Does Inflammatory Bowel Disease Complicate Lumbar Fusion Outcomes?

Inflammatory bowel disease (IBD; Crohn’s disease and ulcerative colitis) is becoming increasingly more common among patients undergoing lumbar fusion, according to a retrospective, cross-sectional analysis of a nationwide database. Comorbid IBD was not linked to an increased risk for post-operative medical or surgical complications, but was associated with a longer length of stay and greater hospitalization charges in this study, as reported in the July issue of The Spine Journal.
Inflammatory bowel disease is becoming more common among patients who undergo lumbar fusion.The reason why IBD is becoming more common among patients undergoing lumbar fusion is unclear at this time. However, some possible explanations include “increased awareness about IBD, improved diagnostic modalities for IBD, and possibly a general lessening in the stigma of having IBD,” lead author Joseph Tanenbaum, PhD, told SpineUniverse. “It is therefore possible that we became better at identifying which patients have IBD over time, rather than there being an actual increase in the prevalence of IBD.” Dr. Tanenbaum is an epidemiologist and MD-PhD Candidate at Case Western Reserve University School of Medicine in Cleveland, Ohio.

Study Rationale
“Over the past 5 to 10 years, the spine surgeons on our team noticed an increase in the number of patients in their clinics who had some type of IBD (either ulcerative colitis or Crohn's disease) included in their medical record,” Dr. Tanenbaum explained. “Among other research interests, our research team at The Cleveland Clinic Center for Spine Health studies the safety and efficacy of common spine surgery procedures in diverse patient populations with an eye toward maximizing patient outcomes and delivering individualized care to each patient. If IBD patients are going to continue to represent a growing share of most spine surgeons’ practices, then it is important to understand both the epidemiology of IBD among spine surgery patients and whether it is safe to operate on IBD patients.”

Nationwide Database Analyzed
The researchers used the Nationwide Inpatient Sample database to identify 514,572 adult patients who underwent primary lumbar fusion between 1998 to 2011. Prevalence of IBD was assessed using ICD-9-CM codes.

A total of 1,791 patients (0.34%) who underwent lumbar fusion had an IBD diagnosis. This prevalence increased significantly over time from 0.21% in 1998 to 0.48% in 2011 (P<0.001). The likelihood of experiencing a post-operative complication was not significantly different among patients with or without IBD, after controlling for patient demographics, comorbidity burden, and hospital characteristics (adjusted odds ratio for with IBD, 1.1; P=0.08; Table).

The only post-operative outcome that was significantly different among patients with IBD was a longer length of stay (LOS) and greater hospitalization charges (Table).
Table. Multivariate Analysis of IBD as a Predictor of Lumbar Fusion Post-operative Complications.
In terms of patient demographics, patients with IBD were significantly older (median: 57 years vs. 55 years; P<0.001) and were more likely to be female (61% vs. 55%; P<0.0001), white (73% vs. 66%; P<0.0001), and have Medicare insurance (37% vs. 32%; P<0.001). In addition, patients with IBD were significantly more likely to have deficiency anemia (12% vs. 8%), arthritis (8% vs. 3%), chronic lung disease (17% vs. 13%), depression (17% vs. 11%), hypertension (48% vs. 42%), hypothyroidism (11% vs. 9%), and electrolyte imbalance (13% vs. 8%; P<0.0001 for all comparisons).

Key Takeaway Points
Calling the study a “very interesting read,” Reginald Q. Knight, MD MHA, said that key takeaways from the paper include the following: 1) the prevalence of IBD patients undergoing lumbar spine fusion is increasing, and 2) IBD is associated with an increase in hospital LOS and overall cost. Dr. Knight is Director of the Bassett Spine Care Institute at Imogene Bassett Medical Center and Vice President of Medical Affairs at AO Fox Memorial Hospital, both in Cooperstown, NY.

“Based on the article, I will be paying closer attention to IBD patients’ nutritional status prior to spinal surgery in general,” Dr. Knight told SpineUniverse. “Improved pre-operative nutritional status will hopefully reduce hospital LOS, which is the ultimate driver in hospital cost post-operatively.”

Samuel K. Cho, MD, viewed the key takeaway from the study to be that “Patients with IBD who undergo spinal fusion of the lumbar spine have similar outcomes as those without IBD with the exception of slightly prolonged length of hospital stay. The IBD diagnosis does not necessarily influence perioperative care.”

“There has been a plethora of large scale studies that utilize administrative databases in recent years,” said Dr. Cho, Associate Professor of Orthopaedics at the Icahn School of Medicine at Mount Sinai, New York, NY.“ While these studies provide high level, bird’s eye view of trends in spinal surgery and short-term outcomes and complications, the studies often lack granular details that may be more relevant to practicing clinicians.”

Disclosures
Dr. Tanenbaum and Dr. Knight have no relevant disclosures.

Dr. Cho is a paid consultant for Globus Medical and Medtronic and has received research support from Zimmer. He is also a board or committee member of the American Academy of Orthopaedic Surgeons, American Orthopaedic Association, AOSpine North America, Cervical Spine Research Society, North American Spine Society, and Scoliosis Research Society.