Transabdominal Pre-peritoneal Mesh Repair versus Lichtenstein ’ s Hernioplasty

Hernia (Latin: rupture) is an abnormal protrusion of an organ or tissue through a defect in its surrounding walls.1 Inguinal hernia most probably has been a disease ever since mankind existed.2 Two thirds of inguinal hernia are indirect. An indirect inguinal hernia is the most common hernia regardless of gender.3 The surgical history of inguinal hernias dates back to ancient Egypt4 in 1883 to today’s mesh based open and laparoscopic repairs, which parallels the evolution in anatomical understanding and development of techniques of general surgery.5,6 Laparoscopic repair was first reported by Ger in 1990.7 There are three techniques of laparoscopic hernia repair, namely transabdominal pre-peritoneal repair (TAPP), totally extraperitoneal repair (TEP), and intraperitoneal onlay mesh repair (IPOM)Laparoscopic


INTRODUCTION
Hernia (Latin: rupture) is an abnormal protrusion of an organ or tissue through a defect in its surrounding walls. 1 Inguinal hernia most probably has been a disease ever since mankind existed. 2 Two thirds of inguinal hernia are indirect. An indirect inguinal hernia is the most common hernia regardless of gender. 3 The surgical history of inguinal hernias dates back to ancient Egypt 4 in 1883 to today's mesh based open and laparoscopic repairs, which parallels the evolution in anatomical understanding and development of techniques of general surgery. 5,6 Laparoscopic repair was first reported by Ger in 1990. 7 There are three techniques of laparoscopic hernia repair, namely transabdominal pre-peritoneal repair (TAPP), totally extraperitoneal repair (TEP), and intraperitoneal onlay mesh repair (IPOM)Laparoscopic Correspondence: Dr Rajan Koju, Department of General Surgery, Dhulikhel Hospital Kathmandu University Hospital, Dhulikhel, Nepal. Email: kojurajan@gmail.com, Phone: +9779840050859.
inguinal hernia repair has benefit of less postoperative pain, reduced recovery time, easier repair of a recurrent hernia, concurrent treatment of bilateral hernias, and improved cosmesis. 8,9 Recurrence rate may be lower in TAPP as compared to open technique due to preperitoneal tension free mesh placement. 10,11 This study was planned to reflect benefit of TAPP in our region.

METHODS
This was a prospective, quasi randomized hospital based study carried out from October 2012 to March 2014 at Dhulikhel Hospital. Written informed consent was taken from the patients willing to participate in the study. The enrolled patients were given numbers which was used to randomize the patients in two groups, namely Lichtenstein's and TAPP. Even number was assigned for Lichtenstein's hernioplasty and odd number for TAPP. All cases of inguinal hernia diagnosed by attending surgeon based on patient's history, clinical examination and relevant investigation were included whereas patients with congenital hernia, obstructed, incarcerated and strangulated inguinal hernia, contraindication to general anesthesia and those who did not give consent to participate in the study were excluded.
Lichtenstein's procedure was done under spinal anesthesia with transverse incision 1.25 cm above inguinal ligament from deep to superficial ring. Subarachnoid block was done with 3 ml 0.5% (15 mg) heavy bupivacaine after preloading with 1000 ml crystalloid solution. Standard technique was followed for hernia repair and mesh was anchored with prolene 3-0 interrupted suture medially upto rectus sheath and first suture was taken at pubic tubercle.TAPP was done under GA (induced with fentanyl 2 mcg/kg, propofol 2 mg/ kg and vecuronium 0.15 mg/kg then maintained with sevoflurane 1-1.5% and vecuronium).
Three ports were used (two 10 mm port, one in umbilical and other 10mm port on the side of hernia at the midclavicular region at the level of umbilicus; one 5mm port used in next side mid clavicular region at the level of umbilicus). Bilateral inguinal region visualized, then pre-peritoneal region was dissected on the hernia side. Sac was reduced then preformed mesh of variable size was used according to size of defect overlapping more than 2 cm on either side from the defect. 12 Size of preformed mesh used were medium (3 by 5 inch), large (4 by 6 inch) and extra large (5 by 7 inch). Mesh was anchored with fructose tacker and peritoneal layer was closed with vilock suture.
After the surgery, patients in both groups were assessed for pain four-hourly using Visual Analogue Score (VAS); then cumulative score of 24 hours was calculated. Patients were followed up for 12 months, return to normal work were inquired with patient and noted.
Altogether there were 102 patients: 51 in Lichtenstein's group and 51 in TAPP group. The sample size of 51 in both groups was calculated using G power 3.1* to detect a medium effect size of 0.5 in pain scores for intervention and control with power of 80%.
Data was collected on a structured performa covering the relevant subjects of the study. A detailed orientation of study and enrollment system was given to all doctors and ward in-charge for admitted patients by the principal investigator. After receiving a case fulfilling the inclusion criteria they were explained about the study in detail. Routine and specific laboratory tests were carried out using standard laboratory protocol.
Patients were admitted as per hospital protocol. The patients underwent hernia repair either Lichtenstein's or laparoscopically and operative findings were noted. The data was entered using SPSS 20 software. Statistical analysis was done using SPSS version 20 software. Results were presented in tables, graphs and diagrams. Chi square test was done. P value less than 0.05 was termed as statistically significant.

RESULTS
The age of the patients enrolled in this study ranged from 21-78 years: 21-70 years in TAPP group and 23-78 years in Lichtenstein's group. There were comparatively less patients in elderly group than in young and middle aged group with inguinal hernia. The mean age difference between the study groups is statistically insignificant ( Table 1).
In both Lichtenstein's and TAPP group, the proportion of direct and indirect hernia are almost similar; around one-fifth of cases demonstrating direct hernia and around four-fifth exhibiting indirect ( Figure 2).
In this study, over half of the patients had right sided hernia and slightly over a third have left sided hernia in both groups. Two percent of patients with bilateral hernia was treated in Lichtenstein's group and seven times more cases of bilateral hernia was operated in TAPP group (Figure 3).
Thus, figure 2 and figure 3 showed that indirect hernia and right sided hernia are common in both groups.   statistically significant low post-operative pain score, less hospital stay and early return to normal work. However, TAPP took significantly lengthier operative duration to repair hernia than Lichtenstein's group. There were two wound infections and one seroma formation in conventional group whereas in TAPP group there were three recurrence (one after 3 months, one after 2 weeks and one after one year of surgery) and one conversion due to adhesion (  13 which also showed that most hernia occurred in patients above 45 years of age, and the mean age in Lichtenstein's group and TAPP group was 57.1±9.6 and 55.9±9.7, respectively. Our study showed that indirect inguinal hernia and right sided hernia are the most common hernia in our patients. These findings are consistent with the various other studies from Nepal, Korea and India. [14][15][16] Our study also significantly showed the operative duration for TAPP hernia repair was longer (almost twice) than that of conventional repair and the result was in accordance to various other studies. [17][18][19][20] However, a Roman experience on open and TAPP repair 21 showed no significant difference between the two methods.
Pain was analyzed by using Visual Analogue Score. In our study, cumulative score for 24 hours was analyzed.
Significant difference in pain score with low pain score in TAPP group was seen in our study (2.00±0.63 vs 3.90±0.73, P value <0.001) which is consistent with an Egyptian study 17 showing 20% vs 5% severe pain, with P value 0.04 which is statistically significant. Another study done in the United States from 1991 -1993 22 also showed less post-operative pain in TAPP group with P value <0.001. A meta-analysis from 41 eligible controlled trials comprising of 7161 participants 20 also showed less persisting pain (P value <0.0001), and less persisting numbness (P value <0.0001) in the laparoscopic groups.
In our study, patients were charged same amount for both Lichtenstein's and TAPP but if we take into consideration of the charge of materials used in TAPP (like preformed mesh, V Loc suture and tacker), it is around 6 times more expensive than Lichtenstein's repair.

CONCLUSIONS
This study has shown that TAPP is more effective as it reduces hospital stay, early return to normal work, reduced complications like seroma and SSI in patients undergoing TAPP repair in short follow-up. However, operative duration is prolonged in TAPP group.