Laparoscopic Retroperitoneal Lymph-Node Dissection with the Waterjet Is Technically Feasible and Safe in Testis-Cancer Patient

Hydrodissection for improved microsurgical denervation of the spermatic cord: prospective blinded randomized control trial in a rat model

Microsurgical denervation of the spermatic cord (MDSC) can provide up to an 86% improvement in pain in patients with chronic orchialgia (CO) who have failed conservative management. Failures in MDSC could be due to small diameter nerves (≤1 mm) left behind on the spermatic cord. The objective of this study was to assess if hydrodissection (HD) of the spermatic cord after MDSC could decrease the number of residual nerve fibers without compromising blood flow. Prospective blinded randomized control trial: bilateral MDSC was performed on 22 adult rats (44 cords). HD of the spermatic cord was performed on one side of each rat (side randomized) using the ERBEJET2. The contralateral cord (no HD) was the control for each animal. Blood flow through the vessels was monitored using a micro-Doppler probe. After completion a cross-section of the residual cord was sent to pathology (blinded to technique) to assess for small diameter nerves and signs of damage in vascular integrity. Blood flow had been maintained in the vessels when the ERBEJET2 was set to 6 bar (87 psi). The cord where HD had been performed had a significantly lower total median residual nerve count of 5 (0-10), compared to 8 (2-12) on the non-HD side (p = 0.007). No structural damage was seen in the vessels in the spermatic cord that had undergone HD (gross exam and histology). HD of the spermatic cord significantly decreases residual nerve density without compromising vascular integrity in a rat model.

Evolving Technologies for Tissue Cutting

This article reviews evolving and lesser known technologies for tissue cutting and their application in oral and maxillofacial surgery.

Robotic waterjet wound debridement - Workflow adaption for clinical application and systematic evaluation of a novel technology

Objective

We evaluated the clinical potential of a novel robotic system for autonomous performance of waterjet wound debridement.

Summary background data

Within the last decade, waterjet wound debridement has proven to be a valid alternative to the conventional approach using sharp spoons and scalpel.

Methods

The DLR MIRO robot using the DLR MICA instrument for robotic surgery was adapted for actuation of an ERBEJET 2 flexible endoscopic waterjet probe. Waterjet debridement of various wound shapes and sizes using a porcine skin model was compared between this novel robotic system and a control group of human medical professionals with regard to wound area cleaned by the waterjet, off-target area, and procedural time.

Results

After the wound area was registered in the robotic system, it automatically generated a cleaning path and performed debridement based on generated surface model. While the robotic system demonstrated a significant advantage for the covered wound area (p = 0.031), the average off-target area was not significantly different from human controls. Human participants had high variability in cleaning quality across users and trials, while the robotic system provided stable results. Overall procedural time was significantly lower in trials performed by humans.

Conclusions

Robotic waterjet wound debridement is a promising new technological approach compared to the current clinical standard of interventional wound therapy, providing higher efficiency and quality of wound cleaning compared to human performance. Additional trials on more complicated wound shapes and in vivo tissue are necessary to more thoroughly evaluate the clinical potential of this technology.

Extending the Capability of Using a Waterjet in Surgical Interventions by the Use of Robotics

In waterjet surgery, a thin high-pressure jet is used for dissections and surface abrasion of soft tissue. This selective preparation method preserves nerves and vessels, whereas the surrounding soft tissue is washed away.

OBJECTIVE

The aim of this study is to enhance the application field of this technique by resolving technological limitations.

METHODS

A technical task definition of handling a hand-guided waterjet applicator is derived from the literature. All reported procedures require to follow a trajectory superimposed with an oscillating movement. By introducing a robotic system and a specialized kinematic approach, the limited dexterity of the waterjet applicator is increased. Additionally, the system provides assistance by automatically performing parts of the task.

RESULTS

The method is applied to two different procedures: a minimally invasive dissection and a surface abrasion for open medical treatments. On the basis of experiments with gelatine phantoms, the performance of the method is shown for both procedures.

CONCLUSION

In the minimally invasive use case, the reachability limited by the conventional manual tools is extended by the capabilities of the robotic system. Simultaneously, the handling is simplified by automation of the superimposed oscillation. In the surface abrasion case, a dense coverage of the treated area is achievable. The risk of cross infections could be reduced by spatial separation of patient and staff.

SIGNIFICANCE

Thus, the waterjet technology can be fully integrated into robotic surgery systems and benefit from their inherent abilities.

[Natural orifice transluminal endoscopic surgery in urology: feasability of a transrectal, flexible retroperitoneoscopy in a porcine model]

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) in urology is becoming more and more interesting due to technical innovations. One of those innovations is the HybridKnife®, a multifunctional sonde that combines high-frequency electrosurgery and water jet surgery. The aim of this study was to establish a transrectal, flexible endoscopic retroperitoneoscopy in a porcine model by means of the HybridKnife® for further development of a transrectal retroperitoneal NOTES lymphadenectomy (NOTES-RLA).

MATERIAL AND METHODS

Five female pigs (25-30 kg body mass) were anesthetized and placed in a supine position. The rectal mucosa was opened 3-5 cm cranially of the linea dentata. After submucosal tunneling, the retrorectal space was opened. We performed a flexible endoscopic retroperitoneoscopy by means of a double-channel gastroscope 13.806 PKS (Karl Storz-Endoskope, Tuttlingen, Germany) and the HybridKnife® I-type (ERBE Elektromedizin, Tübingen, Germany).

RESULTS

Transrectal access was safe and feasible without any difficulties. Using the HybridKnife® water jet technology, the retroperitoneal space could be distended which enabled safe access to the iliacal vessels, the bifurcation of the aorta/vena cava, and the pre- and paraaortal/-caval space up to the renal vessels. The water jet did not lacerate or injure blood vessels, nerves, or lymph vessels in any of the surgical procedures.

CONCLUSIONS

By means of the HybridKnife®, transrectal access into the retrorectal space is safe and easily feasible. The water jet technology combined with electrosurgery prevented injuries of blood vessels, nerves, and lymph vessels and enabled transrectal flexible endoscopic retroperitoneoscopy as a precondition for further establishment of a transrectal NOTES-RLA.

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.

Multi-stream saline-jet dissection using a simple irrigation system defines difficult tissue planes

A readily available, low-cost technology is described to assist in dissecting difficult tissue planes.

Introduction:

Single-stream hydro-jet dissection is increasingly used in various laparoscopic procedures, but its use requires special equipment. We describe a simple method for using an irrigation system for saline-jet tissue dissection as a useful adjunct prior to adhesiolysis.

Material and Methods:

Intraabdominal adhesions prolong laparoscopic procedures, because tissue planes are difficult to identify. We performed multi-jet saline dissection (MSSJ) between 2000 and 2009 in more than 500 patients during laparoscopy involving hernias, gallbladders, appendices, and intestinal obstructions. We use a standard suction irrigation probe, which is attached to a 1-liter saline bag with an inflatable cuff around to create a pressure of 250mm Hg to 300mm Hg. In effect, this is the standard setup generally used for irrigation. After using saline dissection, tissue planes can be better defined and the structures can then be separated.

Result and Discussion:

Using this method, we have successfully identified tissue planes in spite of dense adhesions, and our conversion rates to open have been reduced dramatically. This method is relatively safer than other modalities of tissue dissection, such as diathermy, ultrasonic, blunt or sharp dissection. The disadvantage is that with tissues saturated with saline it becomes more difficult to use diathermy hemostasis. Care has to be exercised in monitoring the temperature and volume of the fluid used.

Retroperitoneal lymph node dissection after chemotherapy

Retroperitoneal lymph node dissection after chemotherapy (PC-RPLND) plays a crucial role in managing patients with advanced germ cell tumours (GCTs). In the last few years improvements in radiographic staging, a better understanding of the role of serum tumour markers, and the introduction of cisplatin-based chemotherapy have all contributed to this surgical therapy. PC-RPLND is necessary when residual radiographic abnormalities are present after chemotherapy. The need for a PC-RPLND in the face of normal findings from computed tomography (CT) is controversial. CT criteria alone are not sufficiently reliable to distinguish viable tumour or teratoma from necrosis. No combination of variables can predict negative retroperitoneal pathology with sufficient accuracy after induction chemotherapy. Unresected teratoma or viable GCT are at least partly chemorefractory and, if untreated, will progress. So completeness of resection is an independent and consistent predictive variable of clinical outcome. In PC-RPLND surgical margins should not be compromised in an attempt to preserve ejaculation, although nerve-sparing dissections are possible in patients with marker normalization after chemotherapy and necrotic tissue in frozen-section histology. In these patients nerve-sparing techniques and the reduction of surgical field to the left- or right-sided template are applicable to preserve antegrade ejaculation and consecutive fertility. The size and location of residual masses coupled with the retroperitoneal desmoplastic reaction make PC-RPLND a technically demanding procedure that should be performed by experienced surgeons in dedicated referral centres.

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.

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.

Laparoscopic retroperitoneal lymph node dissection: does it still have a role in the management of clinical stage I nonseminomatous testis cancer? A European perspective

CONTEXT

Laparoscopic retroperitoneal lymph node dissection (L-RPLND) is not recommended as standard tool in European Association of Urology (EAU) guidelines.

OBJECTIVE

To update the role of L-RPLND in patients with clinical stage I nonseminomatous germ cell tumour (NSGCT) compared to open retroperitoneal lymph node dissection (O-RPLND).

EVIDENCE ACQUISITION

A systematic literature search from 1992 to 2008 was performed in Medline, EMBASE, and Cochrane. The largest series from each group was considered. Comparative analysis was based on raw data of series published in 2000 and later.

EVIDENCE SYNTHESIS

Results of >800 patients treated by L-RPLND reported in 34 articles were analyzed. Lymph node dissection (LND) was based on modified templates, removing an average of 16 (5-36) lymph nodes. At experienced centres, complication rates were 15.6% (9.4-25.7), including 2% (0-5) retrograde ejaculation and 1.7% (0-6) reintervention. Operating room times are longer compared to O-RPLND (204 vs 186min). Five publications with a follow-up of 63 (36-89) mo include 557 patients. One hundred twenty-six of 140 (90%) patients with positive nodes (25%, range: 17-38) received adjuvant chemotherapy, resulting in a local relapse rate of 1.4% (0.7-2.3) with no in-field recurrence; rate of distant relapses was 3.3% (1.8-4.6), including one port-site metastasis; and rate of biochemical failure was 0.9% (0.7-2.3). Two of 14 patients with positive nodes (pN1) who did not receive adjuvant chemotherapy relapsed, both 8 mo after surgery, and were salvaged by chemotherapy. Compared with O-RPLND, there was no difference in relapse rates, percentage of patients receiving chemotherapy (29% vs 31%), chemotherapy (CTx) cycles per cohort (0.6), rate of salvage surgery (1.2% vs 1.5%), and patients with no evidence of disease (NED; 100% vs 99.7%).

CONCLUSIONS

L-RPLND offers similar staging accuracy and long-term outcome to O-RPLND. In a late series of experienced L-RPLND centres, there was a trend towards fewer complications. L-RPLND represents a valuable tool for experienced laparoscopic surgeons. Further studies must focus on the curative potential of the procedure in pathologic stage IIA.

Complications of laparoscopic retroperitoneal lymph node dissection in testicular cancer

OBJECTIVES

A proposed benefit of laparoscopic retroperitoneal lymph node dissection (LRPLND) is more favorable morbidity in comparison to open retroperitoneal lymph node dissection (RPLND). The objective of this review is to examine and summarize the literature regarding complications in both primary and post-chemotherapy LRPLND (PC-LRPLND) and, where appropriate, we include the opinions of the senior author regarding management.

METHODS

A MEDLINE search was performed using the terms "laparoscopy" or "laparoscopic," "retroperitoneal lymph node dissection" or "RPLND," and "testicular neoplasms." Articles were included on the basis of study design and content. For series updated over time, an effort was made to include only the most recent data to avoid duplicate reporting of patients.

RESULTS

In primary LRPLND, vascular injury is the most common complication, occurring in 2.2-20% of reported cases. Bowel injury is rarely reported but potentially catastrophic. Rates of retrograde ejaculation are less than 5%. Chylous ascites and lymphocele are delayed post-operative complications. Rarely reported complications include nerve injury, retroperitoneal hematoma, and ureteral injury requiring internal stent placement. PC-LRPLND is challenging, with high rates of conversion and complications. Hemorrhage is common. Retrograde ejaculation is several-fold more common in PC-LRPLND than in primary LRPLND. No peri-operative mortality has been reported for either LRPLND or PC-LRPLND.

CONCLUSIONS

LRPLND and PC-LRPLND are technically demanding. Hemorrhage and vascular injury are the most commonly reported complications. Prospective studies will help clarify the proposed benefits of LRPLND.

Laparoscopic retroperitoneal lymph node dissection for nonseminomatous germ cell tumors: long-term oncologic outcomes

PURPOSE OF REVIEW

Laparoscopic retroperitoneal lymph node dissection was first described in 1992, and has become more commonly practiced at certain centers. Laparoscopic retroperitoneal lymph node dissection may be less morbid than open retroperitoneal lymph node dissection, but more costly. Controversy exists, however, regarding the oncologic adequacy of the procedure. The published literature regarding the oncologic outcomes of laparoscopic retroperitoneal lymph node dissection is reviewed herein.

RECENT FINDINGS

Laparoscopic retroperitoneal lymph node dissection has not been as widely adopted as other laparoscopic procedures for genitourinary malignancy. There have only been seven publications in the last 3 years, often coming from the same centers. Recently there has been a change in practice with a greater effort to perform therapeutic laparoscopic retroperitoneal lymph node dissection and not simply a staging procedure. Adjuvant chemotherapy is no longer routinely offered to all patients with positive nodes.

SUMMARY

The impressive cure rate and decreasing morbidity associated with conventional open retroperitoneal lymph node dissection are difficult to improve upon. While on par with open retroperitoneal lymph node dissection series, the current oncologic outcomes are difficult to attribute to successful laparoscopic retroperitoneal lymph node dissection alone. Most patients with viable tumor in the retroperitoneal lymph node dissection specimen received chemotherapy. Thus, we must await follow-up of the patients who declined adjuvant chemotherapy after laparoscopic retroperitoneal lymph node dissection or the results of more recent initiatives with laparoscopic retroperitoneal lymph node dissection alone.

Laparoscopic retroperitoneal lymph node dissection for nonseminomatous germ-cell tumors: current status

We review the published literature regarding the technical feasibility, oncologic outcomes, morbidity, and cost-effectiveness of laparoscopic retroperitoneal lymph node dissection (LRPLND). With proof that it is feasible, several centers have become expert in LRPLND and morbidity appears to be less than that of open RPLND. As the technique improves, it is likely that LRPLND will become equally if not more cost-effective than conventional RPLND. However, the oncologic outcomes, while on par with open RPLND series, are difficult to attribute to successful LRPLND alone when nearly all patients with positive lymph nodes received chemotherapy postoperatively. Although uncertainties exist, LRPLND holds much future promise.