Ryotaro Tomida, Tomoya Fukawa, Yoshito Kusuhara, Keisuke Hashimoto, Marika Atagi, Fumiya Kadoriku, Testuhiro Yano, Mitsuki Nishiyama, Kyotaro Fukuta, Saki Kobayashi, Ryoei Minato, Keito Shiozaki, Kei Daizumoto, Yutaro Sasaki, Tadanori Hosokawa, Kazuyoshi Izumi, Iku Ninomiya, Kunihisa Yamaguchi, Yasuyo Yamamoto, Hirofumi Izaki, Takushi Naroda, Masahito Yamanaka, Kenjiro Okamoto and Junya Furukawa : Perioperative outcomes after Robot-assisted partial nephrectomy for very small (2cm) versus larger small (>2-4cm) renal tumors: a multi-institutional propensity score-matched study., Journal of Robotic Surgery, 20, 1, 2026.
(要約)
The detection of incidentally identified small renal masses has increased, prompting greater use of nephron-sparing procedures. Robot-assisted partial nephrectomy (RAPN) is established for tumors4cm; however, evidence directly comparing its use for very small tumors (2cm) and slightly larger lesions (>2-4cm) is limited, particularly in Asian populations. We evaluated how tumor size affects perioperative outcomes, renal function preservation, and oncological safety in RAPN. The data of 649 Japanese patients who underwent RAPN for clinically localized renal cell carcinoma were retrospectively analyzed. Patients were grouped according to maximal tumor diameter (2cm or >2-4cm). Propensity score matching was performed to mitigate disparities in patient backgrounds including tumor complexity and location. Outcomes assessed included operative and console times, warm ischemia time, estimated blood loss (EBL), postoperative complications, trifecta and pentafecta achievement, renal functional preservation, and recurrence-free survival (RFS). After matching, 193 patient pairs were included. Tumors2cm were associated with significantly shorter operative and console times, lower warm ischemia, reduced EBL, fewer major complications, and higher trifecta achievement, compared with tumors>2-4cm. Renal function preservation was comparable between groups. Oncological outcomes were excellent in both cohorts, with 5-year RFS of 98.2% and 98.0% for tumors2cm and >2-4cm, respectively. RAPN for tumors2cm offers superior perioperative outcomes without compromising oncological control, compared with that for tumors>2-4cm. These findings support RAPN as a safe and effective nephron-sparing approach for managing incidentally detected sub-2cm renal tumors.
Yutaro Sasaki, Kunihisa Yamaguchi, Kohei Kamoi, Asaka Tada, Keito Shiozaki, Ryotaro Tomida, Tomoya Fukawa and Junya Furukawa : Clinical Application of Three-Dimensional Printed Donor Kidney Models in Recipient Surgery for Living Donor Kidney Transplantation, Surgical Innovation, 15533506261417220, 2026.
(要約)
IntroductionIn living donor kidney transplantation, recipient surgery is often performed concurrently with donor nephrectomy, limiting preoperative understanding of graft anatomy before graft arrival. This study evaluated the feasibility, safety, and perceived usefulness of intraoperative application of sterilized three-dimensional (3D) printed donor kidney models for surgical planning.MethodsPatient-specific 3D kidney models were created from preoperative contrast-enhanced computed tomography using SYNAPSE VINCENT software, printed with a Cara Print 4.0 Pro, and gas sterilized for intraoperative use. Ten consecutive transplants using 3D models (June 2024-July 2025) were compared with the most recent 10 without models (June 2022-May 2024). Surgical outcomes were analyzed, and eight surgeons completed a 5-point Likert scale questionnaire on accuracy, handling, and usefulness.ResultsThe models reproduced donor kidney anatomy with reasonable accuracy. Surgeons reported benefits for graft orientation, anastomosis, and graft bed preparation, especially for less-experienced surgeons. Handling was satisfactory, although vessel rigidity was noted. No intraoperative complications, graft damage, or contamination events were attributable to model use, and overall surgical outcomes were comparable between groups.ConclusionsIntraoperative use of sterilized 3D-printed donor kidney models is feasible, safe, and cost-effective. These models may serve as practical adjuncts for surgical planning, anatomical visualization, and education in living donor kidney transplantation. Further multicenter studies are warranted to validate their broader clinical and educational impact.
(キーワード)
3D-printed donor kidney model / living donor kidney transplantation / recipient surgery
Yutaro Sasaki, Kazuyoshi Izumi, Kyotaro Fukuta, Fumiya Kadoriku, Kei Daizumoto, Keito Shiozaki, Tomoya Fukawa, Yutaka Yanagihara, Hirofumi Izaki, Kenjiro Okamoto, Masahito Yamanaka and Junya Furukawa : Robot-Assisted Radical Cystectomy in the Very Elderly: A Propensity Score-Matched Comparison of Outcomes Between Patients Aged ≥ 85 Versus 75-84 Years, Geriatrics & Gerontology International, 26, 1, e70346, 2026.
(要約)
This study evaluated the safety and efficacy of robot-assisted radical cystectomy (RARC) in patients aged ≥ 85 years versus 75-84 years, using propensity score matching (PSM) and inverse probability of treatment weighting (IPTW). We retrospectively reviewed 479 RARC cases, including 26 patients aged ≥ 85 years and 193 aged 75-84 years, from four Japanese institutions (2014-2025). Patients were matched 1:2 by sex, ECOG-PS, ASA-PS, clinical stage, and neoadjuvant chemotherapy. Surgical outcomes, complications, and survival (OS, CSS, RFS) were analyzed. IPTW-adjusted Cox models assessed survival differences. Postmatching, baseline characteristics were balanced except for age. Intracorporeal urinary diversion was performed for ileal conduit and orthotopic neobladder cases. Ureterostomy was more frequent in the ≥ 85-year group; LND was less frequent (67% vs. 92%, p = 0.024). Operative time was shorter (380 vs. 428 min, p = 0.041), while blood loss, transfusion, hospital stay, and complications were similar. Kaplan-Meier analysis showed lower 3-year OS in the ≥ 85-year group (59% vs. 83%, p = 0.042), whereas CSS (77% vs. 85%, p = 0.666) and RFS (55% vs. 71%, p = 0.662) were comparable. IPTW-adjusted Cox regression showed no significant differences in OS (HR 1.34, 95% CI 0.69-2.59, p = 0.386), CSS (HR 0.76, 95% CI 0.27-2.18, p = 0.613), or RFS (HR 0.81, 95% CI 0.35-1.87, p = 0.614). RARC is feasible and safe in patients aged ≥ 85 years. Perioperative outcomes, CSS, and RFS were comparable to those aged 75-84 years, while lower OS likely reflects age-related factors, supporting RARC as a viable option for well-selected very elderly patients.
(キーワード)
inverse probability of treatment weighting / patients aged ≥ 85 years / propensity score matching / robot-assisted radical cystectomy
Kyotaro Fukuta, Yutaro Sasaki, Kei Daizumoto, Kazuyoshi Izumi, Fumiya Kadoriku, Seiya Utsunomiya, Keito Shiozaki, Takeshi Nakashima, Tomoya Fukawa, Ryoichi Nakanishi, Hirofumi Izaki and Junya Furukawa : Prognostic Significance of Achieving the Radical Cystectomy-Pentafecta After Neoadjuvant Chemotherapy and Robot-Assisted Radical Cystectomy, International Journal of Urology, 33, 1, e70283, 2025.
(要約)
This collaborative, multi-institutional retrospective study aimed to evaluate whether achieving the radical cystectomy-pentafecta contributes to improved outcomes in patients with muscle-invasive bladder cancer undergoing neoadjuvant chemotherapy followed by robot-assisted radical cystectomy. We retrospectively analyzed 195 patients with muscle-invasive bladder cancer who underwent robot-assisted radical cystectomy with intracorporeal urinary diversion at four affiliated institutions. All had a minimum follow-up of 12 months. According to previously established criteria, patients who simultaneously demonstrated (i) negative soft tissue surgical margins, (ii) ≥ 16 lymph node yield, (iii) absence of major complications at 90 days, (iv) absence of urinary diversion-related long-term sequelae, and (v) absence of clinical recurrence in the first year were considered to have achieved the radical cystectomy-pentafecta. The overall radical cystectomy-pentafecta achievement rate was 46.2% (46.5% in the neoadjuvant chemotherapy group and 45.3% in the no chemotherapy group). In the neoadjuvant chemotherapy group, patients who achieved the radical cystectomy-pentafecta demonstrated significantly better overall survival (p = 0.038), cancer-specific survival (p = 0.009), and recurrence-free survival (p < 0.001) than those who did not. The radical cystectomy-pentafecta is a valuable tool to assess the quality of robot-assisted radical cystectomy with intracorporeal urinary diversion. Its achievement may be associated with improved outcomes in patients with muscle-invasive bladder cancer undergoing neoadjuvant chemotherapy prior to surgery.
Yutaro Sasaki, Saki Kobayashi, Kei Daizumoto, Fumiya Kadoriku, Marika Atagi, Tetsuhiro Yano, Mitsuki Nishiyama, Ryoei Minato, Keito Shiozaki, Ryotaro Tomida, Yoshito Kusuhara, Kunihisa Yamaguchi, Tomoya Fukawa, Yasuyo Yamamoto and Junya Furukawa : Use of the Assistent Guide Facilitates Ureteral Stent Placement in Robot-Assisted Pyeloplasty., Asian Journal of Endoscopic Surgery, 18, 1, e70178, 2025.
(要約)
In robot-assisted pyeloplasty, intraoperative placement of a double-J ureteral stent (DJ stent) is an essential step to ensure ureteral patency and anastomotic healing. However, the procedure can be technically demanding because of limited tactile feedback and the need for precise coordination between the console surgeon (CS) and the patient-side surgeon (PSS). To address these challenges, we applied the Assistent guide (UMIHIRA Co. Ltd., Kyoto, Japan), originally developed for robot-assisted intracorporeal ileal conduit diversion. The device is a stainless-steel instrument with a blunt tip and side hole, accommodating all stent sizes and insertable through a 5-mm trocar. During RAPP, the PSS advances the guide through the trocar to the ureteral anastomosis, the CS inserts the guidewire under direct vision, and the PSS advances the DJ stent antegrade along the guidewire. The CS provides countertraction to stabilize the ureter. Since August 2022, six patients underwent RAPP using this technique. Stent placement was successful in all cases without complications such as stent damage, malpositioning, or ureteral injury. The PSS reported smooth handling and reliable torque transmission compared with conventional methods. The Assistent guide costs approximately ¥80 000 per device and is reusable. Although limited by sample size and single-institution experience, this technique provides a practical solution to a technically challenging step in RAPP. Further multi-institutional evaluation is warranted to confirm safety, efficacy, and broader applicability.