Achieving zero ischemia in minimally invasive partial nephrectomy surgery

“Zero ischemia” laparoscopic partial nephrectomy by high-power GreenLight laser enucleation for renal carcinoma: A single-center experience

BACKGROUND

Laparoscopic partial nephrectomy has been widely used in renal cell carcinoma treatment. The efficacy of GreenLight laser on Laparoscopic partial nephrectomy is still unknown.

AIM

To present the first series of laparoscopic partial nephrectomy (LPN) by GreenLight laser enucleation without renal artery clamping. Due to the excellent coagulation and hemostatic properties of the laser, laser-assisted LPN (LLPN) makes it possible to perform a “zero ischemia” resection.

METHODS

Fifteen patients with T1a exogenous renal tumors who received high-power GreenLight laser non-ischemic LPN in our hospital were retrospectively analyzed. All clinical information, surgical and post-operative data, complications, pathological and functional outcomes were analyzed.

RESULTS

Surgery was successfully completed in all patients, and no open or radical nephrectomy was performed. The renal artery was not clamped, leading to no ischemic time. No blood transfusions were required, the average hemoglobin level ranged from 96.0 to 132.0 g/L and no postoperative complications occurred. The mean operation time was 104.3 ± 8.2 min. The postoperative removal of negative pressure drainage time ranged from 5.0 to 7.0 d, and the mean postoperative hospital stay was 6.5 ± 0.7 d. No serious complications occurred. Postoperative pathological results showed clear cell carcinoma in 12 patients, papillary renal cell carcinoma in 2 patients, and hamartoma in 1 patient. The mean creatinine level was 75.0 ± 0.8 μmol/L (range 61.0-90.4 μmol/L) at 1 mo after surgery, and there were no statistically significant differences compared with pre-operation (P > 0.05). The glomerular filtration rate ranged from 45.1 to 60.8 mL/min, with an average of 54.0 ± 5.0 mL/min, and these levels were not significantly different from those before surgery (P > 0.05).

CONCLUSION

GreenLight laser has extraordinary cutting and sealing advantages when used for small renal tumors (exogenous tumors of stage T1a) during LPN. However, use of this technique can lead to the generation of excessive smoke.

Retroperitoneoscopic partial nephrectomy using a 980/1470-nm dual-diode laser for small exophytic renal tumors

Laser-supported laparoscopic partial nephrectomy is a promising new technique, but remains under experiment. We presented our single institutional experience of laparoscopic partial nephrectomy using the 980/1470-nm dual-diode laser system to investigate its feasibility, and oncological and functional outcomes. The study retrospectively evaluated 25 patients with small exophytic renal tumors, who underwent laparoscopic partial nephrectomy using a 980/1470-nm dual-diode laser. The demographics, surgical data, complications, pathological variables, oncological, and functional outcomes were reviewed. The changes in hemoglobin and estimated glomerular filtration rate (eGFR) before and after surgery were statistically analyzed. The investigators operated on a total of 25 patients. The off-clamping technique was performed for 23 cases, while the other two cases required renal artery clamping due to unsatisfactory hemostasis. The tumor diameter was 24.6± 6.2 mm, and the mean operative time was 104.4± 23.4 min. The median estimated intraoperative blood loss (EBL) was 100 ml (range 50-600 ml). No major complications (Clavien-Dindo >II) occurred perioperatively. The mean change in hemoglobin before and after the operation was 9 g/l, with a P value of <0.001. The mean decrease in eGFR from before the surgery to the 6-month follow-up was 1.4 ml/min, with a P value of 0.463. The postoperative histopathology evaluation did not demonstrate a positive surgical margin. No recurrence or metastasis was found during the follow-up (mean 24 months). Laparoscopic partial nephrectomy using a 980/1470 nm dual-diode laser appears to be a feasible and oncological satisfactory technique for the treatment of small renal mass (SRM), with the advantages of reducing warm ischemia time.

Off-Clamp Robot-Assisted Partial Nephrectomy: Is There Something More to Achieve Optimal Trifecta Outcomes?

Objectives: To report trifecta outcomes of our "off-clamp" partial nephrectomy (PN) patients operated without main renal artery and/or any selective/superselective clamping. Materials and Methods: Between April 2008 and March 2020, 52 patients received "off-clamp" robot-assisted partial nephrectomy. Postoperative sixth month estimated glomerular filtration rate (eGFR) and eGFR decrease were considered for renal function evaluation. Patients with negative surgical margins, <15% postoperative eGFR decrease and absence of grade ≥2 Clavien-Dindo complications were reported to achieve trifecta outcomes. Results: Mean age and body mass index of the patients were 57.51 ± 12.99 years and 27.23 ± 4.35 kg/m², respectively. Mean preoperative hematocrit, serum creatinine, and eGFR were 42.01 ± 3.86%, 0.92 ± 0.28 mg/dL, and 85.26 ± 21.27 mL/min/1.73 m², respectively. Mean tumor size was 30.32 ± 13.64 mm. Mean PADUA and RENAL scores were 7.63 ± 1.46 and 6.21 ± 1.63, respectively. One patient had focal surgical margin positivity. Mean console time and estimated blood loss was 82.11 ± 38.51 minutes and 280.76 ± 278.98 mL, respectively. Complications were observed in two (4%) patients (one Clavien I, one Clavien IIIB). At postoperative sixth month, serum creatinine and eGFR were 0.95 ± 0.32 mg/dL and 83.65 ± 22.44 mL/min/1.73 m², respectively. Eventually seven patients had ≥15% postoperative eGFR decrease, one patient had grade ≥2 complication and one patient had positive surgical margin. Forty-three (83%) patients fulfilled trifecta outcomes. Conclusion: Off-clamp PN is important for optimal renal function preservation. Patient selection and additional operative measures along with experience in robotic procedure can contribute achievement of optimal trifecta outcomes.

Acute kidney injury after nephron sparing surgery and microwave ablation: focus on incidence, survival impact and prediction

Purpose: To compare acute kidney injury (AKI) incidence between nephron sparing surgery (NSS) and microwave ablation (MWA) for T1a RCC patients, reveal the effect of AKI on survival prognosis, construct AKI nomogram and use Law of Total Probability for survival probability (SP) prediction.Materials and methods: Patients were studied retrospectively after NSS (n = 1267) or MWA (n = 210) from January 1, 2011 to June 30, 2017. Using one to one Propensity Score Matching (PSM), 158 pairs of patients were identified for the cohort study. AKI incidence, risk factors and impact on survival outcomes were analyzed using Chi-square test, logistic and cox regression analysis. AKI risk and SP were predicted by nomogram and Law of Total Probability. The performance of the nomogram was assessed with respect to its discrimination, calibration, and clinical usefulness.Results: AKI occurred more commonly in NSS (27.85%) cohort, when compared to MWA (17.72%) cohort (p = 0.032), but treatment modality was not independently predictive of AKI occurrence (odds ratio [OR]: 0.598; 95% confidence interval [CI]: 0.282-1.265; p = 0.178). The 5-yr overall survival (OS) was lower in AKI patients (73.5%) compared with non-AKI patients (94.8%; p < 0.001). AKI was an independent risk factor for all-cause mortality in RCC patients (hazard ratio [HR]: 2.820; 95% confidence interval [CI]: 1.110-7.165; p = 0.029). Predictors for both NSS- and MWA-related AKI included tumor diameter, baseline eGFR and CCI score. RENAL score and tumor blood supply can predict AKI after NSS and MWA, respectively. The AKI normograms demonstrated good discrimination, with AUCs >0.86, excellent calibration and net benefits at the decision curve analysis with probabilities ≥5%. SP predicted by Law of Total Probability was comparable to actual OS.Conclusion: AKI was an early indicator for poor overall survival in RCC patients. It can be predicted by several oncological parameters. Nomogram and Law of Total Probability can accurately predict AKI risk and SP.

Nonischemic or Ischemic Laparoscopic Partial Nephrectomy Using a Newly Developed Hybrid Energy Device in a Porcine Model

Purpose: To compare the efficacy of a newly developed hybrid pencil-type energy device (HD) generating simultaneously monopolar high-frequency electric energy and ultrasonic energy with that of a conventional device (CD) during laparoscopic partial nephrectomy (LPN). Materials and Methods: A total of 16 female pigs (32 kidneys) were divided into 4 groups of 4 animals (8 kidneys) each: nonischemic and ischemic HD-LPN groups, and nonischemic and ischemic CD-LPN groups. We performed bilateral LPN for each pig. HD alone was used in the HD-LPN group, whereas commercially available monopolar scissors and a soft coagulation system were used in the CD-LPN group. After observing the postoperative course for 14 days, we euthanized the animals and harvested the kidneys for histopathological observations. Results: We completed an LPN on a total of 32 kidneys. There were no cases of conversion to open surgery, nor were there any deaths or complications requiring treatment. For nonischemic LPN, LPN time was significantly shorter in the HD-LPN group than in the CD-LPN group (11.4 ± 4.8 vs 17.7 ± 5.3 minutes, p = 0.027). The decrease in postoperative hemoglobin was equally low in both groups. However, the frequency of TachoSil^® use was significantly higher in the CD-LPN group than in the HD-LPN group (6/8 [75%] vs 0/8 [0%], p = 0.007). For ischemic LPN, we found no significant differences in parameters such as LPN time and using TachoSil between the two groups. The depth of thermal injury was the most superficial in the nonischemic HD-LPN group in comparison with the other three groups. Conclusions: The application of an HD allowed nonischemic LPN to be performed safely in a short time with less blood loss and less thermal injury to the kidney in the porcine model. Additional clinical investigations of human kidneys are required.

Robot-assisted retroperitoneal laparoscopic partial nephrectomy without hilar occlusion VS classic robot-assisted retroperitoneal laparoscopic partial nephrectomy: A retrospective comparative study

To discuss the feasibility, safety, and effectiveness of off-clamp robotic partial nephrectomy via retroperitoneal approach and provide data for evidence based medicine in the surgical treatment of renal tumor.The clinical data was documented and compared between robotic retroperitoneal partial nephrectomy with and without hilar occlusion (clamp group and off-clamp group) performed between January 1, 2015 and December 31, 2017.Six-months post-operative renal function was superior in the off-clamp group compared with clamp group, while long-term results remained to be elucidated. No significant difference in post-operative hospital stay was found between the 2 groups. Estimated blood loss in off-clamp group was significantly higher than clamp group, while no significant difference was found in transfusion rate.Off-clamp robotic partial nephrectomy via retroperitoneal approach is a safe and effective technique for the removal of renal tumor while the indication of surgery is strictly limited to small (<4 cm) and exophytic renal tumor.

Long-term renal function following zero ischemia partial nephrectomy

Partial nephrectomy (PN), also known as nephron sparing surgery, is considered as the first-line treatment in small renal masses, especially in T1/2 tumors, and is applied as a standard treatment in advanced centers. The main expected outcomes from an ideal PN are surgical margin negativity, minimal impairment in renal function, and any surgical complications. Many authors have defined PN techniques as “zero ischemia partial nephrectomy”, where surgery is performed without clamping the main renal artery in order to protect the renal parenchyma from ischemic injury. Various PN techniques employed by surgeons include: selective or segmental renal artery clamping technique; off-clamp, clampless, or unclamped technique; preoperative superselective transarterial tumor embolization technique; sequential/modified sequential preplaced suture renorrhaphy technique, radio frequency ablation-assisted technique, and combination of these techniques. The common goal of all these techniques is to provide zero ischemia without hilar clamping. This systematic review focuses on the long-term functional outcomes of PNs performed by zero ischemia techniques.

Non-ischemic laparoscopic partial nephrectomy using 1318-nm diode laser for small exophytic renal tumors

Purpose

Warm ischemia (WI) and bleeding constitute the main challenges for surgeons during laparoscopic partial nephrectomy (LPN). Current literature on the use of lasers for cutting and coagulation remains scarce and with small cohorts. We present the largest case series to date of non-ischemic LPN using a diode laser for small exophytic renal tumors.

Methods

We retrospectively evaluated 29 patients with clinically localized exophytic renal tumors who underwent non-ischemic laser–assisted LPN with a 1318-nm wavelength diode laser. We started applying the laser 5 mm beyond the visible tumor margin, 5 mm away from the tissue in a non-contact fashion for coagulation and in direct contact with the parenchymal tissue for cutting. 

Results

The renal vessels were not clamped, resulting in a WIT (warm ischaemic time) of 0 min, except for one case that required warm ischemia for 12 min and parenchymal sutures. No transfusion was needed, with a mean Hemoglobin drop of 1,4 mg/dl and no postoperative complications. The eGFR did not significantly change by 6 months. Histologically, the majority of lesions (n = 22/29) were renal-cell carcinoma stage pT1a. The majority of malignant lesions (n = 13/22) had a negative margin. However, margin interpretation was difficult in 9 cases due to charring of the tumor base. A mean follow-up of 1.8 years revealed no tumor recurrence. The mean tumor diameter was 19.4 mm.

Conclusion

The 1318-nm diode laser has the advantages of excellent cutting and sealing properties when applied to small vessels in the renal parenchyma, reducing the need for parenchymal sutures. However, excessive smoke, charring of the surgical margin, and inability to seal large blood vessels are encountered with this technique.

The effect of zero-ischaemia laparoscopic minimally invasive partial nephrectomy using the modified sequential preplaced suture renorrhaphy technique on long-term renal functions

Introduction

Laparoscopic minimally invasive partial nephrectomy (MIPN) is the preferred technique in renal surgery, especially T1 phase kidney tumours, and it is recommended for the protection of renal functions in methods that do not involve ischaemia.

Aim

To evaluate long-term renal functions of zero-ischaemia laparoscopic MIPN patients who underwent a modified sequential preplaced suture renorrhaphy technique.

Material and methods

In a total of 17 renal units in 16 patients with kidney tumours that were determined incidentally and did not cause any complaints, the masses were extracted via laparoscopic partial nephrectomy (LPN) using the modified sequential preplaced suture renorrhaphy technique. Creatinine and estimated glomerular filtration rate (eGFR) values of the patients were measured preoperatively and on the first day and after 12 months postoperatively, and the results were compared.

Results

The differences between the pre- and postoperative values were statistically significant (p = 0.033, p = 0.045), but the changes in postoperative creatinine and eGFR values were clinically insignificant. While the differences between preoperative and first-day postoperative creatinine and eGFR values were found to be statistically significant (p = 0.039, p = 0.042, respectively), a statistically significant difference was not detected between preoperative and 12-month postoperative creatinine and eGFR values (p = 0.09, p = 0.065, respectively). The global percentage of functional recovery was measured as 92.5% on the first day and 95.9% at the 12^th month.

Conclusions

The modified sequential preplaced suture renorrhaphy technique is an effective, reliable method for avoiding complications and preserving renal functions and nephrons in appropriate patients.

Nephrometry score-guided off-clamp laparoscopic partial nephrectomy: patient selection and short-time functional results

BACKGROUND

Laparoscopic partial nephrectomy (LPN) is not a novel but a relatively technically challenging surgical procedure. Off-clamp LPN with zero ischemia can completely eliminate ischemic reperfusion injury to the kidney. The purpose of this study was to evaluate the safety and functional outcome of nephrometry score-guided off-clamp technique in LPN.

METHODS

A total of 44 patients underwent LPN between January 2015 and July 2015 for renal mass with radius, exophytic/endophytic, nearness to sinus, anterior/posterior location (RENAL) score 4 were enrolled. Twenty-two of them underwent off-clamp LPN with zero ischemia, and the other 22 received standard LPN with common renal artery clamp. Estimate blood loss (EBL), total operation time, resection time, renorrhaphy time, preoperative estimated glomerular filtration rate (eGFR), postoperative eGFR, eGFR change, and drainage after surgery were compared between these two groups using t test.

RESULTS

Patients' characteristics including gender, age, BMI, tumor size, and RENAL score were balanced between the two groups. Average EBL was more in the off-clamp group than in the on-clamp group (134.32 versus 70.23 ml, p = 0.001). Average eGFR change was less in the off-clamp group than in the on-clamp group (-1.56 versus -6.45, p < 0.001). Average drainage after surgery was 203.41 ml for the off-clamp group and 145.46 ml for the on-clamp group, p = 0.062. No urinary leakage and hematuria occurred in both groups. There were no statistical difference in total operation time, resection time, renorrhaphy time, preoperative eGFR, and postoperative eGFR between the two groups.

CONCLUSIONS

Off-clamp LPN is a safe and feasible approach to excise certain kidney tumors with RENAL score 4. This technique can better preserve kidney function without ischemic reperfusion injury.

Effect of multiple-sweeping on ablation performance during ex vivo laser nephrectomy

BACKGROUND AND OBJECTIVE

Fiber-assisted laser surgery has been employed as a minimally invasive method in various medical fields. In spite of multiple sweeping on tissue during laser treatments, the rate of tissue removal gradually decreases and eventually leads to longer irradiation times as well as deeper thermal injury. The objective of the current study was to quantitatively investigate the effect of multiple fiber sweeps on ablation performance during ex vivo 532-nm laser nephrectomy.

MATERIALS AND METHODS

Porcine kidney tissue was used to evaluate variations in tissue ablation and coagulative necrosis after pre- and multiple-sweeping with a 532 nm wavelength at various fiber speeds (2, 4, and 6 mm/second). The distance between a fiber tip and tissue surface was initially set at 1.5 mm, and no further distance change was performed. Double-integrating spheres in conjunction with an adding-doubling method were employed to measure variations in optical properties of the tested tissue. The extent of ablation and coagulation was quantified to identify the role of multiple-sweeping at various fiber conditions.

RESULTS

Optical property measurements showed a 30% decrease in light absorption but a more than threefold increase in light scattering after irreversible thermal denaturation. Pre-sweeping yielded insignificant effects on tissue coagulation due to almost consistent coagulation depths with numbers of pre-sweeps. Ablation depths increased with more numbers of fiber sweeps and slower fiber speeds whereas coagulation depths thickened primarily with the slower speeds. Multiple-sweeping induced saturation in ablation volume with the increasing numbers of multiple-sweeps irrespective of the fiber speed.

CONCLUSION

A combination of coagulation barriers, spatial distribution of power, and temporal interplay of optical energy could attribute to continuously lessen the amount of the ablated tissue with the multiple sweeps. Optical power modulation with varying fiber conditions (speed and distance) will be examined to optimize surgical parameters and to sustain the equivalent ablation performance of the first sweep with the multiple sweeping for laser nephrectomy. Lasers Surg. Med. 48:616-623, 2016. © 2016 Wiley Periodicals, Inc.