Abstract
The authors provide an interesting and thought-provoking review of a large single-center experience with a complex clinical entity, which although rare in general urologic practice requires a conscientious effort to evaluate. It is especially pertinent to urologists in the academic setting, particularly those linked to spinal cord disease/injury units. The authors must be commended for sharing their vast experience in this regard.
The article raises several questions as to how to best serve this group of patients to minimize the risk incurred by these necessary and definitive procedures. The authors point out that despite perioperative antifungal therapy, more than half of the patients who developed a systemic inflammatory response syndrome (SIRS) had received a full course of treatment. Furthermore, one-third had received single-dose coverage. This is eerily reminiscent of the experience with antibiotic prophylaxis for prostate biopsy, although several orders of magnitude smaller in incidence.
In addition, in those that received full course antifungal therapy, routine documentation of resolution before the procedure was not uniform. Although this could be viewed as a prerequisite, it may also delay definitive intervention and sterile urine may not eliminate SIRS or sepsis.
The authors take several measures to minimize the risk of complications including the use of access sheaths for ureteroscopy and lower pressure irrigation. The preference was for prone percutaneous stone removal. Pressures during prone percutaneous lithotripsy can rise to levels that permit absorption of fluid, fluid that could contain organisms implicated in the SIRS or sepsis. Intact removal, minimal stone disruption, or the use of lithotrite and access/drainage systems enhanced by suction may further ensure low pressures.
Although metabolic evaluation and medically directed therapies will be of value in addressing asymptomatic stones to prevent growth progression and certainly in patients otherwise at the extremes of risk for any intervention, it is unlikely that any medical therapies will result in resolution of these types of stones. As such, comprehensive prevention strategies with close endourologic and lithometabolic along with neurourologic collaboration are essential to ensure that the first stone procedure is, indeed, the last one.
Questions that remain unanswered are how to manage the tubes before intervention and is the stone size in this scenario amenable to treatment by the guidelines approach or should smaller stones mandate intact percutaneous removal rather than ureteroscopy? 1 Should patients with nephrostomy tubes in place have them exchanged followed by instillation of an antifungal agent for a period of days before the definitive percutaneous procedure? Similarly, should patients with chronic stents have them exchanged and antifungal irrigation instituted through a urethral catheter or a parallel ureteral catheter before the ureteroscopic procedure? If so, for how long?
Expert consensus is warranted as a 30% readmission rate remains of concern.