"At-risk" kidney: How surgical factors influence renal functional preservation after partial nephrectomy

Limited non-linear impact of warm ischemia time on renal functional decline after partial nephrectomy: a propensity score-matched study

OBJECTIVE

To quantificationally illustrate the impact of ischemia time (IT) on renal function decline after partial nephrectomy (PN), especially for patients with compromised baseline renal function (estimated glomerular filtration rate [eGFR] < 90 mL/min/1.73 m²).

METHODS

Patients undergoing PN during 2014-2021 from a prospectively maintained database were reviewed. Propensity score matching (PSM) was employed to balance the possible covariates between patients with or without baseline compromised renal function. Specifically, the relationship of IT with postoperative renal function was illustrated. Two machine learning methods (logistic least absolute shrinkage and selection operator [LASSO] logistic regression and random forest) were applied to quantify the relative impact of each covariables.

RESULTS

The average drop percent of eGFR was -10.9% (- 12.2%, - 9.0%). Multivariable Cox proportional regression and linear regression analyses identified five risk factors for renal function decline, namely RENAL Nephrometry Score (RNS), age, baseline eGFR, diabetes and IT (all p < 0.05). Specifically, the relationship of IT with postoperative functional decline emerged as non-linear, with an increase from 10-30 min and a plateau afterwards among patients with normal function (eGFR ≥ 90 mL/min/1.73 m²), whereas with an increase from 10 to 20 min and a plateau afterwards among patients with compromised function (eGFR < 90 mL/min/1.73 m²). Furthermore, the coefficient's path and random forest analysis revealed that the top two most important features were RNS and age.

CONCLUSION

IT exhibits the secondarily non-linear relationship with postoperative renal function decline. Patients with compromised baseline renal function are less tolerant to ischemia damage. The use of a single cut-off interval of IT in the setting of PN is flawed.

Risk Factors of Chronic Kidney Disease after Partial Nephrectomy

Background: In comparison with radical nephrectomy, partial nephrectomy (PN) is considered a better option for small renal mass surgery, because of optimal kidney tissue removal and parenchyma preservation. But there are patients with worsening postoperative renal function (RF) and chronic kidney disease (CKD) after PN. Therefore, the study aimed to evaluate and detect risk factors for CKD after PN.Materials and Methods. A prospective observational study was conducted, which consisted of 91 individuals who received PN with warm ischemia and an estimated preoperative glomerular filtration rate (eGFR) ≥ 60 ml/min/1.72m2 without pathologic albuminuria. Preoperative and intraoperative factors like intraoperative hypotension (IOH), blood loss, and resected part volume were analyzed.Results. At 6-month follow-up, 14 (15.4 %) patients experienced postoperative CKD. After 12 months of follow-up, 15 (16.5 %) patients had CKD. Patients with CKD had a lower preoperative eGFR than non-CKD group (69.0 vs 91.0 ml/min/1.72m2, p < 0.001), longer ischemia (20.0 vs 14.0, p = 0.002) and IOH time (40.0 (40.0; 47.5) vs 0.0 (0.0; 26.2) min, p < 0.001). Also, higher volumes of resected kidney part tumor and removed parenchyma with higher glomerulosclerosis amounts (73.3 % vs 14.5 %, p = 0.009) were found in CKD group. Estimated blood loss > 500 ml during PN was discovered to be the major risk factor for CKD development (OR 11.13, 95 % CI 1.88–65.92, p = 0.008). Furthermore, kidney resected part volume (OR 1.05, 95% CI 1.05-1.10, p = 0.033) and IOH time (OR 1.11, 95% CI 1.03-1.19, p = 0.005) were identified as risk factors for postoperative CKD. Conclusions. Patients after PN are at an increased risk of CKD development. Most commonly, postoperative CKD occurs in the first 6 months after PN and appears stable after 12 months of follow-up. Blood loss > 500 ml during PN, IOH and resected kidney volume can have an impact on postoperative RF and increase the risk of CKD.

Robotic-Assisted Partial Nephrectomy: Techniques to Improve Clinical Outcomes

PURPOSE OF REVIEW

To summarize current options available for robot-assisted partial nephrectomy RECENT FINDINGS: Partial nephrectomy (PN) is a standard treatment option for management of cT1 renal masses. It may be carried out by multiple approaches. Robot-assisted (RA) PN is one such option. The goal of treatment is both correct oncological (negative surgical margins) and functional (preservation of sufficient amount of renal parenchyma of the operated kidney) outcome. Appropriate outcomes depend on multiple factors. There are many, but among others tumor characteristics (size, location, i.e., tumor complexity), patient baseline renal function, patient comorbidities, and performance status etc. Based on all these, the surgeon adapts the intervention for each mass/patient by preoperative planning, absence/use/duration of warm or cold ischemia, perioperative imaging, resection technique adapted to tumor location and depth of invasion, use of hemostatics, type and degree of renal parenchymal closure and others details. Nephroprotective agents have not shown efficacy so far. It should not be forgotten that surgeon's experience plays a key role in the achievement of good results. Although multiple factors have a role in the RA partial nephrectomy, surgeon experience and adaptation of technique of intervention have the crucial role in the achievement of both functional and oncological results.

[Radical nephrectomy and partial nephrectomy]

Renal cell carcinoma is the 2nd most frequent urological malignancy in women and the third most frequent in men, with an age peak in the seventh decade of life. If detected early in a local non-metastatic stage, options for complete recovery are excellent. While two decades ago, even locally limited cancers of the kidney were cured by radical nephrectomy, treatment today mostly consists of local treatment for locally confined cancers. Guidelines today recommend local surgical excision (open or minimally-invasive) or - in selected cases - topical energy application (radio-frequency ablation, cryoablation). The surgeon's expertise is most important in the selection of the appropriate kind of surgery and different guidelines have slightly different recommendations.Treatment decisions should be made on an individual basis in due consideration of an individual's age and co-morbidities. This may lead to the recommendation that, due to low perioperative morbidity, even localised carcinomas should be treated by (minimally-invasive) radical nephrectomy instead of nephron-sparing surgery and, in other cases, a non-interventional, active surveillance strategy may be pursued without compromising the patient's life expectancy. For higher-grade renal cell carcinomas, there is usually an indication for radical nephrectomy, as long as no metastases are detected. This also applies to carcinomas with venous thrombi extending into the atrium of the heart. Complications in the treatment of renal carcinomas are usually rare and easily treatable in most cases.