Upper tract urothelial carcinoma (UTUC) is a clinically aggressive malignancy arising from the urothelium of the renal pelvis and ureter^[1]. High-risk disease is frequently diagnosed at an advanced stage and most often leads to surgical intervention. Although open radical nephroureterectomy (NU) with bladder-cuff excision was historically the gold standard, this is a highly invasive operation associated with significant perioperative morbidity^[1]. Over the last three decades, surgeons have increasingly adopted minimally invasive techniques to reduce operative morbidity while maintaining oncologic control^[2]. As current uro-oncology advances toward risk-stratified and biomarker-informed care, surgical approaches must also balance oncologic effectiveness with patient-specific morbidity and recovery outcomes.

Reflecting this evolution, robot-assisted nephroureterectomy (RANU) on multiport (MP) platforms provides enhanced visualization and wristed instrumentation through several small incisions and has demonstrated favorable perioperative profiles relative to open surgery^[3]. More recently, the da Vinci single-port (SP) platform has enabled true single-site access and facilitated retroperitoneal and extraperitoneal approaches, expanding the surgical options for complex cases^[4]. In the context of NU, these features translate into avoiding the peritoneum altogether with a small single incision allowing retroperitoneal access, reduced bowel manipulation, decreased postoperative pain, and shorter convalescence, preserving the ability to perform multi-quadrant operations through a single docking site^[5,6]. Regarding oncologic control and renal function, a 105-patient study comparing single-port RANU (SP-RANU) and multiport RANU (MP-RANU) demonstrated no statistically significant differences in surgical outcomes, one-year renal function decline, or tumor (T) stage^[7].

Despite the uptake of SP techniques across urology, evidence specific to SP-RANU remains limited. Published reports consist largely of feasibility series and institutional experiences describing techniques, access routes, and early outcomes^[8,9]. Robust data that benchmark SP-RANU are needed to clarify safety, reproducibility, and oncologic equivalence. Additionally, more data is needed to guide standardization of operative workflow and define where SP-RANU may best fit within individualized treatment algorithms for UTUC^[1,2].

Herein we describe our initial series of SP-RANU, detailing and characterizing short-term intraoperative, perioperative, and postoperative outcomes.

Six SP-RANU cases were included in this analysis [Table 1]. Four patients were male (67%), and two (33%) patients were female. The median age at surgery was 75 years (IQR 68-77). All patients had a prior history of abdominal surgery. All patients had American Society of Anesthesiologists (ASA) scores ranging from 2 to 3 and Eastern Cooperative Oncology Group (ECOG) performance status ranging from 0 to 2.

Four patients (67%) underwent SP-RANU via low anterior access, while two patients (33%) underwent surgery via lateral flank access. Median operative time was 297 min (IQR 248-368) and median estimated blood loss was 325 mL (IQR 213-625). There were no documented intraoperative complications.

Five cases of SP-RANU were performed for oncologic indications. The five tumors removed had tumor grades ranging from pTa to pT3. One case of SP-RANU was performed in the setting of an atrophic kidney with severe hydronephrosis and known ureteral stricture. Lymph node dissection was performed in one procedure with one ipsilateral perihilar lymph node removed. The pathology of both the tumor and lymph node from this specimen revealed high-grade urothelial carcinoma. This was the highest graded tumor of the series - the remaining four specimens removed exhibited low grade urothelial carcinoma. All cases of SP-RANU performed for oncologic purposes resulted in negative margins. No patients exhibited evidence of local oncologic recurrence at follow-up; however, the one patient with high-grade urothelial carcinoma experienced distant metastasis. This patient underwent immunotherapy and chemotherapy, with no evidence of cancer on most recent PET scan. In the setting of a short median follow-up duration, these oncologic findings should be interpreted cautiously and are primarily presented descriptively.

Postoperatively, the median hospital length of stay (LOS) following SP-RANU was 1.5 days (IQR 1-5). The median postoperative time with Foley catheter was 4 days (IQR 3-4). Two patients experienced post-operative Clavien-Dindo Grade II complications. One patient experienced a transient acute kidney injury (AKI) and postoperative ileus that resolved with conservative management. A second patient was noted postoperatively to be in atrial fibrillation with rapid ventricular response and was treated medically in the surgical ICU where he subsequently converted to sinus tachycardia. The patient was discharged the following morning, on post-operative day 1.

The median pre-operative creatinine was 1.1 mg/dL (IQR 0.9-1.2), median post-operative day one creatinine was 1.3 mg/dL (IQR 1.2-1.6), and median creatinine on day of discharge was 1.2 mg/dL (IQR 1.1-1.7). Median pre-operative Ce [estimated glomerular filtration rate (eGFR)] was 72 mL/min/1.73 m² (IQR 66.8-78), median post-operative day one eGFR was 57.5 mL/min/1.73 m² (IQR 45-67), and median eGFR on day of discharge was 65.5 mL/min/1.73 m² (IQR 41.5-70.8). There was a median reduction of eGFR between pre-operative and discharge values of 9 mL/min/1.73 m² (IQR 3.3-17).

Five patients required narcotics post-operatively while inpatient, and two patients were discharged without narcotic pain medication. The remaining four patients were discharged with multimodal pain management. The 30-day readmission rate was 33%.

This single-institution series demonstrates SP-RANU as both a safe and feasible surgical approach for patients undergoing radical NU. No intraoperative complications were observed, median estimated blood loss was 325 mL, and median LOS was 1.5 days, demonstrating promising early perioperative outcomes within the range of previously published robotic NU series^[10]. SP-RANU demonstrated a safe peri-operative profile, with two Clavien-Dindo II events occurring, neither requiring reoperation. These findings align with feasibility and safety signals of prior SP series and implementation reports^[5,9,11].

Within this series, perioperative profiles align with minimally invasive advantages seen with similar robotic platforms relative to open NU, including reduced transfusions, shorter hospitalizations and less pain while still preserving oncologic outcomes^[2]. While this study does not directly compare SP-RANU with MP-RANU, the rate of intraoperative complications, operative times, estimated blood loss, and other intraoperative factors are consistent with MP-RANU series^[2,12]. Taken together with prior SP reports, these findings support the technical feasibility of SP-RANU and suggest that acceptable early perioperative outcomes may be achievable in carefully selected patients.

From a technical standpoint, the variability in operative time (median 297 min; range 199-578 min) likely reflects an early learning curve and variability in case complexity. The SP requires additional surgical training to optimize efficiency as teams standardize port placement and instrument sequencing. In particular, the ability to complete bladder-cuff excision and upper-tract dissection within a single docking is a core SP advantage in NU cases. These platform characteristics may be most impactful in patients with significant prior abdominal surgery where retro-/extraperitoneal approaches reduce bowel manipulation, potentially lowering ileus risk and facilitating earlier discharge^[1,5,9].

One possible advantage of SP-RANU is a minimized need for postoperative opioid pain management. With low inpatient postoperative opioid use [median morphine milligram equivalen (MME) 77 mg] and one patient requiring no inpatient opioid pain management at all, the SP approach was associated in this series with minimal postoperative pain burden for patients and less narcotic use, translating to faster patient recovery and shorter hospital stays. Additionally, two patients required no narcotic pain management at discharge, and those who did require narcotics utilized a median MME of 45 mg - supporting multimodal pain management as an adequate strategy for discharge pain management. Similarly, this series showed minimal difference between pre- and post-operative creatinine or eGFR in patients undergoing SP-RANU.

The long-term outcomes of our patients in this study are limited by the short follow-up duration and small sample size. Although no local recurrence was observed at most recent follow-up, definitive conclusions regarding oncologic equivalence, recurrence-free survival, metastasis-free survival, or long-term renal functional preservation cannot be made in the setting of this sample size. The patient with pathologic node positive disease at the time of NU experienced distant recurrence (left supraclavicular lymph node) and was treated with systemic therapy. Importantly, the heterogeneity in tumor stage, grade, and nodal status within this cohort suggests that oncologic outcomes may be influenced by underlying tumor biology in addition to surgical platform. These factors should be considered when interpreting early results. Of the two Clavien-Dindo Grade II events occurring, neither required reoperation. There were no documented long-term complications, supporting the overall safety profile of SP-RANU.

Strengths of this study include the breadth of data gathered in combination with the consistent technique and protocol coming from the single institution. This provides uniformity in data and lends credence to the safety, feasibility, and effectiveness of SP-RANU. Conversely, this study is limited by its small single-center sample size, which reduces generalizability. Additionally, the small sample size limits comparison between the two different surgical approaches used (LAA vs. LFA), for which further research is required. The biologic heterogeneity of included tumors further limits broad comparisons across cases. Selection bias presents an additional limitation. The SP approach was selected according to specific reasons including surgeon discretion, anatomy, and disease characteristics, potentially adding bias within the cohort toward favorable operative candidates. As a result, this bias may limit generalizability to broader UTUC populations. Although previously reported meta-analyses suggest robotic NU is comparable to open NU in terms of oncologic control, determining whether SP-RANU surpasses MP-RANU for intravesical recurrence, metastasis-free survival, and overall survival will require larger cohorts, longer follow-up, and uniform imaging surveillance^[13].

Beyond surgical technique alone, modern UTUC management increasingly incorporates molecular heterogeneity, genomic alterations, and biomarker-driven therapeutic strategies. FGFR3 alterations have emerged as a clinically relevant marker in subsets of urothelial carcinoma and may influence future risk stratification and targeted therapeutic approaches^[14,15]. Additionally, evolving urinary and circulating cell-free DNA (cfDNA) surveillance strategies may eventually help better postoperative monitoring and recurrent detection following NU^[16,17]. While these translational approaches were beyond the scope of this surgical series, future studies integrating molecular profiling with perioperative outcomes may further optimize patient selection and direct personalized management in SP-RANU.

In conclusion, SP-RANU offers a safe, feasible, minimally invasive surgical option for select patients requiring NU for both oncologic and benign indications. SP-RANU was associated in this early series with a less invasive approach with low rates of intraoperative complications, shortened length of hospital stay, and postoperative pain control with minimal use of opioid pain medications. The SP platform’s ability to complete multi-quadrant tasks through a single docking access provides an effective and adaptable surgical approach while minimizing bowel manipulation and incision burden. These preliminary findings suggest that SP-RANU may offer promising early perioperative outcomes in carefully selected patients. However, definitive conclusions regarding oncologic equivalence or long-term cancer control cannot yet be established. As experience grows and technique refines, SP-RANU offers a promising surgical option within the NU landscape for patients who will benefit from the most minimally invasive technique.