LAPAROSCOPIC INGUINAL HERNIA REPAIR: THE LONG-TERM ASSESSMENT OF CHRONIC PAIN AND QUALITY OF LIFE

ABSTRACT BACKGROUND: Laparoscopic approaches to inguinal hernia repair include transabdominal extraperitoneal and transabdominal preperitoneal, both of which are widely performed and employ mesh. Indicators of success for these surgical procedures include incidence of complications, time to return to daily activities, incidence of postoperative chronic pain, and the long-term postoperative patient satisfaction. OBJECTIVE: This study aimed to evaluate and compare long-term postoperative incidence of chronic pain and overall quality of life among patients undergoing transabdominal extraperitoneal or transabdominal preperitoneal inguinal hernia repair. METHODS: This was a retrospective cross-sectional study. Medical records were analyzed, and the SF-36 questionnaire and Visual Analog Scale were applied to assess quality of life and chronic pain in patients undergoing laparoscopic inguinal hernia repair between January 2017 and February 2021. RESULTS: A total of 167 patients status post laparoscopic inguinal hernia repair, who were 3 months postoperatively or longer, were included in the study. Among the early complications seen, seroma was most common in the transabdominal preperitoneal group (p=0.04). Subsequently, 40 of the initial 167 patients answered to the survey instrument (SF-36 and Visual Analog Scale). Mean patient-reported pain (Visual Analog Scale score) was statistically similar between groups, with 1.29 for transabdominal preperitoneal and 1.68 for transabdominal extraperitoneal (p=0.92). In the domains evaluated by the SF-36, there was no significant difference between the samples. CONCLUSION: Both transabdominal extraperitoneal and transabdominal preperitoneal techniques for hernia repair have similar results in the late postoperative period regarding quality of life and prevalence of chronic pain. They are also comparable in terms of major early postoperative complications, except for seroma, with a higher incidence in patients undergoing transabdominal preperitoneal.

forceps. The preperitoneal space was dissected and the local anatomy was identified. The hernia was localized, its contents and sac were reduced, and a 15´15 cm polypropylene mesh was positioned covering the entire region of the myopectineal space and secured with 4-5 endostapler staples. The preperitoneal space was deflated and the skin was closed with nonabsorbable suture.
The clinical variables analyzed in patient's medical records were age, sex, time from surgery, comorbidities, surgical technique for repair (TEP or TAPP), and recent postoperative complications. The postoperative complications evaluated for this study were hematoma, seroma, surgical site infection, and ischemic orchitis.
The Charlson Comorbidity Index (CCI) was used to assess comorbidities, analyzing 19 clinical conditions, including cardiovascular disease, diabetes mellitus, liver disease, and lung disease. This index aims to predict risk of death related to having comorbidities 13,18 .
Patients excluded from this study included patients under 18 years of age, time from surgery less than 3 months, open approach to hernia repair, repair of recurrent hernias or femoral hernias, and those for whom the repair was indicated in urgent or emergency situations (incarcerated or strangulated inguinal hernias).
The SF-36 questionnaire was used in eight domains: functional capacity, physical aspects, pain, general health status, vitality, social aspects, emotional aspects, and mental health 6,7,12 .
The tool utilized to assess postoperative pain in this study was the VAS. The VAS is a visual, simple, and effective validated tool for pain assessment. It consists of a line with ends numbered from 0 to 10, in which the patient assigns a score to their pain, with 0 being no pain and 10 being the worst pain imaginable 16 .
Finally, patients who filled out the questionnaire incorrectly, those who could not be contacted (via phone or email), or those who declined to participate in the study were excluded from the analysis.

Statistical Analysis
Data collected from the two groups (TAP and TEP) were analyzed using mean and standard deviation for continuous variables and absolute and relative frequencies for categorical and ordinal variables. Shapiro-Wilk test and histogram generation were used for sample distribution analysis. Student's t-test for normal continuous dependent variables, Mann-Whitney test for non-normal continuous dependent variables, and chi-square test for categorical dependent variables were also used. A significance level of 5% was used for this study.

RESULTS
A total of 167 patients who underwent laparoscopic inguinal hernia repair were included in the study. Data on patient demographics and early postoperative complications were analyzed. Subsequently, the patients were contacted and only 40 responded to the survey tool composed of SF-36 and VAS (18 patients in the TAPP group and 22 in the TEP group).

Epidemiological Profile
Among the 167 medical records that were analyzed, only 12 (7.19%) patients were female. The mean age of the study participants was 55.19 years, with the oldest patient being 86 years old and the youngest being 22 years old. There was no statistically significant difference between the TAPP and TEP groups in terms of age (p=0.33). In all 46 (27.54%) patients had medical history notable for hypertension, 24 (14.37%) for

INTRODUCTION
H ernia can be defined as an abnormal protrusion of an organ or tissue resulting from a deformity in the wall of the cavity containing it. Inguinal hernias can be repaired through open procedures or laparoscopic procedures. Currently, the laparoscopic approach can be transabdominal extraperitoneal (TEP) or transabdominal preperitoneal (TAPP), both of which use mesh and are widely performed 3,10,11 .
Both are minimally invasive and can be performed easily and with smaller incisions. In addition, they allow improvements in quality of life, combined with a faster recovery period, reduction of postoperative pain, and morbidity 1,17 .
Pain is common postoperatively; however, it is expected to occur in the first few days and to respond well to analgesics with progressive improvement, ceasing completely in a few weeks. Nevertheless, persistence of pain for a period longer than 3 months can be characterized as chronic pain. Postoperative pain is an important index, as it has direct implications on morbidity, healthcare-associated costs, and quality of life. It is, therefore, relevant to be evaluated in the surgical practice 6,9 . Given the improvement of minimally invasive surgery techniques with lower complication rates, surgical outcomes are increasingly dictated by patient-reported postoperative satisfaction and their perception of how they feel when performing daily activities. This type of postoperative quality-of-life assessment using a variety of tools has become the main way of measuring parameters of therapeutic success 4 .
The aim of this study was to compare laparoscopic techniques of inguinal hernia repair, considering the two most used methods (i.e., TEP and TAPP), with respect to quality of life and prevalence of chronic pain in the late postoperative period. Secondary objectives include evaluation of epidemiological data on patients with inguinal hernias and occurrence of early postoperative complications.

METHODS
This is a retrospective cross-sectional study, approved by the Institutional Review Board of the Pequeno Príncipe Faculty (CEP/FPP, number 4.259.587). This study consisted in the evaluation of medical records of 167 patients who underwent unilateral or bilateral laparoscopic inguinal hernia repair between January 2017 and February 2021. Subsequently, patients included in the study were contacted to respond to the survey tool for quality of life (SF-36) and for chronic pain (Visual Analog Scale -VAS). Consent was obtained.
All study participants were at least 3 months postoperatively at the time of data collection. Study participants were operated on by the same team of general surgeons and gastrointestinal surgeons. All surgical procedures were performed under general anesthesia. In patients undergoing TAPP, pneumoperitoneum was performed, followed by placement of three trocars for optic access and two for laparoscopic forceps. The preperitoneal space was accessed by opening the parietal peritoneum of the affected inguinal region, followed by dissection and identification of the local anatomy. The hernia was localized, its contents and sac were reduced. Afterward, a 15´15 cm polypropylene mesh was positioned covering the entire region of the myopectineal space and secured with 4-5 endostapler staples. The parietal peritoneum was closed with continuous suture with long-lasting absorbable suture and the abdomen was deflated. Skin was closed with nonabsorbable suture.
For patients undergoing TEP, the suprapubic preperitoneal space was punctured with a Veress needle and then three trocars were positioned, one for optics and two for laparoscopic DISCUSSION Regarding postoperative complications, the incidence of seroma was significantly higher in the TAPP group (Table 1). These results are similar to those found by Köckerling et al. 14 , who carried out with 2246 patients (p<0.001).
There was no significant difference between TEP and TAPP techniques with regard to the incidence of postoperative hematoma, postoperative pain, and ischemic orchitis ( Table   1). This is in agreement with the study by Aiolfi et al. 2 . In their systematic review and meta-analysis, 9 studies with a total of 54,138 patients were evaluated, and results suggested that the open, TAPP, and TEP techniques are comparable in terms of postoperative hematoma, seroma, recurrence, infectious complications, urinary retention, and length of hospital stay.
The SF-36 questionnaire consists of a 36-item generic health survey designed to measure functional health and well-being on a scale (percentage) from 0 (suboptimal) to 100 (optimal) 19 . Results for the TAPP and TEP groups were similar in all domains of the scale, showing no significant difference between the techniques (Figure 1).
The prospective randomized controlled study carried out by Bansal et al. 5 with 314 patients showed that both TAPP and TEP techniques improved patients' quality of life, from comparing preoperative to 3 months postoperatively. The TEP group showed significant improvement in all domains (i.e., mental health, vitality, emotional pain, overall health, pain, emotional, social, and physical functions). The TAPP group showed significant improvement in all domains, except those of vitality and social functions. However, both groups were comparable postoperatively in terms of quality of life.
The Brazilian cohort study of 67 patients by Maliska et al. 15 compared quality of life using the SF-36 survey between preoperative and postoperative periods (3 month postoperative), after open hernia repair. A significant improvement was observed in the domains of physical aspect and pain, and significant differences were seen in the domains of functional capacity, mental health, social aspects, and emotional aspects. Only the domains of overall health and vitality did not demonstrate a statistically significant improvement (p>0.05). A similar result was found in our study in the late postoperative period of TEP and TAPP, in which the lowest means were obtained in the domains of vitality, mental health, and overall health state, while the highest mean was also in the domain of functional capacity (Figure 1). Our results are similar to the studies mentioned. However, there is a lack of studies that utilize the SF-36 scale as a parameter for evaluating quality of life comparing TAPP and TEP inguinal hernia repair techniques.   Regarding chronic pain, present 3 months after surgery, and assessed using the VAS, there was no difference between TEP and TAPP ( Figure 2). The results of this study were similar to those of Bansal et al. 4 , who observed that the TAPP group required more analgesia in the early postoperative period and also had a higher pain score in the first 6 and 24 h after surgery. However, regarding moderate-to-severe chronic pain, there was no significant difference between the two techniques: 1.25% of the TEP group and 1.29% of the TAPP group had a score of >3 on the VAS.
Donovan et al. 8 retrospectively analyzed 77 patients, with 40 undergoing TAPP approach and 37 undergoing TEP approach, and found that there was a significant difference in the use of opioids for pain relief in the immediate postoperative period. In the TEP technique, the time of use of opioids (in days) was shorter than in TAPP (0 vs. 3; p=0.007). However, there was no significant difference in the presence of chronic pain between the TAPP and TEP techniques (p=0.772).
It is worth mentioning that due to the SARS-CoV-2 pandemic, social distancing, and scarcity of human resources and medical supplies, the number of elective surgeries performed in 2020 was significantly lower than in previous years. In addition, getting in contact with patients to carry out this study was done exclusively via telephone, so the insecurity of sharing information and experiences at a distance were factors that could have limited the number of patients participating in the study. The complexity of the SF-36 questionnaire could have also led to a smaller number of participants. In addition, limitations of this study are also related to data being acquired retrospectively and from patients operated in a single center.
Despite these limitations, this study stands out for being one of the first to present national data comparing quality of life and chronic postoperative pain between the two main laparoscopic surgical techniques for inguinal hernia repair.

CONCLUSION
Patients undergoing TAPP inguinal hernia repair in this study had higher incidence of postoperative seroma as compared to those undergoing TEP repair. However, the techniques are comparable in terms of incidence of other early postoperative complications. In addition, no significant difference was seen between TEP and TAPP in quality of life and chronic pain in the late postoperative period.
It is important to emphasize that further research is needed to establish whether there are any significant differences between the techniques, given that our sample is limited and consists of patients operated on in a single institution. Therefore, the choice of technique should take into consideration the surgeon's experience and the patient's overall clinical status and presentation.