Long-term results of retromuscular hernia repair: a single center experience

Introduction Incisional hernia (IH) is one of the most frequent postoperative complications after abdominal surgery. There are multiple surgical techniques described for IH repair. The aim of the study is to evaluate the effect of primary fascial closure on long-term results in retromuscular hernia repair (RHR) for incisional hernias. Methods A total of 132 patients underwent RHR for IH were included in our study. 109 patients were evaluated in 2009 and 55 patients in 2015 for short and long-term results. Results Among 132 patients perfromed RHR, fascia was closed in 107 (81%) and left open in 25 (19%) patients. The mean age of patients was 57.9 ± 11.8 years. Average mesh area was 439.8 ± 194.6 cm2, hernia area was 112 ± 77.5 cm2 and open area after repair was 40.8 ± 43.3 cm2. Mean follow-up of 104 patients regarding postoperative complications evaluated in 2009 was 30.7 ± 14.1 months. Recurrent IH was observed in 6 (4.5%) patients according to data collected in 2009. Long-term results were; mean follow-up period was 91 ± 20.2 months (20-112 months) and recurrent IH was observed in 4 (7.3%) patients. Conclusion Retromuscular repair for incisional hernia regardless of the fascial closure gives high patient satisfaction, less recurrence rates and complications in long-term follow-up.


Introduction
Incisional hernia (IH) is one of the most common postoperative complication after abdominal operations, with an incidence between 11-20% [1,2]. In high-risk patients such as aortic surgery, this incidence can rise over 35% [3][4][5]. IH can result in complications such as gastrointestinal obstruction and enterocutaneous fistula [6,7]. Thus rapid diagnosis and treatment is mandatory for undesirable consequences. There are multiple surgical techniques described in literature. By the invention of prosthetic mesh, there is a trend towards the mesh use for IH. The prosthetic mesh leads improvement in long-term results but the location of the mesh is crucial and it is found to be associated with a high incidence of complications, such as surgical site infection, seroma or gastrointestinal fistula [6,8,9]. Positioning of the mesh can be onlay, sublay and inlay. In Chevrel or onlay repair, after dissecting the subcutaneous tissue and approximating 2 edges of the fascia, mesh is placed on the anterior rectus sheath [10]. This can be perfromed when the two edges of the fascia can be approximated. But for larger defects this approximation can be impossible or yield increased tension on the fascia leading to recurrence. There comes in mind another technique described by Ramirez et al. [11], component seperation technique, composed of bilateral release of the external abdominal oblique muscle and fascia, that aids moving the rectus muscles towards the midline to prevent excessive tension. However, component seperation found to be inappropriate for fascial defects >15 cm regarding high recurrence rates [12][13][14].
There is another alternative technique for component seperation which is described by Rives-Stoppa, sublay repair technique, in which the mesh is placed on the posterior rectus sheath [15]. In a recent meta-analysis, sublay mesh repair is the recommended technique for IH [16]. The retromuscular hernia repair (RHR), the subject of this article, was first described in 1973 [17]. Flament et al. [18] considered this technique as the "gold standard" for midline incisional hernias with a recurrence rate of 6.7 %. Another question for IH repair during RHR was necessity for closure of linea alba.
Therefore the aim of this study is to evaluate the effect of primary fascial closure on long-term results in RHR for incisional hernias. If continuous variables were normal, they were describle as the mean±standard deviation (p>0.05 in Kolmogorov-Smirnov test or Shapira-Wilk (n<30)), and if the continuous variables were not normal, they were described as the median. Comparisons between groups were applied using Student T test for normally distrubited data and Mann Whitney U test were used for the data not normally distrubited. Values of p < 0.05 were considered statistically. investigated as a risk factor for fascial closure and found to have no effect on fascial closure (p=0.421). Hernia area found to be a risk factor for fascial closure (p=0.002) however it has no effect on early postoperative recurrency.

Discussion
Incisional hernias are commonly encountered complications after abdominal operations. They have major complications like intestinal obstruction or enteric fistulas. IH are found to be associated with patient factors such as age, obesity, diabetes and surgical factors such as poor surgical technique and wound infection [19]. Despite advances in surgical techniques IH still have incidence of 11-20% after abdominal operations [1,2]. The use of prosthetic mesh can be named as a "milestone" in IH repair. If we consider repair techniques before the milestone, the recurrence rates were found to be as high as 31-49 % [20]. Therefore nearly half of the patients with IH repiared primarily have recurrent hernia. Burger et al. [21] found mesh repair superior to suture repair and states that suture repair for IH should be abandoned. The foreign body and fibrosis effect of the mesh lead to decrease in recurrent hernias. As this foreign body has unique advantages, it also possess some disadvantages like wound infection reported between 4-18 % [20].
Since a variety of mesh have been introduced, surgical techniques have also been changed and designated according to placement of the mesh. Onlay, inlay and sublay placement of the mesh have been reported. However onlay repair is believed to easily performed and have less operation time, recently there is a trend towards sublay placement regarding lower recurrence rates [9,16]. The intraabdominal pressure may cause fixation of mesh between the posterior fascia and the abdominal muscle and cause reduction in recurrence rates. In a recent review containing 3,945 large incisional hernia repairs with a diameter of 10 cm or a surface of 100 cm2 or more, the use of mesh has better recurrence rates and less hazards and sublay positioning of the mesh is also advised [22].  Long-term results of retromuscular repair is evaluated by a few studies.

What this study adds
 Fascial closure has no effect on recurrence or patient satisfaction;  In long-term follow-up retromuscular repair has a recurrence rate of 7.3 %;  Patient satisfaction rates are high for retromuscular repair.

Competing interests
The authors declare no competing interest.

Acknowledgments
This study did not receive any specific funding or grants.