INTRODUCTION

Ventral hernias of the abdomen are defined as a non-inguinal, non-hiatal defect in the fascia of the abdominal wall and are commonly classified as either primary or incisional hernias(1). Surgical repair either by open or minimally invasive surgical (MIS) approach remains the only curative treatment option for individuals with symptomatic hernias. Surgery is typically recommended for individuals with acceptable operative risk. Laparoscopic repair with use of mesh remains the procedure of choice for all ventral hernias (1).

Surgical understanding of the methods used to treat abdominal wall hernias is advancing quickly. There is an extensive collection of literature, frequently with scant evidence and contradictory findings. The best management techniques for ventral hernias are still debatable (1). 

In recent years, surgeons have recognized small but finite risks of complications with the intraperitoneal location of mesh. This has encouraged them to devise a repair that can keep the mesh sandwiched between the layers of the abdominal wall (2).

 In the 1980s Jean Rives and Rene Stoppa described their technique of sublay mesh placement open Rives-Stoppa (ORS) repair which is a widely accepted procedure (3). 

Recent evidence has suggested that sublay mesh position with wide overlap and midline closure yields the best results with respect to restoration of biomechanics of the abdominal wall (4).

Minimally invasive surgery for ventral hernia repair (MIS-VHR) with mesh in the retro-muscular plane can be performed by either transabdominally (TA-RM) or via enhanced view totally extraperitoneal approach (eTEP). Although both techniques offer the mesh extension in the best anatomical space, closure of hernia defect, avoidance of traumatic fixation, the superiority of one approach over another is not established (5, 6).

LACUNAE IN PRESENT KNOWLEDGE

Although there has been recent increase in popularity of laparoscopic eTEP technique and laparoscopic TA-RM technique with both techniques offer the mesh extension in the best anatomical space, closure of hernia defect, avoidance of traumatic fixation, the superiority of one approach over another is not established. Also, there are paucity of published clinical studies in English biomedical literature and lack of comparative studies between two techniques of ventral hernia repair, we plan to perform randomized controlled trial (RCT) between laparoscopic eTEP and TA-RM techniques in patients with small to medium size midline ventral hernias to have an evidence-based answer to early post-operative pain and intra-operative surgeon workload.

RESEARCH QUESTION

Do patients with midline ventral hernia undergoing laparoscopic eTEP mesh repair experience equal intensity of pain on postoperative day one as compared to patients undergoing repair by laparoscopic TARM mesh repair technique.

RESEARCH HYPOTHESIS

Patients with midline ventral hernia undergoing laparoscopic eTEP mesh repair experience equal intensity of pain as measured by Numeric Pain Rating Scale (NRS-11) on post-operative day one as compared to patients undergoing repair by laparoscopic TARM mesh repair technique.

NULL HYPOTHESIS

There is significant difference in postoperative day one pain scores between patients with midline ventral hernia undergoing laparoscopic eTEP mesh repair as compared to patients undergoing repair by laparoscopic TARM mesh repair technique.

AIMS AND OBJECTIVES

AIM

To compare early post-operative pain following elective laparoscopic mesh repair of midline ventral hernias by laparoscopic eTEP mesh and by laparoscopic TARM mesh technique.

PRIMARY OBJECTIVE

To determine if patients with midline ventral hernia undergoing laparoscopic eTEP mesh repair experience same intensity of postoperative pain as measured by Numeric Pain Rating Scale (NRS-11) on post-operative day one as compared to patients undergoing repair by laparoscopic TARM mesh repair technique.

SECONDARY OBJECTIVE

⦁To determine early intra-operative surgeon workload as measured by modified version of validated Surgical Task Load Index (SURG-TLX) questionnaires between laparoscopic eTEP mesh repair group and laparoscopic TARM mesh repair group.

⦁To determine the proportion of patients requiring rescue analgesia in each group.

⦁To determine total operative time between laparoscopic eTEP mesh repair group and laparoscopic TARM mesh repair group. 

⦁To determine correlation between duration of surgery and level of pain.

MATERIALS AND METHODS

⦁Study type:   Interventional study

⦁Study design:  Randomized Control Trial (RCT) Equivalence 

                         Allocation :              Block Randomisation (Block size 2, 4, 6)

                                                 Intervention Model: Parallel Assignment

                                                 Masking :                 Single (Participants)

                                                Primary Purpose:      Intention to treat

⦁Period of Study:  2Oth  July 2024 to 31st September 2025

⦁Place of Study: Department of General Surgery, Lady Hardinge Medical College and Smt. Sucheta Kriplani Hospital (SSKH) New Delhi 110001

⦁Approval: Institutional Ethics Committee, LHMC New Delhi.

⦁ University study board (University of Delhi, New Delhi.

⦁Study population: Adult patients (18-65 years) with diagnosis of midline primary ventral or incisional hernia admitted in the surgical ward of LHMC and SSKH New Delhi for elective laparoscopic mesh repair.

⦁Sample size:  Adjusted total sample size required 60, with 30 patients in each in study and comparator arm respectively.

⦁Sample size calculation: (13)

   = Desired number of samples size for each group.

 = Standardized value for the corresponding level of confidence. (At 95% CI, it is 1.96)

 = Desired Power (0.84 for 80% power)

𝛿 = (clinically allowable difference) = 1 or 0.5. 

= standard deviation of difference calculated from the pilot study

 = Difference of means.

Based on a similar study in the Indian population by Chaudhary et al where a total of 29 patients underwent laparoscopic ventral hernia repair by eTEP mesh technique the author reported the overall mean post-operative pain score of 4.28 ± 1.12 (12).

Post-op NRS-11 score        Mean ± SD    n = Desired number of samples for each group (Including 10% dropout) if  n = Desired number of samples for each group (Including 10% dropout) if 

6hrs    4.57 ± 1.501 13.2    71.25

12hrs  4.23 ± 1.455 13.2    71.25

24hrs  4.03 ± 1.098 11.1    68.6

Overall           4.28 ± 1.125 11.1    68.6

If we use a value of as 1, we get a sample size of 14 and if we take the value of  as 0.5, we get a sample size of 72. So, in order to select adequate number of subjects and because of the constraints of time and resources, a sample size of 30 in each arm appears to be adequate for the study.

SUBJECTS

Inclusion criteria: Adult patients (18-65 years) with diagnosis of midline uncomplicated primary ventral or incisional hernia admitted in surgical ward of LHMC and SSKH New Delhi for elective laparoscopic mesh repair of one or more ventral hernias in the midline with expected hernial width equal to or less than 8cm having European Hernia Society (EuraHS) severity of co-morbidity score (SOC) between zero to three and body Mass Index (BMI) less than 35 will be included.

Exclusion criteria: 

The following exclusion criteria will be adopted in this study:    

⦁Patient with associated groin hernia

METHODS

Adult patients of either gender with diagnosis of either primary or incisional ventral hernia admitted in surgical ward of LHMC and SSKH New Delhi and planned for elective laparoscopic mesh repair will be evaluated by 

Detailed History including symptoms of ventral hernia

⦁          Swelling

⦁          Duration

⦁          Reducibility

⦁          Site

⦁          Single/ multiple

⦁          History and nature of previous abdominal wall surgery

⦁          Co-morbidities like Coronary Arterial Disease (CAD), Chronic Obstructive Pulmonary Disease (COPD), 

Comorbidities as per below criteria’s by EuraHS- Severity of co-morbidities score

(EuraHS SOC score)

SOC score                Definitions

0                      No co-morbidities 

⦁                     Asymptomatic, no medical consultation needed in last 12 months 

            2                    

3                      Stable disease, continuous therapy with regular medical consultation >4x/year 

4          Progressive disease, with changing or intensified therapy and frequent medical consultation >12x/year 

⦁          Bleeding Disorders

⦁          Medications History like Drug Allergy, Anti-Coagulants

      General Examination to assess for

Obesity (BMI)/ Pallor/ Built and Nutritional Status/ Mental status/ Other features of systemic disease if any

     Physical Clinical examination of the abdomen confirming presence and absence of      swelling including

HERNIA VARIABLES  

⦁          Duration and symptoms like pain, swelling and others

⦁          Types of hernia Primary / Incisional or primary ventral hernia

Primary ventral Hernia –     

⦁          Location- Epigastric/ Umbilical  

⦁          Size- small (<2cm), medium (2-4cm) and large (≥4cm) hernias

Incisional Hernia-                 

Location: M1: subxiphoidal -from the xiphoid till 3 cm caudally, M2: epigastric -from 3 cm below the xiphoid till 3 cm above the umbilicus, M3: umbilical- from 3 cm above till 3 cm below the umbilicus, M4: infraumbilical-from 3 cm below the umbilicus till 3 cm above the pubis, M5: suprapubic- from pubic bone till 3 cm cranially

⦁          

⦁          Nature of previous surgery and duration

⦁          Presence of any lateral ventral hernia or groin hernia

⦁          Any associated palpable organomegaly or evidence of free peritoneal fluid

Biochemistry and relevant test for evaluation of comorbidities and pre-anaesthetic check-up (PAC) like

⦁          Blood sugar/ haemoglobin/ coagulation profile/ ECG/ ECHO/ PFT/ Chest-X-ray as per indications in case wise. 

Radiological assessment of abdomen and ventral hernia by USG Abdomen and or CT- Scan abdomen for any underlying pathology or equivocal finding on physical examination as and when felt necessary.

All patients will be subjected to PAC by the concerned anaesthesia team for assessment and clearance of a case under general anaesthesia (GA). 

After the diagnosis of midline ventral hernia is established by clinical and or radiological tests as and when required the patient will be assessed as per pre-defined above-mentioned inclusion and exclusion criteria and those who will meet the study criteria will be enrolled after obtaining well informed written consent.

A total of 60 subjects will be enrolled, 30 in each study arm and will undergo laparoscopic ventral hernia mesh repair according to the assigned treatment arm. The study will consist of two interventions: Experimental arm (Laparoscopic eTEP mesh repair), Comparator arm (Laparoscopic TARM mesh repair).

All the subjects will be explained in detail about the purpose of study, consent will be taken for both the procedures without disclosure of the assigned group to participants.

All surgeries will be performed by two expert laparoscopic surgeons with more than ten years of experience in the field of advanced laparoscopy with special interest and experience in laparoscopic hernia surgeries at LHMC and SSKH New Delhi India.

The subject will be assigned to either arm using block randomization with block sizes of two, four and six. A computer-based randomization plan will be generated from sealedenvelope.com and the assigned arm of each subject will be disclosed to the operating surgeon in the operation room (17).

Both the procedures will be done under general anaesthesia (GA) with the patient in supine position in a modified lithotomy position. and both arms tucked to the side. A urinary catheter and a nasogastric tube will be passed. A high-definition camera system and two monitors will be used. No intra-operative regional block or epidural analgesia will be used.  will be administered. All opioid drugs administered will be converted to Morphine Equivalent (1 morphine equivalent= 10mg of inj. tramadol). The need for rescue analgesia, if needed shall be recorded.

Study Arm: Laparoscopic eTEP mesh repair operative steps:

⦁          Access to retro rectus space and initial port placement 

Access to retro rectus space will be performed using 10-12mm optical trocar using open method with initial space creation by either blunt telescopic dissection maintaining CO2 insufflations or indigenously developed balloon dissector (gloves finger over suction cannula tip) and initial port placement position medial to semilunaris either in upper abdomen or in lower abdomen depending upon site of the hernia with other working port  in varying in number and locations as per need under vision. 

⦁          Connecting and crossover to opposite retro-rectus space.

Crossover to opposite retro-rectus space will be performed anterior to falciform ligament for lower abdominal defect and anterior to umbilical ligament for upper abdominal defect pre-peritoneally connecting both side retro-rectus space by incising posterior rectus sheath near midline with complete dissection of retro-rectus space using dissector and energy source.

⦁          Dissection of hernial sac

Complete reduction of hernial contents and dissection of sac will be performed with closure of peritoneal rent in sac by absorbable suture.

⦁          Measurement and closure of fascial defects.

Fascial defect and retro-rectus space will be measured using sterile plastic ruler and suture closure of fascial defect using non absorbable suture will be performed.

⦁          Mesh placement

            Non coated large size poly propylene mesh will be placed in flat position in retro-rectus       space without any fixation.

⦁          Desufflation and port closure

All ports will be removed under vision followed by desufflation of space.  Fascial closure of all ports of size 10mm and more will be done.

Comparing arm: Laparoscopic TARM Mesh repair operative steps

⦁          Creation of pneumo-peritoneum 

            Creation of pneumo-peritoneum by closed technique using Veress needle at palmer point and CO2 insufflations maintaining pressure between 10-14 mm Hg.

⦁          Port placement

            Camera and additional two working ports (minimum total of three ports with additional ports if required) will be placed in the subcostal areas for umbilical and infra-umbilical defects and supra-pubic areas for supra-umbilical and epigastric defects respectively. All the working ports will be placed medial to the linea-semilunaris (LS). 

⦁          Identification of hernial defect

            Identification of hernial defect, complete reduction of all contents and adhesiolysis between abdominal contents and abdominal wall will be performed.

⦁          Peritoneal and posterior rectus sheath (PRS) 

      Flap creation using electrocautery or ultrasonic scalpel, a 6–8 cm long transverse        incision will made on the peritoneum (P) and posterior rectus sheath (PRS), underlying the rectus abdominis muscle, 5–6 cm proximal to the defect. 

⦁          Creation of retro-muscular space

            The retromuscular space will be developed by raising a flap of P-PRS, 8 cm beyond the hernial defect, with careful preservation of epigastric vessels, neurovascular bundles at the LS and linea alba (LA). 

⦁          Mesh placement

            Size of fascial defect will be measured using sterile plastic ruler with intra-peritoneal pressure at 10mm Hg and required size of the mesh will be measured overlapping 3-5cm all edges of defect simultaneously. Midline closure will be performed with a running non absorbable suture of No. 1 passing through rectus abdominis muscles, anterior rectus sheath and LA. non-coated large size polypropylene mesh will be placed in flat position in retro-rectus space without any fixation.

⦁          Closure of Peritoneal and posterior rectus sheath (PRS) Flap creation

            The initial P-PRS incision will be closed using running non absorbable suture of No. 1 followed by desufflation and port closure. 

OBSERVATIONS:

⦁          Numeric Pain Rating Scale (NRS-11) (Annexure 1).

       Pain will be assessed by Numeric Pain Rating Scale (NRS-11) on post-operative day one.

The NRS is an 11-point scale comprising a number from 0 through 10; 0 indicates “no pain”, and 10 indicates the “worst imaginable pain”. Patients will be instructed to choose a single number from the scale that best indicates their level of pain. The NRS is freely available on online platform and permits its use for research purposes after due credits to the original author(s) and the source.

⦁          Total operative time

The total operating time in minutes will be calculated from the time of skin incision for first port (eTEP repair) or Veress needle insertion (TARM repair) till skin closure of all ports.

⦁          Intra-operative surgeon workload (Annexure 2).

Surgeon workload will be quantified by using a modified version of validated Surgical Task Load Index (SURG-TLX) questionnaire with the addition of questions from Global Operative Assessment of Laparoscopic Skills (GOALS) to increase its relevance to measuring intraoperative workload. This consists of self-reported scales rating an individual’s mental demand, physical demand, task complexity, distractions and degree of difficulty. The resulting questionnaire will be administered to the operating surgeon immediately after surgical procedure. The (SURG-TLX) questionnaire is freely available on online platform and permits its use for research purposes after due credits to the original author(s) and the source (18). 

STATISTICAL PLAN:

PRIMARY OUTCOME:

            The mean/ median Post-op NRS-11 score at 6 hours, 12 hours, 24 hours and overall score in both groups.

SECONDARY OUTCOMES:

⦁          The mean/ median individual’s mental demand, physical demand, task complexity, distractions and degree of difficulty as reported by operating surgeons as per SURG-TLX questionnaire immediately after surgery. The resulting questionnaire will be administered to operating surgeon immediately after surgical procedure. 

⦁          Proportion of patients requiring rescue analgesia in each group, if any.

⦁          The mean/ median total operating time in minutes in both groups.

⦁          Degree of correlation between duration of surgery and level of pain.

STATISTICAL ANALYSIS:

All the observations will be recorded on the proforma enclosed. These observations will be analysed using the freely available statistical package. Results on categorical measurements will be presented in number (%) and results on continuous measurements will be presented as mean± SD. Continuous variables will be compared using student t test. Categorical variables will be compared with chi-square test or Fisher’s exact test. Values of p<0.05 will be considered statistically significant.

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