Original article 949
Learning curve for endoscopic submucosal dissection of gastric neoplasms Kyong Hee Hong, Sung Joon Shin and Jae Hak Kim Background Endoscopic submucosal dissection (ESD) is a widely accepted method for the treatment of early gastrointestinal neoplasms. Objectives To investigate the learning curve of ESD performed by a single endoscopist focusing on developing the performance of dissection, shortening the procedure time, and preventing complications. Patients and methods Records of 120 consecutive ESD procedures performed by a single endoscopist with an ESD knife from December 2007 to April 2013 were collected. For analysis of the learning curve, total procedures were divided into four periods, each comprising 30 sequential ESD procedures. Adjusted procedure time (min) was calculated as specimen area [π × long length (mm) × short length (mm)/4]÷procedure time. The parameters assessed were the en-bloc resection rate, complete resection rate, duration and speed of procedure time, and related complications.
(19.9 ± 11.0 vs. 30.3 ± 11.8, P = 0.01) and to the fourth quarter (19.9 ± 11.0 vs. 35.8 ± 15.7, P < 0.01), and from the second to the third quarter (21.1 ± 8.3 vs. 30.3 ± 11.8, P = 0.04) and to the fourth quarter (21.1 ± 8.3 vs. 35.8 ± 15.7, P < 0.01). Conclusion ESD for gastric neoplasms can be performed with a steady speed after the experience of 60 ESD procedures with proper clinical outcomes. Further studies with different endoknives will be required for ESD operators as a reference. Eur J Gastroenterol Hepatol 26:949–954 © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins. European Journal of Gastroenterology & Hepatology 2014, 26:949–954 Keywords: dysplasia, endoscopic submucosal dissection, endoscopy, gastric adenocarcinoma, learning curve Department of Internal Medicine, Dongguk University Ilsan Hospital, Graduate School, Goyang, Korea
Results Procedure times were significantly longer with lesions located at the upper third of the stomach and with the specimen sizes exceeding 1500 mm2. There were significant differences in the adjusted overall procedure time from the first to the third quarter
Correspondence to Jae Hak Kim, MD, PhD, Department of Internal Medicine, Dongguk University Ilsan Hospital, Dongguk University, 27 Dongguk-ro, Ilsandong-gu, Goyang, Gyeonggi-do 410-773, Korea Tel: + 82 31 961 7127; fax: + 82 31 961 7141; e-mail: [email protected]
Introduction
procedures under the supervision of an expert as a clinical fellow, were analyzed from December 2007 to April 2013.
Endoscopic submucosal dissection (ESD) is a widely accepted method for the treatment of gastrointestinal neoplasms. Several studies have investigated the learning curve for endoscopic mucosal resection (EMR) and ESD of gastric neoplasms [1–4]. For EMR with circumferential mucosal incision, the experience with 40 cases makes the procedure effective and safe when performed by an experienced endoscopist [1]. As for ESD, the kind of knives and the skill level of the operators were different; therefore, the proper number of cases required to gain adequate experience for ESD remains debatable [2–4]. Providing the consecutive experiences of ESD from an operator’s first case onward would be an instructive reference for novice operators learning the ESD technique. The aim of this study was to assess the learning curve of ESD performed by a single endoscopist focusing on developing dissection performance, shortening the procedure time, and preventing adverse events.
Received 28 April 2014 Accepted 10 June 2014
The procedures involved 112 patients (77 men and 35 women; mean age 65 years; range 48–85 years) and were performed at Dongguk University Ilsan Hospital, Goyang, Korea. The lesions included adenoma, welldifferentiated or moderately differentiated adenocarcinoma, and cellular atypia suggesting malignancy. Nine cases, which converted from ESD to EMR because of uncontrolled arteriolar bleeding or submucosal fibrosis, were excluded. Lesions were located in the mid third in four cases and in the lower third of the stomach in five cases. The mean size was 222.2 ± 166.3 mm2 (range 35–625). The protocol of this study was approved by the Institutional Review Board of Dongguk Medical Center. ESD procedure
Patients and methods Patients
A total of 120 consecutive ESD procedures performed by a single operator (J.H.K.), who had experienced 10 ESD 0954-691X © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins
The time of each step including marking, submucosal injection/mucosal incision, submucosal dissection, and prophylactic hemostasis was recorded using a stop watch in the endoscopy system. The patients were under DOI: 10.1097/MEG.0000000000000156
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
950
European Journal of Gastroenterology & Hepatology 2014, Vol 26 No 9
conscious sedation with intravenous midazolam and pethidine. The hemodynamic status of the patients was monitored throughout the exam. All the procedures were performed using a two-channel endoscope with a transparent cap (GIF-2TQ260M; Olympus Optical Co. Ltd, Tokyo, Japan) equipped with a high-definition video endoscopy system (EVIS LUCERA 260; Olympus Optical Co. Ltd) and with an electrosurgical unit Table 1
Lesion characteristics (N = 120) n (%)
Location Upper third Middle third Lower third Histological type Adenoma Low-grade dysplasia High-grade dysplasia Adenocarcinoma Well differentiated Moderately differentiated Poorly differentiated Macroscopic typea I IIa IIb IIc III Size (mean ± SD) (mm2)
5 (4.2) 33 (27.5) 82 (68.3)
63 (52.5) 17 (14.2) 33 (27.5) 6 (5.0) 1 (0.8) 1 (0.8) 57 (47.5) 30 (25) 29 (24.2) 3 (2.5) 241.49 ± 264.28
a
According to the Japanese classification of early gastric cancer.
(VIO 300D; Erbe Elektromedizin GmbH, Tubingen, Germany). ESD was performed in a conventional manner. In brief, dots were circumferentially marked 5 mm outside of the target lesion with an argon plasma coagulation unit. Then, normal saline with epinephrine and indigo carmine was injected into the submucosa and circumferential mucosal incision was performed using a needle knife (MTW Endoscopie, Wesel, Germany) on Endo cut Q mode (effect 2, duration 2, interval 2). Submucosal dissection was performed using an ESD knife (MTW Endoscopie) on the same mode of incision. When bleeding occurred from a small vessel, the vessel was soft-coagulated (effect 5, watt 60) with the blade of the knife. A hemostatic forcep (FD-410LR; Olympus Optical Co. Ltd) was used for a large vessel coagulation on the same mode. After the resection of the target area, prophylactic hemostasis was performed for exposed vessels with the hemostatic forcep or approximation of muscular tearing with a hemoclip (HX-610–090; Olympus Optical Co. Ltd). Histological assessment
The fixed specimens were serially cut at 2 mm intervals. The specimens were histopathologically examined according to the Japanese classification of gastric carcinoma [5]. En-bloc resection was referred to as
Fig. 1
(a)
P = 0.02
(b)
P < 0.01
P = 0.01
P < 0.01
Procedure time (min)
P = 0.01
200
200
150
150
100
100
50
50
0
0 Upper third
Middle third Location
Lower third
500
1000
1500
Specimen size (mm2)
Overall procedure time according to the location of the lesion and size of the specimen. (a) Location of the lesion; the procedure time was significantly longer for the lesions in the upper third of the stomach compared with the lesions located in the middle and lower third of the stomach. (b) Size of the specimen; the specimen size over 1501 mm2 was performed with a longer procedure time in comparison with a specimen size under 500, 501–1000, and 1001–1500 mm2.
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Learning curve for ESD Hong et al. 951
resection in a single piece. Complete resection was defined as the lesion in which all deep and lateral margins were histologically tumor free. Adjusted procedure time
Adjusted procedure time was referred to as the specimen area [π × long length (mm) × short length (mm)/4]÷procedure time (min).
third quarter and to the fourth quarter, and from the second to the third quarter and to the fourth quarter (Fig. 3a). Moreover, there were significant differences in adjusted submucosal injection/mucosal incision times from the first to the third quarter (P = 0.04) and to the fourth quarter (P < 0.01), and from the second to the fourth quarter (P
Learning curve for endoscopic submucosal dissection of gastric neoplasms Kyong Hee Hong, Sung Joon Shin and Jae Hak Kim Background Endoscopic submucosal dissection (ESD) is a widely accepted method for the treatment of early gastrointestinal neoplasms. Objectives To investigate the learning curve of ESD performed by a single endoscopist focusing on developing the performance of dissection, shortening the procedure time, and preventing complications. Patients and methods Records of 120 consecutive ESD procedures performed by a single endoscopist with an ESD knife from December 2007 to April 2013 were collected. For analysis of the learning curve, total procedures were divided into four periods, each comprising 30 sequential ESD procedures. Adjusted procedure time (min) was calculated as specimen area [π × long length (mm) × short length (mm)/4]÷procedure time. The parameters assessed were the en-bloc resection rate, complete resection rate, duration and speed of procedure time, and related complications.
(19.9 ± 11.0 vs. 30.3 ± 11.8, P = 0.01) and to the fourth quarter (19.9 ± 11.0 vs. 35.8 ± 15.7, P < 0.01), and from the second to the third quarter (21.1 ± 8.3 vs. 30.3 ± 11.8, P = 0.04) and to the fourth quarter (21.1 ± 8.3 vs. 35.8 ± 15.7, P < 0.01). Conclusion ESD for gastric neoplasms can be performed with a steady speed after the experience of 60 ESD procedures with proper clinical outcomes. Further studies with different endoknives will be required for ESD operators as a reference. Eur J Gastroenterol Hepatol 26:949–954 © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins. European Journal of Gastroenterology & Hepatology 2014, 26:949–954 Keywords: dysplasia, endoscopic submucosal dissection, endoscopy, gastric adenocarcinoma, learning curve Department of Internal Medicine, Dongguk University Ilsan Hospital, Graduate School, Goyang, Korea
Results Procedure times were significantly longer with lesions located at the upper third of the stomach and with the specimen sizes exceeding 1500 mm2. There were significant differences in the adjusted overall procedure time from the first to the third quarter
Correspondence to Jae Hak Kim, MD, PhD, Department of Internal Medicine, Dongguk University Ilsan Hospital, Dongguk University, 27 Dongguk-ro, Ilsandong-gu, Goyang, Gyeonggi-do 410-773, Korea Tel: + 82 31 961 7127; fax: + 82 31 961 7141; e-mail: [email protected]
Introduction
procedures under the supervision of an expert as a clinical fellow, were analyzed from December 2007 to April 2013.
Endoscopic submucosal dissection (ESD) is a widely accepted method for the treatment of gastrointestinal neoplasms. Several studies have investigated the learning curve for endoscopic mucosal resection (EMR) and ESD of gastric neoplasms [1–4]. For EMR with circumferential mucosal incision, the experience with 40 cases makes the procedure effective and safe when performed by an experienced endoscopist [1]. As for ESD, the kind of knives and the skill level of the operators were different; therefore, the proper number of cases required to gain adequate experience for ESD remains debatable [2–4]. Providing the consecutive experiences of ESD from an operator’s first case onward would be an instructive reference for novice operators learning the ESD technique. The aim of this study was to assess the learning curve of ESD performed by a single endoscopist focusing on developing dissection performance, shortening the procedure time, and preventing adverse events.
Received 28 April 2014 Accepted 10 June 2014
The procedures involved 112 patients (77 men and 35 women; mean age 65 years; range 48–85 years) and were performed at Dongguk University Ilsan Hospital, Goyang, Korea. The lesions included adenoma, welldifferentiated or moderately differentiated adenocarcinoma, and cellular atypia suggesting malignancy. Nine cases, which converted from ESD to EMR because of uncontrolled arteriolar bleeding or submucosal fibrosis, were excluded. Lesions were located in the mid third in four cases and in the lower third of the stomach in five cases. The mean size was 222.2 ± 166.3 mm2 (range 35–625). The protocol of this study was approved by the Institutional Review Board of Dongguk Medical Center. ESD procedure
Patients and methods Patients
A total of 120 consecutive ESD procedures performed by a single operator (J.H.K.), who had experienced 10 ESD 0954-691X © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins
The time of each step including marking, submucosal injection/mucosal incision, submucosal dissection, and prophylactic hemostasis was recorded using a stop watch in the endoscopy system. The patients were under DOI: 10.1097/MEG.0000000000000156
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
950
European Journal of Gastroenterology & Hepatology 2014, Vol 26 No 9
conscious sedation with intravenous midazolam and pethidine. The hemodynamic status of the patients was monitored throughout the exam. All the procedures were performed using a two-channel endoscope with a transparent cap (GIF-2TQ260M; Olympus Optical Co. Ltd, Tokyo, Japan) equipped with a high-definition video endoscopy system (EVIS LUCERA 260; Olympus Optical Co. Ltd) and with an electrosurgical unit Table 1
Lesion characteristics (N = 120) n (%)
Location Upper third Middle third Lower third Histological type Adenoma Low-grade dysplasia High-grade dysplasia Adenocarcinoma Well differentiated Moderately differentiated Poorly differentiated Macroscopic typea I IIa IIb IIc III Size (mean ± SD) (mm2)
5 (4.2) 33 (27.5) 82 (68.3)
63 (52.5) 17 (14.2) 33 (27.5) 6 (5.0) 1 (0.8) 1 (0.8) 57 (47.5) 30 (25) 29 (24.2) 3 (2.5) 241.49 ± 264.28
a
According to the Japanese classification of early gastric cancer.
(VIO 300D; Erbe Elektromedizin GmbH, Tubingen, Germany). ESD was performed in a conventional manner. In brief, dots were circumferentially marked 5 mm outside of the target lesion with an argon plasma coagulation unit. Then, normal saline with epinephrine and indigo carmine was injected into the submucosa and circumferential mucosal incision was performed using a needle knife (MTW Endoscopie, Wesel, Germany) on Endo cut Q mode (effect 2, duration 2, interval 2). Submucosal dissection was performed using an ESD knife (MTW Endoscopie) on the same mode of incision. When bleeding occurred from a small vessel, the vessel was soft-coagulated (effect 5, watt 60) with the blade of the knife. A hemostatic forcep (FD-410LR; Olympus Optical Co. Ltd) was used for a large vessel coagulation on the same mode. After the resection of the target area, prophylactic hemostasis was performed for exposed vessels with the hemostatic forcep or approximation of muscular tearing with a hemoclip (HX-610–090; Olympus Optical Co. Ltd). Histological assessment
The fixed specimens were serially cut at 2 mm intervals. The specimens were histopathologically examined according to the Japanese classification of gastric carcinoma [5]. En-bloc resection was referred to as
Fig. 1
(a)
P = 0.02
(b)
P < 0.01
P = 0.01
P < 0.01
Procedure time (min)
P = 0.01
200
200
150
150
100
100
50
50
0
0 Upper third
Middle third Location
Lower third
500
1000
1500
Specimen size (mm2)
Overall procedure time according to the location of the lesion and size of the specimen. (a) Location of the lesion; the procedure time was significantly longer for the lesions in the upper third of the stomach compared with the lesions located in the middle and lower third of the stomach. (b) Size of the specimen; the specimen size over 1501 mm2 was performed with a longer procedure time in comparison with a specimen size under 500, 501–1000, and 1001–1500 mm2.
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Learning curve for ESD Hong et al. 951
resection in a single piece. Complete resection was defined as the lesion in which all deep and lateral margins were histologically tumor free. Adjusted procedure time
Adjusted procedure time was referred to as the specimen area [π × long length (mm) × short length (mm)/4]÷procedure time (min).
third quarter and to the fourth quarter, and from the second to the third quarter and to the fourth quarter (Fig. 3a). Moreover, there were significant differences in adjusted submucosal injection/mucosal incision times from the first to the third quarter (P = 0.04) and to the fourth quarter (P < 0.01), and from the second to the fourth quarter (P
