HEMOSTASIS WITH HOOK KNIFE DURING ENDOSCOPIC SUBMUCOSAL DISSECTION

Safe and Efficient Procedures and Training System for Endoscopic Submucosal Dissection

Recent improvements in endoscopists' skills and technological advances have allowed endoscopic submucosal dissection (ESD) to become a standard treatment in general hospitals. As this treatment entails a high risk of accidental perforation or hemorrhage, therapeutic procedures and training methods that enable ESD to be conducted more safely and efficiently are constantly being developed. This article reviews the therapeutic procedures and training methods used to improve the safety and efficiency of ESD and describes the ESD training system used in a Japanese university hospital at which the number of ESD procedures has gradually increased in a newly established Department of Digestive Endoscopy. During the establishment of this department, the ESD perforation rate was zero among all procedures, including those conducted by trainees.

Risk factors of major intraoperative bleeding and postoperative bleeding associated with endoscopic submucosal dissection for gastric neoplasms

Background:

Endoscopic resection bleeding (ERB) classification was proposed by the authors’ team to evaluate the severity of intraoperative bleeding (IB) during endoscopic submucosal dissection (ESD). This study aimed to evaluate the application of ERB classification and to analyze the risk factors of major IB (MIB) and postoperative bleeding (PB) associated with ESD for gastric neoplastic lesions.

Methods:

We retrospectively enrolled a total of 1334 patients who underwent ESD between November 2006 and September 2019 at The First Medical Center of Chinese People's Liberation Army General Hospital. All patients were divided into the non-MIB group (including ERB-0, ERB-controlled 1 [ERB-c1], and ERB-c2) and the MIB group (including ERB-c3 and ERB-uncontrolled [ERB-unc]) according to the ERB classification. Risk factors of major MIB and risk factors of PB were analyzed using a logistic regression model.

Results:

Among the 1334 patients, 773 (57.95%) had ERB-0, 477 (35.76%) had ERB-c1, 77 (5.77%) had ERB-c2, 7 (0.52%) had ERB-c3, and no patients had ERB-unc. The rate of PB in patients with IB classifications of ERB-0, ERB-c1, ERB-c2, and ERB-c3 were 2.20% (17/773), 3.35% (16/477), 9.09% (7/77), and 2/7, respectively. In multivariate analysis, proximal location (odds ratio [OR]: 1.488; 95% confidence interval [CI]: 1.045–3.645; P = 0.047) was the only significant risk factor of MIB. Chronic kidney disease (CKD) (OR: 7.844; 95% CI: 1.637–37.583; P = 0.010) and MIB (ERB-c3) (OR: 13.932; 95% CI: 2.585–74.794; P = 0.002) were independent risk factors of PB.

Conclusions:

Proximal location of lesions was a significant risk factor of MIB. Additionally, CKD and MIB (ERB-c3) were independent risk factors of PB. More attention should be paid to these high-risk patients for MIB and PB.

Hemorrhage control during gastric endoscopic submucosal dissection: Techniques using uncovered knives

Since the last decade, endoscopic submucosal dissection (ESD) has been used as the standard treatment for superficial gastrointestinal neoplasms. Trainees learning ESD frequently encounter difficulties such as vascularity, peristalsis, and fibrosis during the procedure. Because individual vascularity differs, it generally cannot be consistently avoided. Given that massive hemorrhages can prolong the procedure time and diminish treatment efficacy and that insufficient vessel handling may also increase postoperative bleeding, hemorrhage control during ESD becomes important to ensure procedure safety. This article discusses methods for controlling hemorrhage during gastric ESD. Endoscopists should have a basic understanding of the vascular architecture and the high‐density areas in blood vessels, which are susceptible to intraoperative hemorrhage. Efficient preventative coagulation should be performed in addition to mastering the techniques for hemorrhage control using hemostatic forceps. Techniques useful for preventing intraoperative hemorrhage at every step (e.g. submucosal injection, mucosal incision, and dissection) should be learned. Gaining procedural competence and learning hemorrhage control techniques not only during ESD but also in daily work would help provide safe and effective treatment.

Esophageal ESD: technique and prevention of complications

The advantage of endoscopic submucosal dissection (ESD) is the ability to achieve high R0 resection, providing low local recurrence rate. Esophageal ESD is technically more difficult than gastric ESD due to the narrower space of the esophagus for endoscopic maneuvers. Also, the risk of perforation is higher because of the thin muscle layer of the esophageal wall. Blind dissection should be avoided to prevent perforation. A clip with line method is useful to keep a good endoscopic view with countertraction. Only an operator who has adequate skill should perform esophageal ESD.

Current opinions for endoscopic submucosal dissection for colorectal tumors from our experiences: indications, technical aspects and complications

Endoscopic submucosal dissection (ESD) was first applied in the resection of large colorectal tumors 10 years ago. Frequent complications and technical difficulties were serious problems at first, but were gradually improved with experience. Here, we describe the indications, technical aspects and management of complications of ESD for colorectal tumors. In 2009, we introduce the use of small tip insulation-tipped diathermic (IT) knife. Features separating it from the IT knife and IT Knife2 are a smaller ceramic tip and small round disk at the root of the tip. During submucosal dissection, the small tip IT knife could dissect large pieces of tissue intact. This allows us to shorten the procedure time, particularly the submucosal dissection component. A total of 146 ESD for 140 patients were performed between January 2009 and July 2011. En bloc, and en bloc and R0 resection rates were 92.5% and 83.6%, respectively. Median procedural time was 48.5 min for 40.5 mm specimens. Perforation and delayed bleeding occurred in 2.1% and 1.4%, respectively. We successfully performed ESD for colorectal tumors with a shortened procedure time while preserving quality and safety.

Management of bleeding and artificial gastric ulcers associated with endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD), an endoscopic procedure for the treatment of gastric epithelial neoplasia without lymph node metastases, spread rapidly, primarily in Japan, starting in the late 1990s. ESD enables en bloc resection of lesions that are difficult to resect using conventional endoscopic mucosal resection (EMR). However, in comparison to EMR, ESD requires a high level of endoscopic competence and a longer resection time. Thus, ESD is associated with a higher risk of adverse events, including intraoperative and postoperative bleeding and gastrointestinal perforation. In particular, because of a higher incidence of intraoperative bleeding with mucosal incision and submucosal dissection, which are distinctive endoscopic procedures in ESD, a strategy for endoscopic hemostasis, mainly by thermo-coagulation hemostasis using hemostatic forceps, is important. In addition, because of iatrogenic artificial ulcers that always form after ESD, endoscopic hemostasis and appropriate pharmacotherapy during the healing process are essential.

Usefulness of endoscopic ultrasound for the prediction of intraoperative bleeding of endoscopic submucosal dissection for gastric neoplasms

BACKGROUND AND AIM

Intraoperative bleeding is an important determining factor for the technical difficulty and safety of endoscopic submucosal dissection (ESD) for gastric neoplasms, which was previously difficult to predict before ESD. In the present study, we investigated whether endoscopic ultrasound (EUS) could be used to preoperatively predict intraoperative bleeding.

METHODS

The study included 106 patients who underwent EUS before ESD. EUS was used to evaluate the submucosal vascular structure. Patients who had at least 10 vascular structures per field of view or a vessel at least 500 µm in diameter were classified into the rich group (Group R), and others were classified into the non-rich group (Group N). The two groups were compared retrospectively with respect to procedure time, degree of anemia, frequency of clip use, and others.

RESULTS

There were 24 patients in Group R and 82 patients in Group N. Submucosal caner was found in 54.2% of patients in Group R and 18.3% in Group N. The reduction in hemoglobin was 5.8% in Group R and 3.45% in Group N. The procedure time was 151 min in Group R and 100 min in Group N. The frequency of clip use was 79.2% in Group R and 31.7% in Group N. A multivariate analysis revealed a significant difference in the depth of invasion and frequency of clip use between the two groups.

CONCLUSIONS

The results suggest that identification of submucosal vascular structure by EUS might allow prediction of intraoperative bleeding during ESD.

Learning curve for endoscopic submucosal dissection of large colorectal tumors

BACKGROUND AND AIM

No studies have previously described the learning curve for colonic endoscopic submucosal dissection (ESD). The aim of the present study was to describe the learning curve for ESD of large colorectal tumors based on a single colonoscopist's experience.

METHODS

ESD was carried out for 120 colorectal tumors in 115 patients (68 males, median age 70 years). All procedures were carried out by a single experienced colonoscopist. The cases were grouped chronologically into three periods: (1st): cases 1-40; (2nd): cases 41-80; and (3rd): cases 81-120.

RESULTS

The learning curve was the changes in proficiency over time. Proficiency was expressed as procedure time per unit area of specimen. In the 1st, 2nd and 3rd periods, the proficiencies were 18.9, 12.6 and 12.9 (min/cm(2) ), respectively. The proficiencies in the 2nd and 3rd periods were significantly shorter than in the 1st period (t-test, P < 0.05). The en-bloc resection rates of the 1st, 2nd and 3rd periods were 92.5% (37/40), 90% (36/40) and 97.5% (39/40), respectively. The en-bloc and R0 resection rates of the 1st, 2nd and 3rd periods were 85% (34/40), 77.5% (31/40) and 92.5% (37/40), respectively. The perforation rates of the 1st, 2nd and 3rd periods were 12.5% (5/40), 5% (2/40) and 5% (2/40), respectively.

CONCLUSION

Based on our analysis of the learning curve, approximately 80 procedures must be carried out to acquire skill with ESD for large colorectal tumors. However, approximately 40 procedures were sufficient to acquire skill in avoiding perforations during the ESD procedure.