Water Jet Dissection Research Articles

Randomized clinical trial of efficacy and costs of three dissection devices in liver resection

In recent decades a variety of instruments for liver dissection has become available. This randomized controlled trial analysed the efficacy and costs of three different liver dissection devices. Ninety-six patients without cirrhosis undergoing liver resection were randomized to either ultrasonic dissection, waterjet dissection or dissecting sealer (32 in each group). Patients were unaware of the device used. The primary endpoint was dissection speed. Secondary endpoints were intraoperative blood loss, morbidity and mortality, and costs of dissection devices, staplers and haemostatic agents. Dissection was slower with the dissecting sealer (P = 0.004 versus waterjet dissector). The difference was more pronounced for extended resections (mean(s.e.m.) 1.62(0.36) cm(2)/min versus 3.42(0.53) and 3.63(0.51) cm(2)/min for ultrasonic and water dissectors respectively; P = 0.037). Costs were significantly higher for the dissecting sealer when atypical or segmental resections were performed. Four patients died after extended resections; postoperative complications did not differ between groups. The dissecting sealer is slower than the ultrasonic dissector or water dissector. The three devices are equally safe in terms of blood loss, transfusions and postoperative complications. Ultrasonic and water dissectors might be more favourable economically than the dissecting sealer. ISRCTN52294555 (http://www.controlled-trials.com).

Combination of water-jet dissection and needle-knife as a hybrid knife simplifies endoscopic submucosal dissection

The safety and efficacy of endoscopic submucosal dissection (ESD) is very dependent on an effective injection beneath the submucosal lamina and on a controlled cutting technique. After our study group demonstrated the efficacy of the HydroJet in needleless submucosal injections under various physical conditions to create a submucosal fluid cushion (Selective tissue elevation by pressure = STEP technique), the next step was to develop a new instrument to combine the capabilities of an IT-Knife with a high-pressure water-jet in a single instrument. In this experimental study, we compared this new instrument with a standard ESD technique. Twelve gastric ESD were performed in six pigs under endotracheal anesthesia. Square areas measuring 4-cm x 4-cm were marked out on the anterior and posterior wall in the corpus-antrum transition region. The HybridKnife was used as an standard needle knife with insulated tip (i.e., the submucosal injection was performed with an injection needle and only the radiofrequency (RF) part of the HybridKnife was used for cutting (conventional technique)) or the HybridKnife was used in all the individual stages of the ESD, making use of the HybridKnife's combined functions (HybridKnife technique). The size of the resected specimens, the operating time, the frequency with which instruments were changed, the number of bleeding episodes, and the number of injuries to the gastric wall together with the subjective overall assessment of the intervention by the operating physician were recorded. The resected specimens were the same size, with average sizes of 16.96 cm(2) and 15.85 cm(2) resp (p = 0.8125). Bleeding episodes have been less frequent in the HybridKnife group (2.83 vs. 3.5; p = 0.5625). The standard knife caused more injuries to the lamina muscularis propria (0.17 vs. 1.33; p = 0.0313). The operating times had a tendency to be shorter with the HybridKnife technique (47.18 vs. 58.32 minute; p = 0.0313). The combination of a needle-knife with high-pressure water-jet dissection improved the results of endoscopic submucosal dissection in this experimental setting. Because the frequency of complications is still high, further improvements to the instrument are necessary.

Waterjet dissection of the vestibulocochlear nerve: an experimental study

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. 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. 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. 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.

Resection of Colorectal Liver Metastases: Is a Resection Margin of 3 mm Enough?

A safety margin of > or =10 mm is generally accepted in surgery for colorectal metastases. It is reasonable that modern methods of liver parenchyma dissection may allow for a reduction in this distance. A total of 333 patients were included in a multicenter trial after resection of colorectal liver metastases. Dissection of the liver had been performed with a CUSA, UltraCision, or water-jet dissector. The size of the resection margin was correlated with recurrence risk and survival. The median hepatic recurrence-free survival reached 35 months for all patients; median recurrence-free survival was 24 months and overall survival was 41 months. Univariate analysis of different groups denoting the extent of resection margin (> or =10 mm, 6-9 mm, 3-5 mm, 1-2 mm, 0 mm (R1)) indicated that a margin of 1-2 mm leads to a significantly reduced median hepatic recurrence-free survival of 20 months (p = 0.004) and recurrence-free survival of 19 months (p = 0.011). Patients with R1 resection had the worst prognosis. Overall survival was not influenced by the size of the resection margin. Surgical margins were significantly reduced in simultaneous resections of four or more liver metastases and in cases in which metastatic infiltration of central liver segments was present. At multivariate analysis, resection margins of 1-2 mm and 0 mm were independent predictors of hepatic recurrence and overall recurrence. The indication for resection of metastases can be safely extended to cases in which tumors sit closer than 1 cm to nonresectable structures.

Urodynamic outcome of waterjet-assisted total mesorectal excision

Waterjet dissection has been proposed for total mesorectal excision. The present study investigated its impact on urodynamic function and oncological outcome. Thirty patients with rectal cancer were recruited to this prospective study, of whom 25 underwent urodynamic evaluation both before and after surgery. All patients were capable of spontaneous micturition at a median of 5 months after surgery. Urodynamic measurements revealed a decrease in detrusor pressure of more than 30 mmHg, and residual urine volumes of between 100 and 200 ml, in three patients. No patient had a complete neurogenic voiding disorder. Local recurrences developed in two of 22 patients. The extent of micturition disorders observed after total mesorectal excision using the waterjet method in this small series is encouraging.

Submucosal cushioning with water jet before endoscopic mucosal resection

Several new techniques have recently been described that allow the endoscopic mucosal resection even of broad-based flat lesions in the gastrointestinal tract. The technique recently described by us of using a water jet dissector (Helix HydroJet) for a selective deposition of liquid in the submucosal lamina has now been combined with different substances, and their effects have been compared. Gastroscopies were carried out in 8 pigs under intubation anesthesia, and 2 submucosal cushions each were created in the stomach using one out of 4 test substances (gelatin, glucose 50, hydroxyethyl starch [HES] 10%, dextran 40), as well as one cushion of isotonic saline solution placed in each area via the Helix HydroJet). The height of the submucosal cushions was intermittently measured over a period of 40 or 20 min, respectively, by miniprobe endosonography. In 7 of the animals the stomach was subsequently subjected to mucosal resection. The specimens and the gastric wall were histologically assessed to evaluate the localization of the liquid cushion and the effect on adjacent layers of the gastric wall. All test substances produced strictly selective liquid cushions in the submucosa. With HES 10% and dextran the maximum height of the cushions initially increased and then decreased during the further course to an average of 90% of the initial height within 40 min. Isotonic saline solution showed the most rapid decrease in height (72% after 20 min). The histological assessment confirmed the selective nature of the liquid deposit in the submucosa. Plasma expanders produced cushions that initially increased in height but then remained constant for a longer period than cushions produced using glucose 50, gelatin, or isotonic saline solution. The combination of transmucosal jet application for elevation of the mucosa with plasma expanders is therefore an interesting approach to optimize endoscopic mucosal resections.

Hydrodissection versus high‐pressure water jet dissection

Hydrodissection versus high‐pressure water jet dissection

The use of waterjet dissection in endoscopic neurosurgery

Waterjet dissection enables vessel preservation and a reduction in intraoperative blood loss. Because even minimal bleeding should be avoided during neuroendoscopy, the waterjet device may be a particularly valuable tool in such procedures. The authors used this instrument in experimental endoscopic procedures in 20 cadaveric porcine brains and clinically in four patients with obstructive hydrocephalus. A precise and accurate septostomy was achieved in all of the pig brains. In two patients the hydrocephalus was due to intraventricular hemorrhage, in one a posterior fossa tumor, and in one a cystic craniopharyngioma. In all patients the surgical view was kept clear with waterjet irrigation and suction. Using a pressure setting of 10 bars, the waterjet device successfully perforated the cyst wall of the craniopharyngioma in one patient and the floor of the third ventricle in three patients. The use of the waterjet device in selected endoscopic procedures appears safe, and may help reduce intraoperative bleeding. However, further studies are needed to confirm the utility of the waterjet tool in endoscopy.

UP-01.20: The use of water jet dissection for nephron sparing surgery in patients with renal cell cancer

Nephron Sparing Surgery (NSS) is today accepted treatment option for localized, less then 4 cm.- peripheral lesions, of RCC, even in case of normal contralateral kidney (elective or mandatory indications), with 5-year survival over 90% and local recurrence rate of 0-10%. By this presentation we would like to introduce the use of a new technical equipment, the water jet machine, for easier dissection and separation of the tumor from normal kidney tissue which made this operation simple, easier and followed by smaller number of complications.

Water-jet dissection for parenchymal division during hepatectomy

Background. High-pressure water-jet dissection was originally developed for industry where ultra-precise cutting and engraving were desirable. This technology has been adapted for medical applications with favorable results, but little is understood about its performance in hepatic resections. Blood loss may be limited by the thin laminar liquid-jet effect that provides precise, controllable, tissue-selective dissection with excellent visualization and minimal trauma to surrounding fibrous structures. Patients and methods. The efficacy of the Water-jet system for hepatic parenchymal dissection was examined in a consecutive case series of 101 hepatic resections (including 22 living donor transplantation resections) performed over 11 months. Perioperative outcomes, including blood loss, transfusion requirements, complications, and length of stay (LOS), were assessed. Results. Three-quarters of the cases were major hepatectomies and 22% were cirrhotic. Malignancy was the most common indication (77%). Median operative time was 289min. Median estimated blood loss (EBL) was 900ml for all cases, and only 14% of patients had >2000ml EBL. Furthermore, EBL was 1000ml for major resections, 775ml for living donor resections, 600ml in cirrhotic patients, and 1950ml for steatotic livers. In all, 14% of patients received heterologous packed red blood cell (PRBC) transfusions for an average of 0.59 units per case. Median LOS was 7 days. EBL, transfusion requirements, and LOS were slightly increased in the major resection cohort. There was one mortality (1%) overall. These results are equivalent to, or better than, those from our contemporary series of resections performed with ultrasonic dissection. Conclusion. Water-jet dissection minimizes large blood volume loss, requirements for transfusion, and complications. This initial experience suggests that this precision tool is safe and effective for hepatic division, and compares favorably to other established methods for hepatic parenchymal transection.

New water-jet dissector: Initial experience in hepatic surgery

Journal Article New water-jet dissector: Initial experience in hepatic surgery Get access H U Baer, H U Baer Department of Visceral and Transplantation Surgery, Inselspital, University of Berne, Berne, Switzerland Correspondence to: Dr H. U. Baer, Klinik für Viszerale und Transplantationschirurgie, Inselspital, 3010 Bern, Switzerland Search for other works by this author on: Oxford Academic Google Scholar G J Maddern, G J Maddern Department of Visceral and Transplantation Surgery, Inselspital, University of Berne, Berne, Switzerland Search for other works by this author on: Oxford Academic Google Scholar L H Blumgart L H Blumgart Department of Visceral and Transplantation Surgery, Inselspital, University of Berne, Berne, Switzerland Search for other works by this author on: Oxford Academic Google Scholar British Journal of Surgery, Volume 78, Issue 4, April 1991, Pages 502–503, https://doi.org/10.1002/bjs.1800780438 Published: 08 December 2005 Article history Accepted: 10 October 1990 Published: 08 December 2005

The use of water jet dissection for nerve sparing radical prostatectomy

The use of water jet dissection for nerve sparing radical prostatectomy

Liver paper summary: IHPBA meeting 2004, Washington, DC

Liver paper summary: IHPBA meeting 2004, Washington, DC

Waterjet Dissection versus Ultrasonic Aspiration in Epilepsy Surgery

Waterjet dissection is currently under close investigation in neurosurgery. Experimentally, precise brain parenchyma dissection with vessel preservation has been demonstrated. Clinically, the safety of the instrument has already been proved. However, precise data demonstrating that waterjet dissection indeed reduces surgical blood loss are still missing. The authors applied the waterjet device in a prospective randomized study in comparison with the ultrasonic aspirator. Because there is little variability in the procedure, 30 patients with temporal lobe epilepsy receiving a tailored temporal lobe resection between December 1999 and October 2002 were selected for this study. Intraoperative vessel preservation, intraoperative blood loss, surgical complications, and epilepsy outcome were evaluated. All patients were followed at 3-month intervals. During surgery, both instruments were easy to handle. Only with the waterjet dissector, however, were even small intraparenchymal blood vessels preserved. Intraoperative blood loss was significantly reduced with the waterjet (mean, 70 +/- 46 ml) compared with the ultrasonic aspirator (mean, 121 +/- 48 ml). However, no difference in the necessity for blood transfusion occurred. No difference was observed with respect to operation time (238.6 +/- 37.0 min with the waterjet, 247.5 +/- 41.5 min with the ultrasonic aspirator), surgical complications, and outcome. The waterjet dissector enables a significant reduction of intraoperative blood loss in the investigated setting. However, further studies are needed to confirm these results with a larger number of patients. Studies also are needed to prove that the reduction of blood loss is of clinical relevance for the outcome of the patients.

Total mesorectal excision with the water-jet-dissection. Technique and results

The introduction of total mesorectal excision (TME), in particular, has resulted in a dramatic decrease in postoperative functional disorders. Strict adherence to the dissection planes described above, is the prerequisite for good oncological and functional outcome. To facilitate dissection, we have introduced the high-pressure water jet dissector into our surgical routine for the treatment of rectal cancer. Below, we describe the technique of total mesorectal excision we employ in our department and present our perioperative surgical results. We performed total mesorectal excision for rectal cancer on 49 patients, comprising 32 males and 17 females aged between 34 and 88 years. 38 patients underwent low anterior resection of the rectum and 11 patients abdominoperineal resection. The mean operating time was 282 min, mean intraoperative administration of red cell concentrates was 0.55 units. The mean postoperative stay in the ICU was 1.92 days. Anastomotic leakage occurred in 6.1%, wound healing disturbances in 12.2%, urinary tract infection in 12.2% intra-abdominal infection in 4.1% and faecal fistula in 4.1%. Urinary tract infections occurred in 12.2%. Postoperative temporary neurogenic voiding disturbances occurred in 14.3%. Persistent neurogenic bladder dysfunction after three months could be observed in 6.1%. The perioperative results are comparable to those of centres of excellence in the international literature. The Hydro-Jet dissector significantly facilitated TME. The particular feature of this technical aid is that it permits the rapid early development of the embryological plane between the pelvic nerves and the mesorectal fascia, without doing damage to either of them. This leads to optimal radicality and 1 maximum preservation of the autonomic nerves. Before a definitive pronouncement on voiding disturbances can be made, however, we consider it necessary to carry out a prospective randomised study with preoperative and postoperative urodynamic investigations.

Resection of the Spleen Using the Water Jet Dissection Technique

Today, spleen-preserving or splenic-tissue-conserving surgery is both an accepted and desirable principle in the surgical treatment of injuries to the spleen as well as nontraumatic benign splenic lesions. In the rare case of benign tumorous lesions of the spleen, the question whether splenectomy or resection is the preferred successful therapeutic option is still being discussed. We present a case in which a high-pressure water jet dissector (Helix Hydro-Jet, A. Pein Medizintechnik, Schwerin, Germany) was used to perform an elective resection in a 13-year-old boy with a hamartoma of the spleen. The postoperative course was free of complications. The case illustrates the excellent features of water jet dissection in terms of transection of the parenchymal tissue and safe and selective hemostasis, which has also made the Hydro-Jet our preferred instrument for surgery on the splenic parenchyma.

Intraoperative online navigation of dissection of the hepatical tissue—a new dimension in liver surgery?

The functional–anatomical structuring of the liver according to Couinaud regarding the intrahepatical course of the vascular structures is the base of every modern liver surgery. Consequently, using intraoperative ultrasound is an undisputed requirement for every liver resection. Exact following of the planned resection plane can only be realized with the application of a permanent online navigation, based on intraoperative ultrasound during the dissection of the hepatical tissue. We present the combination of a navigation system (US-Guide 2000®) with an intraoperative ultrasound probe and a waterjet dissection instrument for intraoperative online navigation of parenchymal dissection. The use of the navigated liver resection is being shown by the example of a 79-year-old patient with a HCC in segment 5 and 6.

Experimental application of pulsed Ho:YAG laser-induced liquid jet as a novel rigid neuroendoscopic dissection device.

Although water jet technology has been considered as a feasible neuroendoscopic dissection methodology because of its ability to perform selective tissue dissection without thermal damage, problems associated with continuous use of water and the ensuing fountain-effect-with catapulting of the tissue-could make water jets unsuitable for endoscopic use, in terms of safety and ease of handling. Therefore, the authors experimented with minimization of water usage during the application of a pulsed holmium:yttrium-aluminum-garnet (Ho:YAG) laser-induced liquid jet (LILJ), while assuring the dissection quality and the controllability of a conventional water jet dissection device. We have developed the LILJ generator for use as a rigid neuroendoscope, discerned its mechanical behavior, and evaluated its dissection ability using the cadaveric rabbit ventricular wall. The LILJ generator is incorporated into the tip of a stainless steel tube (length: 22 cm; internal diameter: 1.0 mm; external diameter: 1.4 mm), so that the device can be inserted into a commercial, rigid neuroendoscope. Briefly, the LILJ is generated by irradiating an internally supplied water column within the stainless steel tube using the pulsed Ho:YAG laser (wave length: 2.1 microm, pulse duration time: 350 microseconds) and is then ejected through the metal nozzle (internal diameter: 100 microm). The Ho:YAG laser pulse energy is conveyed through optical quartz fiber (core diameter: 400 microm), while cold water (5 degrees C) is internally supplied at a rate of 40 ml/hour. The relationship between laser energy (range: 40-433 mJ/pulse), standoff distance (defined as the distance between the tip of the optical fiber and the nozzle end; range: 10-30 mm), and the velocity, shape, pressure, and average volume of the ejected jet were analyzed by means of high-speed camera, PVDF needle hydrophone, and digital scale. The quality of the dissection plane, the preservation of blood vessels, and the penetration depth were evaluated using five fresh cadaveric rabbit ventricular walls, under neuroendoscopic vision. Jet velocity (7.0-19.6 m/second) and pressure (0.07-0.28 MPa) could be controlled by varying the laser energy, which determined the penetration depth in the cadaveric rabbit ventricular wall (0.07-1.30 mm/shot). The latter could be cut into desirable shapes-without thermal effects-under clear neuroendoscopic vision. The average volume of a single ejected jet could be confined to 0.42-1.52 microl/shot, and there was no accompanying generation of shock waves. Histological specimens revealed a sharp dissection plane and demonstrated that blood vessels of diameter over 100 microm could be preserved, without thermal damage. The present pulsed LILJ system holds promise as a safe and reliable dissection device for deployment in a rigid neuroendoscope.

Towards waterjet dissection in neurosurgery: experimental in-vitro and in-vivo results

Towards waterjet dissection in neurosurgery: experimental in-vitro and in-vivo results

Water Jet Dissection in Neurosurgery: Experimental Results in the Porcine Cadaveric Brain

OBJECTIVE Water jet dissection is currently under investigation as a new tool for use in neurosurgical procedures. The safety of this instrument has already been demonstrated. However, precise data demonstrating highly accurate tissue dissection in the brain in combination with vessel preservation are still missing. METHODS In this study, 50 porcine cadaveric brains were dissected with the use of several nozzle types (80–150 in μm diameter, coherent straight or helically turned jet) and several levels of water jet pressure (1–40 bars). The dissection characteristics in various brain regions and the basilar artery were evaluated morphologically. RESULTS The best results regarding reliable function, dissection accuracy, and the correlation of water jet pressure with dissection depth were obtained with the 120-μm Helix Hydro-Jet nozzle. An almost linear relationship of pressure increase with dissection depth was demonstrated. The dissection depth varied significantly up to threefold, depending on the area investigated (greatest resistance was in the brainstem, followed by hemispheres and then the cerebellum). Vessels including the basilar artery resisted pressure up to 15 bars in most cases, whereas the basilar artery was dissected significantly more often with higher pressure. CONCLUSION The results indicate that 1) use of the water jet enables very precise and reliable brain parenchyma dissection with vessel preservation under conditions corresponding to the clinical situation, and 2) the nozzle type and water jet pressure must be selected carefully according to the brain area and tissue targeted. This study provides the morphological basis for further research with the use of the water jet technique in the brain. The water jet’s characteristics may make this device a useful addition to the neurosurgical armamentarium.