Submucosal cushioning with water jet before endoscopic mucosal resection : Which fluids are effective?

Removal of GIT lesions and the role of impedance of the injection solution-an innovative approach to known methods

In this work, for the first time, the specific impedances of various injection solutions as well as the surface and tissue impedance after injection of these solutions were analyzed and compared regarding the radio-frequency surgical cutting process. The impedances of 0.9% NaCl, 4% gelatine, 6% hydroxyethyl starch, 10% glycerol/5% fructose, 10% glucose, 5% and 20% albumin, blood, and blood plasma as well as aqua destillata have been tested in vitro. Even if EMR and ESD are routinely used in clinical practice, there is so far no easy, fast, and safe method to remove larger lesions en bloc. We show that the impedance of the injected solution shows to be a crucial factor for safe removal, especially of larger lesions (Ø > 20 mm) and more importantly in accordance with the requirements of oncology and pathology. KEY MESSAGES: Impedance is playing a crucial factor in the radio-frequency (RF)-surgery. With a higher Impedance there will be less current necessary to reach the aimed voltage. Injection solution Aqua destillata and 10% Glucose, show significantly higher Impedances. Higher impedances lead to less surgical related complications. Minor changes in existing method to improve patent safety.

Submucosal injection with waterjet improves endoscopic mucosal resection of colorectal adenoma - a randomised controlled clinical trial

PURPOSE

Endoscopic mucosal resection (EMR) of colorectal adenomas leads to a reduced incidence of, and mortality from, colorectal carcinoma. Large adenomas are especially difficult to resect. Submucosal injection is a key part of EMR, as it allows for complete resection and decreased complications. We previously demonstrated in both animal models and a clinical trial that a focussed fluid beam applied to the mucosa creates selective fluid cushions in the submucosa selective tissue elevation by pressure (STEP). In this study, we examined the potential of this new technique compared to the standard inject and cut technique.

METHODS

This was a monocentric prospective two armed randomised controlled clinical trial comparing the STEP technique to the standard needle injection. We included patients with Yamada I and II adenomas ≥12 mm.

RESULTS

One hundred fifty-five patients were treated in the trial. With the STEP technique there was a significantly higher rate of en-bloc resection, whereas piecemeal resection was more common in the standard arm. The odds ratio of piecemeal resection was 2.422 with a 95% confidence interval of 1.163-5.045 (p value .0195). There was no significant difference in resection time between the two techniques, while there was a significant difference in resections speed for the STEP technique. There was also no difference in complication rates.

CONCLUSIONS

This study demonstrated that the new STEP technique leads to a higher rate of en-bloc resections than the standard injection technique in endoscopic mucosa resection of colorectal adenomas. The STEP technique can play an important role in the future of EMR.

Improved Techniques for Endoscopic Mucosal Resection (EMR) in Colorectal Adenoma

Background

Endoscopic therapy of colorectal adenomas and early cancers is a standard method. Besides oncological criteria, the method is limited by polyp location, size, and texture.

Method

Based on the current literature, technical modifications and developments in endoscopic mucosal resection are described.

Results

Numerous approaches exist to improve the conditions of resection, including optimisation of mucosal elevation and modification of techniques, tools, and devices.

Conclusion

Endoscopic therapy of sessile and flat colorectal polyps remains a challenge. Some of the presented modifications can help to address this challenge.

The tissue effect of argon-plasma coagulation with prior submucosal injection (Hybrid-APC) versus standard APC: A randomized ex-vivo study

BACKGROUND

Thermal ablation for Barrett's oesophagus has widely been established in gastrointestinal endoscopy during the last decade. The mainly used methods of radiofrequency ablation (RFA) and argon-plasma coagulation (APC) carry a relevant risk of stricture formation of up to 5-15%. Newer ablation techniques that are able to overcome this disadvantage would therefore be desirable. The aim of the present study was to compare the depth of tissue injury of the new method of Hybrid-APC versus standard APC within a randomized study in a porcine oesophagus model.

METHODS

Using a total of eight explanted pig oesophagi, 48 oesophageal areas were ablated either by standard or Hybrid-APC (APC with prior submucosal fluid injection) using power settings of 50 and 70 W. The depth of tissue injury to the oesophageal wall was analysed macroscopically and histopathologically.

RESULTS

Using 50 W, mean coagulation depth was 937 ± 469 µm during standard APC, and 477 ± 271 µm during Hybrid-APC (p = 0.064). Using 70 W, coagulation depth was 1096 ± 320 µm (standard APC) and 468 ± 136 µm (Hybrid-APC; p = 0.003). During all settings, damage to the muscularis mucosae was observed. Using standard APC, damage to the submucosal layer was observed in 4/6 (50 W) and 6/6 cases (70 W). During Hybrid-APC, coagulation of the submucosal layer occurred in 2/6 (50 W) and 1/6 cases (70 W). The proper muscle layer was only damaged during conventional APC (50 W: 1/6; 70 W: 3/6).

LIMITATIONS

Ex-vivo animal study with limited number of cases.

CONCLUSIONS

Hybrid-APC reduces coagulation depth by half in comparison with standard APC, with no thermal injury to the proper muscle layer. It may therefore lead to a lower rate of stricture formation during clinical application.

Trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife: A pilot animal study

AIM: To investigate the feasibility and safety of Natural orifice trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife in a non-survival porcine model.

METHODS: Pure natural orifice transluminal endoscopic surgery (NOTES) cholecystectomy was performed on three non-survival pigs, by transumbilical approach, using a water-jet hybrid-knife. Under general anesthesia, the following steps detailed the procedure: (1) incision of the umbilicus followed by the passage of a double-channel flexible endsocope through an overtube into the peritoneal cavity; (2) establishment of pneumoperitoneum; (3) abdominal exploration; (4) endoscopic cholecystectomy: dissection of the gallbladder performed using water jet equipment, ligation of the cystic artery and duct conducted using nylon loops; and (5) necropsy with macroscopic evaluation.

RESULTS: Transumbilical endoscopic cholecystectomy was successfully completed in the first and third pig, with minor bleedings. The dissection times were 137 and 42 min, respectively. The total operation times were 167 and 69 min, respectively. And the lengths of resected specimen were 6.5 and 6.1 cm, respectively. Instillation of the fluid into the gallbladder bed produced edematous, distended tissue making separation safe and easy. Reliable ligation using double nylon loops insured the safety of cutting between the loops. There were no intraoperative complications or hemodynamic instability. Uncontrolled introperative bleeding occurred in the second case, leading to the operation failure.

CONCLUSION: Pure NOTES trans-umbilical cholecystectomy with a water-jet hybrid-knife appears to be feasible and safe. Further investigation of this technique with long-term follow-up in animals is needed to confirm the preliminary observation.

Endoscopic tattooing of gastrointestinal and pancreatic lesions

The intraoperative identification of the lesions found at endoscopic examination is often difficult, especially during laparoscopic surgery. At present, the most used technique for the intraoperative detection of pathological lesions is endoscopic tattooing. The large majority of studies carried out concern colorectal lesions; however, endoscopic tattooing has also been described for esophageal, gastric, small bowel and, more recently, pancreatic lesions. In this review, the authors evaluated indications, substances used, injection techniques, accuracy, safety and, finally, the risk of complications related to this procedure.

Selective tissue elevation by pressure for endoscopic mucosal resection of colorectal adenoma: first clinical trial

BACKGROUND

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection of large lateral spreading tumors currently are technically limited by complications such as bleeding, perforation, and disturbed large procedural sites, leading to incomplete resection and secondary surgery. Further technical improvements are necessary. The authors previously demonstrated the effectiveness of a focused water jet for elevation of the lamina submucosa in animal studies. For the first time, the clinical application of selective tissue elevation by pressure (STEP) for the treatment of colorectal adenomas as a prospective single-arm human trial is presented.

METHODS

This trial evaluated 59 patients who had primary colorectal adenomas with diameters exceeding 12 mm classified as 0-IIa or 0-IIb according to Paris classification. A submucosal cushion was created with a flexible water jet applicator using the Helix HydroJet. The adenoma was subsequently resected with a mucosal resection snare. All results were recorded. The resected specimens were assessed histologically.

RESULTS

A total of 59 patients underwent resection of 70 lesions with a maximum diameter of 80 mm (mean, 27 mm). Submucosal elevation with the water jet dissector was possible in all cases and locations from the pectinate line to the ileocecal valve. Of the 70 lesions, 64 (91%) were resected completely in one session. Histologically, the resected specimens were found to be adenocarcinomas (n = 2, 3%), adenomas with high-grade intraepithelial neoplasia (n = 24, 34%), adenomas with low-grade intraepithelial neoplasia (n = 38, 54%), and hyperplastic polyps (n = 6, 9%). Hemostasis during the resection was necessary in 24 cases (34%). No perforation required surgical intervention.

CONCLUSION

This first clinical trial to analyze STEP technique demonstrated that STEP used to elevate large mucosal lesions in any location is feasible and facilitates EMR for colorectal adenoma.

New applicator improves waterjet dissection quality

OBJECTIVE

Waterjet dissection is accomplished with Helix Hydro-Jet, but a new device with improved operative handling and potentially superior dissection qualities has been developed.

MATERIALS AND METHODS

Eighty-four fresh cadaveric pig brains were simultaneously cut with Helix Hydro-Jet and Erbejet 2. A commonly used applicator and a new applicator for the Helix Hydro-Jet were directly compared to the new Erbejet 2. Under standardised conditions, different pressure levels were applied to the brain surface without arachnoids. Technical features, cutting depth, tissue damage and differences of applicators were examined.

RESULTS

Microscopic analysis of cutting depth revealed different dissection characteristics of both the devices. With the standard applicators, waterjet cutting depth was shown to be deeper and with more foaming using the Helix Hydro-Jet compared to that of the Erbejet 2. With the new applicators, less foaming and a lower and more linear increased cutting depth were observed with the Helix Hydro-Jet, very similar to the superior qualities shown by the Erbejet 2.

CONCLUSIONS

The new developed applicator of the Erbejet 2 also improves the intraoperative results of the so far applied Helix Hydro-Jet. The new Erbejet 2 provides some advantages for practicability; but in combination with the new applicator, the Helix Hydro-Jet accomplished almost identical superior dissection qualities of the Erbejet 2.

Waterjet dissection in pediatric cranioplasty

OBJECT

Waterjet dissection has been shown to separate tissues of different resistance, with preservation of blood vessels. In cranioplasty, separation of subcutaneous tissue and dura mater is often difficult to achieve because the various tissue layers strongly adhere to each other after decompressive craniotomy. In the present study, the potential advantages and drawbacks of the waterjet technique in cranioplasty after craniectomy and duraplasty are addressed.

METHODS

The waterjet effect on fresh human cadaveric dura mater specimens as well as on several dural repair patches was tested in vitro under standardized conditions, with waterjet pressures up to 80 bar. Subsequently, 8 pediatric patients (5 boys, 3 girls; mean age 9.9 years, range 1.2-16.7 years) who had been subjected to decompressive craniectomy (7 with duraplasty including bovine pericardium as a dural substitute, 1 without duraplasty in congenital craniosynostosis) underwent waterjet cranioplasty. The waterjet was used to separate the galea and the dura mater. The technique was applied tangentially between the dura and the galea, with different pressure levels up to 50 bar.

RESULTS

In vitro, fresh cadaveric human dura mater as well as 2 different dural repair substitutes showed a very high resistance to waterjet dissection up to 80 bar. The human dura and the various substitutes were dissected only after long-lasting exposure to the waterjet. Human dura was perforated at pressures of 60 bar and higher. Bovine pericardium dural substitute was perforated at pressures of 55 bar and higher. Artificial nonabsorbable polyesterurethane dural substitute was dissected at pressures of 60 bar and higher. In the clinical setting, the waterjet was able to separate galea and dura with minimal bleeding. No blood transfusion was required. Dissection of scarred tissue was possible by a waterjet of 40 bar pressure. Tissue layers were stretched and separated by the waterjet dissection, and a very reliable hemostasis resulted. This resulted in an effective reduction of bleeding, with < 60 ml blood loss in 7 of the 8 cases. Neither a dural tear nor a perforation of any duraplasty occurred during operative preparation. There were no operative or postoperative complications.

CONCLUSIONS

The experimental and clinical data show that waterjet separation of dura mater, dural substitute, and galea can be performed with a high level of safety to avoid dural tears. The waterjet dissection stretches tissue layers, which results in a reliable hemostasis effect. This potentially results in an effective reduction of surgical blood loss, which should be the focus of further studies.

A novel device for endoscopic submucosal dissection that combines water-jet submucosal hydrodissection and elevation with electrocautery: initial experience in a porcine model

BACKGROUND

Endoscopic submucosal dissection requires a high degree of endoscopic skill and specifically designed dissecting instruments.

OBJECTIVE

To describe the technique for endoscopic submucosal dissection when using the ERBE Hybrid Knife, which combines an ultrafine high-pressure water jet with an electrocautery needle.

DESIGN

Descriptive study (ex vivo and in vivo porcine esophagus, stomach, and colon).

INTERVENTIONS

The only instrument used for the dissection was the ERBE Hybrid Knife. The high-pressure water jet was used at a pressure between 45 and 60 bar for creating submucosal fluid elevation. After this, circumferential mucosal incisions and submucosal dissection were performed with the FORCED COAG and ENDOCUT D modes of the same device. The water jet was used intermittently during the dissection process.

MAIN OUTCOME MEASUREMENTS

At the end of the in vivo experiments, animals were killed and the organs removed for evaluation.

RESULTS

Multiple endoscopic submucosal dissection procedures were successfully performed. It was possible to create submucosal fluid cushions rapidly. Repeated fluid injections during dissection were easily facilitated with the same device. All ex vivo gastric endoscopic submucosal dissections of 50 x 40-mm lesions were completed within 10 minutes. In the in vivo studies, the mean size of the gastric and colonic specimens was 3.7 +/- 2.1 x 2.3 +/- 1 cm, and the dissections were completed within 8 minutes. No thermal injury was observed on the serosa, and no perforations were detected.

CONCLUSIONS

Endoscopic submucosal dissection can be safely and effectively achieved in a porcine model with the ERBE Hybrid Knife and should be considered a suitable device for this procedure in humans.

Self-assembled hydro-jet system for submucosal elevation before endoscopic resection of nonpolypoid colorectal lesions (with video)

BACKGROUND

Endoscopic resection of colorectal nonpolypoid lesions requires adequate submucosal lifting of the lesion.

OBJECTIVE

To evaluate a self-assembled hydro-jet system for tissue elevation to improve endoscopic resection of colorectal nonpolypoid lesions.

DESIGN

Prospective study.

SETTING

Single-center teaching hospital.

MAIN OUTCOME MEASUREMENTS

Efficacy and safety of the hydro-jet system and rate of complete resection.

RESULTS

The system was clinically applied in 31 patients to remove a total of 34 lesions throughout the colon. An adequate submucosal fluid cushion was achieved in all but 1 case without any lifting-associated complications. Complete endoscopic resection was possible in all 33 lifted lesions by using a snare. The size of the resected lesions ranged from 7 to 60 mm. Major intraprocedure bleeding occurred in only 1 case. No perforation or late bleeding was recorded. Histological examination showed a selective accumulation of fluid in the submucosa with edema and dissociation of submucosal structures, with no damage to the muscularis mucosa and very limited "burn effect" hampering assessment of radial margins.

LIMITATIONS

Lack of controls.

CONCLUSIONS

This inexpensive system allows safe and rapid submucosal lifting of colorectal nonpolypoid lesions to assist endoscopic resection.

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.

Randomized controlled study of EMR versus endoscopic submucosal dissection with a water-jet hybrid-knife of esophageal lesions in a porcine model

BACKGROUND

Endoscopic submucosal dissection (ESD) seems to be more effective than EMR for curative resection of GI mucosal neoplasia. However, ESD is technically difficult, hazardous, and time consuming. New technologies may overcome these drawbacks.

OBJECTIVE

Our purpose was to compare a new simplified ESD technique with conventional EMR.

DESIGN

Prospective, randomized, and controlled trial in anesthetized pigs.

METHODS

A total of 25 esophageal areas with a diameter of 20 mm were marked with coagulation points in 6 pigs under general anesthesia. These lesions were then randomized to either EMR by use of the cap technique or ESD. Submucosal injection of saline solution was used for both methods. ESD was performed with a hybrid-knife (ESDH), which allows cutting and coagulation as well as a needleless, tissue-selective hydrodissection through an axial water-jet channel with a preselected pressure by using a high-pressure water-jet system (ErbeJet 2). Intraoperative bleedings were treated with hemostatic forceps.

MAIN OUTCOME MEASUREMENTS

A comparison of the rates of complete resection of the lesions, the number and the size of resected specimens, the complication rate, and the procedural duration.

RESULTS

Thirteen lesions were randomized to EMR and 12 to ESDH. ESDH achieved complete resection significantly more frequently than EMR (10/12 vs 6/13; P = .05). All ESDH resections were performed as a single piece, whereas a mean (SD) of 2.5 +/- 0.9 resections were needed for EMR (P < .05). The mean (SD) areas of the specimen were 3.63 +/- 1.20 cm(2) in the ESDH group and 1.83 +/- 0.78 cm(2) in the EMR group (P < .0001). ESDH was performed with a larger amount of fluid for injection and hydrodissection compared with EMR (78.1 +/- 32.8 mL vs 20.9 +/- 7.6 mL; P < .001). The procedural duration was longer for ESDH than for EMR (28.2 +/- 11.9 minutes vs 12.2 +/- 4.9 minutes; P < .001). ESDH and EMR caused bleedings in 6 of 12 and 5 of 13 of the cases (P = .09), respectively. Hemostasis could be achieved in all cases. There was no perforation in either group.

LIMITATIONS

Resection of artificial non-neoplastic lesions, small numbers, an animal trial.

CONCLUSIONS

ESDH achieves complete resection of esophageal lesions significantly more frequently with a fewer number of specimens than EMR. ESDH is more time consuming, but the procedural duration seems to be shorter than conventional ESD because there is no need for exchange of devices for injection and cutting. The easy use of water-jet-assisted repeated injections of fluids may explain why ESDH was as safe as EMRC.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

DISCUSSION

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.