Off-clamp tumor excision using soft coagulation in laparoscopic and robotic partial nephrectomy

Comparison of robot-assisted partial nephrectomy with soft coagulation and double-layer technique for complex and non-complex tumors

OBJECTIVES

To compare the postoperative outcomes of robot-assisted partial nephrectomy when only the inner layer is sutured (single-layer technique with soft coagulation) with those when sutures are placed in the inner and outer layers (double-layer technique) in patients with and without complex renal tumors.

METHODS

This retrospective three-institution study included 371 patients with renal tumors who underwent robot-assisted partial nephrectomy with a double-layer technique or a single-layer technique with soft coagulation. Tumors that were cT1b, completely embedded, located in the renal portal, or had a RENAL score of ≥10 were considered complex. Relevant data were collected from hospital records. Propensity score matching was performed to minimize selection bias.

RESULTS

Propensity score matching created 83 patient pairs with non-complex tumors and 32 with complex tumors. Regardless of tumor complexity, there was no significant difference in operation time, console time, warm ischemia time, positive surgical margin rate, or length of hospital stay between the double-layer and single-layer groups. Although Clavien-Dindo grade I-II urinomas not requiring intervention were significantly more common in the single-layer group regardless of tumor complexity, there was no significant between-group difference in the rate of decline in renal function or grade III-IV complications.

CONCLUSION

Single-layer suturing with soft coagulation achieves renal function and perioperative outcomes comparable to those of double-layer suturing regardless of complexity.

Sutureless Purely Off-Clamp Robot-Assisted Partial Nephrectomy: Avoiding Renorrhaphy Does Not Jeopardize Surgical and Functional Outcomes

To compare outcomes of sutureless (SL) vs. renorrhaphy (RR) off-clamp robotic partial nephrectomy (ocRPN), we retrospectively analyzed procedures performed at our center, from January 2017 to April 2021, for cT1-2N0M0 renal masses. All the patients with a minimum follow-up < 1 month were excluded from the analysis. The trifecta rate defined surgical quality. Any worsening from chronic kidney disease (CKD) I-II to ≧ IIIa (from IIIa to ≧ IIIb, and from IIIb to ≧ IV) was considered as significant stage migration (sCKDsm). A 1:1 propensity score-matched (PSM) analysis minimized baseline imbalances between SL and RR cohorts in terms of age, gender, ASA score, baseline estimated glomerular filtration rate (eGFR), tumor size, and RENAL score. Logistic regression analyses identified predictors of trifecta achievement. Kaplan-Meier (KM) analysis assessed the impact of RR on significant chronic kidney disease sCKDsm-free survival (SMFS), while Cox regression analyses identified its predictors. Overall, 531 patients were included, with a median tumor size of 3.5 cm (IQR: 2.7-5); 70 (13%) presented with a cT2 mass. An SL approach was pursued in 180 cases, but 10 needed conversion to RR. After PSM analysis, patients receiving SL showed a higher trifecta rate (94% vs. 84%; p = 0.007). SMFS probabilities were comparable at KM analysis (log-rank = 0.69). Age (OR: 0.97; 95%CI: 0.95-0.99; p = 0.01), a RENAL score ≧ 10 (OR: 0.29; 95%CI: 0.15-0.57; p < 0.001), and RR (OR: 0.34; 95%CI: 0.17-0.67; p = 0.002) were independent predictors of trifecta achievement. Age (OR: 1.04; 95%CI: 1.003-1.07; p = 0.03) and baseline eGFR (OR: 0.99; 95%CI: 0.97-0.99; p = 0.05) independently predicted sCKDsm. Compared to RR, our experience seems to show that the SL approach significantly increased the probabilities of achieving the trifecta in the observed group of cases.

Histological and radiological evaluation of thermal denaturation depth using soft coagulation during partial nephrectomy in living pigs

OBJECTIVES

To evaluate thermal denaturation depth using soft coagulation in kidneys in vivo.

METHODS

In experiment 1, nine kidneys from five pigs were cauterized using five soft-coagulation settings at 80 W with effect 7 by VIO300D and one monopolar-coagulation setting. The surface of the kidney was cauterized over a period of 2, 5 and 10 s. The temperature change was measured at depths of 5 and 10 mm. In experiment 2, three kidneys from two pigs were excised in a semicircular shape with a diameter of 5, 10 and 20 mm without clamping the renal artery. Cauterization was carried out until hemostasis was confirmed by soft coagulation at 80 W with effect 7. After completion of the experiments, pathology examinations of the kidneys were carried out.

RESULTS

Experiment 1 showed that with proper saline dripping, denaturation spread with increased cauterization time, reaching a depth of 4 mm at 10 s with or without clamps. The depth remained at 2-3 mm at 10 s in the absence or excess of saline. The temperature increased by 15.6°C at a depth of 5 mm and 8.8°C at 10 mm. In experiment 2, the depth was 4.6 mm from the incision surface regardless of the cauterization time or excision size.

CONCLUSIONS

These findings suggest that soft coagulation can be useful for preserving renal function and reducing complications in partial nephrectomy.

Assessment of surgical outcomes of off-clamp open partial nephrectomy without renorrhaphy for ≥T1b renal tumours

PURPOSE

To assess the surgical outcomes of off-clamp open partial nephrectomy without renorrhaphy. In the era of robot-assisted surgeries, open partial nephrectomy remains a surgical option for  ≥ T1b renal tumours. Although the necessity of renal pedicle clamping and renorrhaphy in open partial nephrectomy for larger tumours remains to be discussed, reports on this issue are rare.

METHODS

Twenty-seven open partial nephrectomies for  ≥ T1b renal tumours were performed without renal pedicle clamping or renorrhaphy. A soft coagulation system was used to control bleeding from the resection bed. Surgical results, complications, and predictors of perioperative estimated glomerular filtration rate (eGFR) preservation at 1 month and 3 months after surgery were analysed.

RESULTS

The median estimated volume of blood loss was 420 mL. The rates of perioperative eGFR preservation were 88.9 and 87.3% at 1 and 3 months after surgery, respectively. Tumour size was an independent predictor of perioperative eGFR preservation at 1 month after surgery, whereas age and exophytic/endophytic properties of the tumour were independent predictors of perioperative eGFR preservation at 3 months after surgery.

CONCLUSION

Open partial nephrectomy without renal pedicle clamping or renorrhaphy could be safely performed for  ≥ T1b renal tumours, even when tumours were entirely endophytic and located close to the renal pedicle. Mild perioperative eGFR reduction was observed. Although surgical indications should be carefully considered in these cases, off-clamp open partial nephrectomy without renorrhaphy is a feasible procedure for patients with  ≥ T1b renal tumours.