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Lift and cut biopsy technique for submucosal sampling
Lift and cut biopsy technique for submucosal sampling T. R. Martin, MD
G. R. Onstad, MD S. E. Silvis, MD J. A. Vennes, MD Minneapolis, Minnesota
The lift-and-cut biopsy technique is proposed for the evaluation of selected lesions of the gastric submucosa. The safety and success of the procedure is due to the use of a biopsy forceps to raise a pedicle of tissue before snaring and electrocoagulation. When the specimen is properly obtained and oriented for sectioning, the procedure consistently yields submucosa. It may offer an alternative to exploratory laparotomy for the purpose of adequate biopsy.
W hen an
upper gastrointestinal radiograph shows large gastric folds, a problem arises concerning further evaluation of the patient. In the past, a complete workup has often required a laparotomy and full thickness gastric biopsy. In 1969 Umeda described direct visual biopsy of the stomach with the fibergastroscope. Adequate mucosal samples were obtained 85% of the time.' In an effort to obtain submucosa, 2 other techniques have been described. A 4 mm biopsy forceps has been used by Vennes et al. 2 The samples are large enough to be oriented on Gel-foam. We have been able to obtain submucosa 25% of the time with this instrument.' Big particle biopsy, utilizing a polypectomy snare and a single channel endoscope, has been used by Ottenjann et al. 4 Two of 11 samples contained submucosa. The lift-and-cut technique was initially developed to provide a chronic bleeding ulcer model. Because submucosa was noted on each tissue sample, the technique was adapted for biopsy.
This paper describes an endoscopic biopsy technique that offers an alternative to full thickness biopsy in the evaluation of gastric submucosal lesions. METHODS Eighty-one 10 kg to 20 kg mongrel dogs were anesthetized with Nembutal following a 24-hour fast. An endoscope was introduced orally into the stomach. Sideviewing and a forward-viewing 2-channel endoscopes were available for this study. The biopsy technique is shown diagrammatically in this series of pictures. Step 1: A polypectomy snare and a biopsy forceps are introduced into the instrumentation ports. The snare is opened and placed agai nst the mucosa. The forceps is passed through the snare. Step 2: A bite of mucosa is taken. Step 3: A pedicle of tissue is raised by withdrawing the forceps back into the port. Step 4: The snare is closed and the tissue is cut with electrocautery as though it were a pedunculated polyp. The procedure is performed under direct vision at all
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LIFT AND CUT BIOPSY TECHNIQUE.
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Figure 1. Diagrammatic representation of Iift-and-cut biopsy technique. See text for description. From the gastroenterology sections of the Veterans Administration Hospital and Hennepin County Medical Center, Minneapolis, Minnesota. Reprint requests: Thomas R. Martin, MD, Gastroenterology Section, Veterans Administration Hospital, 54th Street & 48th Avenue South, Minneapolis, Minnesota 55407 VOLUME 23, NO.1, 1976
29
Table I. Results of life-and-cut biopsy technique large biopsy (> 1.5 cm)
small biopsy « 1.0 cm)
Number of dogs
69
12
Number of biopsies
79
24
Submucosa obtained Perforations
100% 2 (2.6%)
100% 0
2/25
0
Bleeding
times. Once the pedicle of tissue is cut, the entire instrument is withdrawn with the biopsy retained in the forceps. The samples are oriented of filter paper, fixed in formalin, and submitted for histologic sectioning and staining. When first obtained in the study of an ulcer model, samples were designed to be as large as possible so that the amount of bleeding and the risk of perforation could be estimated. All of these samples had diameters greater than 1.5 cm. They were obtained by placing the snare at the base of the pedicle of tissue before closing it. Samples with diameters less than 1.0 cm were consistently obtained by placing the snare just distal to the forceps at the apex of the pedicle. The animals were sacrificed immediately, during 10 days after the procedure, or followed to complete endoscopic healing. Hematocrits were drawn. Fifty-one animals were anticoagulated with large doses of heparin or coumadin as part of a second study.s RESULTS The results of the technique are shown in Table I. Submucosa was obtained in all of the samples. Although 2 perforations occurred in the animals that had large biopsies, none occurred in the small biopsy group. Two of the animals in the large biopsy group that were not anticoagulated had drops in hematocrit of 10% and 16%, a significant hematocrit drop being defined as a persistent depression of more than 6%. Blood loss was not apparent in any of the small biopsy group. Animals that were not sacrificed were followed to endoscopic healing which occurred by three weeks in most.
We have used the technique in 2 patients. The first patient had a fever of obscure origin and large gastric folds. Gastric lymphoma was considered in the differential diagnosis. The second patient had large gastric folds that involved the greater curve and extended over the distal body to the mid-antrum. He had lost 40 pounds apparently because of depression. Adequate submucosal samples obviated the need for a laparotomy and full thickness gastric biopsy in both cases. The procedures were performed without complications. Although more experience is necessary, it appears that the technique can be used safely in humans. This would be expected insofar as the human and dog gastric mucosa are of si m ilar th ickness. 6 Potential risks include perforation and bleeding. These possible complications can be minimized by keeping the samples as small as possible.
Figure 3. Low power photomicrograph of a lift-and-cut biopsy specimen. The tissue is properly oriented perpendicular to the surface and contains mucosa, muscularis mucosae, and submucosa.
DISCUSSION The lift-and-cut biopsy technique allows safe submucosal sampling in the dog. Figure 2 compares biopsy specimens obtained with the 4 mm biopsy forceps, the small lift-and-cut technique, and the large lift-and-cut technique. On section, a well oriented specimen contains mucosa, muscularis mucosae, and submucosa.
REFERENCES
1. UMEDA N, HERRERAAF, MAHoooWH: Gastric biopsy under direct vision:
Figure 2. A comparison of specimens obtained by the 4 mm forceps (top), the small lift-andcut biopsy technique (middle), and the large lift-and-cut biopsy technique (bottom). 30
evaluation of a new instrument and the value of the dissecting microscope. Gastrointestinal Endoscopy 16:135, 1970 2. VENNES lA, SILVIS SE, ONSTAD G: Biopsy applications of a large channel endoscope. Gastrointestinal Endoscopy 21 :197,1975 3. MARTIN T, ONSTAD G, FOLEY W, SILVIS SE, VENNES JA: Endoscopic, histologic and symptomatic evaluation of the postgastrectomy patient. Gastrointestinal Endoscopy 22:230, 1976 (Abstract) 4. OTTENJANN R, LUK G, HENKE M, STRAUCH LM: Big particle biopsy. Endoscopy 5:139, 1973 5. MARTIN TR, ONSTAD G, SILVIS SE, VENNES JA: Experimental bleeding ulcer in the dog: a negative study. Gastrointestinal Endoscopy 22:230, 1976 (Abstract) 6. BLACKWOOD WD, SILVIS SE: Gastroscopic electrosurgery. Gastroenterology 61 :305,1971 GASTROINTESTINAL ENDOSCOPY
G. R. Onstad, MD S. E. Silvis, MD J. A. Vennes, MD Minneapolis, Minnesota
The lift-and-cut biopsy technique is proposed for the evaluation of selected lesions of the gastric submucosa. The safety and success of the procedure is due to the use of a biopsy forceps to raise a pedicle of tissue before snaring and electrocoagulation. When the specimen is properly obtained and oriented for sectioning, the procedure consistently yields submucosa. It may offer an alternative to exploratory laparotomy for the purpose of adequate biopsy.
W hen an
upper gastrointestinal radiograph shows large gastric folds, a problem arises concerning further evaluation of the patient. In the past, a complete workup has often required a laparotomy and full thickness gastric biopsy. In 1969 Umeda described direct visual biopsy of the stomach with the fibergastroscope. Adequate mucosal samples were obtained 85% of the time.' In an effort to obtain submucosa, 2 other techniques have been described. A 4 mm biopsy forceps has been used by Vennes et al. 2 The samples are large enough to be oriented on Gel-foam. We have been able to obtain submucosa 25% of the time with this instrument.' Big particle biopsy, utilizing a polypectomy snare and a single channel endoscope, has been used by Ottenjann et al. 4 Two of 11 samples contained submucosa. The lift-and-cut technique was initially developed to provide a chronic bleeding ulcer model. Because submucosa was noted on each tissue sample, the technique was adapted for biopsy.
This paper describes an endoscopic biopsy technique that offers an alternative to full thickness biopsy in the evaluation of gastric submucosal lesions. METHODS Eighty-one 10 kg to 20 kg mongrel dogs were anesthetized with Nembutal following a 24-hour fast. An endoscope was introduced orally into the stomach. Sideviewing and a forward-viewing 2-channel endoscopes were available for this study. The biopsy technique is shown diagrammatically in this series of pictures. Step 1: A polypectomy snare and a biopsy forceps are introduced into the instrumentation ports. The snare is opened and placed agai nst the mucosa. The forceps is passed through the snare. Step 2: A bite of mucosa is taken. Step 3: A pedicle of tissue is raised by withdrawing the forceps back into the port. Step 4: The snare is closed and the tissue is cut with electrocautery as though it were a pedunculated polyp. The procedure is performed under direct vision at all
.,
...
LIFT AND CUT BIOPSY TECHNIQUE.
&lop54j
5'opl
Forcops
" ::::-
" ""
~
Stq,pZ
"<:::jt::>- Pol~pt.elomy So. ro
Figure 1. Diagrammatic representation of Iift-and-cut biopsy technique. See text for description. From the gastroenterology sections of the Veterans Administration Hospital and Hennepin County Medical Center, Minneapolis, Minnesota. Reprint requests: Thomas R. Martin, MD, Gastroenterology Section, Veterans Administration Hospital, 54th Street & 48th Avenue South, Minneapolis, Minnesota 55407 VOLUME 23, NO.1, 1976
29
Table I. Results of life-and-cut biopsy technique large biopsy (> 1.5 cm)
small biopsy « 1.0 cm)
Number of dogs
69
12
Number of biopsies
79
24
Submucosa obtained Perforations
100% 2 (2.6%)
100% 0
2/25
0
Bleeding
times. Once the pedicle of tissue is cut, the entire instrument is withdrawn with the biopsy retained in the forceps. The samples are oriented of filter paper, fixed in formalin, and submitted for histologic sectioning and staining. When first obtained in the study of an ulcer model, samples were designed to be as large as possible so that the amount of bleeding and the risk of perforation could be estimated. All of these samples had diameters greater than 1.5 cm. They were obtained by placing the snare at the base of the pedicle of tissue before closing it. Samples with diameters less than 1.0 cm were consistently obtained by placing the snare just distal to the forceps at the apex of the pedicle. The animals were sacrificed immediately, during 10 days after the procedure, or followed to complete endoscopic healing. Hematocrits were drawn. Fifty-one animals were anticoagulated with large doses of heparin or coumadin as part of a second study.s RESULTS The results of the technique are shown in Table I. Submucosa was obtained in all of the samples. Although 2 perforations occurred in the animals that had large biopsies, none occurred in the small biopsy group. Two of the animals in the large biopsy group that were not anticoagulated had drops in hematocrit of 10% and 16%, a significant hematocrit drop being defined as a persistent depression of more than 6%. Blood loss was not apparent in any of the small biopsy group. Animals that were not sacrificed were followed to endoscopic healing which occurred by three weeks in most.
We have used the technique in 2 patients. The first patient had a fever of obscure origin and large gastric folds. Gastric lymphoma was considered in the differential diagnosis. The second patient had large gastric folds that involved the greater curve and extended over the distal body to the mid-antrum. He had lost 40 pounds apparently because of depression. Adequate submucosal samples obviated the need for a laparotomy and full thickness gastric biopsy in both cases. The procedures were performed without complications. Although more experience is necessary, it appears that the technique can be used safely in humans. This would be expected insofar as the human and dog gastric mucosa are of si m ilar th ickness. 6 Potential risks include perforation and bleeding. These possible complications can be minimized by keeping the samples as small as possible.
Figure 3. Low power photomicrograph of a lift-and-cut biopsy specimen. The tissue is properly oriented perpendicular to the surface and contains mucosa, muscularis mucosae, and submucosa.
DISCUSSION The lift-and-cut biopsy technique allows safe submucosal sampling in the dog. Figure 2 compares biopsy specimens obtained with the 4 mm biopsy forceps, the small lift-and-cut technique, and the large lift-and-cut technique. On section, a well oriented specimen contains mucosa, muscularis mucosae, and submucosa.
REFERENCES
1. UMEDA N, HERRERAAF, MAHoooWH: Gastric biopsy under direct vision:
Figure 2. A comparison of specimens obtained by the 4 mm forceps (top), the small lift-andcut biopsy technique (middle), and the large lift-and-cut biopsy technique (bottom). 30
evaluation of a new instrument and the value of the dissecting microscope. Gastrointestinal Endoscopy 16:135, 1970 2. VENNES lA, SILVIS SE, ONSTAD G: Biopsy applications of a large channel endoscope. Gastrointestinal Endoscopy 21 :197,1975 3. MARTIN T, ONSTAD G, FOLEY W, SILVIS SE, VENNES JA: Endoscopic, histologic and symptomatic evaluation of the postgastrectomy patient. Gastrointestinal Endoscopy 22:230, 1976 (Abstract) 4. OTTENJANN R, LUK G, HENKE M, STRAUCH LM: Big particle biopsy. Endoscopy 5:139, 1973 5. MARTIN TR, ONSTAD G, SILVIS SE, VENNES JA: Experimental bleeding ulcer in the dog: a negative study. Gastrointestinal Endoscopy 22:230, 1976 (Abstract) 6. BLACKWOOD WD, SILVIS SE: Gastroscopic electrosurgery. Gastroenterology 61 :305,1971 GASTROINTESTINAL ENDOSCOPY