Laser-supported partial laparoscopic nephrectomy for renal cell carcinoma without ischaemia time

Preclinical optimization of a diode laser-based clamp-free partial nephrectomy in a large animal model

Kidney cancer is a common urologic malignancy with either laparoscopic (LPN) or robotic partial nephrectomy as therapeutic options of choice for localized tumors. However, renal resection and suturing are challenging steps of the procedure that can lead to complications such as prolonged warm ischemia, bleeding, and urinary fistulas. LPN with a diode laser is an efficient technique due to its cutting and/or coagulation attributes. Surprisingly, key laser features such as wavelength and power remain undefined. Using a large porcine model, we evaluated the laser range of wavelength and power in a clamp-free LPN and compared it to the established gold-standard LPN technique (i.e., cold-cutting and suturing). By analyzing surgery duration, bleeding, presence of urine leak, tissue damage related to the resected renal fragment and the remaining organ, hemoglobin levels, and renal function, we show that an optimized experimental diode laser clamp-free LPN (wavelength, 980 nm; power, 15 W) had shorter surgery time with less bleeding, and better postoperative renal function recovery when compared to the well-established technique. Together, our data indicate that partial nephrectomy with a diode laser clamp-free LPN technique is an improved alternative to the gold-standard technique. Therefore, translational clinical trials towards human patient applications are readily feasible.

Lasers in laparoscopic and robotic surgery: is there a need for them

PURPOSE OF REVIEW

The application of lasers in treating urological disorders is a developing area. In the laparoscopic and robotic surgery, laser energy is not so popular as in the treatment of stone disease and benign prostatic hyperplasia. The aim of this review is to clarify the current status of laser applications in laparoscopic and robotic urology.

RECENT FINDINGS

Laser welding of the pyeloureteral anastomosis is not performed in routine clinical practice. Most investigation of laser applications in laparoscopic and robotic urology has centered on laparoscopic partial nephrectomy and robot-assisted partial nephrectomy. Much less work has been done with regard to lower tract laser laparoscopic and robotic applications. However, laser laparoscopic radical prostatectomy has been investigated.

SUMMARY

Current literature regarding lasers in laparoscopic and robotic surgery is extremely limited. Available data consist mostly of small cohorts providing a low level of evidence. Even though initial studies with currently available laser modalities demonstrated promising results, several drawbacks in each technique need to be addressed before being widely accepted as a standard care. Despite investigation, laser usage during laparoscopic and robotic urological procedures has not gained widespread acceptance and remains experimental at this time.

Usefulness of Thulium-Doped Fiber Laser and Diode Laser in Zero Ischemia Kidney Surgery-Comparative Study in Pig Model

Background: The aim of this study was to evaluate the usefulness of a thulium-doped fiber laser and a diode laser in zero ischemia kidney surgery, by carrying out a comparative study in a pig model. Material and methods: Research was carried out on 12 pigs weighing 30 kg each. A thulium-doped fiber laser (TDFL) and a diode laser (DL) operating at wavelengths of 1940 and 1470 nm, respectively, were used. The cut sites were assessed both macroscopically and microscopically. The zone of thermal damage visible in the histopathological preparations was divided into superficial and total areas. Results: During partial nephrectomy, moderate to minimal bleeding was observed, which did not require additional hemostatic measures. All animals survived the procedure. On day 0, the total thermal damage depth was 837.8 µm for the TDFL and 1175.0 µm for the DL. On day 7, the depths were 1556.2 and 2301.7 µm, respectively. On day 14, the overall thermal damage depth for the DL was the greatest (6800 µm). The width of the superficial zone was significantly reduced on days 7 and 14 after TDFL application. Conclusion: Both lasers are suitable for partial wedge nephrectomy without ischemia in pigs. The TDFL produced similar or better hemostasis than the DL, with a smaller zone of thermal damage and, therefore, seems more suitable for application in human medicine.

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.

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.

Ischemia Techniques in Nephron-sparing Surgery: A Systematic Review and Meta-Analysis of Surgical, Oncological, and Functional Outcomes

CONTEXT

The optimal ischemia technique at partial nephrectomy (PN) for renal masses is yet to be determined.

OBJECTIVE

To summarize and analyze the current evidence about surgical, oncological, and functional outcomes after different ischemia techniques (cold, warm, and zero ischemia) at PN.

EVIDENCE ACQUISITION

A computerized systematic literature search was performed by using PubMed (MEDLINE) and Science Direct. Identification and selection of the studies were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) criteria. Outcomes of interest were estimated blood loss (EBL), overall complications, positive surgical margins, local tumor recurrence, and renal function preservation. Meta-analysis and forest-plot diagrams were performed. Overall pooled estimates, together with 95% confidence intervals (CIs), of the incidence of all parameters were obtained using a random effect model (RE-Model) on the log transformed means (MLN), proportion, or standardized mean change, as deemed appropriate.

EVIDENCE SYNTHESIS

One hundred and fifty-six studies were included. No clinically meaningful differences were found in terms of EBL after cold (mean: 215.5; 95% CI: 154.2-276.8m), warm (mean: 201.8; 95% CI: 175.0-228.7ml), or zero (mean: 261.2; 95% CI: 171.0-351.3ml) ischemia technique. Overall, postoperative complications were recorded in 14.1% (95% CI: 6.7-27.4), 11.1% (95% CI: 10.0-12.3), and 9.7% (95% CI: 7.7-12.2) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Positive surgical margins were recorded in 4.8% (95% CI: 1.9-10.9), 4.0% (95% CI: 3.4-4.8), and 5.6% (95% CI: 3.1-9.8) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Local recurrence was recorded in 3.2% (95% CI: 1.9-5.2) and 3.1% (95% CI: 0.7-11.5) of patients after warm and zero ischemia (p<0.01), respectively. The log₂ of estimated glomerular filtration ratio mean changes were-1.37 (95% CI:-3.42 to 0.68),-1.00 (-2.04 to 0.03), and-0.71 (-1.15 to-0.27) ml/min after cold, warm, and zero ischemia, respectively. Low level of evidence, retrospective nature of most of included studies, a high risk of selection bias, and heterogeneity within included studies limited the overall quality of the analysis.

CONCLUSIONS

The effect of ischemia technique at PN is still debatable and subject to confounding by several factors, namely, patients' selection criteria, surgical technique used, and percentage of functional parenchyma spared during surgery. These confounders bias available evidence and were addressed by only a small part of available studies. Unfortunately, the overall quality of literature evidences and the high risk of selection bias limit the possibility of any causal interpretation about the relationship between the ischemia technique used and surgical, oncological, or functional outcomes. Thus, none of the available ischemia technique could be recommended over the other.

PATIENT SUMMARY

The present analysis shows that none of the available ischemia techniques, namely, cold, warm, or zero ischemia, is universally superior to the others, and other factors play a role in the surgical outcome.

Laparoscopic partial nephrectomy with diode laser: a promising technique

OBJECTIVE

The aim of this study was to evaluate application of diode laser in laparoscopic partial nephrectomy (LPN), and to question this technique in terms of ease of tumor excision and reduction of warm ischemia time (WIT).

BACKGROUND DATA

LPN is the standard operative method for small renal masses. The benefits of LPN are numerous, including preserving renal function and prolonging overall survival. However, reduction of WIT remains main challenge in this operation. In order to shorten WIT, many techniques have been developed, with variable results.

PATIENTS AND METHODS

We performed a prospective collection and analysis of health records for patients who were operated on between March 2011 and August 2012. Inclusion criteria were single tumor ≤ 4 cm, predominant exophytic growth and intraparenchymal depth ≤ 1.5 cm, with a minimum distance of 5 mm from the urinary collecting system.

RESULTS

We operated on 17 patients. Median operative time was 170 min. In all but two patients, we had to perform hilar clamping. Median duration of WIT was 16 min. Pathohistological evaluation revealed clear cell renal cancer and confirmed margins negative for tumor in all cases. Median size of the tumor was 3 cm. Median postoperative hospitalization was 5 days. Average follow up was 11.5 months. There were no intraoperative complications. One postoperative complication was noted: perirenal hematoma.

CONCLUSIONS

Laser LPN is feasible, and offers the benefit of shorter WIT, with effective tissue coagulation and hemostasis. With operative experience and technical advances, WIT will be reduced or even eliminated, and a solution to some technical difficulties, such as significant smoke production, will be found.