CORR Insights®: Lower Urinary Tract Symptoms and Urinary Bother Are Common in Patients Undergoing Elective Cervical Spine Surgery

Where Are We Now?

Lieberman and colleagues [3] performed a cross-sectional study on patients undergoing cervical spine surgery to investigate the incidence of lower urinary tract symptoms (LUTS) in this population. They found that a high proportion of patients (40%) undergoing cervical spine surgery also had LUTS, which is higher than that seen in the general population. Moreover, they found that LUTS was more common in patients with myelopathy than in those without myelopathy. While increased incidence of LUTS has been demonstrated in the lumbar spine [2], this paper in Clinical Orthopaedics and Related Research® [3] is the first of which I am aware to identify increasing risk of LUTS in patients with surgical cervical spine conditions.

These findings are extremely important, as preoperative identification of these symptoms are crucial for later differentiating between worsening spinal symptoms and emergent conditions such as cauda equina syndrome. When faced with a patient after spine surgery who has urinary difficulty, and in the absence of adequate baseline data about the risk of LUTS and how it presents, clinicians often feel the need to err on the side of evaluating such a patient using expensive tests, like MRIs. This study provides the basic background information to help tease out true clinical emergencies from baseline bladder bother, perhaps raising the threshold to perform unnecessary tests.

Where Do We Need To Go?

An important question to consider from this study is why the amount of cord compression, cord signal and canal compromise did not affect the severity LUTS. This concept underscores how poorly spinal cord architecture and physiology are currently understood. We might expect bladder issues to increase generally linearly with apparent radiographic cord damage, yet this appears not to be the case. To predict accurately what functional pathways are affected by cord compromise, we need to be able to corelate radiographic findings with clinical findings to know exactly which patients are at risk for urinary dysfunction.

Furthermore, correlating imaging findings to objective measures such as post-void residual bladder volumes would help sharpen the connection between myelopathy and urinary bother. Such measures might indeed correspond to radiographic compression, but the connection might be missed in studies based on subjective surveys, which can be influenced by recall bias and imprecision in survey instruments.

While Lieberman and colleagues [3] have furthered our understanding of how cervical pathology and lumbar pathology contribute to bladder dysfunction, we still need to learn more about how cervical and lumbar pathologies may interact when they present in tandem. Do patients with tandem stenosis exhibit worse urinary symptoms than those with isolated pathology?

Finally, it is important to consider how the effects of surgical intervention affect bladder function in the days following surgery. Do patients demonstrate a decrease in urinary symptoms following decompressive surgery? In addition, bladder dysfunction is often compounded by the effects of anesthesia and narcotic medication postoperatively. Understanding how to better delineate true bladder dysfunction resulting from baseline cervical disease, medication and emergency syndromes such as cauda equina would be of great benefit to the clinician.

How Do We Get There?

More detailed clinical studies examining patients with advanced imaging are necessary. Diffusion tensor imaging is a new modality that has shown promise in the evaluation of myelopathy [1, 4] and may be useful to help define specific imaging findings associated with bladder dysfunction. In addition, comparing bladder function after in a prospective study would help strengthen the relationship between spinal cord compression and urinary bother. Finally, studies that help us separate postoperative urinary bother caused by an exacerbation of baseline symptoms (such as might occur from anesthetics and analgesic drugs after surgery) from symptoms caused by emergent conditions like cauda equina will be particularly useful. This would require a prospective observational collection of urinary symptom data in this population and separation of the two groups based on predetermined criteria. Differences between the “severe” group and “routine LUTS group would then necessarily be identified posthoc to form and algorithmic model and gates for invoking workup and intervention.