Researchers have said that too little is known about how neuropathic pain develops after bariatric surgery and that lack of knowledge imperils patient care. The study results were presented results of a literature search in a scientific poster at the 30th Annual Meeting of the American Academy of Pain Medicine.
Neurologic complications occur in 5% to 16% of patients, including the development of peripheral neuropathies, which account for up to 62% of such complications (Koffman et al, Muscle Nerve 2006;33(2):166-76). Pain is usually the first symptom in post-surgical neuropathies, which can also cause weakness, numbness and tingling, often in the hands and feet.
"The malabsorption and restricted volume intake concepts exploited by bariatric procedures are not without long-term complications," said Vasanth Kattalai Kailasam, MD, of the Harlem Hospital Center, affiliated with the College of Physicians and Surgeons at Columbia University in New York, N.Y. "Chronic neuropathic pain has a great impact on quality of life in the long run."
In recognition that the factors leading to post bariatric surgery neuropathic pain (PBSNP) have not been well clarified, the investigators searched PubMed, MEDLINE, Google Scholar, EMBASE and the Cochrane Database of Reviews for studies published since 1990. They identified 3 high-quality retrospective cohort studies and case series with a focus on PBSNP (Juhasz-Pocsine et al, Neurology 2007;68(21):1843-50; Thaisetthawatkul et al, Neurology 2004;63:1462-70; Fragoso et al, Arq Neuropsiquiatr 2012;70(9):700-3) and offer the following findings:
- Despite the belief that difficulty in absorbing nutrients may lead to PBSNP, nutritional counseling and follow up failed to slow its development
- Almost two-thirds of 90 bariatric surgery candidates in 1 study had a psychiatric diagnosis, most commonly mood and anxiety disorders, which could affect pain perception
- An observed high prevalence of diabetes mellitus could affect pain development
- Bariatric surgery patients were at risk for reduced bioavailability of ingested medications; for example, a bariatric surgery group absorbed about 40% less duloxetine compared to a nonsurgery control group
- No evidence-based treatment protocol for PBSNP was found
"The studies tell us that we know very little about neuropathic pain in the post bariatric surgery scenario," Dr. Kattalai Kailasam said. "It would be important to start up with identification of precise pathophysiology and incidence of PBSNP."
In the meantime, Dr. Kattalai Kailasam recommended more research into transdermal and parenteral analgesics for neuropathic pain, neuromodulation techniques and behavioral therapy methods for effective management and improved quality of life in PBSNP patients, as well as further research on the optimal dosage of medication to achieve adequate pain control in light of changes to analgesic absorption following the procedure.
Poster 169 - Management of Post Bariatric Surgery Neuropathic Pain (PBSNP): Review of Available Evidence