Is Holmium Laser Enucleation of the Prostate Truly Size-Independent? A Critical Evaluation at the Extreme Ends of the Spectrum.

OBJECTIVE: To assess the outcomes of holmium laser enucleation of the prostate (HoLEP) at the extremes of the size spectrum, comparing whether the results are consistent for very large and small prostates. METHODS: A retrospective review of 402 patient charts was conducted to compare the outcomes of HoLEP in patients with prostate size ≤40 g (group 1), 41-200 g (group 2), and >200 g (group 3). Various preoperative, perioperative, and postoperative variables were collected. RESULTS: HoLEP showed comparable voiding outcomes among all 3 groups, although patients with small prostates had a higher International Prostate Symptom Score during follow-up (P = .022). We noted a higher rate of perioperative blood transfusion in patients with very large prostates (P = .019) and a higher rate of transient acute urinary retention (AUR) in group 1 when compared to group 3 (P = .048). Patients with smaller prostates had a higher rate of bladder neck stenosis and urethral strictures, but the differences were not found to be statistically significant. The incidence of other complications, length of hospital stay, and catheterization duration did not differ significantly among the groups. CONCLUSION: HoLEP has consistent and safe outcomes across a wide range of prostate sizes. Although, the risk of blood transfusion is higher in patients with very large prostates and the risk of transient AUR is greater in patients with small glands, the overall efficacy and safety of HoLEP are not significantly influenced by prostate size.

Delayed fatigue in finger flexion forces through transcutaneous nerve stimulation.

OBJECTIVE: Weakness of the hand is a major impairment which limits independent living. Neuromuscular electrical stimulation (NMES) is a common approach to help restore muscle strength. Traditional NMES directly over the muscle often leads to a rapid onset of muscle fatigue. In this study, we investigated the force sustainability of finger flexor muscles using a transcutaneous nerve stimulation approach. APPROACH: Finger flexion forces and high-density electromyogram (HD EMG) signals were obtained while electrical stimulation was applied to the ulnar and median nerve bundles through a stimulation grid on the proximal arm segment. Stimulation was also applied to the finger flexor muscle belly targeting the motor point, serving as a control condition. The force produced from the two stimulation approaches were initially matched, and muscle fatigue was subsequently induced with 5 min of continuous stimulation. The rate of decay of the force and EMG amplitude were quantified, and the spatial distribution of the muscle activation during the sustained contraction was also evaluated. MAIN RESULTS: The proximal nerve stimulation approach induced a slower decay in both force and EMG, compared with the stimulation at the motor point. The spatial distribution of the elicited muscle activation showed that the proximal nerve stimulation led to a distributed activation across the intrinsic and extrinsic finger flexor muscles and also activated a wider area within the extrinsic muscle. SIGNIFICANCE: Our findings demonstrated that the stimulation of the proximal nerve bundles can elicit sustained force output and delayed decrease in the rate of force decline. This is potentially due to a spatially distributed activation of the muscle fibers, compared with the traditional motor point stimulation. Future development of our nerve stimulation approach may enable prolonged usage during rehabilitation or assistance for better functional outcomes.