In Vivo Evaluation of Corneal Biomechanics Following Cross-Linking Surgeries Using Optical Coherence Elastography in a Rabbit Model of Keratoconus.

Purpose: Validation of the feasibility of novel acoustic radiation force optical coherence elastography (ARF-OCE) for the evaluation of biomechanical enhancement of the in vivo model of keratoconus by clinical cross-linking (CXL) surgery. Methods: Twelve in vivo rabbit corneas were randomly divided into two groups. Both groups were treated with collagenase type II, and a keratoconus model was obtained. Then, the two groups were treated with CXL procedures with different irradiation energy of 15 J and 30 J (CXL-15 J and CXL-30 J, respectively). An ARF-OCE probe with an ultrasmall ultrasound transducer was used to detect the biomechanical properties of cornea. An antisymmetric Lamb wave model was combined with the frequency dispersion relationship to achieve depth-resolved elastography. Results: Compared with the phase velocity of the Lamb wave in healthy corneas (approximately 3.96 ± 0.27 m/s), the phase velocity of the Lamb wave was lower in the keratoconus region (P < 0.05), with an average value of 3.12 ± 0.12 m/s. Moreover, the corneal stiffness increased after CXL treatment (P < 0.05), and the average phase velocity of the Lamb wave was 4.3 ± 0.19 m/s and 4.54 ± 0.13 m/s after CXL-15 J and CXL-30 J treatment. Conclusions: The Young's moduli of the keratoconus regions were significantly lower than the healthy corneas. Moreover, the Young's modulus of the keratoconus regions was significantly higher after CXL-30 J treatment than after CXL-15 J treatment. We demonstrated that the ARF-OCE technique has great potential in screening keratoconus and guiding clinical CXL treatment. Translational Relevance: This work accelerates the clinical translation of OCE systems using ultrasmall ultrasound transducers and is used to guide CXL procedures.

Outcome of simultaneous thulium laser enucleation of bladder tumor and prostate in patients with non-muscle invasive bladder tumor and benign prostatic hyperplasia: a matched-pair comparison with a long-term follow-up.

OBJECTIVE: To access the surgical and oncological outcomes of simultaneous thulium laser enucleation of bladder tumor (ThuLEBT) and thulium laser enucleation of prostate (ThuLEP) in patients with non-muscle invasive bladder tumor (NMIBC) and benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: Between June 2009 and June 2017, 118 men with NMIBC who underwent simultaneous ThuLEBT and ThuLEP and fulfilled the inclusion criteria were matched with 118 patients who received ThuLEBT alone. Clinicopathological parameters, surgical outcome data and oncological outcomes were retrospectively analyzed and compared. RESULTS: The patients who underwent simultaneous ThuLEBT and ThuLEP experienced a longer length of operation time (70.4 vs. 25.5 min; p < 0.001), but there were no statistically significant differences in catheterization period, hospital stay and complication between the two groups. At a mean follow-up of 58.7 and 55.8 months in ThuLEBT/ThuLEP group and ThuLEBT group, no significant differences in overall recurrence rates, progression rates, recurrence in the bladder neck/prostatic fossa and mean elapsed time to recurrence were detected. The 5-year recurrence-free probability was 73.2% for ThuLEBT/ThuLEP and 69.2% for ThuLEBT (p = 0.361). CONCLUSIONS: Our results indicate that simultaneous ThuLEBT and ThuLEP can be safely performed without increasing the surgical risk and the risk of tumor recurrence and progression in patients with NMIBC and BPH, and it may be preferred alternative for select patients.

Thulium Laser-Assisted Versus Conventional Laparoscopic Partial Nephrectomy for the Small Renal Mass.

BACKGROUND AND OBJECTIVES: Laparoscopic partial nephrectomy (LPN) has gained acceptance as a minimally invasive treatment option for small renal masses (SRMs). Laser-assisted LPN (LLPN) provided a bloodless tumor excision without renal artery clamping owing to the excellent coagulative and hemostatic properties of the lasers. The primary aim of this study is to evaluate the technical feasibility and outcomes of 2-µm continuous thulium LLPN and conventional LPN (CLPN) in the treatment of patients with SRMs. STUDY DESIGN/MATERIALS AND METHODS: A retrospective analysis was performed for the medical charts of 312 patients with SRMs who underwent minimally invasive nephron-sparing surgery in our institution between January 2013 and December 2017. All 36 LLPN patients were matched with 36 CLPN patients. Surgical data, complications, pathological variables, oncological, functional, and health-related quality of life (HRQoL) outcomes were reviewed. RESULTS: The two groups were similar in demographic characteristics. The renal vessels were not clamped in the LLPN group. Compared with the CLPN group, patients in the LLPN group had shorter warm ischemia time (WIT) (0 vs. 12.4 minutes, P = 0.000), longer tumor resection time (9.5 vs. 2.2 minutes; P = 0.000), and decreased operative time (84.1 vs. 95.5 minutes, p = 0.029). There were no open conversions and no transfusion in both groups. Median follow-ups for LLPN and CLPN were 56.2 and 48.6 months, respectively. The complication rate, renal functional outcomes, local recurrence rates, recurrence-free survival rates, and SF-36 questionnaire score were similar between the two groups. CONCLUSIONS: Although this matched pair study showed CLPN had a longer WIT and higher operative time, the oncological and functional outcomes of LLPN and CLPN were similar. Both LLPN and CLPN are viable treatment options for select patients with SRMs. Lasers Surg Med. © 2019 Wiley Periodicals, Inc.

Impact of 120-W 2-µm continuous wave laser vapoenucleation of the prostate on sexual function.

The objective of this work is to evaluate the impact of 120-W 2-µm continuous wave (cw) laser vapoenucleation of the prostate in patients with benign prostatic hyperplasia (BPH) on sexual function. One hundred twenty-two consecutive patients with BPH were retrospectively collected in this study and were classified into two groups for surgical treatment with 2-µm cw laser vapoenucleation or transurethral resection of the prostate (TURP). International Index of Erectile Function (IIEF) and general assessment questions were completed before and 12 months after treatment to determine the impact on sexual function. A total of 33 patients (52.4%) in group 1 and 31 (52.5%) in group 2 reported various degrees of erectile dysfunction before surgery. Interestingly, an increase in IIEF-EF score by 2 points was reported by 16 (25.4%) and 14 (23.7%) patients, respectively, and mean EF score did show a marginal but not significant increase postoperatively in both group. Differences about orgasmic intercourse satisfaction, sexual desire domain, and overall satisfaction scores in each group were not significant between preoperative and postoperative, but there was a significant decrease in the orgasmic function domain score at 12 months postoperation in both groups (p < 0.001). The prevalence of postoperative retrograde ejaculation was significantly higher than at baseline assessment in two groups. This study demonstrates that there is no difference between 2 µm laser vapoenucleation and TURP in terms of impact on sexual function. No significant erectile function improvement was observed after surgery, but these two techniques significantly lowered the IIEF orgasmic function domain and this was mainly caused by retrograde ejaculation.

[Comparison of 2 µm continuous-wave laser enucleation of the prostate and transurethral resection of the prostate for benign prostatic hyperplasia].

OBJECTIVE: To compare the safety and efficacy of RevoLix 120 W 2 µm continuous-wave (cw) laser enucleation of the prostate with transurethral resection of prostate (TURP) in patients with symptomatic benign prostatic hyperplasia (BPH). And to evaluate clinical value of 120 W 2 µm cw laser enucleation. METHODS: All 168 patients with BPH underwent 2 µm cw laser enucleation (n = 88) or TURP (n = 80) between January 2010 and January 2011. The operative time, drop in hemoglobin, drop in serum sodium, indwelling catheterization time and operative complications were recorded. International prostate symptom score (IPSS), quality of life (QOL), urinary peak flow rate (Qmax) and post-voiding residual urine (PVR) were also compared. RESULTS: The mean operative time was slightly longer in the 2 µm laser group ((63.2 ± 21.6) min) than the TURP group ((59.4 ± 18.6) min) (P > 0.05). Transfusions were not necessary in 2 µm laser group. Catheter indwelling time were (1.8 ± 0.6) days vs. (3.5 ± 2.6) days in 2 µm laser group than in TURP group (t = 3.912, P < 0.05). All cases were followed up for 3 - 12 months, the IPSS, QOL, Qmax and PVR were 6.1 ± 2.0, 4.4 ± 1.6, (18.8 ± 4.8) ml/s and (21.6 ± 16.5) ml in the 2 µm laser group, and were 6.3 ± 2.4, 1.9 ± 1.1, (18.4 ± 4.2) ml/s, (23.2 ± 14.6) ml in TURP group respectively. All the markers were improved significantly compared with that of preoperative in both groups (t = 12.453 - 26.213, P < 0.01), but no statistical differences could be found between the two groups. Perioperative complications were less in the 2 µm laser group. CONCLUSIONS: The 120 W 2 µm cw laser enucleation is an novel excellent treatment for BPH as well as TURP, and has the advantage of significantly less blood loss, shorter hospitalization, shorter catheter indwelling time and rapid recovery after surgery.

Experimental and density functional theory study of the adsorption of N2O on ion-exchanged ZSM-5: part II. The adsorption of N2O on main-group ion-exchanged ZSM-5.

The adsorption and desorption of N2O on main-group ion-exchanged ZSM-5 was studied using temperature-programmed desorption (TPD) and density functional theory (DFT) calculations. TPD experiments were carried out to determine the desorbed temperature Tmax corresponding to the maximum mass intensity of N2O desorption peak and adsorption capacity of N2O on metal-ion-exchanged ZSM-5s. The results indicated that Tmax followed a sequence of Ba2+ > Ca2+ > Cs+ > K+ > Na+ > Mg2+ and the amount of adsorbed N2O on main-group metal cation followed a sequence of Ba2+ > Mg2+ > Ca2+ > Na+ > K+ > Cs+. The DFT calculations were performed to obtain the adsorption energy (Eads), which represents the strength of the interaction between metal cations and the N-end or O-end of N2O. The calculation results showed that the N-end of the N2O molecule was favorably adsorbed on ion-exchanged ZSM-5, except for Cs-ZSM-5. For alkali metal cations, the Eads of N2O on cations followed the order which was the same to that of Tmax: Cs+ > K+ > Na+. The calculated and experimental results consistently showed that the adsorption performances of alkaline-earth metal cations were better than those of alkali metal cations.