Bridging with reduced overlap: fixation and peritoneal grip can prevent slippage of DIS class A meshes

Follow-up of complex hernia repair with intraoperative fascial traction

BACKGROUND

Different techniques for complex abdominal wall repair are utilised including intraoperative fascial traction (IFT) as the latest development. Despite increasing case numbers for IFT across Europe, long-term data especially on recurrence rates are not available yet.

METHODS

Follow-up data from five different German hernia centers between 12/2019 and 9/2023 were assessed. All patients received Rives-Stoppa repair (RSR) and IFT intraoperatively with an additional transverse abdominis muscle release (TAR) in some cases. 30-day postoperative outcome data were retrospectively collected Standardized follow-up was performed after a minimum of 3 months including clinical examination and standardized ultrasound.

RESULTS

A total of 100 patients were included in the study. The mean age was 60.7 ± 14.3 years; the mean BMI was 31.3 ± 7.3 kg/m² with a mean follow-up of 19.7 ± 10.7 months. The mean defect width was 15.8 ± 5.2 cm. In 94% of the patients complete fascial closure was achieved; in 28% an additional TAR procedure was necessary During follow-up, 2 recurrences were found. The surgical site occurrence (SSO) rate was 33% including mainly seromas (54.5%) and surgical site infections (SSI) of 9% Comparing the groups of IFT + TAR and IFT + RSR a significantly higher incidence of SSO was found in the TAR group (50% vs. 26.4%, p<0.01).

CONCLUSIONS

This study, which is the first long-term follow-up, shows very promising results of the innovative IFT technique in terms of closure rate, wound morbidity, and recurrence rate.

Hernia Correction After Liver Transplantation Using Nonvascularized Fascia

Background

Liver transplantation is an increasingly frequent surgical procedure, with elevated rates of postoperative incisional hernias ranging from 5% to 46%. There are numerous known risk factors for incisional hernia, including the type of incision, patient sex, and presence of comorbidities such as diabetes, ascites, older age, and the use of steroids. Most studies on the treatment of incisional hernias in patients who have undergone liver transplantation have shown consistently high rates of complications. Consequently, we propose the use of nonvascular fascia for the symptomatic treatment of incisional hernias in patients with concomitant liver transplantation.

Methods

We performed our new technique on 8 patients, who had previously undergone liver transplantation, between January 2019 and January 2023. The patients were examined using imaging techniques during the follow-up period.

Results

Of the 8 patients, 7 were liver transplant recipients and 1 was a combined liver-kidney transplant patient. The median donor age was 57 y (5-66 y), whereas the mean recipient age was 58 y (31-66 y). The median patient height and weight were 163 cm (117-185 cm) and 76 kg (17-104 kg), respectively. Immunosuppression did not change in fascia recipients. The median time between transplantation and hernia repair surgery was 41 mo (5-116 mo). The sizes of the aponeurotic defects varied from 6 × 6 to 25 × 20 cm. Two patients experienced complications: one experienced bulging that required reintervention and the other experienced surgical site seroma. There was no mortality related to the use of the technique, and none were reported during follow-up.

Conclusions

With its promising results, nonvascularized fascial transplantation can be a successful treatment for incisional hernias in patients who had previously received a liver transplant.

STRONGHOLD first-year results of biomechanically calculated abdominal wall repair: a propensity score matching

PURPOSE

Every year around 70,000 people in Germany suffer from an abdominal incisional hernia that requires surgical treatment. Five years after reconstruction about 25% reoccur. Incisional hernias are usually closed with mesh using various reconstruction techniques, summarized here as standard reconstruction (SR). To improve hernia repair, we established a concept for biomechanically calculated reconstructions (BCR). In the BCR, two formulas enable customized patient care through standardized biomechanical measures. This study aims to compare the clinical outcomes of SR and BCR of incisional hernias after 1 year of follow-up based on the Herniamed registry.

METHODS

SR includes open retromuscular mesh augmented incisional hernia repair according to clinical guidelines. BCR determines the required strength (Critical Resistance to Impacts related to Pressure = CRIP) preoperatively depending on the hernia size. It supports the surgeon in reliably determining the Gained Resistance, based on the mesh-defect-area-ratio, further mesh and suture factors, and the tissue stability. To compare SR and BCR repair outcomes in incisional hernias at 1 year, propensity score matching was performed on 15 variables. Included were 301 patients with BCR surgery and 23,220 with standard repair.

RESULTS

BCR surgeries show a significant reduction in recurrences (1.7% vs. 5.2%, p = 0.0041), pain requiring treatment (4.1% vs. 12.0%, p = 0.001), and pain at rest (6.9% vs. 12.7%, p = 0.033) when comparing matched pairs. Complication rates, complication-related reoperations, and stress-related pain showed no systematic difference.

CONCLUSION

Biomechanically calculated repairs improve patient care. BCR shows a significant reduction in recurrence rates, pain at rest, and pain requiring treatment at 1-year follow-up compared to SR.

Modified Chevrel technique for abdominal closure in critically ill patients with abdominal hypertension and limited options for closure

Abdominal compartment syndrome is a potentially life-threatening condition seen in critically ill patients, and most often caused by acute pancreatitis, postoperative abdominal vascular thrombosis or mesenteric ischemia. A decompressive laparotomy is sometimes required, often resulting in hernias, and subsequent definitive wall closure is challenging.

AIM

This study aims to describe short term results after a modified Chevrel technique for midline laparotomies in patients witch abdominal hypertension.

MATERIALS AND METHODS

We performed a modified Chevrel as an abdominal closure technique in 9 patients between January 2016 and January 2022. All patients presented varying degrees of abdominal hypertension.

RESULTS

Nine patients were treated with new technique (6 male and 3 female), all of whom had conditions that precluded unfolding the contralateral side as a means for closure. The reasons for this were diverse, including presence of ileostomies, intraabdominal drainages, Kher tubes or an inverted T scar from previous transplant. The use of mesh was initially dismissed in 8 of the patients (88,9%) because they required subsequent abdominal surgeries or active infection. None of the patients developed a hernia, although two died 6 months after the procedure. Only one patient developed bulging. A decrease in intrabdominal pressure was achieved in all patients.

CONCLUSION

The modified Chevrel technique can be used as a closure option for midline laparotomies in cases where the entire abdominal wall cannot be used.

Is mesh fixation necessary in laparoendoscopic techniques for M3 inguinal defects? An experimental study

BACKGROUND

Although international guidelines recommend not fixing the mesh in almost all cases of laparoendoscopic repairs, in case of large direct hernias (M3) mesh fixation is recommended to reduce recurrence risk. Despite lack of high-quality evidence, the recommendation was upgraded to strong by expert panel. The authors conducted a research experiment to verify the hypothesis that it is possible to preserve the mesh in the operating field in large direct hernias (M3) without the need to use fixing materials.

METHOD

The authors conducted an experiment with scientists from Universities of Technology in a model that reflects the conditions in the groin area. By simulating conditions of the highest possible intra-abdominal pressure, they examined the mesh behavior within the groin and its ability to dislocate under the forces generated by this pressure. The experiment involved six spatial implants and one flat macroporous mesh.

RESULTS

Heavyweight spatial meshes and lightweight spatial-individualized meshes showed no tendency to dislocate or move directly to the orifice, which was considered a rapid hernia recurrence. Lightweight meshes, both spatial and flat, underwent significant migration and shifting toward the hernial orifices.

CONCLUSION

Based on the results, we believe that mesh fixation is not the only alternative to preventing recurrence in complex defects. Similar effects can be achieved using a larger, more rigid, and anatomically fitted implant. The type of implant (rather than its fixation) seems to be a key factor from the point of view of mechanics and biophysics. Clinical trials confirming the results in vivo will allow to supplement or amend the guidelines for the treatment of large inguinal hernias.

The Grip Concept of Incisional Hernia Repair-Dynamic Bench Test, CT Abdomen With Valsalva and 1-Year Clinical Results

Incisional hernia is a frequent consequence of major surgery. Most repairs augment the abdominal wall with artificial meshes fixed to the tissues with sutures, tacks, or glue. Pain and recurrences plague at least 10-20% of the patients after repair of the abdominal defect. How should a repair of incisional hernias be constructed to achieve durability? Incisional hernia repair can be regarded as a compound technique. The biomechanical properties of a compound made of tissue, textile, and linking materials vary to a large extent. Tissues differ in age, exercise levels, and comorbidities. Textiles are currently optimized for tensile strength, but frequently fail to provide tackiness, dynamic stiction, and strain resistance to pulse impacts. Linking strength with and without fixation devices depends on the retention forces between surfaces to sustain stiction under dynamic load. Impacts such a coughing or sharp bending can easily overburden clinically applied composite structures and can lead to a breakdown of incisional hernia repair. Our group developed a bench test with tissues, fixation, and textiles using dynamic intermittent strain (DIS), which resembles coughing. Tissue elasticity, the size of the hernia under pressure, and the area of instability of the abdominal wall of the individual patient was assessed with low-dose computed tomography of the abdomen preoperatively. A surgical concept was developed based on biomechanical considerations. Observations in a clinical registry based on consecutive patients from four hospitals demonstrate low failure rates and low pain levels after 1 year. Here, results from the bench test, the application of CT abdomen with Valsalva's maneuver, considerations of the surgical concept, and the clinical application of our approach are outlined.

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.

Increasing hernia size requires higher GRIP values for a biomechanically stable ventral hernia repair

Background

Increasing hernia sizes lead to higher recurrence rates after ventral hernia repair. A better grip might reduce the failure rates.

Material and methods

A biomechanical model delivering dynamic intermittent strain (DIS) was used to assess grip values at various hernia orifices. The model consists of a water-filled aluminium cylinder covered with tissues derived from pig bellies which are punched with a central defect varying in diameter. DIS was applied mimicking coughs lasting for up to 2 s with peak pressures between 180 and 220 mmHg and a plateau phase of 0.1 s. Ventral hernia repair was simulated with hernia meshes in the sublay position secured by tacks, glue or sutures as needed to achieve certain grip values. Grip was calculated taking into account the mesh: defect area ratio and the fixation strength. Data were assessed using non-parametric statistics.

Results

Using a mesh classified as highly stable upon DIS testing (DIS class A) a reduced overlap without fixation led to early slippage (p < 0.001). With the application of 16 fixation points, transmural sutures were better than tacks with Securestrap^® being better than Absorbatack^® (p < 0.001). Plotting the likelihood of a durable repair as a function of the calculated grip higher grip values were needed with increasing hernia diameter to achieve biomechanical stability. This is important for clinical work since the calculated grip values both from a registry and from published data tend to drop as hernia sizes increase indicating biomechanical instability.

Conclusion

The experimental work reported here demonstrates for the first time that higher grip values should be reached when repairing larger ventral hernias.

Assessing the GRIP of Ventral Hernia Repair: How to Securely Fasten DIS Classified Meshes

Recurrences are frequently observed after ventral hernia repair. Based on clinical data, the mesh–defect area ratio (MDAR) can lead to lower recurrence rates. Using dynamic intermittent strain (DIS) in a pig tissue model, MDAR can be modified to give a measure called grip to better assess the mechanical stability of ventral hernia repair. The focus of this experimental study is to assess the different aspects of mesh overlap (OL) and fixation only in bridging repair of ventral hernias. DIS mimics coughing actions in an ex vivo model with the repetition of submaximal impacts delivered via a hydraulically driven plastic containment. Tissue derived from pig bellies simulates a ventral hernia with varying defect sizes. MDAR is calculated from the hernia orifice and the mesh OL. Commercially available meshes were strengthened with glue, tacks, and sutures to bridge the defects. The reconstructions are strained with up to 425 dynamic impacts. The grip of each repair is assessed using MDAR modified by the strength of the fixation. The DIS classification is based on bridging of a 5 cm ventral hernia orifice with an OL of 5 cm in a sublay position. The classification discriminates meshes properties upon DIS strain. MDAR is calculated to be 9 under these conditions. Decreasing the OL or increasing the hernia orifice reduces MDAR to numbers below 9. MDAR is modified to reach GRIP. Closure of the peritoneum adds about 4 to the grip given by MDAR. The multiplying factor of a transmural suture or one tack of Securestrap^® or Protack^® is 0.5 times the number of tacks applied. The multiplier given by a bonding spot of Glubran^® is similar to that of an Absorbatack^® being 0.33. Plotting the likelihood of a bridging repair to survive more than 400 DIS impacts versus the grip estimated from the factors given above, the grip to be passed for a durable repair is 10 for Parietex Progrip^®, and Dynamesh Cicat^® and 25 for Dynamesh IPOM^®. Clinical data previously published can be reculculated to assess MDAR and permit an estimation of the grip of the reconstruction. In these recalculations, a correlation between MDAR and long-term recurrence rates is found. A dimensionless number called grip can be calculated. The grip can be modified by fixation in a reproducible way. A higher grip can improve the durability of ventral hernia repair. We believe that a higher grip leads to lower recurrence rates in the clinical setting.