The Role of Transversus Abdominis Plane Blocks in Enhanced Recovery After Surgery Pathways for Open and Laparoscopic Colorectal Surgery

Abstract

Introduction:

The concepts of Enhanced Recovery After Surgery (ERAS^®) have steadily increased in usage, with benefits in patient outcomes and hospital length of stay. One important component of successful implementation of ERAS protocol is optimized pain control, via the multimodal approach, which includes neuraxial or regional anesthesia techniques and reduction of opioid use as the primary analgesic. Transversus abdominis plane (TAP) block is one such regional anesthesia technique, and it has been widely studied in abdominal surgery.

Materials and Methods:

We performed an extensive literature search in MEDLINE and PubMed. We review the benefits of TAP blocks for colorectal surgery, both laparoscopic and open. We organize the data by surgery type, by method of TAP block performance, and by a comparison of TAP block to alternative analgesic techniques or to placebo. We examine different endpoints, such as postoperative pain, analgesic use, return of bowel function, and length of stay.

Results:

The majority of studies examined TAP blocks in the context of laparoscopic colorectal surgery, with many, but not all, demonstrating significantly less use of postoperative opioids in comparison to placebo, wound infiltration, and standard postoperative patient-controlled analgesia with intravenous opioid administration. There is evidence that use of liposomal bupivacaine may be more effective than conventional long-acting local anesthetics. Noninferiority of TAP infusions has been demonstrated, compared with continuous thoracic epidural infusions.

Conclusion:

TAP blocks are easily performed, cost-effective, and an opioid-sparing adjunct for laparoscopic colorectal surgery, with minimal procedure-related morbidity. The evidence is in concordance with several of the goals of ERAS pathways.

Introduction

Elements of Enhanced Recovery After Surgery

The concept of Enhanced Recovery After Surgery (ERAS^®) was initially introduced in 2001, utilizing evidence-based protocols to attenuate the neural and metabolic response to surgical insult, and to improve the quality of recovery. Multidisciplinary protocols address a range of important elements of perioperative care. These include preoperative optimization of chronic disease and nutritional status, prophylactic measures to reduce postoperative ileus, deep vein thrombosis, and infection, intraoperative fluid and temperature optimization, multimodal pain control, postoperative nutrition optimization, early ambulation, as well as early removal of invasive equipment (i.e., nasogastric tubes, urinary catheters, etc.).¹

The guidelines have been extrapolated to numerous surgical subspecialties, including intra-abdominal, intra-thoracic noncardiac, head and neck, breast, and orthopedic surgery.² Specifically in colorectal surgery, compliance with ERAS guidelines with 900 consecutive colorectal surgery patients resulted in fewer complications, shorter length of stay, and fewer readmissions.³ Lower costs have also been demonstrated in colorectal surgical patients undergoing ERAS protocol, ranging from savings of $2800–$5900 per patient.⁴

Multimodal analgesia

One important element includes optimized pain control with opioid-sparing analgesic techniques.⁵ Adequate pain control reduces the physiologic stress response, insulin resistance, and postoperative ileus, along with supporting early mobilization.¹ Specific benefits of minimizing opioid use may include the reduction of nausea and vomiting, ileus, urinary retention, somnolence (which may delay enteral intake, mobilization, and hospital discharge), hyperalgesia, and postoperative delirium in the elderly.⁶

Within the ERAS Society guidelines for optimal pain control, a multimodal regimen should include nonopioid pharmacologic agents, such as nonsteroidal anti-inflammatory drugs, acetaminophen, and gabapentinoids; usage of neuraxial or regional anesthesia, adjunct therapies such as intravenous dexamethasone, ketamine, and tramadol⁷; and minimization of opioid use (or usage of peripheral opioid-blocking agents).¹ These components are organized effectively, by phase of care, in a Joint Consensus Statement by the American Society for Enhanced Recovery and Perioperative Quality Initiative, in which at least one selection is made within groups labeled Intravenous/oral analgesia, Local Anesthetic, and Other adjuncts.⁷ The local anesthetic grouping includes single-shot blocks such as subarachnoid block, transversus abdominis plane (TAP) block, paravertebral blocks, and wound infiltration; continuous catheter infusions such as thoracic epidural catheters and TAP catheters; and finally, intravenous lidocaine infusion. A number of studies have specifically examined TAP blocks as an analgesic method, many of which are within the ERAS paradigm.

TAP block and techniques

Though many of the studies we examined described the potential benefit of TAP blocks in general, they are more correctly a family of interrelated blocks,⁸ with subtle differences in performance and benefits. In general, the TAP block is a peripheral nerve block that targets the anterior rami of spinal nerves T6-L1, which innervate the anterolateral abdominal wall. However, visceral innervation is spared, which may contribute to postoperative pain after colorectal surgery. The TAP block is usually performed bilaterally, by an anatomic landmark at the Triangle of Petit⁹ or by ultrasound guidance, and with a single shot or continuously via an in situ catheter. The most common method employed in most studies that we reviewed is a single shot with ultrasound guidance, in the mid-axillary line halfway between the costal margin and iliac crest.

There is a more dorsal TAP approach (now known as a quadratus lumborum block), with a possible posterior-cranial extension of local anesthetic to the same-level and higher level paravertebral spaces.¹⁰ Carney et al. demonstrated the spread of contrast in this approach to be up to T4,¹¹ though sensory block was only demonstrated up to T8 by Kadam.¹⁰ A subcostal oblique approach for TAP block was described, providing superior analgesia of the more superior dermatomes of the supraumbilical abdomen. In this approach, the block needle is inserted subcostally, along the oblique line from the xyphoid process to the anterior part of the iliac crest.¹² A mid-axillary approach, with lateral to medial insertion of the block needle, is also described, thus having the puncture site (and potential catheter exit) further from the surgical site.¹³ Rectus sheath blocks can also be performed alongside conventional TAP blocks, again for the reason of blocking higher dermatomes of the central portion of the abdominal wall, up to T6.¹⁴ It is important to consider the anatomic dermatomes to be affected, as there is heterogeneity in the results of the various TAP blocks.⁸

Materials and Methods

We reviewed studies evaluating the benefits of performing TAP blocks for abdominal surgery, and specifically for laparoscopic and open colorectal surgery. We performed an extensive literature search of MEDLINE and PubMed. Keywords included TAP block, regional anesthesia, ERAS, colorectal surgery, and laparoscopic. We reviewed retrospective studies, case series, case reports, and prospective studies. There were variations of the TAP block method, as previously described. In addition, some studies compared TAP blocks with placebo, whereas others compared them with other standards of care, such as continuous thoracic epidural infusions, patient-controlled analgesia (PCA), or wound infiltration. Finally, heterogeneous endpoints were examined, most commonly postoperative pain and analgesic use, but also other endpoints such as return of gut function and length of stay were examined.

Results

Efficacy of TAP block for colorectal surgery

Multiple studies have examined the performance of TAP blocks for abdominal surgery, most often assessing opioid consumption and pain scores (Table 1). A Cochrane systematic review in 2010 regarding TAP blocks for analgesia after abdominal surgery showed limited evidence for reduction of opioid consumption and pain scores, but no evidence to suggest reduction of nausea and vomiting.¹⁵ In almost all the studies included, the TAP blocks were studied as an adjunct to usual care, rather than as a direct comparison to other analgesic techniques, such as epidural analgesia, wound infiltration, or opioid PCA. A limitation of this review was the predominance of single-shot blocks rather than continuous infusion, as would likely be necessary for a direct comparison to continuous epidural analgesia.

Table 1.

Assessment of Transversus Abdominis Plane Block Efficacy for Colorectal Surgery: Summary of Key Papers

Author	Study type	Colorectal surgery type	TAP block type for treatment group	Primary outcome measured	Conclusion
Rashid et al.³³	Double-blind randomized control (71 patients)	Laparoscopic colonic (right hemicolectomy and high anterior resection)	Single-shot, US guided (40 mL 0.25% bupivacaine)	Overall morphine use in first 48 hours	No significant difference in morphine use. Also, no significant difference in pain scores, time to mobilization, resumption of diet, and length of hospital stay
Rashid et al.³³	Comparison of ultrasound guided TAP block to local wound infiltration		Single-shot, US guided (40 mL 0.25% bupivacaine)	Overall morphine use in first 48 hours
Pedrazzani et al.¹⁹	Single-center, prospective, nonrandomized trial (48 patients)	Laparoscopic colorectal surgery (right hemicolectomy, left/sigmoid hemicolectomy, low anterior resection)	Single-shot, US guided (20 mL of 0.35% ropivacaine)	Improvement of definite items of ERAS^® pathway	Local wound infiltration+TAP block group had significantly reduced use of opioids, experienced less nausea, needed less time to return bowel function, remove urinary catheter, and tolerate oral diet
Pedrazzani et al.¹⁹	Comparison of local wound infiltration plus TAP block to local wound infiltration		Single-shot, US guided (20 mL of 0.35% ropivacaine)	Improvement of definite items of ERAS^® pathway
Tikuisis et al.¹⁶	Prospective, randomized, double-blind, placebo-controlled single-center study (64 patients)	Laparoscopic, hand-assisted left hemicolectomy	Single-shot, US guided (20 mL 0.375% bupivacaine)	Postoperative pain control (pain score and analgesic use)	TAP block group experienced significantly less pain and used less analgesics (fentanyl and ketorolac). Mean time to resumption of intestinal function and hospital length of stay significantly shorter
Tikuisis et al.¹⁶	Comparison of TAP block to saline placebo	Laparoscopic, hand-assisted left hemicolectomy	Single-shot, US guided (20 mL 0.375% bupivacaine)	Postoperative pain control (pain score and analgesic use)
Stokes et al.²⁵	Retrospective, single-center, cohort study (407 patients)	Open, minimally invasive, laparoscopic, and robotic segmental colectomy or proctectomy, stoma creation/reversal, total proctocolectomy, abdominoperineal resection, IPAA, exploratory surgery	Single-shot, US guided (10 mL liposomal bupivacaine+10 mL saline+5 mL 0.25% bupivacaine)	Postoperative pain scores and opioid use	Superior pain control in liposomal bupivacaine group, significant decrease in opioid and ketorolac use (for laparoscopic and robotic surgery, not laparotomy)
Stokes et al.²⁵	Comparison of TAP block with liposomal bupivacaine to TAP block with conventional bupivacaine			Postoperative pain scores and opioid use
Oh et al.¹⁷	Double-blind, randomized, placebo-controlled study (58 patients)	Laparoscopic colorectal resection	Single-shot, US guided (0.5 mL/kg of 0.25% bupivacaine)	Postoperative pain	No significant difference in pain intensity, postoperative opioid consumption, sedation scores, nausea scores, and length of hospital stay
Oh et al.¹⁷	Comparison of TAP block to saline placebo	Laparoscopic colorectal resection	Single-shot, US guided (0.5 mL/kg of 0.25% bupivacaine)	Postoperative pain
Smith et al.³⁴	Prospective, double-blind randomized clinical trial (142 patients)	Laparoscopic colorectal resection (right colectomy, left colectomy, rectal resection)	Single-shot, US guided (ropivacaine 3 mg/kg)	Postoperative pain measured by analgesic consumption	No significant difference of analgesic consumption, pain scores, respiratory outcome, time to return of gut function, length of hospital stay, and patient satisfaction
Smith et al.³⁴	Comparison of TAP block to standard postoperative care		Single-shot, US guided (ropivacaine 3 mg/kg)	Postoperative pain measured by analgesic consumption
Park et al.¹⁸	Nonrandomized, single-blind prospective study (60 patients)	Laparoscopic colorectal surgery (anterior resection, low anterior resection, hemicolectomy)	Single-shot, US guided (20 mL 0.25% ropivacaine)	Postoperative pain and analgesic use	TAP block group had decreased cumulative morphine use at 6, 24, and 48 hours compared with local anesthetic infiltration group
Park et al.¹⁸	Comparison of TAP block to infiltration of surgical wound		Single-shot, US guided (20 mL 0.25% ropivacaine)	Postoperative pain and analgesic use
Keller et al.²¹	Retrospective review of 200 consecutive patients	Laparoscopic colorectal surgery (segmental colectomy, low anterior resection, other)	Single-shot, laparoscopic visualization with two “distinct pops” (30 mL 0.25% bupivacaine)	Length of stay and patient outcomes	Addition of TAP blocks to enhanced recovery protocol facilitates shorter length of stay with low readmission and reoperation rates compared with previously published series
Niraj et al.²⁹	Single-center, open-label, randomized, noninferiority trial (70 patients)	Laparoscopic colorectal surgery (right hemicolectomy, left hemicolectomy, anterior resection, sigmoid colectomy, ileocolic resection)	Continuous “four-quadrant” TAP infusion (2.5 mg/kg levobupivacaine, then infusion of 0.25% levobupivacaine)	Postoperative pain by visual analog scale	Noninferiority, or no significant difference between visual analogue scores or tramadol consumption
Niraj et al.²⁹	Comparison of continuous TAP infusion to continuous thoracic epidural infusion			Postoperative pain by visual analog scale
Favuzza and Dalaney²⁰	Review of 100 consecutive patients	Laparoscopic colorectal surgery	Single-shot, laparoscopic visualization with two “distinct pops”	Discharge outcomes	Addition of TAP blocks to an established enhanced recovery protocol contributes to short length of stay, without increasing complication or readmission rates
Walter et al.³⁶	Prospective, double-blind randomized trial (68 patients)	Laparoscopic colorectal surgery (left sided colorectal resection, right sided colorectal resection)	Single-shot, US guided (2 mg/kg levobupivacaine in 40 mL)	Cumulative postoperative opioid use to 24 hours	TAP block group had significantly less cumulative morphine usage. Pain scores and length of stay were similar
Walter et al.³⁶	Comparison of TAP block to no TAP block		Single-shot, US guided (2 mg/kg levobupivacaine in 40 mL)	Cumulative postoperative opioid use to 24 hours
Bharti et al.³⁷	Prospective, randomized, double-blind trial (40 patients)	Open colorectal surgery (resection anastomosis, hemicolectomy, other)	Single-shot, performed before fascial closure	Postoperative pain and analgesic consumption	TAP block group had significantly lower cumulative morphine requirement, significantly lower pain scores at rest, and less sedation
Bharti et al.³⁷	Comparison of TAP block to saline placebo		Single-shot, performed before fascial closure	Postoperative pain and analgesic consumption
Conaghan et al.³²	Prospective, nonrandomized comparative study (74 patients)	Laparoscopic colorectal surgery (right-sided resection, left-sided resection, other)	Single-shot, US guided (40 mL 0.25% levobupivacaine)	Postoperative pain and analgesic consumption	TAP/PCA group had significant reduction in intravenous opiate use, with a trend toward shorter hospital stay
Conaghan et al.³²	Comparison of TAP block and morphine PCA to PCA alone		Single-shot, US guided (40 mL 0.25% levobupivacaine)	Postoperative pain and analgesic consumption

PCA, patient-controlled analgesia; TAP, transversus abdominis plane; IPAA, ileal pouch-anal anastamosis; US, ultrasound.

With regard to colorectal surgery, in particular, TAP blocks were almost always studied when the approach was laparoscopic rather than open. Again, there was heterogeneity on a comparison of the TAP block to placebo or to other standards of pain control, and also the endpoint measured. In a comparison of TAP block to placebo, Tikuisis et al. demonstrated that the TAP block group had significantly less pain and less analgesic use (fentanyl and ketorolac), with a significantly shorter time to resumption of intestinal function and shorter hospital length of stay.¹⁶ However, Oh et al. demonstrated no significant differences of the TAP and placebo groups with regard to pain intensity, opioid consumption, sedation, nausea, or length of hospital stay.¹⁷ When directly compared with other standards of pain control, Park et al. demonstrated that TAP blocks were superior to local wound infiltration with regard to morphine use.¹⁸ Pedrazzani et al., in a slight variation, compared the TAP block plus wound infiltration with only wound infiltration, showing that the TAP block group used less opioid, had less nausea, and needed less time for bowel function return, urinary catheter removal, and tolerance of oral diet.¹⁹ Several studies were unique in that the TAP block was performed by the surgical team, with direct laparoscopic visualization and the feeling of “2 distinct pops” as the block needle traversed the external and internal oblique muscle planes.^20,21 In a retrospective review of 100 consecutive patients, Favuzza and Dalaney stated that the addition of TAP blocks performed by the surgical team contributed to shorter length of stay, without increasing complication or readmission rates.²⁰ Another topic studied was the efficacy of liposomal bupivacaine use in TAP blocks. Liposomal bupivacaine is a longer-acting, sustained-release bupivacaine formulation that may dramatically increase the utility of single-shot blocks.^22–24 Stokes et al. compared liposomal bupivacaine in TAP blocks with traditional local anesthetic, via the institutional database, demonstrating lower pain scores for the first 24–36 hours, a one-third decrease in opioid consumption during the hospitalization (only seen in laparoscopic and robotic procedures but not with laparotomies), and a trend toward shorter length of stay and decreased total cost.²⁵

A full review of the relevant studies is summarized in Table 1.

Continuous TAP block versus continuous epidural analgesia in abdominal surgery and colorectal surgery

Another recent controversial topic is the status of thoracic epidural analgesia as the “gold-standard” for analgesia after abdominal surgery, of which it has been regarded in the ERAS paradigm.²⁶ However, this status has been questioned.²⁷ There are issues with thoracic epidural analgesia to consider, including high failure rates²⁸ and potential hypotension resulting from sympathectomy. In comparison, TAP analgesia preserves lower limb motor function, does not cause hemodynamic lability, is generally not contraindicated with anticoagulant use, and does not cause urinary retention.²⁹

Hughes et al. performed a meta-analysis of studies including patients undergoing the ERAS pathway for open abdominal surgery, with a comparison of epidural analgesia to alternative analgesic techniques, including morphine PCA and continuous wound infusion. They demonstrated that the epidural group had lower pain scores and faster return of gut function, but without differences in length of stay.³⁰ A few studies have examined the efficacy of continuous TAP catheters, which can be more effectively compared with continuous epidural analgesia in abdominal surgery.^13,29,31 For laparoscopic colorectal surgery in particular, “four-quadrant” TAP infusions were shown to be noninferior to epidurals, with regard to postoperative pain and analgesic consumption (tramadol).²⁹

Discussion

The heterogeneity of the studies of TAP blocks in colorectal surgery made efficacy evaluation more difficult to quantify. However, several points are clear. TAP blocks have minimal procedure-related morbidity; they are easily performed and are cost-effective. Single-shot TAP blocks have been shown numerous times to be an opioid-sparing adjunct for laparoscopic colorectal surgery. With less robust evidence, there is a trend toward improved bowel recovery,^16,19 less nausea,¹⁹ faster urinary catheter removal,^19,29 and shorter hospital length of stay.^16,20,21,32 This efficacy evidence is in concordance with several important intraoperative and postoperative goals of ERAS pathways. It is important to note that a few studies did not corroborate these positive findings.^17,33,34 Quadratus lumborum blocks have been shown to more reliably block T8-10 compared with more anterior TAP blocks,³⁵ so future protocols should explore this adaptation of TAP blocks in colorectal surgery. Further studies directly comparing single-shot liposomal bupivacaine TAP blocks or continuous TAP infusions via catheter placement with thoracic epidural analgesia are likely to be helpful to guide future practice, especially in compliance with multimodal analgesia recommended in ERAS pathways.

Footnotes

Disclosure Statement

Richard D. Urman received research funding and consulting fees from Mallinckrodt, Inc. Other authors report no conflicts of interest. This article is not under consideration for publication elsewhere and it has never been partially published. There were no sources of financial support. ERAS^® is a registered trademark of the ERAS^® Society.

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