T colonoscopy (Fig. 1) which permits direct

Transcription

1 FLEXIBLE COLONOSCOPY HIROMI SHINYA, MD,* AND WILLIAM WOLFF, MD~ Colonoscopy with fiberoptic instruments has opened new vistas in diagnosis and treatment of colonic disease. Such endoscopy requires skill, experience, and judgment to be accomplished readily and safely but permits visual examination of the entire colon and, frequently, the terminal ileum as well. Although in experienced hands colonoscopy may have greater diagnostic accuracy than the barium enema, particularly with respect to colorectal cancer and polyps, the two are complementary modalities and with their combined use an extremely high rate of detection and confirmed diagnosis can be expected. The Beth Israel group introduced the technique of snare-cautery removal of colonic polyps via the colonoscope and has now successfully resected over 2500 such polyps without a single death. This is the largest world experience. Selected polyps can be removed endoscopically as an ambulatory procedure, reducing costs and incapacitation time. Neoplastic polyps often harbor invasive cancer and their extirpation is expected to reduce the incidence of overt colorectal cancer. Colonoscopy and endoscopic polypectomy offers the opportunity to check the rising incidence, morbidity, and mortality related to colorectal cancer. Cancer 37: , HE RECENT INTRODUCTION OF FIBEROPTIC T colonoscopy (Fig. 1) which permits direct visualization of the entire colon has opened new vistas in diagnosis and treatment of colonic lesions.7~10 Although its performance requires skill, experience, and judgment, colonoscopy has for some time now proved itself as an extremely valuable method of solving the diagnostic dilemma sometimes presented by barium enema studies.11~13 Colonoscopy can be easily performed on an ambulatory basis in the endoscopy room of the hospital or in a doctor s office with minimal discomfort to the patient. The colonoscope permits examination not only of the entire colon but often the distal ileum as well, with excellent illumination and magnicfication (Fig. 2). Colonoscopy and the contrast enema should not be regarded as competitive, but as mutu- Presented at the ACS-NCI National Conference on Advances in Cancer Management, Part 11: Detection and Diagnosis, Denver, CO, May 1-3, From the Department of Surgery, Beth Israel Medical Center, New York, NY. Chief, Surgical Endoscopy, Beth Israel Medical Center. t Director of Surgery, Beth Israel Medical Center. Address for reprints: William I. Wolff, MD, Director of Surgery, Beth Israel Medical Center, 10 Nathan D. Perlrnan Place, New York, NY ally supportive and complementary modalities.13 Radiologic diagnostic problems can usually be solved promptly by endoscopic examination and biopsy. We still regard the barium enema as an extremely valuable diagnostic method. Note the following data which compare the diagnostic accuracies of colonoscopy and the barium enema: in a consecutive series, 700 patients were studied because of bleeding per rectum in some form; 120 cases of colon carcinoma were found. On review only 57 were stated to be radiologically positive for cancer, 10 had been reported as negative, and four were regarded as unsatisfactory examinations. In three no radiologic study preceded colonoscopy. Of the 120 total, 118 of these cancers were proven by colonoscopy; of the two remaining cases, the cancer could not be reached in one because of a distal inflammatory narrowing related to diverticulitis and the other was a cecal lesion in which repeat endoscopy was recommended because ileal emptying obscured the field. Thus, the diagnostic accuracy by colonoscopy was 98.3% successful, as opposed to 48.7 % by contrast enema. Additional advantages of endoscopic study are revealed when this group is analyzed in further detail. In 17 instances the barium enema report contained the term suspicious,

2 No. 1 COLONOSCOPY Shinya and WolD 463 FIG. 1. Colonoscopes. and in 29 the diagnosis made was benign polyp. Moreover, 16 additional cases purportedly disclosed colonic pathology suggestive of cancer by x-ray study but no intrinsic disease was disclosed when the area in question was carefully examined by the endoscopic route. Thus, colonoscopy combined with the contrast enema is capable of offering the following: when cancer is present, colonoscopy can establish or confirm the diagnosis, and operative intervention can be undertaken promptly and without harmful delay. When carcinoma is shown not to be the cause of a demonstrated radiologic abnormality, unnecessary exploratory surgery can be avoided. ENDOSCOPIC POLYPECTOMY When polypoid lesions of the colon are discovered by barium enema or colonoscopy, it is now possible to remove them by endoscopic means from all parts of the colon, from the cecum on down.9 In our unit, over 2500 co- lonic polyps beyond the reach of the conventional rigid sigmoidoscope have been removed via the colonoscope by the snare-cautery technique without a mortality and with an extremely low morbidity. This is the largest world experience. Table 1 shows the diagnoses made on 1822 benign polypoid lesions over 0.5 cm in diameter excised via the colonoscope. These include adenomatous polyps (tubular adenomas), villous adenomas, mixed villous and adenomatous polyps (villotubular adenomas), hyperplastic polyps, juvenile polyps, lipomas, leiomyomas, fibrovascular polyps, carcinoid tumors, and lymphomas. Polypectomy via the colonoscope is a procedure which we now believe may be performed on an ambulatory basis as well as on hospitalized patients.6 The important decisive factors are the size and nature of the polyp and the general condition of the patient. Table 2 shows a group of excised polyps analyzed according to size. Polypoid lesions smaller than 0.5 cm in size were not included in the two series mentioned. The largest lesion re-

3 464 CANCER January Supplement 1976 Vol. 37 FIG. 2. Roentgenograph of a colonoscope traversing the entire length of the colon and the distal 50-cm of the ileum. moved was 12 cm in diameter. We do not recommend removal of such large lesions other than in a hospital. Endoscopic removal of be- nign polyps has many obvious advantages as compared to transabdominal excision of these lesionsl.3 (Fig. 3). TABLE 1. Polypoid Lesions Excised via Colonoscope ( cm Diameter) Adenoinntous polyps Villous or papillary adenomas Mixed villous & adenomatoiis Hyperplastic polyps Juvenile polyps Lipomas Leiom yomas Fibrovascular polyps Carcinoid tumors Lymphomas (benign) TOTAL I 1822 COLORECTAL POLYPS AND CANCER Despite the controversy with respect to the precise relationship between colonic polyps and cancer, and the frequency with which benign polyps become cancerous, evidence is accumulating that polyps are indeed premalignant lesions."4~6j2j4 By colonoscopy it is possible to identify a given lesion as polypoid cancer and not merely a benign polyp. Figure 4 shows an approximately 2-cm polypoid car-

4 No. 1 COLONOSCOPY - cinoma removed from the cecum. When this was excised via the colonoscope, the resection line was free of carcinoma. One polyp approximately 0.6 cm in diameter found in the sigmoid colon proved after removal to show about %yo of lesion to be invasive cancer. Figure 5 shows an 8-mm lesion removed from the descending colon which was entirely cancerous. Figure 6 shows a 2-cm polypoid lesion with deep central ulceration diagnosed correctly by colonoscopy. This is a small carcinoma. Barium enema reported the benign pedunculated polyp which was also present. In one instance a dilemma was presented by a patient with rectal bleeding whose previous barium enemas had shown only diverticulosis. When the scope was advanced to the splenic flexure there was a large ulcerating constricting cancer. Subsequent contrast enema now confirmed this diagnosis (Fig. 7). NEOPLASTIC COLONIC POLYPS We will now discuss neoplastic colonic polyps, which are the only polyp forms having a malignant potential, according to many authori tie~.2~5~1~~1~ Tubular adenomas or benign adenonzatous polyps: These are true neoplasms. They are one-tenth as common as hyperplastic polyps,' from which they must be differentiated. They Shinya and Wolf 465 TABLE 2. Colonoscopic Polypectomy ( 1934 Polyps Excised) Size of Excised Polyps Size (Greatest diameter) No. of polyps cm O-1.9 cm cm cm cni cm 4 12 cm 1 TOTAL 1934 come in all sizes and shapes and can be pedunculated or sessile. They are the most common of the neoplastic polyps. In Fig. 3 the polyp has a much slimmer stalk. Tubular adenomas can and do demonstrate malignant changes of an invasive nature. In one series we analyzed" there were 17 tubular adenomas with invasive carcinoma. These constituted 3.37& of 511 of the tubular adenomas excised through the colonoscope. Villous adenomas: These are also true neoplasms and the least common form of neoplastic polyp. They are often sessile in configuration and vary greatly in size and shape. They have the highest possibility of malignant change. Because of their larger size and frequently sessile gross morphology, villous adenomas sometimes have to be removed in piecemeal fashion. FIG. 3. Photograph of 3-cm lobulated adenomatous polyp (tubular adenoma) resected endoscopically Elom the descending colon.

5 466 CANCER Janziary Supplement I Val. 31 FIG. 4. Polypoid lesion removed from cecum. This proved to be a polypoid carcinoma. The line of resection was free of cancer. FIG. 5. Polypoid lesion 0.8 cm in diameter endoscopically removed from the descending colon. Diagnosis: polypoid carcinoma. No residuum of a benign polyp could be found. No residual tumor was present on subsequent colectomy.

6 No. 1 COLONOSCOPY - Shinya and Wol8 467 FIG. 6. A small ulcerating polypoid carcinoma (arrows) diagnosed by colonoscopy in a patient whose barium enema reported a benign pedunculated polyp (seen on right). In the series mentioned, of 11 1 excised villous adenomas, there were 14 or 12.6% containing invasive carcinoma. Villotubular adenomas, or villoglandular or mixed polyps: These are also true neoplasms, and are more common than has been previ- FIG. 7. A patient with a previous history of diverticulitis presented with rectal blding. Colonoscopic examination disclosed the cancer of the splenic flexure seen on the right. Radiologic confirmation was established by a more recent contrast enema, seen on the left.

7 468 CANCER Jantmry Supplement 1976 Vol. 31 ously recognized.8 There is a variable mixture of villous and tubular architecture (Fig. 8). These lesions are intermediate in their malignant potential, between tubular adenomas and villous adenomas. Among villotubular adenomas, 260 of which were excised, there were 10 or 3.8y0 which had invasive carcinoma." Hyperplustic polyps: These are not true neoplasms. They constitute of all colonic polyps according to studies done by Lane and co-workers. They are usually small, 1-5 mm in size. There is no evidence that they are in any way related to adenomatous polyps or cancer. In our experience, taking all polyps measuring over 0.5 cm in diameter, neoplastic and other, which are endoscopically removed, a fairly constant 6.5y0 incidence of cancerous change has been found. Carcinomatous changes have been found only in the neoplastic forms FIG. 8. Photomicrograph of villotubular adenoma (mixed adenomatous and villous polyp): (a) stalk, (b) area with villous configuration, and (c) tubular or adenomatous portion.

8 No. 1 COLONOSCOPY Shinya and Wol8 469 FIG. 9. (a) (top left) Roentgenograph of small bowel endoscope starting down the small intestine, (b) (top right) same case with scope more advanced, (c) (botton]) small bowel scope in cecum and colonoscope simultzneouly introduced into the cecum froin below.

9 470 CANCER January Supplement 1976 Vol. 37 described above. In roughly half of these, the cancer has not extended through the muscularis mucosae. These are called carcinoma in situ. Such superficial cancer is not itself clinically malignant, if the polyp has been completely removed. Such lesions never metastasize, but the natural history of polyps with carcinoma in situ is still a matter of speculation. Once endoscopic removal has been accomplished, nothing other than periodic re- observation is required in our e~timati0n.l~ When cancerous cells invade into or through the muscularis mucosae in an otherwise benign polyp, the lesion must be regarded as a true cancer, whether the polyp is sessile or pedunculated. The factor of penetration or invasion can be ascertained only by complete removal of the polyp and multiple fixed tissue sections with the proper orientation.6 Fractional biopsies and mutilation of the polyp through frozen section can lead only to great errors in this regard. For any given patient, the risks of the disease must be carefully weighed against the risks of a bowel resection. When the polyp is pedunculated, if there is adequate clearance between the level of cancer invasion and the line of cautery section, our present policy calls for endoscopic reobservation only. Where carcinoma celis extend close to or through the line of cautery resection, we recommend abdominal exploration if the patient's condition justifies this risk. This is particularly applicable for the sessile type of polyp. Our own overall experience, however, indicates that if the lesion is completely excised via the colonoscope, residual tumor is not unusually found in the subsequently resected colon. Superficially invasive cancer in the sessile polyp with adequate clearance between it and the resection line may also be managed conservatively, but requires very close follow-up care.14 Particular attention must be directed to the completeness of removal and the overall number of colonic polyps present in order to decide whether further operative intervention is required. There must be frequent follow-up examinations if no operative intervention is decided upon. Finally, it is our feeling that the full impact of colonoscopy on improving the cure rate for cancer of the colon and rectum will come to be felt as more tumors are discovered and operated upon at a favorable stage of the disease, and as premalignant lesions are identified and removed before the cancer process becomes advanced.'? In the last illustration (Fig. 9) we see photographs of a small bowel endoscope10 which has reached the cecum and, at the same time, a colonoscope has been introduced u'p to the cecum from below. In this way, both scope tips have met from above and below and visualized the entire gastrointestinal tract. REFERENCES 1. Bloom, B. S., Goldhaber, S. Z., Sugarbaker, P. H., 8. U'olff, W. I., and Shinya, H.:.4 new approach and O'Connor, N. E.: Fiheroptics-Morbidity and to colonic polyps. Ann. Sztrg. 3: , cost. Editorial. N. Engl. J. Med. 288:369, Wolff, W. I., and Shinya, H.: Polypectomy via 2. Fenoglio, C. M.3 and Lane, N.: The anatomical the fiheroptic colonoscope. N. Engl.,I. Afed. 288:329- precursor of colorectal carcinoma. Concer 34:819:823, 332, Wolff, W. I., and Shinya, H.: Modern endo- 3. Goldhaber, S. z.3 Bloom, B. S., Sugarbaker, P. H., scopy of thc alimentary tract. ~ tcurrent l Problems in and ''Connor, N' E.: Effects Of the fiberoptic laparo- Surgery. Chicago, Yea,- Book hfedical Piil,lishers, Inc. scope and colonoscope on morbidity and cost. Ann Surg. 179: , Lane, N., Kaplan, H., and Pascal, R. R.: Minute 11. Wolff, W. I., and Shinya, H.: Earlier diagnosis adenomatous and hyperplastic polyps of the colon- Of cancer Of the through encloscopy Divergent patterns of epithelial growth with specific (colonoscopy). Cancer 34: , associated mesenchymal changes. Gastroenterology 60: 12. Wolff, W. I., and Shinya, H.: Endoscopic poly , pectomy: therapeutic and clinico-pathologic aspects. 5. Morson, B. C., and Dawson, I. M. P.: Gastro- Cancer (supp1.) 36:683-69* intestinal Pathology. Oxford, Blackwell Scientific Pub- 13. Wolff, W. I., Shinya, H., Geffen, A., Ozoktay, S., lications, and debeer, R.: Comparison of colonoscopy and the 6. Shinya, H., and Wolff, W. I.: Colonoscopy. ~n contrast enema in five hundred patients with colorcctal Surgery Annual, Vol. VIII. New York, Appleton-Cen- disease. Am. J. Surg. 129: , tury Crofts, Wolff, W. I., and Shinya, H.: Definitive treat- 7. Wolff, W. I., and Shinya, H.: Colonofiberoscopy. ment of malignant polyps of the colon. Ann. Stcrg. 182: JAMA 217: , , 1975.