Reply to Dr. Roberts

Letters to the Ed itor Case of the duplicate case report To the Editor: The August 1986 issue contains two case reports beginning on pages 292 ' and 3092 that describe the same patient. Publication of the letter on page 309 seems redundant. Was this an oversight?

of Barkin et al.,4 a median of four biopsies per patient were obtained with a pediatric colonoscope and at least one biopsy was adequately oriented. (These investigators also did not give details on orientation; presumably, the biopsies were placed unoriented directly into formalin.) In the study by Achkar et al., the endoscopic biopsies of Figures 1 and 2 appear to be of better "quality" than the suction biopsies. Further prospective experience in examining both endoscopic and suction biopsy techniques is clearly indicated before the conclusion that they are comparable in the routine diagnosis of small bowel pathology. Ingram M. Roberts, MD

David D. Clarke, MD

Division of Gastroenterology George Washington University School of Medicine Washington, DC

Clackamas, Oregon

REFERENCES 1. Greif JM, Ragland JJ, Ochsner MG, Riding R. Fatal necrotizing fasciitis complicating percutaneous endoscopic gastrostomy. Gastrointest Endosc 1986;32:292-4. 2. Person JL, Brower RA. Necrotizing fasciitis/myositis following percutaneous endoscopic gastrostomy. Gastrointest Endosc 1986;32:309.

Editor's Response:

Dr. Clarke is to be congratulated for his thorough reading of Gastrointestinal Endoscopy. Indeed, the case report of Greif et al. (Gastrointest Endosc 1986;32:292-4) refers to the same patient in the letter of Person and Brower (Gastrointest Endosc 1986;32:309). The authors involved have acknowledged that this double exposure was inadvertent and unintentional.

REFERENCES 1. Achkar E, Carey WD, Petras R, Sivak MV, Revta R. Comparison of suction capsule and endoscopic biopsy of small bowel mucosa. Gastrointest Endosc 1986;32:278-81. 2. Trier JS. Diagnostic value of peroral biopsy of the proximal small intestine. N Engl J Med 1971;285:1470-3. 3. Perera DR, Weinstein WM, Rubin CEo Small intestinal biopsy. Hum PathoI1975;6:157-217. 4. Barkin JS, Schonfeld W, Thomsen S, Manten HD, Rogers AI. Enteroscopy and small bowel biopsy: an improved technique for the diagnosis of small bowel disease. Gastrointest Endosc 1985;31:215-7.

Reply to Dr. Roberts To the Editor:

Are endoscopic duodenal biopsies really adequate? To the Editor: I read with interest the recent paper by Achkar et aLl The authors should be lauded for attempting to perform this important study; however, in their abstract they conclude that "the endoscope is the preferred way to obtain tissue from the proximal small bowel." There are several points that require explanation and clarification before endorsing the authors' recommendations. First, what were the indications for the small bowel biopsies and what were the final diagnoses in the 36 patients studied? In only five patients was disease found (one had nontropical sprue). Presumably, the majority of patients in this study had normal biopsies. Second, the authors argue that the quality of the biopsies in the 10 patients who had both techniques was comparable. The inability to detect differences in quality between the endoscopic and suction biopsies may represent a type II statistical error due to the small sample size. Finally, the authors describe how the suction biopsies were oriented properly, but they do not give details on their method for orienting the endoscopic biopsies; specimens obtained with the 8-mm endoscopic biopsy forceps are smaller than suction specimens. Proper specimen orientation is a crucial step in preparation of a small bowel biopsy to ensure optimal diagnostic interpretation. 2 • 3 In the study 264

We thank Dr. Roberts for his interest in our recent report on endoscopic small bowel biopsy.) There are certain limitations to our study. We agree that additional investigation is necessary. The answers to some of the points raised will be available from studies currently being conducted in our laboratory. Nevertheless, we do not think it premature to communicate a technique which has substantially simplified our ability to assess proximal small bowel mucosal architecture. Dr. Roberts notes that the small bowel mucosa in the majority of the patients studied was normal. It is entirely appropriate to document the technical feasibility of obtaining adequate biopsy material by studying normal as well as abnormal cases. Indeed, many of the early reports of endoscopically retrieved small bowel tissue were cases in which normal mucosa was distorted by the presence of Brunner's glands and by poor orientation of specimens. 2 Our demonstration that artifact is not a significant problem in normal individuals forms the cornerstone of our report. While it is theoretically possible that our technique could provide useful information when the small bowel is normal but not when there is diffuse proximal mucosal disease, we think it quite unlikely. The second comment raises the possibility that one technique is substantially better than the other and that no difference was found because of the small sample size (type II statistical error). Only additional observation will be able to answer this question. On the other hand, Roberts has provided no additional information on this score, and we are GASTROINTESTINAL ENDOSCOPY

unaware of others who have tried our technique or that of Barkin et al. 3 and been disappointed. 4 •5 We continue to find endoscopic small bowel biopsy extremely satisfactory in our clinical work. Weare in complete agreement that proper orientation of biopsy specimens is the most important step in obtaining small bowel biopsy specimens. 6 Of course, this principle applies regardless of how the specimen is obtained. In our practice, the biopsy material is not handled in the fashion inferred by Roberts. Instead, the endoscopy assistant carefully rolls out the curled up specimen and places it mucosal side up on a piece of filter paper, which is then placed in preservative. The pathologist takes special precautions to assure that the specimen is properly oriented during fixation and sectioning. We are pleased Roberts finds, as we do, that the quality of the product obtained endoscopically is quite good. This, after all, was the point of our report. Further prospective research into the possibilities and limitations of endoscopic small bowel biopsy is clearly indicated.

ogy of the gastrointestinal tract. II. Small intestinal biopsy. Hum Pathol 1975;6:157-217.

Comparison of suction capsule and endoscopic biopsy of small bowel mucosa To the Editor: Achkar et al. l reported the results of a comparison between suction capsule and endoscopic biopsy of small bowel in 56 patients and concluded that endoscopic biopsy is the preferred way to obtain tissue from the proximal small bowel. By this technique they obtained material in 100% of attempts (vs. 81% with suction capsule), and the tissue obtained was excellent in 65% (vs. 58% with suction capsule). As we do not know of similar studies in a pediatric population where endoscopic biopsies performed with pediatric forceps give smaller specimens, we reviewed the results of a 2 years' experience in our pediatric gastrointestinal unit (September 1984-September 1986). A total of 313 small bowel biopsies were carried out in this period. 137 children underwent biopsy with a pediatric Watson suction biopsy capsule for suspected celiac disease at various stages (malabsorption, or after gluten-free diet, or after gluten challenge) according to the criteria of the European Society of Pediatric Gastroenterology and Nutrition (ESPGAN) for the diagnosis of celiac disease. 2 Most children received an intravenous premedication with diazepam (0.2 mg/kg) but this was avoided in infants. In the same period 167 biopsies were performed with an Olympus GIF P3 pediatric endoscope and a pediatric forceps (Olympus FB 21K) with an open cup diameter of 1.7 mm. Gastroduodenoscopies were performed in 66 cases for suspected celiac disease at various stages and in 110 cases for other upper gastrointestinal tract disease (peptic ulcer, esophagitis, gastritis, or duodenitis). All children received oral premedication with 1 to 2 mg of diazepam and tetracaine. Results are summarized in Table 1. Of 137 biopsies performed with the Watson capsule, 26

Edgar Achkar, MD William D. Carey, MD Department of Gastroenterology The Cleveland Clinic Foundation Cleveland, Ohio

REFERENCES 1. Achkar E, Carey WD, Petras R, Sivak MV, Revta R. Comparison of suction capsule and endoscopic biopsy of small bowel mucosa. Gastrointest Endosc 1986;32:278-81. 2. Korn ER, Foroozan P. Endoscopic biopsies of normal duodenal mucosa. Gastrointest Endosc 1974;21:51-4. 3. Barkin JS, Schonfelt W, Thomsen S, Mantan HD, Rogers AI. Enteroscopy and small bowel biopsy-an improved technique for the diagnosis of small bowel disease. Gastrointest Endosc 1985;31:215-7. 4. Scott BB, Jenkins D. Endoscopic small intestinal biopsy. Gastrointest Endosc 1981;27:162-7. 5. Gillberg, Ahren C. Coeliac disease diagnosed by means of duodenoscopy and endoscopic duodenal biopsy. Scand J Gastroenterol 1977;12:911-6. 6. Perera DR, Weinstein WM, Rubin CEo Symposium on pathol-

Table 1. Comparison of the adequacy of small bowel biopsy specimens obtained with pediatric forceps during endoscopy or with Watson pediatric suction capsule for suspected celiac disease and other diseases· Technique and indications

Specimen quality

Specimen not obtained

No. Adequate

Not adequate

Pediatric forceps Suspected CD

66

58 (87%)

8 (12%)

OD Watson capsule

110

96 (87%)

14 (12%)

Suspected CD

137

111 (81%)

10 (n)

313

264 (84%)

32

Total

o

{NR 1 (12%) VA 6 (76%) N 1 (12%)

rR3130%)

VA 5 (50%) N 1 (10%) D 1 (10%)

16 (12%)

r

7143

%) VA 3 (18%) N 6 (37%)

16

CD, celiac disease; OD, other diagnosis (gastritis, esophagitis, duodenitis, peptic ulcer); NR, not repeated; VA, villous atrophy; N, normal small bowel mucosa; D, duodenitis. a

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