Is Modeling Alone Enough for Management of Significant Curvature During Inflatable Penile Prosthesis (IPP) Implantation?
Although IPP insertion with modeling was described over 20 yrs ago, there has been a paucity of data since defining its role in significant curvature cases. Further, due to a historically reported 5% risk of urethral perforation when applying 2 traditional modeling cycles, many are apprehensive to utilize this procedure for significant deformities due to concerns regarding technical feasibility and durability. As such, debate continues amongst implanters regarding the optimal management of curvature during IPP surgery. In this contemporary series, we incorporate a modified modeling maneuver (MMM) incorporating as many cycles as necessary and evaluate its long-term utility in correcting significant curvature.
We reviewed our single surgeon series from Nov 2015 to Oct 2017. We identified all men with >/= 30° curvature undergoing MMM during IPP surgery (group MMM, Figure 1). Their outcomes were compared to IPP patients without significant (<30°) deformity that underwent no ancillary straightening (group NAS). Patients undergoing any other concomitant straightening procedure were excluded from both arms. Device outcomes and functionality were compared.</p>
Of 153 urologic prosthesis cases over the 2 year period, 96 patients (median f/u 15.6 mo) met criteria with 14 MMM and 82 NAS pts (mean age 60 vs. 62 yrs, p=0.36) undergoing analysis. Mean preoperative curvature for group MMM was 42.1 (range 30-90 degs) while post-curvature correction following MMM was significantly improved (mean 13.6 degs, range 5-30, p<0.0001). No patient in either arm sustained an intraoperative urethral perforation and one NAS (1/82, 1.2%) patient developed a urethral erosion >12 mo following IPP surgery (p=0.68). Infection rates between MMM and NAS groups were comparable (0% vs. 4.8%, p=0.40). All MMM patients on follow-up reported a functionally straight outcome and were using the device satisfactorily without pain or partner pain during coitus.
This represents the only known contemporary series critically assessing the utility of MMM in significant cases of penile curvature at the time of IPP placement. Based on our findings, modeling can be performed repetitively in severe cases of curvature with excellent and durable functional outcomes.