Surgical and Minimally Invasive Therapies for the Management of the Small Renal Mass

The evolving management of small renal masses

Small renal masses (SRMs) are a heterogeneous group of tumours with varying metastatic potential. The increasing use and improving quality of abdominal imaging have led to increasingly early diagnosis of incidental SRMs that are asymptomatic and organ confined. Despite improvements in imaging and the growing use of renal mass biopsy, diagnosis of malignancy before treatment remains challenging. Management of SRMs has shifted away from radical nephrectomy, with active surveillance and nephron-sparing surgery taking over as the primary modalities of treatment. The optimal treatment strategy for SRMs continues to evolve as factors affecting short-term and long-term outcomes in this patient cohort are elucidated through studies from prospective data registries. Evidence from rapidly evolving research in biomarkers, imaging modalities, and machine learning shows promise in improving understanding of the biology and management of this patient cohort.

Perioperative, functional, and oncological outcomes after cryoablation or partial nephrectomy for small renal masses in solitary kidneys: a systematic review and meta-analysis

AIM

This study aims to compare the perioperative, functional, and oncological outcomes of cryoablation (CA) and partial nephrectomy (PN) for managing small renal masses in patients with solitary kidneys. The study seeks to assess the efficacy and safety of both interventions, evaluating their impact on kidney function and their ability to mitigate cancer recurrence.

METHODS

Searches were systematically conducted on PubMed, Scopus, EMBASE, SinoMed, and Google Scholar, identifying seven observational studies. Statistical analysis was performed using Stata v.12.0 and Review Manager version 5.2. Results for dichotomous variables are expressed using odds ratios, and weighted mean differences are used for continuous variables.

RESULTS

Our findings revealed that patients undergoing CA experienced significantly shorter operative time (p < 0.0001), reduced estimated blood loss (p < 0.00001), a shorter length of stay (p = 0.0001), and fewer postoperative complications (p = 0.02) compared to those undergoing PN. Although the CA group exhibited a lower transfusion rate (p = 0.69) compared with the PN group, the difference was not statistically significant. The combined data analysis demonstrated a significantly lower increase in serum creatinine levels after surgery in the CA group compared with the PN group (p = 0.003). Similarly, there was a noteworthy decrease in the estimated glomerular filtration rate after surgery in the PN group compared with the CA group (p < 0.0001). While not statistically significant, the CA group showed a lower postoperative dialysis rate (p = 0.11). Regarding oncological outcomes, the analysis revealed no significant differences between CA and PN concerning local recurrence (p = 0.2) and distant metastasis (p = 0.12), respectively.

CONCLUSIONS

Our analysis indicates comparable efficacy between PN and CA in controlling tumour recurrence and metastasis. However, CA is associated with superior preservation of renal function, significantly enhanced perioperative outcomes, and fewer postoperative complications. Based on our data, it can be inferred that the scope for applying CA might be expanded to encompass more patients seeking a less invasive treatment option.

The Outcome of Sutureless in Partial Nephrectomy: A Systematic Review and Meta-Analysis

Purpose

To compare the effect of sutureless versus standard suture (double-layer suture) during renorrhaphy in laparoscopic or robotic-assisted partial nephrectomy on perioperative and renal function outcomes.

Methods

PubMed, Embase, and other sources were searched for randomized controlled trials or retrospective studies comparing sutureless partial nephrectomy versus standard suture partial nephrectomy. A systematic review and meta-analysis were performed by two reviewers independently.

Results

Five retrospective studies were included with a total of 634 patients. The results showed that there was a significant difference in the decline of estimated glomerular filtration rate (I² = 98.5%; WMD, -4.19 ml/min; 95% CI, -7.64 to -0.73; P < 0.001) and no significant difference in postoperative complications (I² = 0; RR, 1.31; 95% CI, 0.61 to 2.81; P = 0.623). A significant advantage in terms of operating time (I² = 53.9%; WMD, -29.08 min; 95% CI, -33.06 to -25.10; P = 0.069) and warm ischemia time (I² = 38.5%; WMD, -6.17 min; 95% CI, -6.99 to -5.36; P = 0.165) favored sutureless, while there was no significant difference in blood loss (I² = 58.1%; WMD, 3.10 ml; 95% CI, -39.18 to 45.38; P = 0.049).

Conclusion

Sutureless during renorrhaphy is feasible and safe compared with standard suture. Sutureless can shorten the operating time and warm ischemia time without increasing postoperative complications, and thus, it protects renal function.

A Systematic Review and Meta-Analysis of Minimally Invasive Partial Nephrectomy Versus Focal Therapy for Small Renal Masses

Background

Minimally invasive partial nephrectomy (MIPN) and focal therapy (FT) are popular trends for small renal masses (SRMs). However, there is currently no systematic comparison between MIPN and FT of SRMs. Therefore, we systematically study the perioperative, renal functional, and oncologic outcomes of MIPN and FT in SRMs.

Methods

We have searched the Embase, Cochrane Library, and PubMed for articles between MIPN (robot-assisted partial nephrectomy and laparoscopic partial nephrectomy) and FT {radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation (CA), irreversible electroporation, non-thermal [irreversible electroporation (IRE)] ablation, and stereotactic body radiation therapy (SBRT)}. We calculated pooled mean difference (MD), odds ratios (ORs), and 95% confidence intervals (CIs) (CRD42021260787).

Results

A total of 26 articles (n = 4,420) were included in the study. Compared with MIPN, the operating time (OP) of FT had significantly lower (SMD, −1.20; CI, −1.77 to −0.63; I2 = 97.6%, P &lt; 0.0001), estimated blood loss (EBL) of FT had significantly less (SMD, −1.20; CI, −1.77 to −0.63; I2 = 97.6%, P &lt; 0.0001), length of stay (LOS) had shorter (SMD, −0.90; CI, −1.26 to −0.53; I2 = 92.2%, P &lt; 0.0001), and estimated glomerular filtration rate (eGFR) of FT was significantly lower decrease (SMD, −0.90; CI, −1.26 to −0.53; I2 = 92.2%, P &lt; 0.0001). However, FT possessed lower risk in minor complications (Clavien 1–2) (OR, 0.69; CI, 0.45 to 1.07; I2 = 47%, P = 0.023) and overall complications (OR, 0.71; CI, 0.51 to 0.99; I2 = 49.2%, P = 0.008). Finally, there are no obvious difference between FT and MIPN in local recurrence, distant metastasis, and major complications (P &gt; 0.05).

Conclusion

FT has more advantages in protecting kidney function, reducing bleeding, shortening operating time, and shortening the length of stay. There is no difference in local recurrence, distant metastasis, and major complications. For the minimally invasive era, we need to weigh the advantages and disadvantages of all aspects to make comprehensive choices.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier PROSPERO (CRD42021260787).

A retrospective study of open and endoscopic nephron sparing surgery in the treatment of complex renal tumors

Objective:

To investigate clinical outcomes of open and retroperitoneal laparoscopic nephron-sparing surgery in the treatment of complex renal tumours.

Methods:

A retrospective case study was conducted. Patients with complex renal tumours admitted to our hospital between January 2018 and September 2019 were enrolled; the included patients (n=40) were divided into the observation group (open partial nephrectomy, n=20) and control group (laparoscopic partial nephrectomy, n=20) according to operation modes. The operation time, renal warm ischaemia time, intraoperative blood loss, renal pedicle blocking time, intestinal function recovery time, postoperative hospital stay, and postoperative complications were recorded.

Results:

Significant differences were noted regarding renal warm ischaemia time, renal pedicle blocking time, intraoperative blood loss, operation time, and postoperative hospital stay between the observation and control groups (P<0.05); however, no significant difference was observed in intestinal function recovery time and postoperative drainage days (P>0.05).

Conclusion:

Open surgery remains the recommended surgical method for the treatment of few complex tumours in the renal hilus region and has gradually become the renal surgery of choice at present, although laparoscopic surgery has evolved tremendously.

Superselective renal artery embolization for treatment of urological hemorrhage after partial nephrectomy in a solitary kidney

Embolization is a well-known and accepted form of treatment for bleeding caused by a multitude of renal procedures. We present a case of a 66-year-old woman who had a history of left nephrectomy for clear cell carcinoma seven years previously and now presented with a 6 cm tumor involving the solitary kidney. She underwent partial laparoscopic nephrectomy with removal of the tumor on the right kidney. In the immediate postoperative period she had important and persistent hematuria associated with tachycardia, hypotension, and lumbar pain. After showing signs of hemodynamic instability, she was taken to the catheter laboratory where selective angiography of the right kidney was performed. Superselective embolization with controlled release of fibrous microcoils was performed. The superselective renal embolization technique performed on an emergency basis to control hemorrhage after a urological procedure is effective and achieves lasting resolution of symptoms.

Renal artery embolization for iatrogenic renal vascular injuries management: 5 years' experience

OBJECTIVE

Evaluate the efficacy and safety of renal artery embolization (RAE) for iatrogenic renal vascular injuries (IRVI) management at Fondazione Policlinico Universitario "A. Gemelli" IRCCS, in the last 5 years.

METHODS

Retrospective analysis of all RAE procedures performed from January 2013 to December 2017. Patients-related (age, sex, vascular variants, hemoglobin and serum creatinine), IRVI-related (type and vascular level of IRVI, presence and extension of hematoma), management-related (temporal interval between diagnostic imaging and RAE) and procedure-related (embolic materials, technical success, clinical success and complications) parameters were evaluated.

RESULTS

28 RAE procedures performed on 28 patients (21 males; 7 females) were included. 19/28 patients had pseudoaneurysm, 7/28 active bleeding and 1/28 arteriovenous fistula; 4/28 patients had a combination of 2 IRVI.The extent of perirenal hematoma showed correlation with the cause of IRVI (p = 0.028).Technical success was achieved in all patients whereas clinical success in 25/28 (89.3%), with 3 patients requiring re-treatment. Minor complications were observed during 2/28 (7.1%) endovascular procedures. No major complications occurred. A longer procedural time was observed in patients with lower pre-procedural levels of hemoglobin (p = 0.016).No differences were found in mean serum creatinine (p = 0.23) before and immediately after treatment, while values of creatinine at 1 week from the procedure were significantly lower (p = 0.04).

CONCLUSION

RAE is safe and effective for the management of iatrogenic IRVI showing high technical and clinical success rate and low complication rate.

ADVANCES IN KNOWLEDGE

Low pre-procedural hemoglobin levels increase procedural duration time. Glue alone or in combination with other materials is as safe as coils.

Active Surveillance in Small Renal Masses in the Elderly: A Literature Review

CONTEXT

Small renal masses have become increasingly common due to widespread imaging; however, optimal management of these lesions in the elderly can be complex due to the competing risks of intervention, natural history of disease, patient comorbidities, and expectations. In the properly selected elderly patient, active surveillance remains an accepted and attractive treatment approach.

OBJECTIVE

We completed a literature review of small renal masses (enhancing, <4cm, T1aN0M0 disease) in the elderly, aged ≥70 yr, aimed at identifying the utility of active surveillance in this population. The primary outcomes were conversion to active treatment while on active surveillance and cancer-specific mortality. Secondary outcomes included predictors of treatment, type of treatment performed (partial nephrectomy, radical nephrectomy, and ablation), progression to metastases, all-cause mortality, tumor growth rate, and demographic data including age and Charlson Comorbidity Index.

EVIDENCE ACQUISITION

A comprehensive search of electronic databases (e.g., MEDLINE, EMBASE, SCOPUS, Web of Science, and the Cochrane Library) using search terms "small renal mass" OR "SRM", AND "elderly," "senior," "aging," "geriatric," OR "octogenarian" was completed. All randomized controlled trials, nonrandomized comparison studies, and case series were included and screened by the reviewers. All comparison studies included in the systematic review were assessed for methodological quality using the Cochrane Risk of Bias tools.

EVIDENCE SYNTHESIS

Seventeen primary studies including 36495 patients met the inclusion criteria for the systematic review. All studies were retrospective institutional chart or the Surveillance, Epidemiology, and End Results database reviews. There was a low (4-26%) rate of conversion to active treatment for active surveillance in the identified studies over a follow-up interval of up to 91.5 mo. Overall mortality was substantial in this elderly cohort, with 15-51% of patients being deceased over the course of study follow-up; however, there was minimal cancer-specific mortality due to patients succumbing to alternative comorbid disease. In the future, patient comorbidity and biological age versus the natural history of the individualized tumor biology may play an increasing role in the discussion regarding treatment options and consideration of active surveillance.

CONCLUSIONS

Active surveillance is an effective management strategy in the elderly population. Few patients required the conversion to active treatment and there was low cancer-specific mortality. The majority of patients who expired over the course of the identified studies succumbed to alternative disease. The goal of treatment strategies should include weighing patient-specific prognosis relative to their competing health risks and treatment goals against the natural history of disease and risks of intervention.

PATIENT SUMMARY

In this review article, the authors examined the utility of active surveillance in the setting of a small localized renal mass in the elderly population. Despite being on surveillance, we found that cancer-specific outcomes were excellent, and overall mortality was often a result of comorbid disease. However, there is significant heterogeneity among elderly patients, and treatment approaches should be focused around patient-centered goals and prognosis.