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An endoscopic sewing machine
An endoscopic sewing machine
c. Paul Swain, MD Timothy N. Mills, PhD
The availability of an endoscopically controlled sewing machine might enable endoscopists to perform a range of new internal surgical procedures without having to make an external incision in the patient. The problems involved in the design of such a machine are not trivial. There is access to only one side of the tissue. The suture depth must be precisely controlled to limit the risk of damaging other organs. Tissue is poorly supported. The machine must operate in the presence of mucus, blood, and acid. Power to and control of the machine is restricted to two smalldiameter biopsy channels. The machine has to be small enough to swallow. This study reports the design and construction of an endoscopic sewing machine (Figs. 1 and 2; Fig. 2 is on page 38) and its testing in the human cadaveric stomach and esophagus. Survival studies in dogs are also described. MATERIALS AND METHODS
The body of the sewing machine was formed from a solid rod of transparent Perspex, 14 mm in diameter and 38 mm long. Two cavities were machined into the side of the body. The dimensions of one cavity were chosen so that a small fold of tissue could be sucked into it and pierced by a threaded needle running in a hole drilled through the length of the body. The other cavity housed a mechanism comprising a hook and sprung shoe designed to catch the loop of thread once the needle had pierced the tissue. Both the needle and the catch mechanism were actuated by wires running through the biopsy channels of a standard twochannel endoscope. The machine operates as follows. The machine is positioned as shown in Figure 2A above a layer of tissue in which stitches are to be formed. As shown in Figure 2B, suction is then applied through the machine to suck into the slot a double layer of tissue. The shape and depth of the slot controls the volume and depth of tissue which is sucked in. The needle is then forced forward carrying a loop of thread held in the eye of the needle through the double layer of tissue. The tip of the needle strikes the sprung shoe which is caused to pivot down against the biasing force of the spring of the shoe. The control wire is then pulled to cause the hook to pivot so as to catch the loop of thread carried by the eye of the needle. The head portion of the needle has a groove formed in it to allow the hook to pass between the needle and the thread. The needle is then withdrawn, leaving the loop of thread held between the hook and the shoe. Suction is then released to allow the double layer of tissue to leave the slot. As shown in Figure 2C, the effect of these steps is to pass a loop of From the Department of Medu:al Physu:s and Bioengineering, University College Hospital, the Norman Tanner Gastroenterology Unit, St. James's Hospital and St. George's Hospital, London, England. Reprint requests: Department of Medical Physics and Bioengineering, University College Hospital, Shropshire House, 11-20 Capper Street, London, WCIE 6JA England. 36
thread from one side of the tissue through the tissue at a first position and back out of the tissue on the same side at a second position, a controlled distance from the first position. This is achieved without requiring access to the opposite or serosal side of the tissue which would be endoscopically inaccessible under normal circumstances. The machine is then moved to the site of the next stitch, suction is then reapplied, and the needle passes through a double layer of tissue at a different point. The forward end of the needle passes through the loop of thread caught between the hook and the shoe, carrying a new loop of thread with it. To assist this process a small groove was formed in the upper surface of the shoe in which the tip of the needle may slide. This enables the needle to pass under the loop of thread already caught between the hook and shoe, without the risk that the needle may simply push the existing loop further up the surface of the shoe. Once the needle has placed the second loop through the first loop, the hook is pivoted by pushing on the control wire to allow the first loop to be cast off by pulling on the thread. The hook is then pivoted downward by pushing on the control wire, the hook passing between needle and thread, so that the second loop of thread is caught before the needle is withdrawn. In this way a chain of stitches is formed as indicated in Figure 2D in which each of the loops formed by the hook and the shoe passes through the preceding loop. The body of the sewing machine is preferably made of a transparent material so as to make it easier for the operator to see and hence control the operation of the machine. The flexible control cables can pass down the channel of an existing endoscope or the machine can be used independently with a small supervising endoscope passed in parallel with the control channel of the machine.
RESULTS
Rows of chain stitches have been formed using this machine at endoscopy in the stomach and esophagus of 18 human cadavers (Fig. 3). A modular design of an endoscopic sewing machine (Fig. 4), having interchangeable cavity sizes to provide adjustment of suture length and depth, has been used to form single and chains of stitches at the cardioesophageal junction and stomach in survival studies in dogs at endoscopy with and without laparotomy. The machine has been used without laparotomy to sew nasogastric tubes into the dog stomach and to leave marker stitches to indicate the site of gastric ulcers and lesions. It was effective at endoscopy in terminating bleeding from 9 of 10 acute experimental bleeding ulcers in canine submucosa. Nasogastric tubes were sewn into the stomach by passing the sewing machine into the canine gastric antrum, sucking a polyp of tissue into the cavity of the machine, passing a threaded needle through this artificially formed polyp and catching the loop of thread with the catch mechanism, then withdrawing the needle and releasing the suction so that a single loop of thread has passed from one mucosal point through the muscularis propria to emerge at a mucosal GASTROINTESTINAL ENDOSCOPY
Figure 1. A prototype endoscopic sewing machine of transparent Perspex, showing needle, thread, hooked catch mechanism, and endoscope. Figure 3. A chain of stitches formed in the postmortem human stomach with the machine. The control wires and the suction tubing may be seen. Figure 4. The modular design of the sewing machine seen with hand controls and a two-channel endoscope. Figure 5. An endoscopically positioned sewing machine stitch is formed in the canine stomach at laparotomy.
point a short distance from the first point of entry. The machine is then withdrawn through the mouth pulling the loop of thread through the tissue until the threads passing through the polyp can be detached at the mouth from the sewing machine. The thread is then passed through a hole in the distal tip of the . nasogastric tube, knotted and pulled into position by gentle traction on the other end of the thread. The tube is secured by running a knot to the mucosal surface over the loose thread or can be tied to the proximal end of the nasogastric tube so that the tie can be released without requiring another endoscopy to cut the thread. Acute ulcers of I-em diameter were formed with a suction biopsy (Quinton ulcer maker) in canine mucosa. These ulcers were then oversewn using the endoscopic sewing machine. The machine was positioned over the ulcer and the whole ulcer was sucked into the VOLUME 32, NO.1, 1986
machine's cavity. The suction pressure exerted by the machine on the ulcer was usually able to terminate bleeding in these ulcers. The threaded needle was then passed from one side of the ulcer through the muscularis propria or serosal level to appear at the other side of the ulcer. The loop of thread was then caught and the ulcer was oversewn, terminating the bleeding by compressing the bleeding vessels with single or a chain of stitches which were subsequently tied at endoscopy. DISCUSSION
This study has shown that a machine sewing under flexible endoscopic control is feasible in the gastrointestinal tract. The clinical value, if any, of such a method can only be established by empiric clinical study. Potential medical uses of such machines could conceivably in37
1M :=E3l
CATCH MECHANISM
ENDOSCOPE
4
[J;:UCTION
A
'
00''"0' : . ' "
~TI;:::AD ~
SUCTION ON
~~:: SUCTION OFF
c
.'
..
. ..
'.
Figure 2. The mechanism of the endoscopic sewing machine. A, The sewing machine and its relationship to the endoscope is shown indicating the tissue, needle, thread, catch mechanism, and control wires. B, A fold of tissue is sucked into a cavity while a threaded needle pierces the double layer of tissue. C, The catch mechanism retains the loop of thread which has passed through the tissue. D, A row of chain stitches is formed in the tissue by the machine.
Hydrostatic balloon dilation of a terminal il~al stricture secondary to Crohn's disease R. A. Brower, MD
The Gruntzig balloon catheter has been used for several years in the management of vascular stenoses.! Recently, there have been favorable results using similarly designed catheters to deal with gastrointestinal From the Internal Department, Gastroenterology Division, and the Clinical Investigation Department, Naval Hospital, San Diego, California. Reprint requests: LCDR R. A. Brower, MC, USNR, c/o Clinical Investigation Department, Naval Hospital, San Diego, California 92134. The opinions or assertions expressed in this paper are those of the author and are not to be construed as official or as necessarily reflecting the views of the Department of the Navy or the naval service at large. 38
elude the oversewing of bleeding or perforated ulcers, the oversewing of bleeding varices, the narrowing of lax anatomical sphincters or organs, the elosure of internal holes or fistulae, the assistance in the removal of normal or abnormal tissue, and the attachment of materials or objects to the walls of tissue (for example, for attaching gastric tubes for feeding purposes to the wall of the stomach, or for attaching x-ray opaque markers to mark the site of a cancer, or for attaching a piece of material containing a drug to permit localized internal treatment). The method of machine sewing as described here has limitations and requires further development. It can be difficult at endoscopy to place the sewing machine cavity precisely over the desired area. Methods for tying knots under endoscopic control need to be made more rapid and secure. This machine works most effectively on gastrointestinal tissue of normal compliance and may be less effective in the presence of scar tissue. There are three basic technical aspects to surgery: cutting, controlling bleeding, and joining together living tissue to materials or other living tissues. There have been striking advances in endoscopic surgical techniques of cutting and controlling bleeding. We hope that this development of a prototype endoscopic sewing machine might stimulate further study of endoscopic methods of joining living tissue to materials or other living tissues in the pursuit of the goal of less invasive but effective surgery. ACKNOWLEDGMENT
This work was supported by a grant from the Trustees of St. George's Hospital, London.
strictures of diverse etiologies. Successful dilations of esophageal strictures,2,3 pyloric outlet obstructions,4,5 biliary and pancreatic strictures,G.7 postgastric stapling syndrome,S and colorectal strictures9 have all appeared in the literature. The application of a balloon catheter in the treatment of a symptomatic terminal ileal stricture secondary to Crohn's disease is reported. CASE REPORT
A 24-year-old woman initially presented for medical attention 5 years previously with watery diarrhea, cramping abdominal pain, nausea, and distension. Evaluation at that time demonstrated radiographic abnormalities compatible with Crohn's disease confined to the terminal ileum. She was started on high dose corticosteroids, initially as an outpatient, then later as an inpatient in association with bowel rest. This treatment resulted in marginal improvement, but severe steroid-related side effects led to discontinGASTROINTESTINAL ENDOSCOPY
c. Paul Swain, MD Timothy N. Mills, PhD
The availability of an endoscopically controlled sewing machine might enable endoscopists to perform a range of new internal surgical procedures without having to make an external incision in the patient. The problems involved in the design of such a machine are not trivial. There is access to only one side of the tissue. The suture depth must be precisely controlled to limit the risk of damaging other organs. Tissue is poorly supported. The machine must operate in the presence of mucus, blood, and acid. Power to and control of the machine is restricted to two smalldiameter biopsy channels. The machine has to be small enough to swallow. This study reports the design and construction of an endoscopic sewing machine (Figs. 1 and 2; Fig. 2 is on page 38) and its testing in the human cadaveric stomach and esophagus. Survival studies in dogs are also described. MATERIALS AND METHODS
The body of the sewing machine was formed from a solid rod of transparent Perspex, 14 mm in diameter and 38 mm long. Two cavities were machined into the side of the body. The dimensions of one cavity were chosen so that a small fold of tissue could be sucked into it and pierced by a threaded needle running in a hole drilled through the length of the body. The other cavity housed a mechanism comprising a hook and sprung shoe designed to catch the loop of thread once the needle had pierced the tissue. Both the needle and the catch mechanism were actuated by wires running through the biopsy channels of a standard twochannel endoscope. The machine operates as follows. The machine is positioned as shown in Figure 2A above a layer of tissue in which stitches are to be formed. As shown in Figure 2B, suction is then applied through the machine to suck into the slot a double layer of tissue. The shape and depth of the slot controls the volume and depth of tissue which is sucked in. The needle is then forced forward carrying a loop of thread held in the eye of the needle through the double layer of tissue. The tip of the needle strikes the sprung shoe which is caused to pivot down against the biasing force of the spring of the shoe. The control wire is then pulled to cause the hook to pivot so as to catch the loop of thread carried by the eye of the needle. The head portion of the needle has a groove formed in it to allow the hook to pass between the needle and the thread. The needle is then withdrawn, leaving the loop of thread held between the hook and the shoe. Suction is then released to allow the double layer of tissue to leave the slot. As shown in Figure 2C, the effect of these steps is to pass a loop of From the Department of Medu:al Physu:s and Bioengineering, University College Hospital, the Norman Tanner Gastroenterology Unit, St. James's Hospital and St. George's Hospital, London, England. Reprint requests: Department of Medical Physics and Bioengineering, University College Hospital, Shropshire House, 11-20 Capper Street, London, WCIE 6JA England. 36
thread from one side of the tissue through the tissue at a first position and back out of the tissue on the same side at a second position, a controlled distance from the first position. This is achieved without requiring access to the opposite or serosal side of the tissue which would be endoscopically inaccessible under normal circumstances. The machine is then moved to the site of the next stitch, suction is then reapplied, and the needle passes through a double layer of tissue at a different point. The forward end of the needle passes through the loop of thread caught between the hook and the shoe, carrying a new loop of thread with it. To assist this process a small groove was formed in the upper surface of the shoe in which the tip of the needle may slide. This enables the needle to pass under the loop of thread already caught between the hook and shoe, without the risk that the needle may simply push the existing loop further up the surface of the shoe. Once the needle has placed the second loop through the first loop, the hook is pivoted by pushing on the control wire to allow the first loop to be cast off by pulling on the thread. The hook is then pivoted downward by pushing on the control wire, the hook passing between needle and thread, so that the second loop of thread is caught before the needle is withdrawn. In this way a chain of stitches is formed as indicated in Figure 2D in which each of the loops formed by the hook and the shoe passes through the preceding loop. The body of the sewing machine is preferably made of a transparent material so as to make it easier for the operator to see and hence control the operation of the machine. The flexible control cables can pass down the channel of an existing endoscope or the machine can be used independently with a small supervising endoscope passed in parallel with the control channel of the machine.
RESULTS
Rows of chain stitches have been formed using this machine at endoscopy in the stomach and esophagus of 18 human cadavers (Fig. 3). A modular design of an endoscopic sewing machine (Fig. 4), having interchangeable cavity sizes to provide adjustment of suture length and depth, has been used to form single and chains of stitches at the cardioesophageal junction and stomach in survival studies in dogs at endoscopy with and without laparotomy. The machine has been used without laparotomy to sew nasogastric tubes into the dog stomach and to leave marker stitches to indicate the site of gastric ulcers and lesions. It was effective at endoscopy in terminating bleeding from 9 of 10 acute experimental bleeding ulcers in canine submucosa. Nasogastric tubes were sewn into the stomach by passing the sewing machine into the canine gastric antrum, sucking a polyp of tissue into the cavity of the machine, passing a threaded needle through this artificially formed polyp and catching the loop of thread with the catch mechanism, then withdrawing the needle and releasing the suction so that a single loop of thread has passed from one mucosal point through the muscularis propria to emerge at a mucosal GASTROINTESTINAL ENDOSCOPY
Figure 1. A prototype endoscopic sewing machine of transparent Perspex, showing needle, thread, hooked catch mechanism, and endoscope. Figure 3. A chain of stitches formed in the postmortem human stomach with the machine. The control wires and the suction tubing may be seen. Figure 4. The modular design of the sewing machine seen with hand controls and a two-channel endoscope. Figure 5. An endoscopically positioned sewing machine stitch is formed in the canine stomach at laparotomy.
point a short distance from the first point of entry. The machine is then withdrawn through the mouth pulling the loop of thread through the tissue until the threads passing through the polyp can be detached at the mouth from the sewing machine. The thread is then passed through a hole in the distal tip of the . nasogastric tube, knotted and pulled into position by gentle traction on the other end of the thread. The tube is secured by running a knot to the mucosal surface over the loose thread or can be tied to the proximal end of the nasogastric tube so that the tie can be released without requiring another endoscopy to cut the thread. Acute ulcers of I-em diameter were formed with a suction biopsy (Quinton ulcer maker) in canine mucosa. These ulcers were then oversewn using the endoscopic sewing machine. The machine was positioned over the ulcer and the whole ulcer was sucked into the VOLUME 32, NO.1, 1986
machine's cavity. The suction pressure exerted by the machine on the ulcer was usually able to terminate bleeding in these ulcers. The threaded needle was then passed from one side of the ulcer through the muscularis propria or serosal level to appear at the other side of the ulcer. The loop of thread was then caught and the ulcer was oversewn, terminating the bleeding by compressing the bleeding vessels with single or a chain of stitches which were subsequently tied at endoscopy. DISCUSSION
This study has shown that a machine sewing under flexible endoscopic control is feasible in the gastrointestinal tract. The clinical value, if any, of such a method can only be established by empiric clinical study. Potential medical uses of such machines could conceivably in37
1M :=E3l
CATCH MECHANISM
ENDOSCOPE
4
[J;:UCTION
A
'
00''"0' : . ' "
~TI;:::AD ~
SUCTION ON
~~:: SUCTION OFF
c
.'
..
. ..
'.
Figure 2. The mechanism of the endoscopic sewing machine. A, The sewing machine and its relationship to the endoscope is shown indicating the tissue, needle, thread, catch mechanism, and control wires. B, A fold of tissue is sucked into a cavity while a threaded needle pierces the double layer of tissue. C, The catch mechanism retains the loop of thread which has passed through the tissue. D, A row of chain stitches is formed in the tissue by the machine.
Hydrostatic balloon dilation of a terminal il~al stricture secondary to Crohn's disease R. A. Brower, MD
The Gruntzig balloon catheter has been used for several years in the management of vascular stenoses.! Recently, there have been favorable results using similarly designed catheters to deal with gastrointestinal From the Internal Department, Gastroenterology Division, and the Clinical Investigation Department, Naval Hospital, San Diego, California. Reprint requests: LCDR R. A. Brower, MC, USNR, c/o Clinical Investigation Department, Naval Hospital, San Diego, California 92134. The opinions or assertions expressed in this paper are those of the author and are not to be construed as official or as necessarily reflecting the views of the Department of the Navy or the naval service at large. 38
elude the oversewing of bleeding or perforated ulcers, the oversewing of bleeding varices, the narrowing of lax anatomical sphincters or organs, the elosure of internal holes or fistulae, the assistance in the removal of normal or abnormal tissue, and the attachment of materials or objects to the walls of tissue (for example, for attaching gastric tubes for feeding purposes to the wall of the stomach, or for attaching x-ray opaque markers to mark the site of a cancer, or for attaching a piece of material containing a drug to permit localized internal treatment). The method of machine sewing as described here has limitations and requires further development. It can be difficult at endoscopy to place the sewing machine cavity precisely over the desired area. Methods for tying knots under endoscopic control need to be made more rapid and secure. This machine works most effectively on gastrointestinal tissue of normal compliance and may be less effective in the presence of scar tissue. There are three basic technical aspects to surgery: cutting, controlling bleeding, and joining together living tissue to materials or other living tissues. There have been striking advances in endoscopic surgical techniques of cutting and controlling bleeding. We hope that this development of a prototype endoscopic sewing machine might stimulate further study of endoscopic methods of joining living tissue to materials or other living tissues in the pursuit of the goal of less invasive but effective surgery. ACKNOWLEDGMENT
This work was supported by a grant from the Trustees of St. George's Hospital, London.
strictures of diverse etiologies. Successful dilations of esophageal strictures,2,3 pyloric outlet obstructions,4,5 biliary and pancreatic strictures,G.7 postgastric stapling syndrome,S and colorectal strictures9 have all appeared in the literature. The application of a balloon catheter in the treatment of a symptomatic terminal ileal stricture secondary to Crohn's disease is reported. CASE REPORT
A 24-year-old woman initially presented for medical attention 5 years previously with watery diarrhea, cramping abdominal pain, nausea, and distension. Evaluation at that time demonstrated radiographic abnormalities compatible with Crohn's disease confined to the terminal ileum. She was started on high dose corticosteroids, initially as an outpatient, then later as an inpatient in association with bowel rest. This treatment resulted in marginal improvement, but severe steroid-related side effects led to discontinGASTROINTESTINAL ENDOSCOPY