Digestive Endoscopy

(2003)

15

(Suppl.), S22–S25

AIMING FOR SAFE, SURE, SWIFT ESTABLISHMENT OF EMR FOR

ESOPHAGEAL CANCERS

Blackwell Science, LtdOxford, UKDENDigestive Endoscopy0915-56352003 Blackwell Science Asia Pty Ltd

15280

EMR OF EARLY ESOPHAGEAL CANCERSS-W PARK

ET AL.10.1046/j.0915-5635.2003.00280.x

aiming for safe, sure, swift establishment of emr foresophageal cancers2225BEES SGML

Correspondence: Seung Woo Park, Department of Internal Medicine,Yonsei University College of Medicine, 134 Shinchon-dong,Seodaemun-gu, Seoul 120-752. Email: swoopark@yumc.yonsei.ac.kr

ENDOSCOPIC MUCOSAL RESECTION OF EARLY ESOPHAGEAL CANCERS: OUR METHOD

S

EUNG

W

OO

P

ARK

, Y

OUNG

S

OO

P

ARK

AND

S

I

Y

OUNG

S

ONG

Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea

Though endoscopic mucosal resection (EMR) may provide definitive treatment for selected cases of early esophagealcarcinoma, the standard method has not been determined yet. There have been several EMR techniques so far developed,including strip biopsy, EMR using a cap, Makuuchi tube method, etc. The selection of EMR method largely depends onpersonal experience and preference of an endoscopist. Here we present our EMR method along with its advantages anddisadvantages. With the extension of indications, more cases of early esophageal cancer will be treated by EMR. Since onlylong-term results tell what the ideal EMR method is, well-designed comparative studies are necessary in the future toestablish a standard method.

Key words: Early esophageal cancer, EMR.

INTRODUCTION

Contrary to early gastric cancer in which endoscopic mucosalresection (EMR) is already a standard method, providing ahigh success rate and favorable long-term results, EMR forearly esophageal cancer awaits further investigation into itseffectiveness and safety. The relative lack of widespreadacceptance of EMR as a standard treatment in early esoph-ageal carcinoma is in part due to the relatively infrequentdetection of early esophageal carcinomas, the relatively lim-ited indications for esophageal EMR when compared toEMR for early gastric cancer, and the fear of fatal complica-tions, such as an esophageal perforation and a resultant medi-astinal infection. Thus far, there have been a various numberof EMR techniques developed, including the lift-and-cutmethod (strip biopsy,

1

double snare polypectomy,

2

precut andcutting,

3

, etc.), suction methods (EMR utilizing a cap,

4

theMakuuchi tube method,

5

, etc.), and the recently developedEMR method utilizing an insulted-tip knife (IT-EMR).

6

Anideal method would meet the following criteria: (i) a certainlevel of technical ease and simplicity such that most endos-copists would be able to perform the procedure without greatdifficulty; (ii) a low complication rate; and (iii) a high rate ofcomplete resection with favorable long-term outcomes, com-parable to radical resection by a surgical approach. However,thus far, the ideal method for esophageal EMR has not beendetermined. Presented here is a new method of EMR forearly esophageal cancer.

LESION IDENTIFICATION AND MARKING

Precise identification of the lesion is a crucial step in com-plete removal of an esophageal tumor. In case 1, endoscopicfindings were quite different when one compares the findings

before and after chromoscopy. Administration of iodine isthe method of choice in identifying an esophageal lesion.Removal of the mucus by flushing the esophageal lumen withwater is a crucial step before spraying iodine. Then 20–30 mLof a 1.5% iodine solution is sprayed via a polyethylene cath-eter. Often applying the iodine solution twice, 30 s apart out-lines the lesion vividly. Markings are then made 3 mm outsidethe outer margin of the lesion by an electrosurgical knifeusing a coagulation current. The distance between the mark-ings should be less than 1 cm apart.

EMR USING AN INSULATED-TIP ELECTROSURGICAL KNIFE

IT-EMR, first applied for

en bloc

resections of large gastriclesions, is a fascinating method. Though the strip biopsy orsuction method is technically easy and convenient,

en bloc

resections of lesions larger than 1.5 cm by these methods arevery difficult and often multiple piecemeal resections becomeinevitable. With multiple piecemeal resections, completereconstitution of the pieces of tissue is sometimes difficult.Therefore in those cases, precise pathologic evaluation of theresection margin is difficult and may result in a higher relapserate.

In response, Ohkuwa

et al

.

6

developed an electrosurgicalknife, which has a ceramic ball at its tip to prevent inadvert-ent cutting of deeper layers of the stomach and thus makesperforation a less likely event. This tool has also been appliedto colonic and esophageal tumors. The major advantage ofIT-EMR is that it enables a single piece resection of largelesions and thus allows precise pathologic evaluation of theresection margin.

Although IT-EMR is theoretically ideal, IT-EMR whenapplied to esophageal tumors has several limitations. Whilethe relatively spacious gastric lumen permits fine manipula-tion for correct positioning of the endoscope to allow aproper incision, this is not the case in the esophagus. Amongendoscopists who are familiar with EMR, IT-EMR is not a

EMR OF EARLY ESOPHAGEAL CANCERS S23

commonly practised procedure for esophageal lesions forseveral reasons. First, the angle between the knife and theesophageal wall is inevitably acute and creating a circumfer-ential incision along the margin of the lesion is very difficult.Second, since the esophageal wall is thinner than the gastricwall, the risk of perforation may accordingly rise with esoph-ageal IT-EMR. Third, during initial incision, the esophagealwall is more likely to bleed than in the stomach, which createsa bloody field and interferes with making further incisions.Fourth, the submucosa of the esophagus is comparativelylooser in the stomach. Therefore, submucosally injectedsaline rapidly spreads into the surrounding area, necessitat-ing repeated submucosal saline injections during the incisionof the tumor margin. Therefore, the process becomes labori-ous and time-consuming for the endoscopist, and very pain-ful for the patient.

In case 1 (Fig. 1), though the lesion was successfullyresected in an

en-bloc

fashion, the entire procedure tookabout 90 min. Further development and modifications of theIT-knife will be necessary to apply the IT-EMR method forearly esophageal carcinomas.

EMR USING A CAP (EMRC)

In our opinion, the suction method will most likely gainwidespread acceptance as the method of choice for esoph-ageal EMRs. Presently, the EMRC technique devised byInoue

et al

.

4

is the most commonly used method for endo-scopic resection of early esophageal carcinomas. We preferto use this method as well for esophageal lesions with somemodifications because it is technically easy, effective, andsafe. However, EMRC has one major pitfall. The disadvan-tage of the EMRC approach is that lesions larger than 1.5 cmare not amenable to an

en bloc

resection. This necessitatesmultiple, well-planned, successive resections of the tumor ina piecemeal fashion (Fig. 2). Successive resections should beperformed in an oral to caudal direction. An important pointthat should be kept in mind is to attach the cap and aspiratethe lesion, making sure to overlap a small portion of theprevious resection site to ensure complete removal of thelesion. Therefore on the subsequent resection, the cap should

be attached to the esophageal wall, overlapping the caudaledge of the previous resection site by 1–2 mm. In addition,another key point to be mindful of is one should be cautiousnot to grasp too great a portion of the previously resectedsite to avoid inadvertent perforation. In case 2 (Fig. 3), twiceas much EMRC was needed to completely remove the lesion.The amount of EMRC depends on the area of the lesion.Once well-planned cautious resections are performed, theperforation risk does not seem to be increased as the numberof resections increases.

When the lesion is resected in two or three pieces, it ispossible to accurately reconstitute the tumor mass to evalu-ate the resection margin. However, it is virtually impossibleto determine the correct orientation when the resected piecesnumber greater than three. After resection, iodine solutionshould be sprayed again to ascertain if there are any residuallesions. Determining whether a tumor has been completelyresected without any residual particles is largely dependenton the judgment of the endoscopist. The basal depth of inva-sion should be evaluated through pathologic examination ofall the collected specimens.

A modified suction method such as the Makuuchi tubemethod is a useful alternative to EMRC, especially when thesize of the lesion is larger than 1.5 cm; this method may allowan

en bloc

resection for lesions up to 3 cm in size.

DISCUSSION AND CONCLUSION

Endoscopic mucosal resection is an emerging tool, whichcan provide definitive treatment for early esophageal cancerand offers good long-term results. However, it has notgained worldwide acceptance as a standard treatment forearly esophageal cancer and EMR is not commonly used inthe Western world. Most of the reported cases of esophagealEMR are from Japanese studies.

7,8

According to thereported series by Japanese doctors,

7,9

EMR for early esoph-ageal carcinoma produces favorable long-term results whencompared to surgical resection. This is not the case in othercountries where the fear of fatal complication of esophagealEMR and a lack of confidence in EMR to provide definitivetreatment for early esophageal carcinoma runs high. The

Fig. 1.

Endoscopic mucosal resection for early esophageal carcinoma performed by the IT-EMR method. (a) Geographic-shapediodine-unstained lesion is seen. The largest diameter of the lesion was about 2.5 cm (b) Markings were made by a needle knife usinga coagulation current. (c) After resection of the lesion. An

en bloc

resection was possible, but the whole procedure took 90 min.

S24 S-W PARK

ET AL.

uneasiness that many endoscopists face is due to the highrate of nodal metastasis in early esophageal carcinoma whencompared to early gastric carcinoma. Another factoraccounting for the difference between the situation experi-

enced by Japanese endoscopists and endoscopists in theWestern world is due to the differences in diagnostic criteriafor esophageal squamous carcinoma utilized by Japaneseand Western pathologists. Many cases diagnosed as dysplas-tic lesions by Western pathologists are diagnosed as definitecarcinomas by Japanese pathologists.

10

This may contributeto the high incidence and good prognosis of early esoph-ageal carcinoma after treatment by EMR in Japan. There-fore, uniform pathologic criteria should be adopted tocommunicate and compare the long-term results of EMRacross the world.

Nonetheless, with the broadening of indications for EMRand the increased effort to detect early esophageal lesions, agreater number of cases of esophageal cancer will be treatedby endoscopic resection. Although the ideal method has yetto be determined, the suction method using a cap or special-ized tube has been the most widely used method, demon-strating an acceptable level of safety and offering favorableoutcomes. However, only long-term results will reveal theideal method for esophageal EMR. Therefore, well-designedcomparative studies are necessary in the future to establisha standard method, and in addition, further refinement oftechnique and advances in the development of better devicesare essential.

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Fig. 2.

Planned piecemeal resection. (a) Oral to caudal direction is necessary not only to ensure complete resection of whole tumorbut also to avoid grasping too much portion of previous resection site. (b) Resection starting from caudal side makes it difficult todetermine the precise contact site of cap during next resection. (c) Imprudent resection may cause residual tumor at the peripheryof the resection site.

Fig. 3.

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EMR OF EARLY ESOPHAGEAL CANCERS S25

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