Near-infrared fluorescence imaging for intraoperative margin assessment during robot-assisted partial nephrectomy

The impact of indocyanine green on partial nephrectomy perioperative outcomes

We conducted a retrospective analysis of the impact of indocyanine green (ICG) on perioperative outcomes in partial nephrectomy. The utility of ICG in partial nephrectomy remains unclear. We performed a retrospective cohort study of all patients at a single institution who underwent laparoscopic or robotic partial nephrectomy in 2014-2019. Some surgeons used ICG while others did not. Outcomes of interest were estimated blood loss, positive surgical margins, ischemia time, and postoperative kidney function. We used multivariate regression to assess ICG use and outcomes. We identified 150 patients meeting inclusion criteria. The majority of cases (58%) used ICG. Patients who did and did not receive ICG were similar in age, sex, and histologic subtype. Median estimated blood loss was 100 mL (IQR 50-200), 9% had a positive surgical margin, and median ischemia time was 21 min (IQR 16-26). Of those with renal function follow-up, 17% had increased chronic kidney disease stage and mean percent creatinine change was + 4.7 ± 14.9%. On multivariate analysis, ICG use was associated with change in CKD stage (OR 9.9, 95% CI 1.0-93.9, p = 0.05). It was not associated with positive surgical margin status (OR 1.20, 95% CI 0.38-3.85, p = 0.755), percent change creatinine (beta 5.18, 95% CI -1.87-12.23, p = 0.155), ischemia time (beta 0.86, 95% CI - 1.38-3.09, p = 0.45), or EBL (beta - 0.13, 95% CI - 0.53-0.28, p = 0.53). We observed a difference in CKD change according to ICG in partial nephrectomy, but not other perioperative outcomes. ICG may have impacted surgical decision-making in unmeasured ways but did not significantly affect perioperative outcomes.

Augmenting Laparoscopic Surgery with Fluorescence Imaging

Minimally invasive endoscopic surgery is growing in veterinary medicine, in large part, due to the advantages associated with reduced pain, potential for decreased complications, and increased visualization of structures through magnification and illumination. With advancing technologies, we can now improve upon natural "white light" endoscopy with fluorescence-guided imaging. Near-infrared (NIR) cameras allow for real-time, high-definition visualization of vessels, anatomic structures, and perfusion. New uses of NIR technologies during laparoscopy are continuing to grow for vascular, lymphatic, and oncologic-related techniques. Limitations exist, and future efforts need to determine optimal dosing, tissue-specific fluorophores, and veterinary-specific techniques.

Current Application of Navigation Systems in Robotic-Assisted and Laparoscopic Partial Nephrectomy: Focus on the Improvement of Surgical Performance and Outcomes

Kidney cancer represents the third most prevalent malignancy among all types of genitourinary cancer worldwide. Currently, there is a growing trend of employing partial nephrectomy for the management of large and complex tumors. Surgical outcomes are associated with some amendable surgical factors, including warm ischemic time, pedicle clamping, preserved volume of renal parenchyma, appropriate surgical strategy, and precise resection of the tumor. Improving surgical performance is pivotal for achieving favorable surgical outcomes. Due to advancements in imaging visualization technology and the shift of the medical paradigm toward precision medicine, an increasing number of navigation systems have been implemented in partial nephrectomy procedures. The navigation system can assist surgeons in formulating optimal surgical strategies and enhance the safety, precision, and feasibility of resecting complex renal tumors. In this review, we provide an overview of currently available navigation systems and their feasible applications, with a focus on how they contribute to the improvement of surgical performance and outcomes during robotic-assisted and laparoscopic partial nephrectomy.

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.

Can near-infrared imaging distinguish a gelatin-based matrix granuloma from a malignancy in a kidney?

Aim: Differentiating granulomas from cancerous tissue poses a significant challenge in upper urinary tract surgery. We present the case of a 62-year-old male with a gelatin-based matrix (SurgifloTM) granuloma in the kidney following renal cyst decortication eight years earlier.Methods: Contrast-enhanced abdominal tomography revealed a Bosniak type-4 cyst at the previous operation site. The patient underwent laparoscopic partial nephrectomy with near-infrared imaging.Results: The lesion presented as hypofluorescent relative to normal kidney tissue. Histopathological examination revealed a foreign body granuloma due to unabsorbed Surgiflo.Conclusion: The fluorescence pattern could not distinguish a Surgiflo granuloma from a malignant lesion of the kidney.

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).

Robotic Partial vs Radical Nephrectomy for Clinical T3a Tumors: A Narrative Review

Introduction: T3a renal masses include a diverse group of tumors that invade the perirenal and/or sinus fat, pelvicaliceal system, or renal vein. The majority of cT3a renal masses represent renal cell carcinoma (RCC) and have historically been treated with radical nephrectomy (RN) given their aggressive nature. With the adoption of minimally invasive approaches to renal surgery, the combination of improved observation, pneumoperitoneum, and robotic articulation has allowed urologists to consider partial nephrectomy (PN) for more complex tumors. Herein, we review the existing literature regarding robot-assisted PN (RAPN) and robot-assisted RN (RARN) in the management of T3a renal masses. Methods: A literature search was performed using PubMed for articles evaluating the role of RARN and RAPN for T3a renal masses. Search parameters were limited to English language studies. Applicable studies were abstracted and included in this narrative review. Results: T3a RCC caused by renal sinus fat or venous involvement is associated with ∼50% lower cancer-specific survival than those with perinephric fat invasion alone. CT and MRI can both be used to stage cT3a tumors, however, MRI is more accurate when assessing venous involvement. Upstaging to pT3a RCC during RAPN does not confer a worse prognosis than pT3a tumors treated with RARN; however, patients who undergo RAPN for T3a RCC with venous involvement have relatively higher rates of recurrence and metastasis. Intraoperative tools including drop-in ultrasound, near-infrared fluorescence, and 3D virtual models improve the ability to perform RAPN for T3a tumors. In well-selected cases, warm ischemia times remain reasonable. Conclusions: cT3a renal masses represent a diverse group of tumors. Depending on substratification of cT3a, RARN or RAPN can be employed for treatment of such masses.

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.

Early results of minimally invasive fluorescent guided pediatric oncology surgery with delivery of indocyanine green during induction of anesthesia

BACKGROUND

Indocyanine green (ICG) fluoresces in the near infra-red (NIR) spectrum. It is widely used in adult oncological surgery for identification of tumor margins and lymph node sampling. However, deliver of ICG in almost all studies is 24 h or more prior to surgery. This is the first study in children to assess its feasibility in minimally invasive surgery (MIS) for oncological disease following ICG injection during induction of anesthesia.

METHODS

This was an open label, prospective, single center, feasibility study recruiting consecutive patients eligible for MIS tumor resection or metastectomy. ICG was injected intravenously at induction of anesthesia. Patient demographics, intraoperative appearances, post-operative histopathology, and surgeon Likert ratings were collected.

RESULTS

Fourteen patients were included. Five had lung metastases (Wilms, Osteosarcoma (2), Hodgkin's, melanoma) and 9 had other tumors (neuroblastoma, inflammatory myofibroblastic tumor, ganglioneuroma, phaeochromocytoma, adrenal tumor). Lung metastases were easily identifiable, and all had negative margins. Tumors containing viable disease fluoresced and were completely resected, whilst benign and heavily treated tumors were afluorescent. There were no adverse events relating to ICG or issues with background fluorescence.

CONCLUSION

Based on this small sample, injection of ICG during induction of anesthesia is safe and effective in showing tumor margins in patients who have had little or no neoadjuvant chemotherapy as well as in metastectomy in Wilms and osteosarcoma. Further studies are needed to confirm these preliminary results.

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.

Three-dimensional Model-assisted Minimally Invasive Partial Nephrectomy: A Systematic Review with Meta-analysis of Comparative Studies

CONTEXT

Use of three-dimensional (3D) guidance for nephron-sparing surgery (NSS) has increased in popularity, especially for laparoscopic and robotic approaches. Different 3D visualization modalities have been developed as promising new tools for surgical planning and intraoperative navigation.

OBJECTIVES

To summarize and evaluate the impact of 3D models on minimally invasive NSS in terms of perioperative, functional, and oncological outcomes.

EVIDENCE ACQUISITION

A systematic literature search was conducted in December 2021 using the Medline (PubMed), Embase (Ovid), Scopus, and Web of Science databases. The protocol was registered on PROSPERO (CRD42022300948). The search strategy used the PICOS (Population, Intervention, Comparison, Outcome, Study design) criteria and article selection was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The risk of bias and the quality of the articles included were assessed. A dedicated data extraction form was used to collect the data of interest. Meta-analysis was performed using the Mantel-Haenszel method for binary outcomes, with results summarized as the odds ratio (OR), and the inverse variance method for continuous data, with results reported as the mean difference (MD). All effect estimates are reported with the 95% confidence interval (CI) and p ≤ 0.05 was considered statistically significant. All analyses were performed using R software and the meta package.

EVIDENCE SYNTHESIS

The initial electronic search identified 450 papers, of which 17 met the inclusion criteria and were included in the analysis. Use of 3D technology led to a significant reduction in the global ischemia rate (OR 0.22, 95% CI 0.07-0.76; p = 0.02) and facilitated more frequent enucleation (OR 2.54, 95% CI 1.36-4.74; p < 0.01) and less frequent opening of the collecting system (OR 0.36, 95% CI 0.15-0.89; p = 0.03) and was associated with less blood loss (MD 23.1 ml, 95% CI 31.8-14.4; p < 0.01). 3D guidance for NSS was associated with a significant reduction in the transfusion rate (OR 0.20, 95% CI 0.07-0.56; p < 0.01). There were no significant differences in rates of conversion to radical nephrectomy, minor and major complications, change in glomerular filtration rate, or surgical margins (all p > 0.05).

CONCLUSIONS

3D guidance for NSS is associated with lower rates of detriment and surgical injury to the kidney. Specifically, a lower amount of nontumor renal parenchyma is exposed to ischemia or sacrificed during resection, and opening of the collecting system is less frequent. However, use of 3D technology does not lead to significant improvements in oncological or functional outcomes.

PATIENT SUMMARY

We reviewed the use of three-dimensional tools for minimally invasive surgery for partial removal of the kidney in patients with kidney cancer. The evidence suggests that these tools have benefits during surgery, but do not lead to significant improvements in cancer control or functional outcomes for patients.

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.

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.

Optical Coherence Tomography Angiography and Attenuation Imaging for Label-Free Observation of Functional Changes in the Intestine after Sympathectomy: A Pilot Study

We present in this study optical coherence tomography angiography (OCTA) and OCT attenuation imaging (OCTAI) for in vivo non-destructive visualization of intramural blood and lymphatic vessels of the intestine wall. Rabbit small intestine in the norm and after thoracolumbar sympathectomy served as the object of the intraoperative study. Compared to OCTA real-time imaging, OCTAI takes several minutes and can be termed as “nearly real time”. OCTAI signal processing was modified to take into account the signal-to-noise ratio and the final thickness of the intestine wall. The results showed that, after sympathectomy, changes in functioning of intramural blood and lymphatic vessels were observed with a high statistical significance. The occurrence of trauma-induced constriction of the blood and lymphatic vessels led to an especially pronounced decrease in the length of small-caliber (<30 µm) blood vessels (p < 10−5), as well as in the volumetric density of lymphatic vessels (on average by ~50%) compared to their initial state. Remarkably, OCTA/OCTAI modalities provide the unique ability for “nearly-instant detection” of changes in functional status of the tissues, long before they become visible on histology. The proposed approach can be used in further experiments to clarify the mechanisms of changes in intestinal blood and lymph flows in response to trauma of the nervous system. Furthermore, potentially it can be used intraoperatively in patients requiring express diagnosis of the state of intramural blood and lymph circulation.

Retroperitoneal Robot-Assisted Partial Nephrectomy (rRAPN): Surgical Technique and Review

PURPOSE OF REVIEW

We aim to offer a description of the surgical technique and to review the current state retroperitoneal robot-assisted partial nephrectomy (rRAPN).

RECENT FINDINGS

Partial nephrectomy is the standard treatment for localized kidney tumours. rRAPN is especially useful for kidney tumours of posterior location. It offers advantages such as direct access to the renal artery and no need for bowel mobilization. The disadvantages are the small working space and the less familiar anatomical landmarks. It is a reproducible technique that achieves similar oncological and functional results to the more traditional transperitoneal route (tRAPN). High-quality randomized studies are needed to ascertain the role of new technologies as modern high-flow insufflation systems, intracavitary ultrasound, 3D planning, and augmented reality (AR), in the performance of this operation. rRAPN is especially useful for kidney tumours of posterior location. Robotic surgeons ideally should become familiar with both approaches, transperitoneal or retroperitoneal.