Different techniques for mesh application give the same abdominal muscle strength

Evaluation of Extracellular Matrix Remodeling in Full-thickness Skin Grafts in Mice

Abdominal hernia is a protruding weakness in the abdominal wall. It affects abdominal strength and life quality and can lead to complications due to intestinal entrapment. Autologous full-thickness skin graft (FTSG) has recently become an alternative material for reinforcement in the surgical repair of large abdominal hernias instead of synthetic mesh. FTSG eventually integrates with the abdominal wall, but the long-term fate of the graft itself is not fully understood. This has implications as to how these grafts should be optimally used and handled intraoperatively. This study investigates the remodeling of FTSG in either the onlay or the intraperitoneal position 8 weeks after FTSG transplantation in an experimental mouse model. There was a significant presence of fibroblasts, indicated by vimentin and S100A4 staining, but there were significant variations among animals as to how much of the graft had been remodeled into dense connective tissue. This correlated significantly with the proportion of vimentin-positive cells in the dense connective tissue. We also found that collagen hybridizing peptide staining intensity, a marker of active remodeling, was significantly associated with the proportion of S100A4-positive cells in the dense connective tissue of the FTSG.

What is the best method to assess the abdominal wall? Restoring strength does not mean functional recovery

Background:

Restoring the contractile function to the abdominal wall is a major goal in hernia repair. However, the core understanding is required when choosing the method for outcome assessment.

Aim:

To assess the role of the anterolateral abdominal muscles on abdominal wall function in patients undergoing hernia repair by analysis of correlation between the surface electromyography activation signal of these muscles and torque produced during validated strength tests.

Methods:

Activation of the rectus abdominis, external oblique, and internal oblique/transverse abdominis muscles was evaluated by surface electromyography during two validated tests: Step: 1-A, isometric contraction in dorsal decubitus; 1-B, isometric contraction in lateral decubitus; 2-A, isokinetic Biodex testing; and 2-B, isometric Biodex testing.

Results:

Twenty healthy volunteers were evaluated. The linear correlation coefficient between root mean square/peak data obtained from surface electromyography signal analysis for each muscle and the peak torque variable was always <0.2 and statistically non-significant (p<0.05). The agonist/antagonist ratio showed a positive, significant, weak-to-moderate correlation in the external oblique (Peak, p=0.027; root mean square, 0.564). Surface electromyography results correlated positively among different abdominal contraction protocols, as well as with a daily physical activity questionnaire.

Conclusions:

There was no correlation between surface electromyography examination of the anterolateral abdominal wall muscles and torque measured by a validated instrument, except in a variable that does not directly represent torque generation.

One-year outcome after repair of giant incisional hernia using synthetic mesh or full-thickness skin graft: a randomised controlled trial

PURPOSE

Repair of giant incisional hernia often requires complex surgery and the results of conventional methods using synthetic mesh as reinforcement are unsatisfactory, with high recurrence and complication rates. Our hypothesis was that full-thickness skin graft (FTSG) provides an alternative reinforcement material for giant incisional hernia repair and that outcome is improved. The aim of this study was to compare FTSG with conventional materials currently used as reinforcement in the repair of giant incisional hernia.

METHODS

A prospective randomised controlled trial was conducted, comparing FTSG with synthetic mesh as reinforcement in the repair of giant (> 10 cm minimum width) incisional hernia. One-year follow-up included a blinded clinical examination by a surgeon and objective measurements of abdominal muscle strength using the Biodex-4 system.

RESULTS

52 patients were enrolled in the study: 24 received FTSG and 28 synthetic mesh. Four recurrences (7.7%) were found at 1-year follow-up, two in each group. There were no significant differences regarding pain, patient satisfaction or aesthetic outcome between the groups. Strength in the abdominal wall was not generally improved in the study population and there was no significant difference between the groups.

CONCLUSION

The outcome of repair of giant incisional hernia using FTSG as reinforcement is comparable with repair using synthetic mesh. This suggests that FTSG may have a future place in giant incisional hernia repair.

Risk Factors for Surgical Complications in Ventral Hernia Repair

BACKGROUND

The aim of this study was to identify risk factors for an adverse event, i.e. early surgical complication, need for ICU care and readmission, following ventral hernia repair. Our hypothesis was that there is an association between an increased complication rate following ventral hernia repair and specific factors, including hernia size, BMI > 35, concomitant bowel surgery, ASA-class, age, gender and method of hernia repair.

METHODS

Data from a hernia database with prospectively entered data on 408 patients operated for ventral hernia between 2007 and 2014 at two Swedish university hospitals were analysed. A 3-month follow-up of complications, need for intensive care and readmission, was performed by reviewing the medical records.

RESULTS

Eighty-one of 408 patients (20%) had a registered complication. Fifty-eight (14%) of these were classed as Clavien I-IIIa, and in 19 cases a Clavien IIIb-IV complication was reported. Large hernia size was associated with increased risk for early complication. A Kendall Tau test analysis revealed a proportional relationship between hernia size and modified Clavien outcome class (p < 0.001). Morbid obesity, ASA-class, method, hernia recurrence, age and concomitant bowel surgery were not statistically significant predictors of adverse events.

CONCLUSIONS

Assessment of hernia aperture size is of great importance in the preoperative evaluation of ventral hernia patients to consider risk for post-operative complications. These results suggest a careful attitude when applying watchful waiting concepts and when postponing hernia surgery to achieve weight loss. A delaying attitude may result in increased risk of complications caused by increasing hernia size.

Full-thickness skin graft vs. synthetic mesh in the repair of giant incisional hernia: a randomized controlled multicenter study

PURPOSE

Repair of large incisional hernias includes the implantation of a synthetic mesh, but this may lead to pain, stiffness, infection and enterocutaneous fistulae. Autologous full-thickness skin graft as on-lay reinforcement has been tested in eight high-risk patients in a proof-of-concept study, with satisfactory results. In this multicenter randomized study, the use of skin graft was compared to synthetic mesh in giant ventral hernia repair.

METHODS

Non-smoking patients with a ventral hernia > 10 cm wide were randomized to repair using an on-lay autologous full-thickness skin graft or a synthetic mesh. The primary endpoint was surgical site complications during the first 3 months. A secondary endpoint was patient comfort. Fifty-three patients were included. Clinical evaluation was performed at a 3-month follow-up appointment.

RESULTS

There were fewer patients in the skin graft group reporting discomfort: 3 (13%) vs. 12 (43%) (p = 0.016). Skin graft patients had less pain and a better general improvement. No difference was seen regarding seroma; 13 (54%) vs. 13 (46%), or subcutaneous wound infection; 5 (20%) vs. 7 (25%). One recurrence appeared in each group. Three patients in the skin graft group and two in the synthetic mesh group were admitted to the intensive care unit.

CONCLUSION

No difference was seen for the primary endpoint short-term surgical complication. Full-thickness skin graft appears to be a reliable material for ventral hernia repair producing no more complications than when using synthetic mesh. Patients repaired with a skin graft have less subjective abdominal wall symptoms.

An ex vivo model using human peritoneum to explore mesh-tissue integration

Biological compatibility, in terms of implantation of foreign mesh material in hernia surgery, still needs experimental investigation. The present study develops an experimental model using human peritoneum to study the integration between tissue and different mesh material. The ex vivo model using peritoneal tissue was studied with different mesh material, and integration was monitored over time using microscopy. The peritoneal model could be kept viable in culture for several weeks. Cell migration was seen after 7-10 days in culture and could be further monitored over several weeks. The use of a human artificial model environment enabling the investigation of tissue/mesh integration has, to our knowledge, not been described previously. This proof-of-concept model was developed for the investigation of peritoneal biology and the integration between tissue and different mesh material. It has the potential to be useful in studies on other important biological mechanisms involving the peritoneum.

Summary: This study developed a human experimental model for long-term studies using peritoneal tissue to evaluate integration with different materials, such as synthetic meshes.

Abdominal Wall Reconstruction for Incisional Hernia Optimizes Truncal Function and Quality of Life: A Prospective Controlled Study

OBJECTIVE

The aim of the study was to examine abdominal wall function in patients undergoing abdominal wall reconstruction (AWR) for incisional hernia.

BACKGROUND

The literature on abdominal wall function in patients with incisional hernia is sparse. It has been suggested that AWR leads to improvement in function, but it is unknown whether this is specific to the abdominal wall or due to an improvement in overall physical fitness.

METHODS

We performed a prospective case-control study of 18 consecutive patients with large incisional hernia undergoing AWR with linea alba restoration. Truncal flexion and extension strength, hand grip strength, leg extension power, and quality of life (SF-36 and Carolinas Comfort Scale) were assessed preoperatively and 1 year postoperatively. Patients were compared with a control group of patients with an intact abdominal wall undergoing colorectal resection (n = 18). The study was registered at ClinicalTrials.gov (NCT02011048).

RESULTS

Compared with preoperative measurements, 1-year follow-up after AWR demonstrated an increase of both truncal flexion strength (from mean 505.6 N to 572.3 N, P < 0.001) and truncal extension strength (from 556.7 to 606.0 N, P = 0.005). There was no significant change of either hand grip strength or leg extension power. After AWR, the physical component of overall quality of life improved, whereas the mental component score remained unchanged. In the control group, surgery resulted in a decrease in both truncal flexion and truncal extension.

CONCLUSIONS

AWR for incisional hernia specifically improved long-term abdominal wall muscular function and quality of life.

Open retromuscular mesh repair versus onlay technique of incisional hernia: A randomized controlled trial

INTRODUCTION

The aim of this prospective randomized clinical study was to compare and analyze the results of two methods of treatment of incisional hernia: open retromuscular mesh repair and onlay technique.

METHODS

180 patients who underwent open elective surgery for middle primary incisional hernia were randomized into two groups. The retomuscular mesh repair was used in the first group and the onlay technique - in the second group. Several preoperative and intraoperative factors, also wound complications (wound infection, hematoma, seroma) and hernia recurrence rate were determined and compared between the groups.

RESULTS

The operative time was significantly longer in the retromuscular group compared with the onlay group (P < 0.001). In the retromuscular group 17 (22.1%) wound complications were observed, in the onlay group-39 (50.0%) wound complications. The difference was statistically significance (P < 0.001). Seroma was the most frequent postoperative wound complication, ranging from 16.9% to 41.0% among the groups, respectively (P = 0.0013). No significantly difference has been found between groups by wound infection and hematoma. 2 (2.6%) case of hernia recurrence was marked in retromuscular group and 4 (5.1%) case of hernia recurrence - in onlay group. But there was no statistically significantly difference between the two groups.

CONCLUSION

Our research shows no significant difference in frequency of hernia recurrence between retromuscular mesh repair and onlay technique for treatment of incisional hernia. The usage of the retromuscular mesh repair is associated with significantly less wound complications than onlay technique. That can be considered as an advantage of retromuscular method, which makes it more preferential than onlay method.

Giant ventral hernia-relationship between abdominal wall muscle strength and hernia area

Background

Symptoms arising from giant ventral hernia have been considered to be related to weakening of the abdominal muscles. The aim of this study was to investigate the relationship between the area of the abdominal wall defect and abdominal wall muscle strength measured by the validated BioDex system together with a back/abdominal unit.

Methods

Fifty-two patients with giant ventral hernia (>10 cm wide) underwent CT scan, clinical measurement of hernia size and BioDex measurement of muscle strength prior to surgery. The areas of the hernia derived from CT scan and from clinical measurement were compared with BioDex forces in the modalities extension, flexion and isometric contraction. The Spearman rank test was used to calculate correlations between area, BMI, gender, age, and muscle strength.

Result

The hernia area calculated from clinical measurements correlated to abdominal muscle strength measured with the Biodex for all modalities (p-values 0.015–0.036), whereas no correlation was seen with the area calculated by CT scan. No relationship was seen between BMI, gender, age and the area of the hernia.

Discussion

The inverse correlation between BioDex abdominal muscle strength and clinically assessed hernia area, seen in all modalities, was so robust that it seems safe to conclude that the area of the hernia is an important determinant of the degree of loss of abdominal muscle strength. Results using hernia area calculated from the CT scan showed no such correlation and this would seem to concur with the results from a previous study by our group on patients with abdominal rectus diastasis. In that study, defect size assessed clinically, but not that measured by CT scan, was in agreement with the size of the diastasis measured intra-operatively.

The point at which the area of a hernia begins to correlate with loss of abdominal wall muscle strength remains unknown since this study only included giant ventral hernias.

Design and initial implementation of HerQLes: a hernia-related quality-of-life survey to assess abdominal wall function

BACKGROUND

Success of a surgical intervention is often measured by hard clinical outcomes. In ventral hernia repair (VHR) these include wound morbidity and hernia recurrence. These outcomes fail to account for a surgical intervention's effect on a patient's quality of life (QofL). Our objective was to design a hernia-specific QofL instrument with a focus on abdominal wall function, evaluate its measurement properties, and assess the impact of VHR on QofL using this new instrument.

STUDY DESIGN

A 16-question QofL survey tool, HerQLes, was constructed. Patients presenting for elective VHR completed the survey. Rasch modeling was used to evaluate the items; fit statistics, person-item mapping, separation index, and reliability were examined. Associations between baseline characteristics and QofL were assessed.

RESULTS

Eighty-eight patients completed the survey before assessment for VHR. Mean age was 57.2 years (±12.4 years), mean American Society of Anesthesiologists score was 2.8 (±0.5), and mean body mass index was 34.9 kg/m(2) (±9.3 kg/m(2)). Based on Rasch modeling, 12 of 16 items met model fit criteria. The 4 poorly fitting items were eliminated from further analysis. The 12 items retained have good internal consistency reliability (0.86). On a 0- to 100-point scale, mean QofL score was 47.2 (±15.6). Patients with higher grade hernias had lower HerQLes scores (p = 0.06). Patients showed significant improvement in abdominal wall function and QofL 6 months after VHR (p < 0.01).

CONCLUSIONS

Quality-of-life is an important component of surgical management of ventral hernias. The 12-question QofL survey, HerQLes, is reliable and valid. At baseline, patients with more complex hernias tended to have a decreased abdominal wall function and QofL. Six months after surgical repair, HerQLes scores change in the predicted direction. We believe HerQLes is potentially a valuable tool to assess patient-centered abdominal wall functional improvements after VHR.