease were found to be independent risk factors, as derived from eight studies. Two retrospective comparative cohort studies showed significantly lower rates of stoma site incisional hernia with prophylactic mesh reinforcement compared with nonmesh controls [6.4% vs 36.1% (P = 0.001); 3% vs 19% (P = 0.04)]. CONCLUSION: Stoma site incisional hernia should not be underestimated as a long-term problem. Body mass index, diabetes and malignancy seem to be potential risk factors. Currently, limited data are available on the outcomes of prophylactic mesh reinforcement to prevent stoma site incisional hernia.

An anatomical study on the effectiveness of Arthrex Mini TightRope® ligament reconstruction in an unstable trapeziometacarpal joint.

INTRODUCTION: Laxity in the trapeziometacarpal (TMC) joint is a debilitating condition usually affecting a young population. It can be treated operatively with ligament reconstruction. The purpose of this study was to determine the effectiveness of the Arthrex Mini TightRope® in reinforcing the stabilizing ligaments in an unstable TMC joint without decreasing the range of motion of the thumb. This method was compared with the "gold standard" published by Eaton and Littler in 1973. MATERIALS AND METHODS: Six fresh frozen arms from five cadavers were included. TMC joint laxity was measured on stress view radiographs as the ratio of the radial subluxation (RS) of the first metacarpal in relation to the trapezium, by the first metacarpal articular width (AW) (as described by Wolf in 2009). Measurements of the pre- and post-operative range of motion (ROM) were performed and compared. RESULTS: Both the Arthrex Mini TightRope® and the Eaton-Littler stabilization improved the stability of the TMC joint. The pre-operative laxity value (ratio RS/AW) of 0.27 was significantly (P = 0.02) improved by each of the surgical interventions (Eaton-Littler RS/AW = 0.05 and Tightrope RS/AW = 0.09). The pre- and post-operative range of motion was not significantly different by each of the surgical interventions. There were no significant differences between the two stabilizing methods regarding laxity or range of motion. CONCLUSION: The Arthrex Mini TightRope® provided a good stabilization method for the TMC joint in this anatomical model without compromising the range of motion.

Systemic Inflammatory Cytokines Predict the Infectious Complications but Not Prolonged Postoperative Ileus after Colorectal Surgery.

AIM: Postoperative ileus (POI) is common after surgery. Animal studies indicate that the POI mechanism involves an inflammatory response, which is also activated during postoperative complications. This study aimed to determine whether inflammatory biomarkers might facilitate an early detection of prolonged POI (PPOI) or infectious complications. METHODS: Forty-seven adult patients who underwent oncological colorectal surgery were included. They filled out a perioperative diary to report their gastrointestinal symptoms. Blood samples were collected preoperatively, and on postoperative day (POD) 1 and 3. Levels of leucocytes, C-reactive protein (CRP), interleukin (IL)-6, TNF-α, and IL-1ß were analyzed. RESULTS: Patients with PPOI had significantly longer stay in hospital than patients without (13.6 ± 10.5 versus 7.4 ± 3.2 days, p < 0.001); they also had higher levels of IL-6 ratios, leucocytes, and CRP levels, but did not reach significance. Higher levels of postoperative IL-6 and CRP levels (p < 0.05, resp.) were found in patients with infectious complications. The receiver operating characteristic (ROC) analysis found better diagnostic values of IL-6 ratio on both POD 1 and 3 than that of CRP (POD 1: ROC 0.825, p < 0.001). CONCLUSION: Blood levels of inflammatory cytokines cannot predict PPOI after colorectal surgery. Instead, postoperative IL-6 changes may predict the infectious complications with a better diagnostic value than the current leukocytes or CRP tests.

A step towards stereotactic navigation during pelvic surgery: 3D nerve topography.

BACKGROUND: Long-term morbidity after multimodal treatment for rectal cancer is suggested to be mainly made up by nerve-injury-related dysfunctions. Stereotactic navigation for rectal surgery was shown to be feasible and will be facilitated by highlighting structures at risk of iatrogenic damage. The aim of this study was to investigate the ability to make a 3D map of the pelvic nerves with magnetic resonance imaging (MRI). METHODS: A systematic review was performed to identify a main positional reference for each pelvic nerve and plexus. The nerves were manually delineated in 20 volunteers who were scanned with a 3-T MRI. The nerve identifiability rate and the likelihood of nerve identification correctness were determined. RESULTS: The analysis included 61 studies on pelvic nerve anatomy. A main positional reference was defined for each nerve. On MRI, the sacral nerves, the lumbosacral plexus, and the obturator nerve could be identified bilaterally in all volunteers. The sympathetic trunk could be identified in 19 of 20 volunteers bilaterally (95%). The superior hypogastric plexus, the hypogastric nerve, and the inferior hypogastric plexus could be identified bilaterally in 14 (70%), 16 (80%), and 14 (70%) of the 20 volunteers, respectively. The pudendal nerve could be identified in 17 (85%) volunteers on the right side and in 13 (65%) volunteers on the left side. The levator ani nerve could be identified in only a few volunteers. Except for the levator ani nerve, the radiologist and the anatomist agreed that the delineated nerve depicted the correct nerve in 100% of the cases. CONCLUSION: Pelvic nerves at risk of injury are usually visible on high-resolution MRI with dedicated scanning protocols. A specific knowledge of their course and its application in stereotactic navigation is suggested to improve quality of life by decreasing the likelihood of nerve injury.

Comparing different modalities for the diagnosis of incisional hernia: a systematic review.

PURPOSE: Incisional hernia (IH) is the most frequent complication after abdominal surgery. The diagnostic modality, observer, definition, and diagnostic protocol used for the diagnosis of IH potentially influence the reported prevalence. The objective of this systematic review is to evaluate the diagnostic accuracy of different modalities used to identify IH. METHODS: Embase, MEDLINE OvidSP, Web of Science, Google Scholar, and Cochrane databases were searched to identify studies diagnosing IH. Studies comparing the IH detection rate of two different diagnostic modalities or inter-observer variability of one modality were included. Quality assessment of studies was done by Cochrane Collaboration's tool. Article selection and data collection were performed independently by two researchers. PROSPERO registration: CRD42017062307. RESULTS: Fifteen studies representing a total of 2986 patients were included. Inter-observer variation for CT-scan ranged from 11.2 to 69% (n = 678). Disagreement between ultrasound and CT-scan ranged between 6.6 and 17% (n = 221). Ten studies compared physical examination to CT-scan or ultrasound. Disagreement between physical examination and imaging ranged between 7.6 and 39% (n = 1602). Between 15 and 58% of IHs were solely detected by imaging (n = 483). Relative increase in IH prevalence for imaging compared to physical examination ranged from 0.92 to 2.4 (n = 1922). CONCLUSIONS: Ultrasound or CT-scan will result in substantial additional IH diagnosis. Lack of consensus regarding the definition of IH might contribute to the disagreement rates. Both the observer and diagnostic modality used could be additional factors explaining variability in IH prevalence and should be reported in IH research.

Non-operative treatment as a strategy for patients with parastomal hernia: a multicentre, retrospective cohort study.

AIM: Parastomal hernia is the most common complication following stoma construction. Surgical treatment is usually chosen over non-operative treatment, but a clear rationale for the choice of management is often lacking. This study aims to investigate the reasons for non-operative treatment, cross-over rates and postoperative complications. METHOD: A multicentre, retrospective cohort study was conducted. Patients diagnosed with a parastomal hernia between January 2007 and December 2012 were included. Data on baseline characteristics, primary surgery and hernias were collected. For non-operative treatment, reasons for this treatment and cross-over rates were evaluated. For all patients undergoing surgery (surgical treatment and cross-overs), complication and recurrence rates were analysed. RESULTS: Of the 80 patients included, 42 (53%) were in the surgical treatment group and 38 (48%) in the non-operative treatment group. Median follow-up was 46 months (interquartile range 24-72). The reasons for non-operative treatment were absence of symptoms in 12 patients (32%), comorbidities in nine (24%) and patient preference in three (7.9%). In 14 patients (37%) reasons were not documented. Eight patients (21%) crossed over from non-operative treatment to surgical treatment, of whom one needed emergency surgery. In 23 patients (55%), parastomal hernia recurred after the original surgical treatment, of whom 21 (91%) underwent additional repair. CONCLUSION: Parastomal hernia repair is associated with high recurrence and additional repair rates. Non-operative treatment has a relatively low cross-over and emergency surgery rate. Given these data, non-operative treatment might be a better choice for patients without complaints or with comorbidities.

The course of the radial nerve in the distal humerus: A novel, anatomy based, radiographic assessment.

METHODS AND FINDINGS: Measurements were done on both arms of ten specially embalmed specimens. Arms were dissected and radiopaque wires attached to the radial nerve in the distal part of the upper arm. Digital radiographs were obtained to determine the course of the radial nerve in the distal 20 cm of the humerus in relation to bony landmarks; medial epicondyle and capitellum-trochlea projection (CCT). Analysis was done with ImageJ and Microsoft Excel software. We also compared humeral nail specifications from different companies with the course of the radial nerve to predict possible radial nerve damage. RESULTS: The distance from the medial epicondyle to point where the radial nerve bends from posterior to lateral was 142 mm on AP radiographs and 152 mm measured on the lateral radiographs. The average distance from the medial epicondyle to point where the radial nerve bends from lateral to anterior on AP radiographs was 66 mm. On the lateral radiographs where the nerve moves away from the anterior cortex 83 mm to the center of capitellum and trochlea (CCT). The distance from the bifurcation of the radial nerve into the posterior interosseous nerve (PIN) and superficial radial nerve was 21 mm on AP radiographs and 42 mm on the lateral radiographs (CCT). CONCLUSIONS: The course of the radial nerve in the distal part of the upper arm has great variety. Lateral fixation is relatively safe in a zone between the center of capitellum-trochlea and 48 mm proximal to this point. The danger zone in lateral fixation is in-between 48-122 mm proximal from CCT. In anteroposterior direction; distal fixation is dangerous between 21-101 mm measured from the medial epicondyle. The more distal, the more medial the nerve courses making it more valuable to iatrogenic damage. The IMN we compared with our data all show potential risk in case of (blind) distal locking, especially from lateral to medial direction.

The 'AbdoMAN': an artificial abdominal wall simulator for biomechanical studies on laparotomy closure techniques.

PURPOSE: Incisional hernia remains a frequent complication after abdominal surgery associated with significant morbidity and high costs. Animal and clinical studies have exhibited some limitations. The purpose of this study was to develop an artificial human abdominal wall (AW) simulator in order to enable investigations on closure modalities. We hypothesized that a physical model of the human AW would give new insight into commonly used suture techniques representing a substantial complement or alternative to clinical and animal studies. METHODS: The 'AbdoMAN' was developed to simulate human AW biomechanics. The 'AbdoMAN' capacities include measurement and regulation of intra-abdominal pressure (IAP), generation of IAP peaks as a result of muscle contraction and measurements of AW strain patterns analyzed with 3D image stereo correlation software. Intact synthetic samples were used to test repeatability. A laparotomy closure was then performed on five samples to analyze strain patterns. RESULTS: The 'AbdoMAN' was capable of simulating physiological conditions. AbdoMAN lateral muscles contract at 660 N, leading the IAP to increase up to 74.9 mmHg (range 65.3-88.3). Two strain criteria were used to assess test repeatability. A test with laparotomy closure demonstrated closure testing repeatability. CONCLUSIONS: The 'AbdoMAN' reveals as a promising enabling tool for investigating AW surgery-related biomechanics and could become an alternative to animal and clinical studies. 3D image correlation analysis should bring new insights on laparotomy closure research. The next step will consist in evaluating different closure modalities on synthetic, porcine and human AW.

Development of incisional herniation after midline laparotomy.

BACKGROUND: Incisional herniation is a common complication after abdominal surgery associated with considerable morbidity. The aim of this study was to determine whether incisional hernia is an early complication, in order to understand better the aetiology of incisional hernia formation. METHODS: This study involved the secondary analysis of a subset of patients included in a large RCT comparing small and large tissue bites (5 mm every 5 mm, or 1 cm every 1 cm) in patients scheduled to undergo elective abdominal surgery by midline laparotomy. The distance between the rectus abdominis muscles (RAM distance) was measured by standardized ultrasound imaging 1 month and 1 year after surgery. The relationship between the 1-year incidence of incisional hernia and the RAM distance at 1 month was investigated. RESULTS: Some 219 patients were investigated, 113 in the small-bites and 106 in the large-bites group. At 1 month after surgery the RAM distance was smaller for small bites than for large bites (mean(s.d.) 1·90(1·18) versus 2·39(1·34) cm respectively; P = 0·005). At 1 year, patients with incisional hernia had a longer RAM distance at 1 month than those with no incisional hernia (mean(s.d.) 2·43(1·48) versus 2·03(1·19) cm respectively; relative risk 1·14, 95 per cent c.i. 1·03 to 1·26, P = 0·015). CONCLUSION: A RAM distance greater than 2 cm at 1 month after midline laparotomy is associated with incisional hernia. Closure with small bites results in a smaller distance between the muscles.