Open Access Open Badges Study protocol

Medial open transversus abdominis plane (MOTAP) catheters for analgesia following open liver resection: study protocol for a randomized controlled trial

Paul Karanicolas12*, Sean Cleary23, Paul McHardy45, Stuart McCluskey56, Jason Sawyer4, Salima Ladak6, Calvin Law12, Alice Wei56, Natalie Coburn12, Raynauld Ko56, Joel Katz6, Alex Kiss7, James Khan5, Srinivas Coimbatore5, Jenny Lam-McCulloch1 and Hance Clarke56

Author Affiliations

1 Department of Surgery, Sunnybrook Health Sciences Centre, Toronto, Canada

2 Department of Surgery, University of Toronto, Toronto, Canada

3 Department of Surgery, University Health Network, Toronto, Canada

4 Department of Anaesthesia, Sunnybrook Health Sciences Centre, Toronto, Canada

5 Department of Anaesthesia, University of Toronto, Toronto, Canada

6 Department of Anaesthesia and Pain Management, University Health Network, Toronto, Canada

7 Clinical Epidemiology Unit, Sunnybrook Research Institute, Toronto, Canada

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Trials 2014, 15:241  doi:10.1186/1745-6215-15-241

Published: 21 June 2014



The current standard for pain control following liver surgery is intravenous, patient-controlled analgesia (IV PCA) or epidural analgesia. We have developed a modification of a regional technique called medial open transversus abdominis plane (MOTAP) catheter analgesia. The MOTAP technique involves surgically placed catheters through the open surgical site into a plane between the internal oblique muscle and the transverse abdominis muscle superiorly. The objective of this trial is to assess the efficacy of this technique.


This protocol describes a multicentre, prospective, blinded, randomized controlled trial. One hundred and twenty patients scheduled for open liver resection through a subcostal incision will be enrolled. All patients will have two MOTAP catheters placed at the conclusion of surgery. Patients will be randomized to one of two parallel groups: experimental (local anaesthetic through MOTAP catheters) or placebo (normal saline through MOTAP catheters). Both groups will also receive IV PCA. The primary endpoint is mean cumulative postoperative opioid consumption over the first 2 postoperative days (48 hours). Secondary outcomes include pain intensity, patient functional outcomes, and the incidence of complications.


This trial has been approved by the ethics boards at participating centres and is currently enrolling patients. Data collection will be completed by the end of 2014 with analysis mid-2015 and publication by the end of 2015.

Trial registration

The study is registered with webcite ( NCT01960049; 23 September 2013)

Liver surgery; Analgesia; Transversus abdominis plane; Randomized controlled trial