Pilot: Intraoperative TAP Block and Post-operative Pain Control for Minimally Invasive Hysterectomy for Endometrial Cancer

Study Overview
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Brief Summary
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Modern postoperative pain management aims to optimizing pain relief while minimizing opiate usage. While opiates are effective for pain relief, they result in common adverse effects such as nausea, constipation, and urinary retention, and most importantly present a long-term risk of abuse and dependency. Commonly used approaches include non-opiate pain medications such as acetominophen and non-steroidal anti-inflammatory agents, as well as regional nerve blocks such as epidurals. The transversus abdominis plane (TAP) block is a fascial plane block performed by injecting local anesthetic into the plane superficial to the transversus abdominis muscle where the anterior rami of the spinal nerves course to provide sensory innervation to the abdominal wall. The injections are generally placed either subcostally or at the midaxillary line bilaterally. The TAP block has been shown to be effective in reducing pain scores and opiate usage in some randomized studies but not others in patients undergoing various abdominal surgeries. There is great variation in method of administration, sites injected, and local anesthetics used, which may in part account for the heterogeneity of trial results.

Detailed Description
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The investigators believe that the disappointing results thus far with TAP blocks in minimally invasive hysterectomy may relate to several factors. A combination of short and long-acting anesthetic agents may provide the optimal analgesic effect. Large volumes of injection may promote spread of the anesthetics for better coverage, especially as long-acting agents are known to diffuse minimally. Lastly, multiple injections may provide better coverage of the nerves that innervate the abdominal wall. The investigators also believe that laparoscopic TAP blocks, administered by the surgeon, have advantages over the more commonly used ultrasound-guided approach typically performed by anesthesiologists. The laparoscopic approach is quick, on the order of a few minutes, whereas the ultrasound approach can be time-consuming. There is also less risk of visceral injury since the injection is performed under direct laparoscopic view. There are now 2 randomized studies suggesting that the laparoscopic approach is equivalent to the ultrasound approach. An additional potential reason why most studies have been negative is that patients undergoing minimally invasive hysterectomy do not generally experience severe pain, making it more difficult to demonstrate pain reduction with any given intervention. However, the studies to date do indicate that these patients experience moderate pain and do use opiates. An intervention that markedly reduces or even eliminates opiate use would be of potential benefit. The investigators have used a TAP block technique that is performed intraoperatively by the surgeon under direct laparoscopic view. The investigators use a mixture of plain and liposomal bupivacaine injected at multiple sites and in large volume to distribute the drugs widely, potentially resulting in longer and improved efficacy. This method has not been previously studied in a randomized trial. The investigators propose to demonstrate that this technique markedly decreases opiate usage and pain scores in patients undergoing minimally invasive hysterectomy.

Official Title
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A Randomized, Controlled, Observer-blinded Pilot Trial of Laparoscopic Large Volume, Multisite Transversus Abdominal Plane (TAP) Block With Liposomal Bupivacaine in Patients Undergoing Minimally Invasive Hysterectomy for Endometrial Cancer

Conditions
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Post Operative Pain, Gynecologic Cancer

Intervention / Treatment
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* Drug: Liposomal bupivacaine
* Drug: Bupivacain


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18-80 Patients undergoing laparoscopic or robotic hysterectomy; may include other procedures (e.g. lymph node removal) Endometrial cancer or endometrial intraepithelial neoplasia Able to consent to study Exclusion Criteria: Known clinically significant allergy to bupivacaine or liposomal bupivacaine ASA IV or V Emergency surgery Current chronic opiate use Current pregnancy or breastfeeding Severe hepatic or renal impairment Hysterectomy is not for endometrial cancer or endometrial intraepithelial neoplasia

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Potential subjects will be identified in the GYN specialty clinics at Tufts Medical Center and approached for possible study participation. Eligibility criteria will be assessed by the PI or co-I. Eligible subjects who wish to participate in the study will be consented for the study by the PI or co-I. Informed consent for the study may be obtained up to the day of the surgery, prior to anesthesia induction. The following demographics will be collected from the medical record and de-identified: age, race, ethnicity, height, weight, ASA class. On the day of surgery, the subject will be randomized using a random number generator to one of 3 groups: No TAP block TAP block with liposomal and plain bupivacaine: 20 mL liposomal bupivacaine, 30 mL 0.25% bupivacaine, 150 mL normal saline (200 mL total) TAP block with plain bupivacaine alone: 60 mL of 0.25% bupivacaine, 140 mL of normal saline (200 mL total)
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: No TAP block<br> | |
| Active Comparator: TAP block with liposomal and plain bupivacaine<br> | Drug: Liposomal bupivacaine<br>* Liposomal bupivacaine is FDA-approved for use single-dose infiltration in adults to produce postsurgical local analgesia and as an interscalene brachial plexus nerve block to produce postsurgical regional analgesia. The solution will be placed into 20 mL syringes on 18-gauge needles for injection. The injections will be performed percutaneously by the surgeon along the midaxillary line at 4 equidistant points from the anterior superior iliac spine to the costal margin, as well as a single injection subcostally at the anterior axillary line. 20 mL will be injected at each site, 5 sites per side bilaterally, total of 10 sites. The depth of injection will be judged by laparoscopic visualization of a diffuse bulge during injection, indicating injection in the correct plane, just superficial to the transversus abdominis muscle.<br>* Other names: Exparel;Drug: Bupivacain<br>* Bupivacaine is FDA-approved for use as a local or regional anesthetic for surgery. It is widely used in TAP blocks. The solution will be placed into 20 mL syringes on 18-gauge needles for injection. The injections will be performed percutaneously by the surgeon along the midaxillary line at 4 equidistant points from the anterior superior iliac spine to the costal margin, as well as a single injection subcostally at the anterior axillary line. 20 mL will be injected at each site, 5 sites per side bilaterally, total of 10 sites. The depth of injection will be judged by laparoscopic visualization of a diffuse bulge during injection, indicating injection in the correct plane, just superficial to the transversus abdominis muscle.<br>* Other names: Bupivacaine;|
| Active Comparator: TAP block with plain bupivacaine alone<br> | Drug: Bupivacain<br>* Bupivacaine is FDA-approved for use as a local or regional anesthetic for surgery. It is widely used in TAP blocks. The solution will be placed into 20 mL syringes on 18-gauge needles for injection. The injections will be performed percutaneously by the surgeon along the midaxillary line at 4 equidistant points from the anterior superior iliac spine to the costal margin, as well as a single injection subcostally at the anterior axillary line. 20 mL will be injected at each site, 5 sites per side bilaterally, total of 10 sites. The depth of injection will be judged by laparoscopic visualization of a diffuse bulge during injection, indicating injection in the correct plane, just superficial to the transversus abdominis muscle.<br>* Other names: Bupivacaine;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reduced opiate use in both TAP block arms. | Demonstrate a statistically significant change in postoperative opiate use as measured in oral morphine milligram equivalents on postoperative days 0-7. | 7 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Increase in opiate-free participants by day 7 | Demonstrate a change in proportion of subjects that are opiate-free on postoperative days 0-7. | 7 days | 
| Reduction in post-operative resting pain scores | Demonstrate a statistically significant change in maximum resting numeric rating scale (NRS) at the following time points in postoperative days: 0-1, 1-2, 2-3, 0-7. | 7 days | 
| Improvement in patient satisfaction regarding pain control | Demonstrate change in patient satisfaction with regard to pain control (very satisfied, satisfied, unsatisfied). | 7 days | 
| Incidence of Treatment-Emergent Adverse Events | Specific AEs measured will be nausea, headache, rash, itching, hematoma, ecchymosis, seizures | 7 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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hysterectomy, minimally invasive surgery, TAP block, endometrial cancer, endometrial intraepithelial neoplasia