Nerve-sparing retroperitoneal lymphadenectomy using hydro-jet dissection: initial experience

Robotic RPLND for stage IIA/B nonseminoma: the Princess Margaret Experience

PURPOSE

Retroperitoneal lymph node dissection (RPLND) is a treatment option for men in a primary and post-chemotherapy setting. The aim of this review was to explore the published data looking at feasibility, safety and outcomes of robotic RPLND for CSI/II NSGCT but we will in particular highlight how we have approached adoption of robotic RPLND at the Princess Margaret.

METHODS

A review and summary of the published data to date was performed regarding the role of robotic RPLND for stage IIA/B nonseminoma.

RESULTS

Published series of robotic RPLND to date have proven feasibility and safety in experienced centres. Less blood loss, shorter length of stay and decreased morbidity are promising findings. Our data from Princess Margaret strengthen the argument of oncologic efficacy as we operated only on patients with known retroperitoneal disease (Stage at RPLND was IIA (n = 15, 55.6%), IIB (n = 9, 33.3%), IIC (n = 1, 3.7%) and III (n = 2, 7.4%)), did not use adjuvant chemotherapy and found a relapse rate (11%) similar to open RPLND.

CONCLUSIONS

The debate is ongoing regarding the role of robotic RPLND- the excellent oncological outcomes achieved by an open RPLND are the minimum starting point for robotic RPLND. Until such time that robotic RPLND is proven to be gold standard it should be performed in experienced centres by high volume RPLND surgeons and in the setting of a protocol.

Novel Techniques to Improve Precise Cell Injection

We noted recently that the injection of cells with a needle through a cystoscope in the urethral sphincter muscle of pigs failed to deposit them nearby or at the intended target position in about 50% of all animals investigated (n > 100). Increasing the chance for precise cell injection by shotgun approaches employing several circumferential injections into the sphincter muscle bears the risk of tissue injury. In this study, we developed and tested a novel needle-free technique to precisely inject cells in the urethral sphincter tissue, or other tissues, using a water-jet system. This system was designed to fit in the working channels of endoscopes and cystoscopes, allowing a wide range of minimally invasive applications. We analyze key features, including the physical parameters of the injector design, pressure ranges applicable for tissue penetration and cell injections and biochemical parameters, such as different compositions of injection media. Our results present settings that enable the high viability of cells post-injection. Lastly, the method is suitable to inject cells in the superficial tissue layer and in deeper layers, required when the submucosa or the sphincter muscle of the urethra is targeted.

Bilateral laparoscopic ureterolysis using hydrodissection in retroperitoneal fibrosis: a new application of an old technique

Objective: To describe our new laparoscopic approach in ureterolysis using the ERBEJET^® 2 device to hydrodissect the ureters in idiopathic retroperitoneal fibrosis.

Methods: Bilateral laparoscopic ureterolysis was done after medical therapy failure (steroids) in a 47 year old patient with retroperitoneal fibrosis. Ureteral stents were placed before surgery. Only five trocars were used for both sides, Toldt’s fascia was opened and the dissection was performed till the psoas muscle. The ureters were completely freed from the fibrotic tissue using the ERBEJET 2 device (pure hydrodissection). An omental wrap was passed behind the colonic flexure at the right and placed around the ureter. At the left, we closed Toldt’s fascia by running sutures back to the freed ureter.

Results: The operating time was 198 mins. The blood loss was 50 cc. The hospital stay was 3 days. The double J stents were removed at 4 weeks postoperatively. After 2 years, the patient is free of symptoms with normal creatinine level and no urinary tract obstructions.

Conclusions: Hydrodissection of the ureter in retroperitoneal fibrosis is a new application in the upper urinary tract laparoscopic approach that has not been described in literature before. It seems to offer excellent midterm outcomes. The use of ERBEJET 2 device seems to simplify the procedure and make it feasible and safe (less trauma to the ureter and more conservation of its blood supply). We believe that comparative studies are needed to assess the role of hydrodissection in ureterolysis for retroperitoneal fibrosis.

Hydro-Jet Dissection of the Cavernous Nerves Preserves Erection Function in a Radical Prostatectomy Animal Model

Background

Postoperative erectile dysfunction (ED) remains a prevalent consequence of radical prostatectomy (RP) that significantly impacts patient quality of life. Water-jet technology is widely used for dissection in neurosurgical procedures but novel to urologic surgery.

Aim

To establish the impact of hydro-jet dissection (HJD) of the cavernous nerves (CN) on postoperative erectile function in an animal model of RP-induced ED.

Methods

32 male Sprague-Dawley rats were randomized to 4 groups: Sham surgery (n = 8), bilateral HJD of CN (n = 8), blunt CN injury (n = 8), or stretch CN injury (n = 8). After 4 weeks, erectile function was assessed by measuring intracavernous pressure (ICP), and penile tissues were harvested for immunohistologic studies.

Main Outcome Measure

The peak ICP and the area under the curve were calculated for each group. Immunohistologic studies were performed for α-smooth muscle actin and neuronal nitric oxide synthase on cross-sections of penile tissue.

Results

Rats in the HJD group demonstrate a significantly higher mean peak ICP and area under the curve compared with both CN injury groups (P = .001). Postoperative erectile function in the HJD group returned to baseline function. Preservation of α-smooth muscle actin and neuronal nitric oxide synthase was observed in the HJD group compared with the other surgical trauma groups.

Clinical Implications

Hydro-jet dissection used in an RP animal model maintains erectile function and offers a potential benefit that warrants further human studies.

Strengths & Limitations

This is a novel animal study comparing a new technology to established CN dissection techniques. This study uses an animal model, which may not completely translate to post-RP ED in humans.

Conclusion

Hydro-jet dissection of the CN during RP in an animal model is associated with significantly better postoperative erectile function when compared with other CN injury. Clinical studies are needed to further investigate the putative benefit of HJD on erectile function in patients undergoing RP.

Campbell JD, Alenezi H, DeYoung LX, et al. Hydrojet Dissection of the Cavernous Nerves Preserves Erection Function in a Radical Prostatectomy Animal Model. Sex Med 2019;7:104–110.

Waterjet dissection of peripheral nerves: an experimental study of the sciatic nerve of rats

BACKGROUND

Although waterjet dissection has been well evaluated in intracranial pathologies, little is known of its qualities in peripheral nerve surgery. Theoretically, the precise dissection qualities could support the separation of nerves from adjacent tissues and improve the preservation of nerve integrity in peripheral nerve surgery.

OBJECTIVE

To evaluate the potential of the new waterjet dissector in peripheral nerve surgery.

METHODS

Waterjet dissection with pressures of 20 to 80 bar was applied on the sciatic nerves of 101 rats. The effect of waterjet dissection on the sciatic nerve was evaluated by clinical tests, neurophysiological examinations, and histopathological studies up to 12 weeks after surgery.

RESULTS

With waterjet pressures up to 30 bar, the sciatic nerve was preserved in its integrity in all cases. Functional damaging was observed at pressures of 40 bar and higher. However, all but 1 rat in the 80 bar subgroup showed complete functional regeneration at 12 weeks after surgery. Histopathologically, small water bubbles were observed around the nerves. At 40 bar and higher, the sciatic nerves showed signs of direct nerve injury. However, all these animals showed nerve regeneration after 12 weeks, as demonstrated by histological studies.

CONCLUSION

Sciatic nerves were preserved functionally and morphologically at pressures up to 30 bar. Between 40 and 80 bar, reliable functional and morphological nerve regeneration occurred. Waterjet pressures up to 30 bar might be applied safely under clinical conditions. This technique might be well suited to separate intact peripheral nerves from adjacent tumor or scar tissue. Further studies will have to show the clinical relevance of these dissection qualities.

First experimental results with a new waterjet dissector: Erbejet 2

BACKGROUND

Waterjet dissection represents a useful technique for many surgical procedures. In this experimental study, the technical features and dissection qualities of the new Erbejet 2 with its new pump and nozzle applicator system are evaluated for its neurosurgical use compared to the established Helix Hydro-Jet.

METHODS

One hundred twenty-six fresh cadaveric pig brains were simultaneously cut with the Helix Hydro-Jet and Erbejet 2. Different pressure levels were applied to cerebral tissue with and without meninges, cerebellum and brainstem. Additionally, dissection characteristics of various cutting media were investigated.

FINDINGS

There was a nearly equal dissection quality at up to 10 bar of both instruments. In contrast to the Helix Hydro-Jet, Erbejet 2 application at higher pressures resulted in an almost linear increase of dissection depth with a small standard deviation. Smoother cutting margins and less foaming were found. Preserved vessels were observed with both devices. Hydroxyaethyl starch led, in contrast to Ringer's solution and isotonic saline solution, to increased dissection width and more foaming.

CONCLUSIONS

The new Erbejet 2 is more precise, with almost linear correlation of pressure and dissection depth compared to the Helix Hydro-Jet. Less foaming and the possible application of various separating media are a considerable advantage. All things considered, the new Erbejet 2 offers more options to enlarge the field of neurosurgical indications for waterjet dissection.

Outcome of conservative surgery for giant cell tumor of the sacrum

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To estimate the clinical outcome of conservative surgery (intralesional curettage or partial excision) aided by effective intraoperative hemorrhage control in patients with giant cell tumors of the sacrum.

SUMMARY OF BACKGROUND DATA

Giant cell tumors of the sacrum present a challenging therapeutic problem. Wide resection is associated with higher morbidity and spinal instability. Whether conservative surgery aided by effective intraoperative hemorrhage control can achieve low recurrence rates remains uncertain.

METHODS

The clinical records of 24 patients with an average age of 35 years who had undergone conservative surgery for sacral giant cell tumor between 1996 and 2005 were evaluated retrospectively. The disease onset, tumor size, operation records, complications, follow-up status, and functional outcome were analyzed.

RESULTS

The mean duration of follow-up was 58 months (median, 50 months; range: 25-132 months). All the patients had a conservative procedure aided by intraoperative occlusion of the abdominal aorta. The mean estimated blood loss was 3217 mL. The mean length of the operation was 190 minutes. Seven (29.2%) patients developed recurrences. The mean time from the index surgical procedure to the first recurrence was 13 months (range: 8-31 months). The 5-year local recurrence-free survival rate was 69.6%. Seventeen (70.8%) patients retained normal urinary function and 16 (66.7%) patients preserved normal bowel function. No patients had urinary or bowel dysfunction when both S3 nerves were preserved. Ten (41.7%) patients had complications perioperatively or during the follow-up. Seven (29.2%) patients had wound complications.

CONCLUSION

Considering the acceptable local recurrence rate, conservative surgery aided by effective control of intraoperative hemorrhage should be considered as an alternative procedure for patients with giant cell tumors of the sacrum. The advantages include lower morbidity, reduced neurologic deficits, speed and ease of the surgical procedure, reduced blood loss, preservation of spinal and pelvic continuity, and a low recurrence rate.

Waterjet dissection of the vestibulocochlear nerve: an experimental study

Object

Waterjet dissection has been shown to protect intracerebral vessels, but no experience exists in applying this modality to the cranial nerves. To evaluate its potential, the authors examined waterjet dissection of the vestibulocochlear nerve in rats.

Methods

Lateral suboccipital craniectomy and microsurgical preparation of the vestibulocochlear nerve were performed in 42 rats. Water pressures of 2–10 bar were applied, and the effect was microscopically evaluated. Auditory brainstem responses (ABRs) were used to define nerve function compared with preoperative values and the healthy contralateral side. The final anatomical preparation documented the morphological and histological effects of waterjet pressure on the nerve.

Results

In using up to 6 bar, the cochlear nerve was preserved in all cases. Eight bar moderately damaged the nerve surface. A 10-bar jet markedly damaged or even completely dissected the nerve. Time course analysis of the ABR demonstrated complete functional nerve preservation up to 6 bar after 6 weeks in all rats. Waterjet dissection with 8 bar was associated with a 60% recovery of ABR. In the 10-bar group, no recovery was seen.

Conclusions

Microsurgical dissection of cranial nerves is possible using waterjet dissection while preserving both morphology and function. The aforementioned jet pressures are known to be effective in neurosurgical treatment of tumors. Thus, waterjet dissection may be useful in skull base surgery including dissection of cranial nerves from tumors. Further studies on this subject are encouraged.

Open versus laparoscopic retroperitoneal lymph node dissection: assessing adequacy of dissection in a porcine model

BACKGROUND AND PURPOSE

Laparoscopic retroperitoneal lymph node dissection (L-RPLND) is emerging as a viable alternative to traditional open retroperitoneal lymph node dissection (O-RPLND). Despite numerous reports confirming clinical oncologic equivalency between the two approaches, however, concerns still remain over the adequacy of laparoscopic dissection. We therefore sought to compare the completeness of dissection between O-RPLND and L-RPLND in a porcine model.

MATERIALS AND METHODS

Fourteen domestic swine were divided into two equivalent groups. Both groups underwent bilateral retroperitoneal lymph node dissection, approximating templates used in human dissection. In one group, the procedure was performed through an open midline incision, while the other group underwent completely laparoscopic dissection. Tissue was independently analyzed by a pathologist, who recorded lymph node yield based on microscopic evaluation.

RESULTS

All animals in the L-RPLND group underwent successful procedures, without the need for conversion. Two open procedures were aborted because of hemorrhage. Mean lymph node yield from O-RPLND was 32, while the mean yield for L-RPLND was 29. This difference was not statistically significant (P=0.65).

CONCLUSIONS

In the porcine model, L-RPLND is capable of providing a quality of dissection equivalent to that of O-RPLND, in terms of absolute lymph node yield on microscopic examination. The applicability of this data to human patients, however, may be limited by significant anatomic differences between the human and the pig. Further prospective comparison in human patients is critically needed.

CT-guided instillation of 5% dextrose in water into the anterior pararenal space before renal radiofrequency ablation in a porcine model: positive and negative effects

PURPOSE

To assess the positive and negative effects of computed tomographic (CT)-guided instillation of 5% dextrose in water (D5W) into the anterior pararenal space before renal radiofrequency (RF) ablation in a porcine model.

MATERIALS AND METHODS

Under CT guidance, D5W was instilled into the right anterior pararenal space of 10 pigs and RF ablation performed in the right kidney. For the control lesions, RF ablation was performed in the left kidney of the same pigs without pretreatment with D5W. Approximately 1 week after RF ablation, bowel adhesion to both kidneys was compared by using a 5-point scale at open laparotomy, as follows: grade 0=no adhesion, grade 1=detachable adhesion, grade 2=grade 1 adhesion plus other adhesion to organs, grade 3=undetachable adhesion, and grade 4=bowel perforation. The areas of coagulation necrosis in both kidneys were compared at pathologic examination.

RESULTS

Bowel adhesions to the right kidneys were classified as grade 0 in nine pigs and as grade 1 in one pig, whereas those to the left kidneys were classified as grade 2 in two pigs and as grade 3 in eight (P<.05). The mean areas of coagulation necrosis in right and left kidneys were 0.58 cm2+/-0.5 and 1.53 cm2+/-1.3, respectively (P<.05).

CONCLUSIONS

CT-guided D5W instillation has a positive effect in reducing the amount of bowel adhesion injury during RF ablation. However, this technique may limit the area of coagulation necrosis in a swine model. Longer term pathologic evaluation is necessary to fully understand the effects of D5W instillation.

Hydro-Jet technology in urologic surgery

Hydro-Jet technology utilizes an extremely thin, high-pressure stream of water. This technology has been routinely used in industry as a cutting tool for different materials such as metal, ceramic, wood and glass. Recently, Hydro-Jet technology has been used for dissection and resection during open and laparoscopic surgical procedures. A high-pressure jet of water allows selective dissection and isolation of vital structures such as blood vessels and nerves. This has resulted in improved dissection and decreased complication rate in recent experimental and clinical studies. This technology has been successfully applied during open and laparoscopic partial nephrectomy, cholecystecomy and retroperitoneal lymphadenectomy.