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Endoscopic piecemeal resection with submucosal saline injection of large sessile colorectal polyps
Endoscopic piecemeal resection with submucosal saline injection of large sessile colorectal polyps Hiroyasu Iishi, MD, Masaharu Tatsuta, MD, Kazushige Iseki, MD, Hiroyuki Narahara, MD, Noriya Uedo, MD, Noriko Sakai, MD, Hideki Ishikawa, MD, Toru Otani, MD, Shingo Ishiguro, MD Osaka, Japan
Background: Because endoscopic en bloc resection of large, sessile colorectal polyps is technically difficult, they are usually resected piecemeal. However, piecemeal resection makes it difficult to evaluate the completeness of the resection histopathologically. In this study the efficacy of endoscopic piecemeal resection of large, sessile colorectal polyps was investigated after followup greater than 1 year. Methods: We removed 56 sessile colorectal polyps 2 cm or greater in diameter in 56 patients by using an endoscopic submucosal saline injection technique. Endoscopic examinations were repeated at 3, 6, and 12 months and longer after initial endoscopic resection. If no residual tumor was found endoscopically and histologically, the patient was considered to be “cured.” Results: Of the 56 polyps, 14 (25%) were resected en bloc, and 42 (75%) were resected piecemeal. Of the 42 patients treated with piecemeal resection, 23 (55%) required additional endoscopic or surgical interventions. In patients followed 1 year or longer after initial treatment, the cure rate by en bloc resection was 100% (14 of 14) and that by piecemeal resection was 83% (35 of 42). Arterial bleeding occurred in 4 patients (7%) during or after endoscopic resection. In 3 of them, bleeding was stopped by endoscopic clipping, but 1 patient required emergent laparotomy. Conclusions: Endoscopic piecemeal resection after submucosal saline injection with an intensive follow-up program is a safe and effective treatment for large, sessile colorectal polyps. (Gastrointest Endosc 2000;51:697-700.)
Because endoscopic resection of large sessile colorectal polyps is technically difficult and occasionally dangerous, the treatment for these polyps remains controversial.1,2 Maruyama et al.3 reported that endoscopic resection of sessile colorectal polyps larger than 18 mm produced ulcers reaching the muscle layer or deeper. However, we found that ulcers produced by endoscopic resection of these polyps with submucosal saline injection were confined to the submucosal layer and that this technique was safe.4 Although endoscopic piecemeal resection of large sessile colorectal polyps is thought to be appropriate for most patients,5 there are few follow-up studies after resection. We performed follow-up endoscopic examinations to evaluate the effectiveness of endoscopic piecemeal resection with submucosal saline
Received February 5, 1999. For revision May 27, 1999. Accepted November 24, 1999. From the Departments of Gastroenterology and Pathology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan. Reprint requests: Hiroyasu Iishi, MD, Department of Gastroenterology, Osaka Medical Center for Cancer and Cardiovascular Diseases, 3-3, Nakamichi 1-chome, Higashinariku, Osaka 537-8511, Japan. Copyright © 2000 by the American Society for Gastrointestinal Endoscopy 0016-5107/2000/$12.00 + 0 37/1/104652 doi:10.1067/mge.2000.104652 VOLUME 51, NO. 6, 2000
injection for treatment of sessile colorectal polyps 2 cm or greater in diameter. PATIENTS AND METHODS Patients From January 1991 through September 1997, 92 sessile colorectal polyps 2 cm or greater in diameter were found in 92 (0.8%) of 11,340 patients undergoing colonoscopy at our hospital. Fifteen (16%) of these 92 patients underwent open colectomy immediately after colonoscopy, because the polyp could not be visualized in its entirety during colonoscopy or was firm, eroded, or ulcerated so as to raise a suspicion that the lesion was a frankly invasive cancer. The remaining 77 (84%) patients underwent endoscopic resection of colorectal polyps with submucosal saline injection. Most lesions were thought on initial inspection to be not invasive and endoscopically resectable in one session. However, histologic examination of resected specimens revealed that 4 were invasive cancers, which were treated surgically and are excluded from the present study. In addition, because 17 patients did not undergo follow-up colonoscopies 1 year after initial treatment, they are also excluded. Therefore, a total of 56 patients with 56 colorectal polyps were included. To minimize the degree of variability in endoscopic technique, all resections were performed by one senior, experienced endoscopist (H.I.). This study was performed in accordance with the Declaration of Helsinki, and written informed consent was obtained from all patients. GASTROINTESTINAL ENDOSCOPY
697
H Iishi, M Tatsuta, K Iseki, et al.
Endoscopic piecemeal resection of large sessile colorectal polyps
remained asymptomatic. If no residual tumor tissue was detected on inspection and in biopsies of the initial resection site 1 year or more after initial treatment, patients were considered cured. Statistical analysis Results were analyzed with the Fisher exact probability test9 or Student t test.10 Data are shown as means ± SE. Calculated p values of less than 0.05 were considered to indicate statistical significance.
RESULTS Clinicopathologic features Figure 1. Outcome of endoscopic resection with submucosal saline injection of sessile colorectal polyps 2 cm or greater in diameter. Endoscopic technique Endoscopic resection was performed with a submucosal saline injection technique according to the strip biopsy method of Tada.4,6,7 Briefly, an injection needle was inserted into the submucosal layer near the sessile polyp. Ten milliliters or more of 0.9% saline solution was injected until the entire tumor was elevated. If the tumor was not elevated after 1 injection, additional injections were made around the tumor. It was then entrapped with a snare device. After the snare device was positioned, the lesion was severed by using electrosurgical coagulation current, a combination of coagulation and blended currents in sequence. When en bloc resection was not considered possible, lesions were removed in a piecemeal fashion by excising fragments larger than 10 mm in diameter.8 As a last step, 0.05% indigo carmine solution was sprayed over the area of resection so that residual tumor tissue, if present, could be identified and resected. Histologic examination The specimens were spread out so that the cut edge did not roll inward, pinned flat on a Styrofoam mat, and fixed in 10% buffered formaldehyde solution. The fixed specimens were cut into 2 mm wide strips perpendicular to the base and then embedded in paraffin. Five micrometer thick serial sections were stained with H&E. The sections were examined by one of us (S.I.) to determine the histologic diagnosis and the necessity for further treatment. If the tumors had been removed in a piecemeal fashion, the adequacy of resection at the lateral margins could not be determined. If submucosal tissue was present and tumor tissue was not seen at the resected margin, the deep margins were considered adequate. Patients in whom histologic examination revealed that the resected tumors were invasive cancers underwent open resection. Follow-up Colonoscopic examinations were repeated at 3, 6, and 12 months or longer in all patients, including those who 698
GASTROINTESTINAL ENDOSCOPY
Thirty-five patients (63%) were men. Patient age ranged from 34 to 80 years, with a mean of 61 years. Nineteen (34%) and 15 (27%) polyps were excised from the rectum and the ascending colon, respectively (Table 1). Polyp size was estimated on barium enema x-ray films or with a rubber disc 1 cm in diameter during colonoscopy before treatment. The maximum diameter of the polyps ranged from 2 to 5 cm. Thirty-eight (68%) were histologically adenocarcinomas confined to the mucosal layer. Success rates of piecemeal resection All 56 polyps were removed completely, 14 (25%) polyps en bloc and 42 (75%) piecemeal. The tumors resected en bloc and piecemeal did not differ significantly in their location or histologic classification (Table 1). All patients entered the follow-up surveillance protocol except 1 who required emergent colectomy as a result of intractable massive hemorrhage immediately after piecemeal resection; residual tumor was found in the resected specimen (Fig. 1). Other patients were followed for a median of 34 months after initial treatment (range 12 to 84 months). In the en bloc resection group (n = 14), no residual tumor was found in any patient followed for 1 year or more after initial treatment; therefore, the cure rate was 100% (Fig. 1). In the piecemeal resection group (n = 41) excluding 1 patient who required emergent colectomy, no residual tumor was found in 19 patients at 1 year or more after initial treatment. However, residual tumor was found in 22 patients within 1 year. Of these 22 patients, 1 underwent open colectomy and 21 underwent a second colonoscopic resection; 13 of these 21 patients were considered cured, because no residual tumor was detected on colonoscopic inspection and in biopsies after the second resection procedure. Of the remaining 8 patients in whom residual tumors were present after the second resection procedure, 3 subsequently underwent open colectomy, 3 were successfully treated with a third colonoscopic VOLUME 51, NO. 6, 2000
Endoscopic piecemeal resection of large sessile colorectal polyps
H Iishi, M Tatsuta, K Iseki, et al.
Table 1. Clinical data on patients with sessile colorectal polyps 2 cm or greater in diameter treated by colonoscopic resection Data No. of patients Men:women Age (yr, mean ± SE) Location of tumors (%) Cecum Ascending colon Transverse colon Descending colon Sigmoid colon Rectum Histologic diagnosis (%) Adenoma Adenocarcinoma
Polyps resected en bloc
Polyps resected piecemeal
Total
14 8:6 57 ± 2
42 27:15 62 ± 1
56 35:21 61 ± 1
1 (7) 3 (22) 2 (14) 1 (7) 2 (14) 5 (36)
4 (10) 12 (28) 6 (14) 2 (5) 4 (10) 14 (33)
5 (9) 15 (27) 8 (14) 3 (5) 6 (11) 19 (34)
2 (14) 12 (86)
16 (38) 26 (62)
18 (32) 38 (68)
resection, and 2 underwent no further treatment but were observed. In the 4 patients who underwent colectomy, there were no adverse outcomes attributable to delayed definitive treatment. In the piecemeal resection group, cure was ultimately achieved in 35 (83%) of the 42 patients including 1 who underwent emergent colectomy (Fig. 1). There were no significant characteristics of polyps associated with cure including polyp size, location or histologic classification. Complication rates of piecemeal resection Arterial bleeding occurred in 4 (7%) of 56 patients during or after initial colonoscopic resection. In 3 of these 4 patients, bleeding was successfully treated by endoscopic clipping, but emergent surgery was required in 1 patient. During the second and third colonoscopic resections for residual tumors, no arterial bleeding occurred. No patients died or suffered a colonic perforation as a result of colonoscopy. DISCUSSION The results of this study clearly show that endoscopic piecemeal resection with submucosal saline injection is safe and effective for the treatment of colorectal polyps 2 cm or greater in diameter. Although a concern has been raised that piecemeal resection of colorectal polyps may thwart accurate pathologic evaluation, Nivatvongs et al.11 have reported that the orientation and margin of the tissue fragments excised piecemeal can be correctly determined with careful handling. Briefly, the base of the polyp should be pressed onto a piece of filter paper so that the cut edge does not roll inward. The specimens must be sectioned perpendicular to the base. Nivatvongs et al. reported that no focal malignancies were missed with this procedure. Similarly, Okamoto et al.8 examined whether the orientation VOLUME 51, NO. 6, 2000
and margin of specimens resected in a piecemeal fashion could be correctly determined and found that an accurate pathologic diagnosis could easily be made if fragments were larger than 10 mm in diameter. In the present study we tried to take piecemeal fragments of 10 mm or greater in diameter, which were then carefully examined histologically. Colonoscopic piecemeal resection has been accepted as an appropriate treatment for large sessile polyps.5,11-14 Karita et al.13 reported that lesions 50 mm or less in diameter could be excised safely and completely with the successive strip biopsy partial resection technique. However, few follow-up studies have examined the effectiveness of colonoscopic piecemeal resection of large sessile polyps. Walsh et al.15 followed 65 patients for 3 months to 10 years (average 2.8 years) after piecemeal colonoscopic resection of large sessile polyps. Although locally recurrent or persistent neoplasia was discovered in 18 (28%) patients, cure was ultimately achieved in 88%. Inoue et al.16 evaluated the results of endoscopic piecemeal polypectomy in 35 patients with mucosal colorectal cancer, including the pedunculated type, and found no recurrence during a follow-up period of 3 to 48 months (median 21.2 months). Our results show that after a median follow-up period of 34 months (range 12 to 84 months), cure was ultimately achieved in 83% of patients with sessile colorectal polyps 2 cm or greater in diameter resected in a piecemeal fashion. Endoscopic piecemeal resection after submucosal saline injection with an intensive follow-up care program is thus a safe and effective treatment for large sessile colorectal polyps. REFERENCES 1. Webb WA, McDaniel L, Jones L. Experience with 1000 colonoscopic polypectomies. Ann Surg 1985;201:626-32. GASTROINTESTINAL ENDOSCOPY
699
H Iishi, M Tatsuta, K Iseki, et al.
2. Stulc JP, Petrelli NJ, Herrera L, Mittelman A. Colorectal villous and tubulovillous adenomas equal to or greater than four centimeters. Ann Surg 1988;207:65-71. 3. Maruyama M, Sakaki H, Takahashi T, Ota H, Kokaji A, Kato Y, et al. Histologic changes at the polypectomy site of the colon and rectum. Stomach Intest 1985;20:1063-76. 4. Iishi H, Tatsuta M, Kitamura S, Narahara H, Iseki K, Ishiguro S. Endoscopic resection of large sessile colorectal polyps using a submucosal saline injection technique. Hepatogastroenterology 1997;44:698-702. 5. Binmoeller KF, Bohnacker S, Seifert H, Thonke F, Valdeyar H, Soehendra N. Endoscopic snare excision of “giant” colorectal polyps. Gastrointest Endosc 1996;43:183-8. 6. Tada M, Karita M, Yanai H, Kawano H, Shigeeda M, Fukumoto Y, et al. Treatment of early gastric cancer using strip biopsy, a new technique for jumbo biopsy. In: Takemoto T, Kawai K, editors. Recent topics of digestive endoscopy. Tokyo: Excerpta Medica; 1987. p. 137-42. 7. Takemoto T, Tada M, Yanai H, Karita M, Okita K. Significance of strip biopsy, with particular reference to endoscopic “mucosectomy.” Dig Endosc 1989;1:4-9. 8. Okamoto H, Sasaki T, Tsubomizu Y, Satake Y, Fujita R. Piecemeal polypectomy of large sessile colonic polyps. Gastroenterol Endosc 1988;30:1517-22.
Endoscopic piecemeal resection of large sessile colorectal polyps
9. Siegel S. Nonparametric statistics for the behavioral sciences. New York: McGraw-Hill; 1956. 10. Snedecor GW, Cochran WG. Statistical methods. Ames (IA): The Iowa State University Press; 1967. 11. Nivatvongs S, Snover DC, Fang DT. Piecemeal snare excision of large sessile colon and rectal polyps: is it adequate? Gastrointest Endosc 1984;30:18-20. 12. Bedogni G, Bertoni G, Ricci E, Conigliaro R, Pedrazzoli C, Rossi G, et al. Colonoscopic excision of large and giant colorectal polyps: technical implications and results over eight years. Dis Colon Rectum 1986;29:831-5. 13. Karita M, Tada M, Okita K. The successive strip biopsy partial resection technique for large early gastric and colon cancers. Gastrointest Endosc 1992;38:174-8. 14. Bardau E, Bat L, Melzer E, Shemesh E, Bar-Meir S. Colonoscopic resection of large colonic polyps: a prospective study. Isr J Med Sci 1997;33:778-80. 15. Walsh RM, Ackroyd FW, Shellito PC. Endoscopic resection of large sessile colorectal polyps. Gastrointest Endosc 1992;38: 303-9. 16. Inoue Y, Suzuki S, Suzuki M, Murata Y, Iizuka B, Nakamura T, et al. Clinical evaluation of endoscopic piecemeal polypectomy for early colorectal cancers. Gastroenterol Endosc 1998; 40:1857-63.
Submission of ACCEPTED manuscript on diskette Gastointestinal Endoscopy strongly encourages the submission of final manuscripts on disk. Although files created with WordPerfect are preferred, please send your final manuscript in any electronic format. On your disk, please indicate computer system (e.g., IBM, MacIntosh) and word processing software used (e.g., WordPerfect 6.1).
700
GASTROINTESTINAL ENDOSCOPY
VOLUME 51, NO. 6, 2000
Background: Because endoscopic en bloc resection of large, sessile colorectal polyps is technically difficult, they are usually resected piecemeal. However, piecemeal resection makes it difficult to evaluate the completeness of the resection histopathologically. In this study the efficacy of endoscopic piecemeal resection of large, sessile colorectal polyps was investigated after followup greater than 1 year. Methods: We removed 56 sessile colorectal polyps 2 cm or greater in diameter in 56 patients by using an endoscopic submucosal saline injection technique. Endoscopic examinations were repeated at 3, 6, and 12 months and longer after initial endoscopic resection. If no residual tumor was found endoscopically and histologically, the patient was considered to be “cured.” Results: Of the 56 polyps, 14 (25%) were resected en bloc, and 42 (75%) were resected piecemeal. Of the 42 patients treated with piecemeal resection, 23 (55%) required additional endoscopic or surgical interventions. In patients followed 1 year or longer after initial treatment, the cure rate by en bloc resection was 100% (14 of 14) and that by piecemeal resection was 83% (35 of 42). Arterial bleeding occurred in 4 patients (7%) during or after endoscopic resection. In 3 of them, bleeding was stopped by endoscopic clipping, but 1 patient required emergent laparotomy. Conclusions: Endoscopic piecemeal resection after submucosal saline injection with an intensive follow-up program is a safe and effective treatment for large, sessile colorectal polyps. (Gastrointest Endosc 2000;51:697-700.)
Because endoscopic resection of large sessile colorectal polyps is technically difficult and occasionally dangerous, the treatment for these polyps remains controversial.1,2 Maruyama et al.3 reported that endoscopic resection of sessile colorectal polyps larger than 18 mm produced ulcers reaching the muscle layer or deeper. However, we found that ulcers produced by endoscopic resection of these polyps with submucosal saline injection were confined to the submucosal layer and that this technique was safe.4 Although endoscopic piecemeal resection of large sessile colorectal polyps is thought to be appropriate for most patients,5 there are few follow-up studies after resection. We performed follow-up endoscopic examinations to evaluate the effectiveness of endoscopic piecemeal resection with submucosal saline
Received February 5, 1999. For revision May 27, 1999. Accepted November 24, 1999. From the Departments of Gastroenterology and Pathology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan. Reprint requests: Hiroyasu Iishi, MD, Department of Gastroenterology, Osaka Medical Center for Cancer and Cardiovascular Diseases, 3-3, Nakamichi 1-chome, Higashinariku, Osaka 537-8511, Japan. Copyright © 2000 by the American Society for Gastrointestinal Endoscopy 0016-5107/2000/$12.00 + 0 37/1/104652 doi:10.1067/mge.2000.104652 VOLUME 51, NO. 6, 2000
injection for treatment of sessile colorectal polyps 2 cm or greater in diameter. PATIENTS AND METHODS Patients From January 1991 through September 1997, 92 sessile colorectal polyps 2 cm or greater in diameter were found in 92 (0.8%) of 11,340 patients undergoing colonoscopy at our hospital. Fifteen (16%) of these 92 patients underwent open colectomy immediately after colonoscopy, because the polyp could not be visualized in its entirety during colonoscopy or was firm, eroded, or ulcerated so as to raise a suspicion that the lesion was a frankly invasive cancer. The remaining 77 (84%) patients underwent endoscopic resection of colorectal polyps with submucosal saline injection. Most lesions were thought on initial inspection to be not invasive and endoscopically resectable in one session. However, histologic examination of resected specimens revealed that 4 were invasive cancers, which were treated surgically and are excluded from the present study. In addition, because 17 patients did not undergo follow-up colonoscopies 1 year after initial treatment, they are also excluded. Therefore, a total of 56 patients with 56 colorectal polyps were included. To minimize the degree of variability in endoscopic technique, all resections were performed by one senior, experienced endoscopist (H.I.). This study was performed in accordance with the Declaration of Helsinki, and written informed consent was obtained from all patients. GASTROINTESTINAL ENDOSCOPY
697
H Iishi, M Tatsuta, K Iseki, et al.
Endoscopic piecemeal resection of large sessile colorectal polyps
remained asymptomatic. If no residual tumor tissue was detected on inspection and in biopsies of the initial resection site 1 year or more after initial treatment, patients were considered cured. Statistical analysis Results were analyzed with the Fisher exact probability test9 or Student t test.10 Data are shown as means ± SE. Calculated p values of less than 0.05 were considered to indicate statistical significance.
RESULTS Clinicopathologic features Figure 1. Outcome of endoscopic resection with submucosal saline injection of sessile colorectal polyps 2 cm or greater in diameter. Endoscopic technique Endoscopic resection was performed with a submucosal saline injection technique according to the strip biopsy method of Tada.4,6,7 Briefly, an injection needle was inserted into the submucosal layer near the sessile polyp. Ten milliliters or more of 0.9% saline solution was injected until the entire tumor was elevated. If the tumor was not elevated after 1 injection, additional injections were made around the tumor. It was then entrapped with a snare device. After the snare device was positioned, the lesion was severed by using electrosurgical coagulation current, a combination of coagulation and blended currents in sequence. When en bloc resection was not considered possible, lesions were removed in a piecemeal fashion by excising fragments larger than 10 mm in diameter.8 As a last step, 0.05% indigo carmine solution was sprayed over the area of resection so that residual tumor tissue, if present, could be identified and resected. Histologic examination The specimens were spread out so that the cut edge did not roll inward, pinned flat on a Styrofoam mat, and fixed in 10% buffered formaldehyde solution. The fixed specimens were cut into 2 mm wide strips perpendicular to the base and then embedded in paraffin. Five micrometer thick serial sections were stained with H&E. The sections were examined by one of us (S.I.) to determine the histologic diagnosis and the necessity for further treatment. If the tumors had been removed in a piecemeal fashion, the adequacy of resection at the lateral margins could not be determined. If submucosal tissue was present and tumor tissue was not seen at the resected margin, the deep margins were considered adequate. Patients in whom histologic examination revealed that the resected tumors were invasive cancers underwent open resection. Follow-up Colonoscopic examinations were repeated at 3, 6, and 12 months or longer in all patients, including those who 698
GASTROINTESTINAL ENDOSCOPY
Thirty-five patients (63%) were men. Patient age ranged from 34 to 80 years, with a mean of 61 years. Nineteen (34%) and 15 (27%) polyps were excised from the rectum and the ascending colon, respectively (Table 1). Polyp size was estimated on barium enema x-ray films or with a rubber disc 1 cm in diameter during colonoscopy before treatment. The maximum diameter of the polyps ranged from 2 to 5 cm. Thirty-eight (68%) were histologically adenocarcinomas confined to the mucosal layer. Success rates of piecemeal resection All 56 polyps were removed completely, 14 (25%) polyps en bloc and 42 (75%) piecemeal. The tumors resected en bloc and piecemeal did not differ significantly in their location or histologic classification (Table 1). All patients entered the follow-up surveillance protocol except 1 who required emergent colectomy as a result of intractable massive hemorrhage immediately after piecemeal resection; residual tumor was found in the resected specimen (Fig. 1). Other patients were followed for a median of 34 months after initial treatment (range 12 to 84 months). In the en bloc resection group (n = 14), no residual tumor was found in any patient followed for 1 year or more after initial treatment; therefore, the cure rate was 100% (Fig. 1). In the piecemeal resection group (n = 41) excluding 1 patient who required emergent colectomy, no residual tumor was found in 19 patients at 1 year or more after initial treatment. However, residual tumor was found in 22 patients within 1 year. Of these 22 patients, 1 underwent open colectomy and 21 underwent a second colonoscopic resection; 13 of these 21 patients were considered cured, because no residual tumor was detected on colonoscopic inspection and in biopsies after the second resection procedure. Of the remaining 8 patients in whom residual tumors were present after the second resection procedure, 3 subsequently underwent open colectomy, 3 were successfully treated with a third colonoscopic VOLUME 51, NO. 6, 2000
Endoscopic piecemeal resection of large sessile colorectal polyps
H Iishi, M Tatsuta, K Iseki, et al.
Table 1. Clinical data on patients with sessile colorectal polyps 2 cm or greater in diameter treated by colonoscopic resection Data No. of patients Men:women Age (yr, mean ± SE) Location of tumors (%) Cecum Ascending colon Transverse colon Descending colon Sigmoid colon Rectum Histologic diagnosis (%) Adenoma Adenocarcinoma
Polyps resected en bloc
Polyps resected piecemeal
Total
14 8:6 57 ± 2
42 27:15 62 ± 1
56 35:21 61 ± 1
1 (7) 3 (22) 2 (14) 1 (7) 2 (14) 5 (36)
4 (10) 12 (28) 6 (14) 2 (5) 4 (10) 14 (33)
5 (9) 15 (27) 8 (14) 3 (5) 6 (11) 19 (34)
2 (14) 12 (86)
16 (38) 26 (62)
18 (32) 38 (68)
resection, and 2 underwent no further treatment but were observed. In the 4 patients who underwent colectomy, there were no adverse outcomes attributable to delayed definitive treatment. In the piecemeal resection group, cure was ultimately achieved in 35 (83%) of the 42 patients including 1 who underwent emergent colectomy (Fig. 1). There were no significant characteristics of polyps associated with cure including polyp size, location or histologic classification. Complication rates of piecemeal resection Arterial bleeding occurred in 4 (7%) of 56 patients during or after initial colonoscopic resection. In 3 of these 4 patients, bleeding was successfully treated by endoscopic clipping, but emergent surgery was required in 1 patient. During the second and third colonoscopic resections for residual tumors, no arterial bleeding occurred. No patients died or suffered a colonic perforation as a result of colonoscopy. DISCUSSION The results of this study clearly show that endoscopic piecemeal resection with submucosal saline injection is safe and effective for the treatment of colorectal polyps 2 cm or greater in diameter. Although a concern has been raised that piecemeal resection of colorectal polyps may thwart accurate pathologic evaluation, Nivatvongs et al.11 have reported that the orientation and margin of the tissue fragments excised piecemeal can be correctly determined with careful handling. Briefly, the base of the polyp should be pressed onto a piece of filter paper so that the cut edge does not roll inward. The specimens must be sectioned perpendicular to the base. Nivatvongs et al. reported that no focal malignancies were missed with this procedure. Similarly, Okamoto et al.8 examined whether the orientation VOLUME 51, NO. 6, 2000
and margin of specimens resected in a piecemeal fashion could be correctly determined and found that an accurate pathologic diagnosis could easily be made if fragments were larger than 10 mm in diameter. In the present study we tried to take piecemeal fragments of 10 mm or greater in diameter, which were then carefully examined histologically. Colonoscopic piecemeal resection has been accepted as an appropriate treatment for large sessile polyps.5,11-14 Karita et al.13 reported that lesions 50 mm or less in diameter could be excised safely and completely with the successive strip biopsy partial resection technique. However, few follow-up studies have examined the effectiveness of colonoscopic piecemeal resection of large sessile polyps. Walsh et al.15 followed 65 patients for 3 months to 10 years (average 2.8 years) after piecemeal colonoscopic resection of large sessile polyps. Although locally recurrent or persistent neoplasia was discovered in 18 (28%) patients, cure was ultimately achieved in 88%. Inoue et al.16 evaluated the results of endoscopic piecemeal polypectomy in 35 patients with mucosal colorectal cancer, including the pedunculated type, and found no recurrence during a follow-up period of 3 to 48 months (median 21.2 months). Our results show that after a median follow-up period of 34 months (range 12 to 84 months), cure was ultimately achieved in 83% of patients with sessile colorectal polyps 2 cm or greater in diameter resected in a piecemeal fashion. Endoscopic piecemeal resection after submucosal saline injection with an intensive follow-up care program is thus a safe and effective treatment for large sessile colorectal polyps. REFERENCES 1. Webb WA, McDaniel L, Jones L. Experience with 1000 colonoscopic polypectomies. Ann Surg 1985;201:626-32. GASTROINTESTINAL ENDOSCOPY
699
H Iishi, M Tatsuta, K Iseki, et al.
2. Stulc JP, Petrelli NJ, Herrera L, Mittelman A. Colorectal villous and tubulovillous adenomas equal to or greater than four centimeters. Ann Surg 1988;207:65-71. 3. Maruyama M, Sakaki H, Takahashi T, Ota H, Kokaji A, Kato Y, et al. Histologic changes at the polypectomy site of the colon and rectum. Stomach Intest 1985;20:1063-76. 4. Iishi H, Tatsuta M, Kitamura S, Narahara H, Iseki K, Ishiguro S. Endoscopic resection of large sessile colorectal polyps using a submucosal saline injection technique. Hepatogastroenterology 1997;44:698-702. 5. Binmoeller KF, Bohnacker S, Seifert H, Thonke F, Valdeyar H, Soehendra N. Endoscopic snare excision of “giant” colorectal polyps. Gastrointest Endosc 1996;43:183-8. 6. Tada M, Karita M, Yanai H, Kawano H, Shigeeda M, Fukumoto Y, et al. Treatment of early gastric cancer using strip biopsy, a new technique for jumbo biopsy. In: Takemoto T, Kawai K, editors. Recent topics of digestive endoscopy. Tokyo: Excerpta Medica; 1987. p. 137-42. 7. Takemoto T, Tada M, Yanai H, Karita M, Okita K. Significance of strip biopsy, with particular reference to endoscopic “mucosectomy.” Dig Endosc 1989;1:4-9. 8. Okamoto H, Sasaki T, Tsubomizu Y, Satake Y, Fujita R. Piecemeal polypectomy of large sessile colonic polyps. Gastroenterol Endosc 1988;30:1517-22.
Endoscopic piecemeal resection of large sessile colorectal polyps
9. Siegel S. Nonparametric statistics for the behavioral sciences. New York: McGraw-Hill; 1956. 10. Snedecor GW, Cochran WG. Statistical methods. Ames (IA): The Iowa State University Press; 1967. 11. Nivatvongs S, Snover DC, Fang DT. Piecemeal snare excision of large sessile colon and rectal polyps: is it adequate? Gastrointest Endosc 1984;30:18-20. 12. Bedogni G, Bertoni G, Ricci E, Conigliaro R, Pedrazzoli C, Rossi G, et al. Colonoscopic excision of large and giant colorectal polyps: technical implications and results over eight years. Dis Colon Rectum 1986;29:831-5. 13. Karita M, Tada M, Okita K. The successive strip biopsy partial resection technique for large early gastric and colon cancers. Gastrointest Endosc 1992;38:174-8. 14. Bardau E, Bat L, Melzer E, Shemesh E, Bar-Meir S. Colonoscopic resection of large colonic polyps: a prospective study. Isr J Med Sci 1997;33:778-80. 15. Walsh RM, Ackroyd FW, Shellito PC. Endoscopic resection of large sessile colorectal polyps. Gastrointest Endosc 1992;38: 303-9. 16. Inoue Y, Suzuki S, Suzuki M, Murata Y, Iizuka B, Nakamura T, et al. Clinical evaluation of endoscopic piecemeal polypectomy for early colorectal cancers. Gastroenterol Endosc 1998; 40:1857-63.
Submission of ACCEPTED manuscript on diskette Gastointestinal Endoscopy strongly encourages the submission of final manuscripts on disk. Although files created with WordPerfect are preferred, please send your final manuscript in any electronic format. On your disk, please indicate computer system (e.g., IBM, MacIntosh) and word processing software used (e.g., WordPerfect 6.1).
700
GASTROINTESTINAL ENDOSCOPY
VOLUME 51, NO. 6, 2000