Introduction: 

Surgery is the main method for the treatment of inguinal hernia. With the development of laparoscopic technology, laparoscopic inguinal hernia repair (LIHR) has gradually been adopted in clinical practice. The preferred LIHR operations for adult inguinal hernia management are transabdominal preperitoneal (TAPP) inguinal hernia repair and totally extraperitoneal (TEP) inguinal hernia repair. TAPP is more commonly performed surgery than TEP. Compared with traditional open surgery, minimally invasive surgery can relieve patients’ surgical trauma, reduce the risk of postoperative complications, and limit patients’ postoperative pain, making it the preferred surgical method for the clinical treatment of inguinal hernia at present .

In a qualitative systematic review, pain after both TAPP and TEP repair was found to be of a similar character, that is, lower abdominal groin pain of moderate to severe intensity, more on the first day that increased on coughing and mobilization. Shoulder tip pain due to pneumoperitoneum or somatic pain was not prominent after either type of repair. This has led to the use of techniques such as preperitoneal instillation of local anaesthetic at port site, epidural analgesia, and transversus abdominis plane block for postoperative pain control.

Transverse Abdominis Plane (TAP) block has been used to provide effective analgesia for a number of lower abdominal procedures such as lower segment caesarean section, total abdominal hysterectomy, open appendicectomy, open hernia surgery, and in renal transplant recipients. However, there is inconclusive literature regarding the timing of TAP block for providing better postoperative analgesia for laparoscopic hernia repair.

This study will be designed to compare  effect of TAP block before peritoneal incision  with TAP block after peritoneal incision closure on pain score at multiple times postoperatively at rest and on movement and postoperative analgesic requirement in the first 6 hours, 24 hours and after 7 days of laparoscopic hernia TAPP repair.

 Rationale of the study supported by cited literature:

Inguinal Hernia is one of the most common surgical condition with preferred surgical management being transabdominal preperitoneal (TAPP) inguinal hernia repair. According to previous studies, mild/moderate pain (VAS= 0-6) is present after this surgery. TAP block, an already established method of postoperative pain control can be used for management of this postoperative pain. Determining the time of TAP block administration for better postoperative pain control will help reduce patient morbidity, reduce postoperative analgesic requirement, reduce hospital stay and will ensure early return to work.

Hypothesis:

Administration of TAP block before peritoneal incision will cause less postoperative pain in TAPP inguinal hernia repair patients as compared to administration of TAP block after peritoneal incision closure.

Research questions: 

Does the timing of Tranversus abdominis plane (TAP) block - before peritoneal incision vs after closure of peritoneal incision affect the post operative pain in laparoscopic and robotic TAPP inguinal hernia repair patients?

Aim: 

To evaluate the role of timing of Tranversus abdominis plane (TAP) block in decreasing postoperative pain in laparoscopic TAPP hernia repair.

Objectives: 

Primary Objective:

            1.Compare postoperative pain scores between patients receiving TAP block before peritoneal incision and those receiving it after peritoneal incision closure.

Secondary Objective:

1. To compare postoperative analgesic requirement after 1 hour, 6hrs, 24hr and 7 days of inguinal hernia repair in each group.

2. Assess the duration and quality of postoperative analgesia in both groups.

                      3. Evaluate the overall patient satisfaction with pain management in each group.

Detailed methodology:

Study Design:

This will be a randomized controlled trial

Study setting:

This comparative study will be conducted in the Department of General Surgery, AIIMS, Jodhpur after obtaining due clearance from the Institutional Review board and Ethics Committee. The ICMR/ GCP guidelines for randomized trials will be followed and the study will be registered in the Clinical Trial Registry- India (CTRI).

Study Duration:

18 months after obtaining due clearance from the Institutional Review board and Ethics Committee

Method:

Patients recruited in the study will be randomized into two groups:

Group A - Patients undergoing Elective Laparoscopic TAPP inguinal hernia repair with TAP block done before peritoneal incision.

Group B - Patients undergoing Elective Laparoscopic TAPP inguinal hernia repair with TAP block done after peritoneal incision closure.

All patients will receive I.V. anaesthetic (Propofol) induction with fentanyl 2mcg/kg and maintenance with inhalation agents (Isoflurane). I.V. Paracetamol  in all patients before finishing surgery ( dose: 1 gm in > 50 kgs or 15 mg/kg in <50 kgs)

All patients will receive subcutaneous bupivacaine (0.25%) at port sites at least 2 minutes 

before incision of skin.

Timing of TAP block will be different in two groups but stepsof giving TAP block will be same.

Steps for TAP Block:

1.Set-up a sterile field

2.Mark the following external landmarks :costal margin and iliac crest

 and make a line where these intersect laterally.                 

3.Insert  needle at this point of intersection under direct vision. 

4.Identify the correct plane between Internal Oblique muscle and Transversus Abdominis Muscle before administering anaesthetic agent using following sign: 

"Double pop sign"- 2 pops are felt while the  needle passes through the External Oblique and Internal Oblique muscles respectively.

5. Aspirate to ensure no blood return

6. Inject required amount of  anaesthetic agent

7. Gently remove the needle

Postoperative pain management protocol:

All patients to receive Paracetamol 1 gm 8 hourly for pain management

For rescue analgesia, Tramadol 100 mg as needed and requirement to be recorded in data collection 

Patients not giving consent will not be included in the study. Details of patients who refuse consent and the reason for refusal of consent will be noted. Refusal of consent for the participation in the study will not affect the treatment of the patients in any way.

Data Collection:

a. Demographic data, intraoperative variables, and postoperative pain scores will be recorded.

b. Patient-reported outcomes will be collected using standardized questionnaires

Inclusion criteria:

1.    Patients who give informed consent

2.    Patients scheduled for elective TAPP inguinal hernia repair.

3.    Patients between 18 and 75 years.

4.    Patient with ASA (American Society of Anaesthesiologists) physical status I or II.

Exclusion criteria:

1. Patients who underwent a conversion to open surgery.
2. Patients who are allergic to local anaesthetics.
3. Patient with known history of chronic opioid use.
4. Patient with known history of coagulopathy or bleeding disorders.
5. Local skin conditions excluding block administration
6. Irreducible and strangulated hernia.

Data analysis plan:

a. Descriptive statistics will be used for demographic data.
b. Inferential statistics will be employed to compare outcomes between groups.