<p><strong>Prior to procedural intervention in patients with LUTS/BPH, clinicians should obtain a PVR. (<em>Clinical Principle</em>)</strong></p>
Discussion
Discussion
<p>The assessment of PVR can help clinicians to assess and monitor improvements of incomplete bladder emptying. The etiology of an elevated PVR does not necessarily mean BOO caused by BPH since it can also be increased in patients with DU or other obstructive etiologies. The PVR assessment can be done by catheterization, bladder scan, or transabdominal ultrasound. The use of PVR to diagnose BOO has an accuracy of only 63% if a PVR threshold of 50 mL is used. However, larger PVR volumes may indicate poor response to watchful waiting and has been identified as a risk factor for poor response to treatment in large clinical trials.<sup>116-118</sup> There is no established threshold for PVR that would predict treatment failure and the need for surgery. Subsequent increases in PVRs can be associated with treatment failure and warrant further workup, especially in patients with associated symptoms such as overflow incontinence, bladder stones, hydronephrosis, and/or worsening of renal function. In patients with obstructive uropathy and highly elevated PVRs, proper workup should be performed to identify the etiology and guide the treatment decision. When a PVR is abnormal prior to surgical intervention, postoperative assessment can be a useful tool for postoperative monitoring. </p>