Can selective arterial clamping with fluorescence imaging preserve kidney function during robotic partial nephrectomy?

A Green Lantern for the Surgeon: A Review on the Use of Indocyanine Green (ICG) in Minimally Invasive Surgery

Indocyanine green (ICG) fluorescence imaging has revolutionized surgical practice across various medical and surgical specialties. This article reviews the clinical applications of ICG in abdominal, urological, thoracic, and gynecological surgery. ICG fluorescence imaging has been widely adopted in general surgery for various applications, including perfusion assessment, intraoperative visualization of the ureter, and tumor localization. It is particularly valuable in evaluating anastomotic leaks and aiding in precise tumor resection during minimally invasive surgeries. Studies have shown mixed results on its effectiveness in reducing anastomotic leak rates, highlighting the need for further research. In thoracic surgery, ICG facilitates the identification and resection of pulmonary bullae, as well as the precise localization of pulmonary nodules during video-assisted surgery. In urology, ICG aids in localizing renal tumors and guiding selective arterial occlusion during partial nephrectomy. Its role in identifying the lymphatic pathway in prostate cancer and sentinel lymph node biopsy in gynecological cancer is also discussed. Despite its benefits, the use of ICG fluorescence faces challenges such as limited tissue penetration, the potential for false results, a lack of standardized protocols, and high equipment costs. Nonetheless, it remains a powerful tool that could improve surgical outcomes.

Tracing the evolving dynamics and research hotspots in the kidney neoplasm and nephron sparing surgery field from the past to the new era

BACKGROUND

With increasing detection of small renal masses and accumulating evidence that nephron sparing surgery (NSS) could achieve oncological equivalence and functional superiority compared with radical nephrectomy (RN), NSS has become first-line therapy for some patients with localized renal masses.

OBJECTIVE

This study aims to review the publications in the kidney neoplasm and NSS field, exploring the research hotspots.

METHOD

Kidney neoplasm and NSS related publications before July 3th 2023 were obtained from the Web of Science Core Collection database. We then used bibliometric analysis to conduct performance analysis, citation analysis and co-citation network of publications, together with keyword co-occurrence analysis.

RESULTS

Seven thousand five hundred and sixty-four documents were finally retrieved, and the annual publications increased exponentially. The most productive authors were "KAOUK JH" and "GILL IS", while USA, and 12 American affiliations such as CLEVELAND CLINIC FOUNDATION and MAYO CLINIC were far leading in this field. Journal of Urology and European Urology were journals with the highest citations and h-index.

DISCUSSION

Through literature reviewing plus co-occurrence and clustering analysis, the therapeutic effects of partial nephrectomy (PN) versus RN on patients with localized renal cell carcinoma, different operative approaches of PN, and conservative NSS methods were deemed as the most focused topics.

CONCLUSION

Three aspects were the most important hotspots in this field. Firstly, how to provide the optimal management choices for different patients. Secondly, therapeutic effects of different management options and surgical techniques needed more prospective and randomized studies. Finally, more novel technologies and surgical techniques were required.

Biophotonics-Intraoperative Guidance During Partial Nephrectomy: A Systematic Review and Meta-analysis

CONTEXT

Partial nephrectomy (PN) with intraoperative guidance by biophotonics has the potential to improve surgical outcomes due to higher precision. However, its value remains unclear since high-level evidence is lacking.

OBJECTIVE

To provide a comprehensive analysis of biophotonic techniques used for intraoperative real-time assistance during PN.

EVIDENCE ACQUISITION

We performed a comprehensive database search based on the PICO criteria, including studies published before October 2022. Two independent reviewers screened the titles and abstracts followed by full-text screening of eligible studies. For a quantitative analysis, a meta-analysis was conducted.

EVIDENCE SYNTHESIS

In total, 35 studies were identified for the qualitative analysis, including 27 studies on near-infrared fluorescence (NIRF) imaging using indocyanine green, four studies on hyperspectral imaging, two studies on folate-targeted molecular imaging, and one study each on optical coherence tomography and 5-aminolevulinic acid. The meta-analysis investigated seven studies on selective arterial clamping using NIRF. There was a significantly shorter warm ischemia time in the NIRF-PN group (mean difference [MD]: -2.9; 95% confidence interval [CI]: -5.6, -0.1; p = 0.04). No differences were noted regarding transfusions (odds ratio [OR]: 0.5; 95% CI: 0.2, 1.7; p = 0.27), positive surgical margins (OR: 0.7; 95% CI: 0.2, 2.0; p = 0.46), or major complications (OR: 0.4; 95% CI: 0.1, 1.2; p = 0.08). In the NIRF-PN group, functional results were favorable at short-term follow-up (MD of glomerular filtration rate decline: 7.6; 95% CI: 4.6, 10.5; p < 0.01), but leveled off at long-term follow-up (MD: 7.0; 95% CI: -2.8, 16.9; p = 0.16). Remarkably, these findings were not confirmed by the included randomized controlled trial.

CONCLUSIONS

Biophotonics comprises a heterogeneous group of imaging modalities that serve intraoperative decision-making and guidance. Implementation into clinical practice and cost effectiveness are the limitations that should be addressed by future research.

PATIENT SUMMARY

We reviewed the application of biophotonics during partial removal of the kidney in patients with kidney cancer. Our results suggest that these techniques support the surgeon in successfully performing the challenging steps of the procedure.

Comparison of perioperative outcomes of selective arterial clipping guided by near-infrared fluorescence imaging using indocyanine green versus undergoing standard robotic-assisted partial nephrectomy: a systematic review and meta-analysis

BACKGROUND

This study employs a meta-analytic approach to investigate the impact of robotic-assisted partial nephrectomy, with and without near-infrared fluorescence imaging (NIRF-RAPN vs S-RAPN), on patients' perioperative outcomes and postoperative changes in renal function.

MATERIALS AND METHODS

The authors conducted a comprehensive and rigorous systematic review and cumulative meta-analysis of primary outcomes following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), AMSTAR (Assessing the Methodological Quality of Systematic Reviews) Guidelines, and Risk-of-Bias Tool (RoB2). To ensure a thorough search, the authors systematically searched five major databases, including Medline, PubMed, Cochrane Library, Scopus, and Web of Science, from databases' inception to April 2023.

RESULTS

No significant differences were found between the two groups in terms of age ( P =0.19), right side ( P =0.54), BMI ( P =0.39), complexity score ( P =0.89), tumor size ( P =0.88), operating time ( P =0.39), estimated blood loss ( P =0.47), length of stay ( P =0.87), complications ( P =0.20), transfusion ( P =0.36), and positive margins ( P =0.38). However, it is noteworthy that the NIRF-RAPN group exhibited significant reductions in warm ischemia time ( P =0.001), the percentage change in estimated glomerular filtration rate at discharge ( P =0.01) compared to the S-RAPN group.

CONCLUSION

This meta-analysis provides evidence that the group undergoing NIRF-RAPN showed a statistically significant protective effect on the estimated glomerular filtration rate (eGFR).

Technologic advances in robot-assisted nephron sparing surgery: a narrative review

BACKGROUND AND OBJECTIVE

Nephron sparing surgery (NSS) is the preferred management for clinical stage T1 (cT1) renal masses. In recent years, indications have expanded to larger and more complex renal tumors. In an effort to provide optimal patient outcomes, urologists strive to achieve the pentafecta when performing partial nephrectomy. This has led to the continuous technologic advancement and technique refinement including the use of augmented reality, ultrasound techniques, changes in surgical approach and reconstruction, uses of novel fluorescence marker guided imaging, and implementation of early recovery after surgery (ERAS) protocols. The aim of this narrative review is to provide an overview of the recent advances in pre-, intra-, and post-operative management and approaches to managing patients with renal masses undergoing NSS.

METHODS

We performed a non-systematic literature search of PubMed and MEDLINE for the most relevant articles pertaining to the outlined topics from 2010 to 2022 without limitation on study design. We included only full-text English articles published in peer-reviewed journals.

KEY CONTENT AND FINDINGS

Partial nephrectomy is currently prioritized for cT1a renal masses; however, indications have been expanding due to a greater understanding of anatomy and technologic advances. Recent studies have demonstrated that improvements in imaging techniques utilizing cross-sectional imaging with three-dimensional (3D) reconstruction, use of color doppler intraoperative ultrasound, and newer studies emerging using contrast enhanced ultrasound play important roles in certain subsets of patients. While indocyanine green administration is commonly used, novel fluorescence-guided imaging including folate receptor-targeting fluorescence molecules are being investigated to better delineate tumor-parenchyma margins. Augmented reality has a developing role in patient and surgical trainee education. While pre-and intra-operative imaging have shown to be promising, near infrared guided segmental and sub-segmental vessel clamping has yet to show significant benefit in patient outcomes. Studies regarding reconstructive techniques and replacement of reconstruction with sealing agents have a promising future. Finally, ERAS protocols have allowed earlier discharge of patients without increasing complications while improving cost burden.

CONCLUSIONS

Advances in NSS have ranged from pre-operative imaging techniques to ERAS protocols Further prospective investigations are required to determine the impact of novel imaging, in-vivo fluorescence biomarker use, and reconstructive techniques on achieving the pentafecta of NSS.

Exploring the Applications of Indocyanine Green in Robot-Assisted Urological Surgery: A Comprehensive Review of Fluorescence-Guided Techniques

This comprehensive review aims to explore the applications of indocyanine green (ICG) in robot-assisted urological surgery through a detailed examination of fluorescence-guided techniques. An extensive literature search was conducted in PubMed/MEDLINE, EMBASE and Scopus, using keywords such as "indocyanine green," "ICG", "NIRF", "Near Infrared Fluorescence", "robot-assisted", and "urology". Additional suitable articles were collected by manually cross-referencing the bibliography of previously selected papers. The integration of the Firefly^® technology in the Da Vinci^® robotic system has opened new avenues for the advancement and exploration of different urological procedures. ICG is a fluorophore widely used in near-infrared fluorescence-guided techniques. The synergistic combination of intraoperative support, safety profiles and widespread availability comprises an additional asset that empowers ICG-guided robotic surgery. This overview of the current state of the art illustrates the potential advantages and broad applications of combining ICG-fluorescence guidance with robotic-assisted urological surgery.

Spectral imaging enables contrast agent-free real-time ischemia monitoring in laparoscopic surgery

Laparoscopic surgery has evolved as a key technique for cancer diagnosis and therapy. While characterization of the tissue perfusion is crucial in various procedures, such as partial nephrectomy, doing so by means of visual inspection remains highly challenging. We developed a laparoscopic real-time multispectral imaging system featuring a compact and lightweight multispectral camera and the possibility to complement the conventional surgical view of the patient with functional information at a video rate of 25 Hz. To enable contrast agent-free ischemia monitoring during laparoscopic partial nephrectomy, we phrase the problem of ischemia detection as an out-of-distribution detection problem that does not rely on data from any other patient and uses an ensemble of invertible neural networks at its core. An in-human trial demonstrates the feasibility of our approach and highlights the potential of spectral imaging combined with advanced deep learning-based analysis tools for fast, efficient, reliable, and safe functional laparoscopic imaging.

European Association for Endoscopic Surgery (EAES) consensus on Indocyanine Green (ICG) fluorescence-guided surgery

BACKGROUND

In recent years, the use of Indocyanine Green (ICG) fluorescence-guided surgery during open and laparoscopic procedures has exponentially expanded across various clinical settings. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on this topic with the aim of creating evidence-based statements and recommendations for the surgical community.

METHODS

An expert panel of surgeons has been selected and invited to participate to this project. Systematic reviews of the PubMed, Embase and Cochrane libraries were performed to identify evidence on potential benefits of ICG fluorescence-guided surgery on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by the panel; they were then submitted to all EAES members through a two-rounds online survey and results presented at the EAES annual congress, Barcelona, November 2021.

RESULTS

A total of 18,273 abstracts were screened with 117 articles included. 22 statements and 16 recommendations were generated and approved. In some areas, such as the use of ICG fluorescence-guided surgery during laparoscopic cholecystectomy, the perfusion assessment in colorectal surgery and the search for the sentinel lymph nodes in gynaecological malignancies, the large number of evidences in literature has allowed us to strongly recommend the use of ICG for a better anatomical definition and a reduction in post-operative complications.

CONCLUSIONS

Overall, from the systematic literature review performed by the experts panel and the survey extended to all EAES members, ICG fluorescence-guided surgery could be considered a safe and effective technology. Future robust clinical research is required to specifically validate multiple organ-specific applications and the potential benefits of this technique on clinical outcomes.

Functional Outcomes after Selective Clamping in Robot-Assisted Partial Nephrectomy

This study aimed to assess the risks and benefits of selective clamping in robot-assisted partial nephrectomy (RAPN). We retrospectively analyzed 372 patients who had undergone RAPN at our hospital between July 2010 and March 2021. After propensity score matching between the full and selective clamping groups, perioperative outcomes and postoperative preservation ratio of the estimated glomerular filtration rate (eGFR) were compared at 6 and 12 months of follow-up. After propensity score matching, we evaluated 47 patients from each group. While no significant differences were observed in surgical time, warm ischemia time, or incidence rates of all grades of complications between the two cohorts, the estimated blood loss (EBL) was significantly lower in the full clamping group than in the selective clamping group (30 vs. 60, p = 0.046). However, no significant intergroup differences were observed in the postoperative preservation ratio of eGFR at 6 or 12 months of follow-up (full clamping 94.0% vs. selective clamping 92.7%, p = 0.509, and full clamping 92.0% vs. selective clamping 91.6%, p = 0.476, respectively). Selective clamping resulted in higher EBL rates than did full clamping in RAPN. However, selective clamping provided no renal functional advantage over full clamping in our propensity-score-matched cohort.

Clinical Benefits of Indocyanine Green Fluorescence in Robot-Assisted Partial Nephrectomy

Background: To compare the intraoperative and postoperative outcomes of indocyanine green (ICG) administration in robot-assisted partial nephrectomy (RAPN) and report the differences in the results between patients with benign and malignant renal tumors. Methods: From 2017 to 2020, 132 patients underwent RAPN at our institution, including 21 patients with ICG administration. Clinical data obtained from our institution’s RAPN database were retrospectively reviewed. Intraoperative, postoperative, pathological, and functional outcomes of RAPN were assessed. Results: The pathological results indicated that among the 127 patients, 38 and 89 had received diagnoses of benign and malignant tumors, respectively. A longer operative time (311 vs. 271 min; p = 0.006) but superior preservation of estimated glomerular filtration rate (eGFR) at 3-month follow-up (90% vs. 85%; p = 0.031) were observed in the ICG-RAPN group. Less estimated blood loss, shorter warm ischemia time, and superior preservation of eGFR at postoperative day 1 and 6-month follow-up were also noted, despite no significant differences. Among the patients with malignant tumors, less estimated blood loss (30 vs. 100 mL; p < 0.001) was reported in the ICG-RAPN subgroup. Conclusions: Patients with ICG-RAPN exhibited superior short-term renal function outcomes compared with the standard RAPN group. Of the patients with malignant tumors, ICG-RAPN was associated with less blood loss than standard RAPN without a more positive margin rate. Further studies with larger cohorts and prospective designs are necessary to verify the intraoperative and functional advantages of the green dye.

Application and clinical efficacy of modified early unclamping technique in robot-assisted laparoscopic partial nephrectomy

OBJECTIVE

To investigate the clinical safety and efficacy of a modified early unclamping technique in robot-assisted laparoscopic partial nephrectomy (RAPN).

METHODS

The clinical data of 38 patients with renal tumors who underwent the modified early unclamping technique in RAPN surgery admitted to the Department of Urology, the Third People's Hospital of Hangzhou and the First Affiliated Hospital of Nanchang University from January 2018 to April 2021 were retrospectively analyzed. The control group consisted of 78 patients with renal tumors who underwent standard clamping during the RAPN surgery completed by the same surgeon during the same period. The perioperative-related indicators and postoperative renal function recovery were analyzed and compared between the two groups.

RESULTS

All patients (n = 116) finished the RAPN successfully, and none were transferred to radical or open surgery in either group. The warm ischemia time in the modified early unclamping group was significantly lower than that in the standard clamping group (P < 0.001). After surgery, the renal function index at each time point in the modified early unclamping group was higher than that in the standard clamping group; renal function gradually returned to near preoperative levels after 3 months in both groups. Postoperative follow-up showed no tumor recurrence or metastasis.

CONCLUSION

The application of a modified early unclamping technique in RAPN surgery is safe and feasible. Compared with standard clamping, modified early unclamping can significantly shorten the warm ischemia time of kidneys without increasing the volume of intraoperative blood loss and complications, which helps to protect the postoperative renal function of patients.

New imaging technologies for robotic kidney cancer surgery

Objective

Kidney cancers account for approximately 2% of all newly diagnosed cancer in 2020. Among the primary treatment options for kidney cancer, urologist may choose between radical or partial nephrectomy, or ablative therapies. Nowadays, robotic-assisted partial nephrectomy (RAPN) for the management of renal cancers has gained popularity, up to being considered the gold standard. However, RAPN is a challenging procedure with a steep learning curve.

Methods

In this narrative review, different imaging technologies used to guide and aid RAPN are discussed.

Results

Three-dimensional visualization technology has been extensively discussed in RAPN, showing its value in enhancing robotic-surgery training, patient counseling, surgical planning, and intraoperative guidance. Intraoperative imaging technologies such as intracorporeal ultrasound, near-infrared fluorescent imaging, and intraoperative pathological examination can also be used to improve the outcomes following RAPN. Finally, artificial intelligence may play a role in the field of RAPN soon.

Conclusion

RAPN is a complex surgery; however, many imaging technologies may play an important role in facilitating it.

Could fluorescence-guided surgery be an efficient and sustainable option? A SICE (Italian Society of Endoscopic Surgery) health technology assessment summary

BACKGROUND

Indocyanine green fluorescence vision is an upcoming technology in surgery. It can be used in three ways: angiographic and biliary tree visualization and lymphatic spreading studies. The present paper shows the most outstanding results from an health technology assessment study design, conducted on fluorescence-guided compared with standard vision surgery.

METHODS

A health technology assessment approach was implemented to investigate the economic, social, ethical, and organizational implications related to the adoption of the innovative fluorescence-guided view, with a focus on minimally invasive approach. With the support of a multidisciplinary team, qualitative and quantitative data were collected, by means of literature evidence, validated questionnaires and self-reported interviews, considering the dimensions resulting from the EUnetHTA Core Model.

RESULTS

From a systematic search of literature, we retrieved the following studies: 6 on hepatic, 1 on pancreatic, 4 on biliary, 2 on bariatric, 4 on endocrine, 2 on thoracic, 11 on colorectal, 7 on urology, 11 on gynecology, 2 on gastric surgery. Fluorescence guide has shown advantages on the length of hospitalization particularly in colorectal surgery, with a reduction of the rate of leakages and re-do anastomoses, in spite of a slight increase in operating time, and is confirmed to be a safe, efficacious, and sustainable vision technology. Clinical applications are still presenting a low evidence in the literature.

CONCLUSION

The present paper, under the patronage of Italian Society of Endoscopic Surgery, based on an HTA approach, sustains the use of fluorescence-guided vision in minimally invasive surgery, in the fields of general, gynecologic, urologic, and thoracic surgery, as an efficient and economically sustainable technology.

Superselective Ischemia in Robotic Partial Nephrectomy Does Not Provide Better Long-term Renal Function than Renal Artery Clamping in a Randomized Controlled Trial (EMERALD): Should We Take the Risk?

BACKGROUND

Superselective clamping of tumor-targeted arteries aims to eliminate ischemia of the remnant kidney while keeping tumor bed bloodless during excision.

OBJECTIVE

To evaluate the impact of superselective clamping on long-term renal function, compared with renal artery early unclamping.

DESIGN, SETTING, AND PARTICIPANTS

A randomized monocentric single-blind trial (1:1) was conducted from February 2018 to August 2019. Patients with a single renal tumor were candidates for a robot-assisted partial nephrectomy (RAPN) in a referral center. EMERALD (NCT03679572) was powered to include 50 patients with an interim analysis after 30 cases.

INTERVENTION

Superselective RAPN (SS-RAPN) with near-infrared fluorescence (NIRF) or conventional RAPN with renal artery early unclamping.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was the percent change of estimated glomerular filtration rate (eGFR) in the operated kidney after 6 mo (combination of eGFR and relative function on ^99mTc-DMSA scintigraphy). Secondary endpoints assessed feasibility and safety of the technique.

RESULTS AND LIMITATIONS

Relative eGFR reduction in the operated kidney at 6 mo did not differ significantly (-21.4% vs -23.4%, p=0.66). This absence of difference remained after adjusting on percentage of kidney volume preserved, which was an independent predictor of functional preservation. There were no significant differences in terms of blood loss, change in hemoglobin, postoperative complications, transfusion, and conversion to radical nephrectomy (two vs zero) or to open surgery (one vs zero). Despite a good accrual, the steering committee interrupted the trial after the interim analysis for futility given the absence of trend in favor of SS-RAPN.

CONCLUSIONS

SS-RAPN using NIRF does not provide better renal function preservation than renal artery clamping, questioning the interest of this technique at a higher risk of bleeding.

PATIENT SUMMARY

In this randomized controlled trial, superselective clamping of tumor feeding arteries did not show any advantage in terms of long-term renal function compared with conventional artery clamping.

Robotic-assisted partial nephrectomy (RAPN) and standardization of outcome reporting: a prospective, observational study on reaching the "Trifecta and Pentafecta"

Partial nephrectomy (PN) for small renal masses is common, but outcomes are not reported in a standard manner. Traditionally, parameters such as 90-day mortality, blood loss, transfusion rates, length of stay, nephrometry scoring and complications are published but their collective impact on warm ischemia time (WIT) and post-surgery GFR is rarely determined. Thus, our aim was to assess if “Trifecta” and “Pentafecta” outcomes could be used as useful surgical outcome markers. A prospective database of 252 Robotic-Assisted PN (RAPN) cases (2008–2019) was analysed. “Pentafecta” was defined as achievement of “Trifecta” (negative surgical margin, no postoperative complications and WIT of < 25 min) plus over 90% estimated GFR preservation and no CKD stage upgrading at 1 year. Binary logistic regression analysis was conducted to predict factors which may prevent achieving a Trifecta/Pentafecta. Median tumour size was 3 cm and mean WIT was 15 min. Positive surgical margins (PSM) occurred in 2 cases. Overall, the intra-operative complication rate was 7%. One recurrence conferred 5-year cancer-free survival of 97%. Trifecta outcome was achieved in 169 (67%) and Pentafecta in 141 (56%) of cases. At logistic regression analysis, intraoperative blood loss was the only factor to affect Trifecta achievement (p = 0.018). Advanced patient age negatively impacted Pentafecta achievement (p = 0.010). The Trifecta and Pentafecta outcomes are easily applicable to PN data, and offer an internationally comparable PN outcome, quality measure. We recommend applying this standardization to national data collection to improve the quality of reporting and ease of interpretation of surgeon/centres’ outcomes.

Segmental artery clamping versus main renal artery clamping in nephron-sparing surgery: updated meta-analysis

OBJECTIVES

Ischemia-reperfusion injury is harmful in partial nephrectomy (PN) in renal cell carcinoma. Choosing an appropriate surgical method is important to reduce ischemia-reperfusion injury. This study aimed to compare the effect of segmental artery clamping (SAC) and main renal artery clamping (MAC) on patients who underwent PN.

METHODS

Studies from January 2008 to November 2019 were identified by an electronic search of English and Chinese databases, including PubMed, Excerpt Medica Database, Cochrane Library, Wanfang, VIP, and Chinese National Knowledge Internet, without language restriction. Two reviewers were involved in the trial. The effects on operation time (OT), warm ischemia time (WIT), length of hospital stay (LOS), blood transfusion rate, postoperative complication rate, Clavien classification (≥ 3), and positive surgery margin (PSM) were evaluated using Stata software. Standardized mean difference (SMD, for continuous data) and pooled odds ratios (for count data) with 95% confidence interval (CI) were used as effect indicators.

RESULTS

Thirty-two studies were included. SAC decreased the 1-week (SMD = - 0.973; 95% CI = - 1.414, - 0.532; P = 0.000), 1-month (SMD = - 0.411; 95% CI = - 0.769, - 0.053; P = 0.025), and 3-month (affected kidney: SMD = - 0.914; 95% CI = - 1.662, - 0.617; P = 0.000) percentages of postoperative changes in renal function (estimated glomerular filtration rate) between the SAC and MAC groups. Sub-group analysis showed that the SAC group had longer OT (SMD = 0.562; 95% CI = 0.252, 0.871; P = 0.000) than the MAC group. However, no differences were observed in the OT, WIT, LOS, blood transfusion rate, postoperative complication rate, Clavien classification (≥ 3), and PSM between the two groups.

CONCLUSIONS

SAC is superior to MAC in terms of short-term postoperative renal function recovery. The use of SAC or MAC depends on tumor size, location, surgical modality, and surgeon's judgments.

Robot-Assisted Laparoscopic Partial Nephrectomy Vs Conventional Laparoscopic Partial Nephrectomy: Functional and Surgical Outcomes of a Prospective Single Surgeon Randomized Study

Background: Laparoscopic partial nephrectomy (LPN) and robot-assisted partial nephrectomy (RAPN) are commonly used techniques for treating small renal masses. Regarding renal function (RF) preservation, no superiority of one technique over the other has yet been definitely demonstrated. Objective: To compare functional and surgical outcomes of LPN and RAPN. Patients and Methods: Between 2015 and 2019, we prospectively randomized 115 patients with cT1-T2 renal masses to LPN in total ischemia or RAPN in selective ischemia. Primary endpoint was RF preservation, assessed by renal scintigraphy (RS). RS assessments were performed preoperatively and at 6 months follow-up. Secondary endpoints included clinical, histopathologic, and surgical outcomes. Results: One hundred eight patients were included in the final analysis. Patient and tumor characteristics were comparable. No significant difference in RS values after 6 months was observed between both groups. Median (interquartile range) RF change after 6 months was -18.0% (-26.5 to -11.0) in LPN group and -20.0 (-33.2 to -12.0) in RAPN group (p = 0.3). Mean (standard deviation [SD]) warm ischemia time was 21.1 (6.1) minutes in LPN group and 19.6 (7.7) minutes in RAPN group (p = 0.2). No positive surgical margins (PSMs) occurred in the LPN group, whereas RAPN group had PSM in 4.9% (n = 3); p = 0.099. Renal volume loss after 6 months was 27.5% (22.7-45.7) in the LPN group vs 37.5 (13.7-54.2) in the RAPN group (p = 0.5). Mean operative times were lower in the LPN group (192.3 minutes [SD 44.5] vs 230.2 minutes [SD 59.6], p = 0.001). More complications occurred in the LPN group (31% vs 21%, p = 0.075). Transfusion rates were 15% for LPN and 11% for RAPN. Conclusions: In terms of preserving RF, LPN in total ischemia and RAPN in selective ischemia are comparable. In most patients, RF decrease of the affected kidney after PN seems to not exceed 25%, regardless of the surgical approach.

Endophytic Renal Cell Carcinoma Treated with Robot-Assisted Surgery: Functional Outcomes - A Comprehensive Review of the Current Literature

INTRODUCTION

Robotic surgery for the management of localized renal cell carcinoma (RCC) has gained increasing popularity during the last decade. An endophytic renal tumour represents a surgical technical challenge in terms of identification and resection related to the lack of external visual cues on the kidney surface.

MATERIALS AND METHODS

There is little evidence of functional outcomes of robotic surgery on treating endophytic masses. For this reason, we wanted to review the contemporary literature on the functional outcomes of endophytic RCC treated with robotic surgery.

RESULTS

Many studies investigating robotic partial nephrectomy for totally endophytic RCC confirmed the good functional results of this approach at intermediate follow-up. The greater relative importance of volume loss versus ischaemia duration in predicting long-term renal function after partial nephrectomy is now established, and the robotic technique may facilitate volume preservation. Accurate use of intra-operative ultrasonography, enucleation, and intra-operative techniques using near-infrared fluorescence imaging with indocyanine green dye could minimize excision of the parenchyma and prevent devascularization of adjacent healthy parenchyma.

CONCLUSIONS

Unfortunately, the overall quality of the literature evidence and the high risk of selection bias limit the possibility of any causal interpretation about the relationship between the surgical technique used and functional outcomes.

Selective clamping during robot-assisted partial nephrectomy in patients with a solitary kidney: is it safe and does it help?

OBJECTIVES

To obtain the most accurate assessment of the risks and benefits of selective clamping in robot-assisted partial nephrectomy (RAPN) we evaluated outcomes of this technique vs those of full clamping in patients with a solitary kidney undergoing RAPN.

PATIENTS AND METHODS

Data from institutional review board-approved retrospective and prospective databases from 2006 to 2019 at multiple institutions with sharing agreements were evaluated. Patients with a solitary kidney were identified and stratified based on whether selective or full renal artery clamping was performed. Both groups were analysed with regard to demographics, risk factors, intra-operative complications, and postoperative outcomes using chi-squared tests, Fisher's exact tests, t-tests and Mann-Whitney U-tests.

RESULTS

Our initial cohort consisted of 4112 patients, of whom 72 had undergone RAPN in a solitary kidney (51 with full clamping and 21 with selective clamping). There were no significant differences in demographics, tumour size, baseline estimated glomerular filtration rate (eGFR), or warm ischaemia time (WIT) between the groups (Table 1). Intra-operative outcomes, including estimated blood loss, operating time, and intra-operative complications were similar in the two groups. Short- and long-term postoperative percentage change in eGFR, frequency of acute kidney injury (AKI), and frequency of de novo chronic kidney disease (CKD) were also not significantly different between the two techniques.

CONCLUSION

In a large cohort of patients with solitary kidney undergoing RAPN, selective clamping resulted in similar intra-operative and postoperative outcomes compared to full clamping and conferred no additional risk of harm. However, selective clamping did not appear to provide any functional advantage over full clamping as there was no difference observed in the frequency of AKI, CKD or change in eGFR. Short WIT in both groups (<15 min) may have prevented identification of benefits in the selective clamping group; a similar study analysing cases with longer WIT may elucidate any beneficial effects of selective clamping.

Application of indocyanine green in pediatric surgery

The use of near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) has gained popularity in many fields in adult surgery, such as sentinel lymph node mapping, intra-operative solid tumor identification, and organ perfusion assessment. However, the clinical application of ICG in pediatric surgery is just at the beginning. This review paper presents the advantages, current applications and potential developments of NIR fluorescence imaging with ICG in our field.

Best practices in near-infrared fluorescence imaging with indocyanine green (NIRF/ICG)-guided robotic urologic surgery: a systematic review-based expert consensus

PURPOSE

The aim of the present study is to investigate the impact of the near-infrared (NIRF) technology with indocyanine green (ICG) in robotic urologic surgery by performing a systematic literature review and to provide evidence-based expert recommendations on best practices in this field.

METHODS

All English language publications on NIRF/ICG-guided robotic urologic procedures were evaluated. We followed the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) statement to evaluate PubMed^®, Scopus^® and Web of Science™ databases (up to April 2019). Experts in the field provided detailed pictures and intraoperative video-clips of different NIRF/ICG-guided robotic surgeries with recommendations for each procedure. A unique QRcode was generated and linked to each underlying video-clip. This new exclusive feature makes the present the first "dynamic paper" that merges text and figure description with their own video providing readers an innovative, immersive, high-quality and user-friendly experience.

RESULTS

Our electronic search identified a total of 576 papers. Of these, 36 studies included in the present systematic review reporting the use of NIRF/ICG in robotic partial nephrectomy (n = 13), robotic radical prostatectomy and lymphadenectomy (n = 7), robotic ureteral re-implantation and reconstruction (n = 5), robotic adrenalectomy (n = 4), robotic radical cystectomy (n = 3), penectomy and robotic inguinal lymphadenectomy (n = 2), robotic simple prostatectomy (n = 1), robotic kidney transplantation (n = 1) and robotic sacrocolpopexy (n = 1).

CONCLUSION

NIRF/ICG technology has now emerged as a safe, feasible and useful tool that may facilitate urologic robotic surgery. It has been shown to improve the identification of key anatomical landmarks and pathological structures for oncological and non-oncological procedures. Level of evidence is predominantly low. Larger series with longer follow-up are needed, especially in assessing the quality of the nodal dissection and the feasibility of the identification of sentinel nodes and the impact of these novel technologies on long-term oncological and functional outcomes.

Comparison of Intermittent Versus Continuous Ischemia During Laparoscopic Partial Nephrectomy in a Porcine Model

Renal ischemic time is one of the most variable risk factors in partial nephrectomy (PN). Our purpose was to investigate if intermittent ischemia could decrease renal impairment in the process of PN in porcine model and explore the feasibility of this surgical procedure in nephrectomy. A kidney ischemia-reperfusion injury model was successfully established in six pigs under laparoscopic surgery. One kidney of each pig was continuously ischemic, and intermittent ischemia was administered to the kidney of another side. Laparoscopic renal artery occlusion was applied to each kidney for 120 minutes. Intermittent ischemia was 15/3 minutes of cycles (ischemia for 15 minutes and reperfusion for 3 minutes). Microdialysis technique, immunohistochemistry, and histopathology were used to evaluate the extent of renal function injures. The concentration of glycerol in intermittently ischemic group was significantly lower than that in continuously ischemic group (F = 19.06, p = 0.001). NGAL and BCL-2 immunostaining of the renal tubular epithelial cell in the intermittent ischemia kidneys was significantly reduced compared with that in the continuously ischemic kidneys (F = 5.51, p = 0.041; F = 13.53, p = 0.004). Our study has shown that intermittent ischemia is a possibly effective and practicable surgical process for reducing renal ischemic damage in porcine model nephrectomy.

Ischemia Techniques in Nephron-sparing Surgery: A Systematic Review and Meta-Analysis of Surgical, Oncological, and Functional Outcomes

CONTEXT

The optimal ischemia technique at partial nephrectomy (PN) for renal masses is yet to be determined.

OBJECTIVE

To summarize and analyze the current evidence about surgical, oncological, and functional outcomes after different ischemia techniques (cold, warm, and zero ischemia) at PN.

EVIDENCE ACQUISITION

A computerized systematic literature search was performed by using PubMed (MEDLINE) and Science Direct. Identification and selection of the studies were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) criteria. Outcomes of interest were estimated blood loss (EBL), overall complications, positive surgical margins, local tumor recurrence, and renal function preservation. Meta-analysis and forest-plot diagrams were performed. Overall pooled estimates, together with 95% confidence intervals (CIs), of the incidence of all parameters were obtained using a random effect model (RE-Model) on the log transformed means (MLN), proportion, or standardized mean change, as deemed appropriate.

EVIDENCE SYNTHESIS

One hundred and fifty-six studies were included. No clinically meaningful differences were found in terms of EBL after cold (mean: 215.5; 95% CI: 154.2-276.8m), warm (mean: 201.8; 95% CI: 175.0-228.7ml), or zero (mean: 261.2; 95% CI: 171.0-351.3ml) ischemia technique. Overall, postoperative complications were recorded in 14.1% (95% CI: 6.7-27.4), 11.1% (95% CI: 10.0-12.3), and 9.7% (95% CI: 7.7-12.2) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Positive surgical margins were recorded in 4.8% (95% CI: 1.9-10.9), 4.0% (95% CI: 3.4-4.8), and 5.6% (95% CI: 3.1-9.8) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Local recurrence was recorded in 3.2% (95% CI: 1.9-5.2) and 3.1% (95% CI: 0.7-11.5) of patients after warm and zero ischemia (p<0.01), respectively. The log₂ of estimated glomerular filtration ratio mean changes were-1.37 (95% CI:-3.42 to 0.68),-1.00 (-2.04 to 0.03), and-0.71 (-1.15 to-0.27) ml/min after cold, warm, and zero ischemia, respectively. Low level of evidence, retrospective nature of most of included studies, a high risk of selection bias, and heterogeneity within included studies limited the overall quality of the analysis.

CONCLUSIONS

The effect of ischemia technique at PN is still debatable and subject to confounding by several factors, namely, patients' selection criteria, surgical technique used, and percentage of functional parenchyma spared during surgery. These confounders bias available evidence and were addressed by only a small part of available studies. Unfortunately, the overall quality of literature evidences and the high risk of selection bias limit the possibility of any causal interpretation about the relationship between the ischemia technique used and surgical, oncological, or functional outcomes. Thus, none of the available ischemia technique could be recommended over the other.

PATIENT SUMMARY

The present analysis shows that none of the available ischemia techniques, namely, cold, warm, or zero ischemia, is universally superior to the others, and other factors play a role in the surgical outcome.

Comparison of selective and main renal artery clamping in partial nephrectomy of renal cell cancer: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

The aim of the present study was to perform a systematic review and meta-analysis of the studies comparing the efficiency and safety of selective renal artery clamping (SAC) and main renal artery clamping (MAC) in partial nephrectomy (PN) for renal cell cancer (RCC).

METHODS

According to the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement, a literature search on PubMed, EMBASE, Web of Science, and Chinese National Knowledge Infrastructure were conducted to identify relevant studies published through December 2017. Outcomes of interest included baseline characteristics and perioperative surgical variables.

RESULTS

In all, 14 studies involving 2824 RCC patients comparing SAC and MAC were included in this meta-analysis. No differences were detected in mean patient body mass index (P = .08), tumor size (P = .22), baseline estimated glomerular filtration rate (eGFR) (P = .60), American Society of Anesthesiologists score (P = .97), or RENAL score (P = .70). The mean age was significantly younger in the SAC group compared with the MAC group (P = .002). There was no difference between SAC and MAC groups in terms of warm ischemia time (P = .31), transfusion rate (P = .18), length of hospital stay (P = .47), or postoperative complication rate (P = .23). Although SAC had longer operating time (OT) (P = .04) and more estimated blood loss (EBL) (P = .0002), a lower percentage decrease in eGFR in the SAC group was found compared to the MAC group (P = .002).

CONCLUSIONS

Patients undergoing PN with SAC had longer OT and higher EBL. SAC was more frequently used in younger patient. SAC offered better renal function preservation when compared with MAC for RCC. Given the inherent limitations of the included studies, further well-designed randomized controlled trials are required to verify these findings.

A practical guide for the use of indocyanine green and methylene blue in fluorescence-guided abdominal surgery

Near-infrared (NIR) fluorescence imaging is gaining clinical acceptance over the last years and has been used for detection of lymph nodes, several tumor types, vital structures and tissue perfusion. This review focuses on NIR fluorescence imaging with indocyanine green and methylene blue for different clinical applications in abdominal surgery with an emphasis on oncology, based on a systematic literature search. Furthermore, practical information on doses, injection times, and intraoperative use are provided.

Super-selective robot-assisted partial nephrectomy using near-infrared flurorescence versus early-unclamping of the renal artery: results of a prospective matched-pair analysis

Introduction

Super-selective clamping of tumor-specific segmental arteries was developed to eliminate ischemia of the remnant kidney while limiting hemorrhage during partial nephrectomy. The objective is to evaluate the benefice of super-selective clamping on renal functional outcome, compared to early-unclamping of the renal artery.

Materials and Methods

From March 2015 to July 2016, data from 30 patients undergoing super-selective robot-assisted PN (RAPN) for a solitary tumor by a single surgeon were prospectively collected. Tumor devascularization was assessed using indocyanine green near-infrared fluorescence. A matched-pair analysis with a retrospective cohort undergoing early-unclamping was conducted, adjusting on tumor complexity and preoperative eGFR. Perioperative, oncologic and functional outcomes using DMSA-renal scintigraphy were assessed. Multivariate analysis was performed to identify predictors of postoperative renal function and de novo chronic kidney disease (CKD).

Results

Super-selective RAPN was successful in 23/30 patients (76.7%), 5 requiring secondary main artery clamping due to persistent tumor fluorescence. Matched-pair analysis showed similar operating time, blood loss, positives margins and complication rates. Super-selective clamping was associated with an improved eGFR variation at discharge (p=0.002), 1-month (p=0.01) and 6-month post-op (-2%vs-16% p=0.001). It also led to a better relative function on scintigraphy (46%vs40% p=0.04) and homolateral eGFR (p=0.04), and fewer upstaging to CKD stage ≥3 (p=0.03). On multivariate analysis, super-selective clamping was a predictor of postoperative renal function.

Conclusion

Super-selective RAPN leads to an improved preservation of renal function and a reduced risk of de novo CKD stage≥3, while keeping the benefit of main artery clamping on perioperative outcomes.

Determinant factors for chronic kidney disease after partial nephrectomy

The objective of this review is to evaluate the factors that determine the development or deterioration of Chronic Kidney Disease (CKD) after partial nephrectomy (PN).

When current literature is reviewed, it is found that factors that influence renal function after partial nephrectomy, are multifactorial. Those are divided into pre-surgical factors, such as hypertension, diabetes mellitus, urolithiasis, obesity, metabolic syndrome among others; intra-surgical factors, like the surgical technique used, the remaining healthy tissue, the experience of the surgeon, the time and type of ischemia among others. Lastly, post-surgical factors, also impose some influence on the post-surgical renal performance.

It was also found that minimally invasive surgery, in addition to its known advantages, seems to offer a greater field of action in the future that will allow more nephrons preservation in any future surgical scenario.

Finally, the current trend is to perform PN on all patients, in whom surgery is technically feasible regardless of the approach used, without risking oncological outcomes, patient safety, and without being exposed to any additional complications.

Selective arterial clamping does not improve outcomes in robot-assisted partial nephrectomy: a propensity-score analysis of patients without impaired renal function

OBJECTIVES

To assess the benefit of selective arterial clamping (SAC) as an alternative to main renal artery clamping (MAC) during robot-assisted partial nephrectomy (RAPN) in patients without underlying chronic kidney disease (CKD).

PATIENTS AND METHODS

Our study cohort comprised 665 patients without impaired renal function undergoing MAC (n = 589) or SAC (n = 76) during RAPN from four medical institutions in the period 2008-2015. We compared complication rates, positive surgical margin (PSM) rates, and peri-operative and intermediate-term renal functional outcome between 132 patients undergoing MAC and 66 undergoing SAC after 2-to-1 nearest-neighbour propensity-score matching for age, sex, body mass index, RENAL nephrometry score, tumour size, baseline estimated glomerular filtration rate (eGFR), American Society of Anesthesiologists (ASA) score, Charlson comorbidity index (CCI) and warm ischaemia time (WIT).

RESULTS

In propensity-score-matched patients, PSM (5.7 vs 3.0%; P = 0.407) and complication rates (13.8 vs 10.6%; P = 0.727) did not differ between the MAC and SAC groups. The incidence of acute kidney injury for MAC vs SAC (25.0 vs 32.0%; P = 0.315) within the first 30 days was similar. At a median follow-up of 7.5 months, the percentage reduction in eGFR (-9.3 vs -10.4%; P = 0.518) and progression to CKD ≥ stage 3 (7.2 vs 8.5%; P = 0.792) showed no difference.

CONCLUSIONS

Our study findings show no difference in PSM rates, complication rates or intermediate-term renal functional outcomes between patients with unimpaired renal function who underwent SAC vs those who underwent MAC. When expected WIT is low, the routine use of SAC may not be necessary. Further studies will need to determine the role of SAC in patients with a solitary kidney or with significantly impaired renal function.

The future of partial nephrectomy

Innovation in recent times has accelerated due to factors such as the globalization of communication; but there are also more barriers/safeguards in place than ever before as we strive to streamline this process. From the first planned partial nephrectomy completed in 1887, it took over a century to become recommended practice for small renal tumours. At present, identified areas for improvement/innovation are 1) to preserve renal parenchyma, 2) to optimise pre-operative eGFR and 3) to reduce global warm ischaemia time. All 3 of these, are statistically significant predictors of post-operative renal function. Urologists, have a proud history of embracing innovation & have experimented with different clamping techniques of the renal vasculature, image guidance in robotics, renal hypothermia, lasers and new robots under development. The DaVinci model may soon no longer have a monopoly on this market, as it loses its stranglehold with novel technology emerging including added features, such as haptic feedback with reduced costs. As ever, our predictions of the future may well fall wide of the mark, but in order to progress, one must open the mind to the possibilities that already exist, as evolution of existing technology often appears to be a revolution in hindsight.

Fluorescence in robotic surgery

Currently, there are several clinical applications for intraoperative ICG, such as identification of vascular and biliary anatomy, assessment of organ and tissue perfusion, lymph node mapping, and real-time identification of lesions. In this paper we present a review of the available literature related to the use of ICG fluorescence in robotic surgery in order to provide a better understanding of the current applications, show the rapid growth of this technique, and demonstrate the potential future applications.

Review of robot-assisted partial nephrectomy in modern practice

Partial nephrectomy (PN) is currently the standard treatment for T1 renal tumors. Minimally invasive PN offers decreased blood loss, shorter length of stay, rapid convalescence, and improved cosmesis. Due to the challenges inherent in laparoscopic partial nephrectomy, its dissemination has been stifled. Robot-assisted partial nephrectomy (RAPN) offers an intuitive platform to perform minimally invasive PN. It is one of the fastest growing robotic procedures among all surgical subspecialties. RAPN continues to improve upon the oncological and functional outcomes of renal tumor extirpative therapy. Herein, we describe the surgical technique, outcomes, and complications of RAPN.

Decline in renal function after partial nephrectomy: etiology and prevention

PURPOSE

Partial nephrectomy is the reference standard for the management of small renal tumors and is commonly used for localized kidney cancer. A primary goal of partial nephrectomy is to preserve as much renal function as possible. New baseline glomerular filtration rate after partial nephrectomy can have prognostic significance with respect to long-term outcomes. Recent studies provide an increased understanding of the factors that determine functional outcomes after partial nephrectomy as well as preventive measures to minimize functional decline. We review these advances, highlight ongoing controversies and stimulate further research.

MATERIALS AND METHODS

A comprehensive literature review consistent with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria was performed from January 2006 to April 2014 using PubMed®, Cochrane and Ovid Medline. Key words included partial nephrectomy, renal function, warm ischemia, hypothermia, nephron mass, parenchymal volume, surgical approaches to partial nephrectomy, preoperative and intraoperative imaging, enucleation, hemostatic agents and energy based resection. Relevant reviews were also examined as well as their cited references. An additional Google Scholar search was conducted to broaden the scope of the review. Only English language articles were included in the analysis. The primary outcomes of interest were the new baseline level of function after early postoperative recovery, percent decline in function, potential etiologies and preventive measures.

RESULTS

Decline in function after partial nephrectomy averages approximately 20% in the operated kidney, and can be due to incomplete recovery from the ischemic insult or loss of nephron mass related to parenchymal excision or collateral damage during reconstruction. Compensatory hypertrophy in the contralateral kidney after partial nephrectomy in adults is marginal and decline in global renal function for patients with 2 kidneys averages about 10%, although there is some variance based on tumor size and location. Irreversible ischemic injury can be minimized by pharmacological intervention or surgical approaches such as hypothermia, limited warm ischemia, or zero or segmental ischemia. Excessive loss of nephron mass can be minimized by improved preoperative or intraoperative imaging, use of a bloodless field, enucleation and vascular microdissection. Hemostatic agents or energy based resection that minimizes the need for parenchymal and capsular suturing can also optimize preservation of the vascularized nephron mass.

CONCLUSIONS

Our understanding of the decline in renal function after partial nephrectomy has advanced considerably, including better appreciation of its magnitude and impact in various settings, possible etiologies and potential preventive measures. Many controversies persist and this remains an important area of investigation.