Celiac Plexus Block

Performed by Top Pain Management Doctors in San Antonio, Texas


Celiac plexus blocks (CPB)are nerve blocks that are used to control pain originating within abdominal structures, including the pancreas, liver, gallbladder, omentum (intra-abdominal fat deposits), mesentery (tissues that support and hold abdominal organs), and portions of the gastrointestinal tract (Mehta & Rathmell, 2011). CPB’s are most commonly utilized in the management of pain associated with malignant or invasive cancer, affecting abdominal structures- particularly pancreatic cancer.  Blocking, or even destroying nerves of the celiac plexus have been shown to provide significant pain relief, reduce the need for many oral pain relievers with detrimental side effects, and otherwise improve the quality of life for cancer patients.

CPB’s are perhaps most important to the treatment of pancreatic cancer, a deadly condition due to the circumstances of its onset.  Because of its location and innervations pattern within the abdomen, pancreatic cancer is often asymptomatic until it reaches advanced stages.  When symptoms do present, one of the initial signs is abdominal pain and pain in the mid back.  In advanced stages, surgical treatment which offers the best hope for battling the cancer is often impossible, and the cancer is considered terminal.  For patients with terminal pancreatic (and other intra-abdominal) cancers, CPB offers an effective method for pain-reduction and quality of life improvement for the remainder of the life span.

CPB’s have also been used as part of an anesthesia protocol for intra-abdominal surgery, since blocking the plexus can inhibit transmission of autonomic nervous system signals which convey stress and other responses to surgery (Wedel & Horlocker, 2009). Further investigation is underway to determine if CPB’s may be beneficial for the treatment of non-cancer related, inflammatory pancreatitis pain (Mehta & Rathmell, 2011).

Anatomy

The spinal column consists of several bones, called vertebrae, which are stacked atop one another from the pelvis to the base of the skull, forming a protective channel for the spinal cord (Leonard, 1995).  There are 33 of these vertebrae divided into five regions: (1) cervical, which are found in the neck closest to the skull (identified as C1-C7), (2) thoracic, found along the upper back (identified as T1-T12), (3) lumbar, found along the lower back (identified as L1-L5), (4) sacral, which are contiguous with the pelvis or hip (identified as S1-S5), and (5) coccygeal, which are fused as the tailbone.

The celiac plexus is composed of ganglia (nerve cell bodies) and nerve fibers; it contains primarily afferent (sensory) and efferent (motor) nerve fibers carried by the splanchnic nerves from spinal levels T5-T12 (Wedel & Horlocker, 2009). These nerve fibers innervated the majority of abdominal visceral organs, and they cluster as the celiac plexus in front of the L1 vertebrae, but just behind and in between the major vein (vena cava) and artery (aorta) of the body.  Because of its location amongst organs and blood vessels, great care must be taken to avoid damaging nearby structures during a CPB procedure.

Procedure

The classic technique for performing a CPB involves a posterior approach with needle placement through the back; however other newer techniques use imaging technology to approach the plexus from other directions (Mehta & Rathmell, 2011).  In general, radiographic guidance such as fluoroscopy (real-time x-ray), ultrasound or CT imaging is recommended to perform the procedure.

For the classic, posterior approach, a patient is positioned in a prone position (on their stomach), with a pillow placed beneath the abdomen. The injection site is locally anesthetized to prevent patient discomfort, and sterilized to prevent infection. Lines are drawn on the patients back connecting the bony protrusion of the T12 vertebrae to lower points to the right and left on the back to create a triangle as guides for needle placement (Wedel & Horlocker, 2009).  A needle is inserted at an angle at the left point of the triangle until it contacts the vertebral body, after which it is repositioned to slide a few centimeters over the front of the vertebral body to reach the plexus.  Pulses from the nearby aortic artery can confirm proper needle placement. A second needle can then be placed from the right side in the same manner.  Anesthetic can then be delivered via each needle to achieve a nerve block.

The procedure is typically performed in under a half-hour, and after a short observation period to monitor for potential adverse reactions, the patient is able to return home.  6-8% of patients may require a second block to achieve adequate pain control (Benedetti, et al., 2008).

Benefits

Neurolytic CPB’s have been shown to have a long-lasting benefit for 70-90% of patients with pancreatic and other abdominal malignancies (Mehta & Rathmell, 2011).

Research has shown enough benefit from CPB’s for the treatment of cancer pain to warrant a ‘B’ recommendation; there is a high certainty that the net benefit of the procedure is moderate and/or that there is a moderate certainty that the net benefit is moderate to substantial (Benedetti, et al., 2008).

The duration and character of pain relief varies from person to person.  Some patients may experience pain relief for many years with just one block, while another may experience relief for just weeks.  CPB’s are a minimally invasive procedure, however, and can thus be repeated as needed with minimal risk. Studies have shown that CPB may be more effective in treating pain when performed earlier after pain onset instead of later (Levy & Wiersema, 2012).

Risks

Potential side effects associated with CPB include transient hypotension (low blood pressure), diarrhea, inadvertent injection/puncture of the spine, blood vessels or other organs/tissue, and pneumothorax (collapsed lung) (Wedel & Horlocker, 2009).  Some of these side effects are fairly common but minor, such as diarrhea and the temporary low blood pressure, while the more serious side effects are rare and mitigated by performance of the procedure by a properly trained and experience interventional pain specialist.  With any medical procedure, infection and bleeding are also possible risks, but tend to be very rare with CPB’s.

Side effects tend to be more common and persistent with neurolytic blocks in comparison to conventional anesthetic-only plexus blocks.  Neurolytic blocks also carry an increased risk for additional side effects, including alcohol intoxication, central nervous system excitability, seizures and other cardiovascular problems (Mehta & Rathmell, 2011).  Perhaps the most devastating potential side effect is partial paralysis if the degrading medications within the injection spread beyond the celiac plexus.  But again, these side effects are exceedingly rare, and the benefit achieved by CPB’s in abdominal cancer patients with intractable pain greatly exceeds the risks as evidenced by the ‘B’ recommendation level evidence from research studies.

Outcomes

A large review of 31 studies on CPB’s in nearly 1600 patients found that CPB’s “achieved good to excellent pain relief” for 85-90% of patients treated (Benedetti, et al., 2008).

Intra-abdominal cancers, especially pancreatic, can be highly aggressive and associated with high mortality.  CPB may be the best option for pain control in these patients (Wong, et al., 2004). Through effective pain management, there is a possibility to improve the quality of life for the duration of the lifespan (Wedel & Horlocker, 2009).

References/ Journal Articles

  1. Benedetti, C., et al. (2008). Cancer Pain: Anesthetic and Neurosurgical Interventions. Retrieved April 2, 2012, from MD Consult. Walsh: Palliative Medicine , 1st ed.: http://www.mdconsult.com.ezproxy1.library.arizona.edu/books/page.do?eid=4-u1.0-B978-0-323-05674-8..50251-6–cesec17&isbn=978-0-323-05674-8&sid=1303276206&uniqId=331951233-3#4-u1.0-B978-0-323-05674-8..50251-6–cesec18
  2. Leonard, R. (1995). Human Gross Anatomy: An Outline Text. Oxford University Press USA.
  3. Levy, M., & Wiersema, M. (2012). Endoscopic ultrasound-guided celiac plexus and ganglia interventions. Retrieved April 2, 2012, from UpToDate.
  4. Mehta, P., & Rathmell, J. (2011). Pain Management. Retrieved April 2, 2012, from MD Consult. Miller: Basics of Anesthesia, 6th ed.: http://www.mdconsult.com.ezproxy1.library.arizona.edu/books/page.do?eid=4-u1.0-B978-1-4377-1614-6..00015-X–s0120&isbn=978-1-4377-1614-6&sid=1303276206&uniqId=331951233-3#4-u1.0-B978-1-4377-1614-6..00015-X–s0150
  5. Wedel, D., & Horlocker, T. (2009). Nerve Blocks. Retrieved April 2, 2012, from MD Consult. Miller: Miller’s Anesthesia, 7th ed.: http://www.mdconsult.com.ezproxy1.library.arizona.edu/books/page.do?eid=4-u1.0-B978-0-443-06959-8..00052-2–s1220&isbn=978-0-443-06959-8&sid=1303276206&uniqId=331951233-3#4-u1.0-B978-0-443-06959-8..00052-2–s1290
  6. Wong, G., et al. (2004). Effect of Neurolytic Celiac Plexus Block on Pain Relief, Quality of Life, and Survival in Patients With Unresectable Pancreatic Cancer: A Randomized Controlled Trial. JAMA , 1092-1099.