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THE PRE-LOOPED INTRACORPOREAL KNOT: A NEW TECHNIQUE FOR KNOT TYING IN LAPAROSCOPIC SURGERY
0022-5347/01/1661-0195/0 THE JOURNAL OF UROLOGY® Copyright © 2001 by AMERICAN UROLOGICAL ASSOCIATION, INC.®
Vol. 166, 195–197, July 2001 Printed in U.S.A.
THE PRE-LOOPED INTRACORPOREAL KNOT: A NEW TECHNIQUE FOR KNOT TYING IN LAPAROSCOPIC SURGERY YASSINE NOUIRA
AND
ALI HORCHANI
From the Department of Urology, La Rabta Hospital, Tunis, Tunisia
ABSTRACT
Purpose: Intracorporeal knot tying in laparoscopic surgery is time-consuming and difficult to learn. We present a new technique, that we call the pre-looped intracorporeal knot technique, which obviates the difficulties and saves time. Materials and Methods: We devised a homemade suture ring that allows the introduction of the suture thread wrapped on the needle driver and ready for knot tying simply by pulling on both extremities of the thread. Results: Our experience with this technique proved it to be easy to apply and to learn. Conclusions: The prelooped intracorporeal knot technique allies the sophistication of intracorporeal knot tying to the easiness and simplicity of the extracorporeal classic suturing. It renders intracorporeal knotting an easy and rapid task to achieve. KEY WORDS: laparoscopy, suture techniques, endoscopy, sutures, equipment and supplies
With the increasing number of open surgical procedures shifting to laparoscopy, laparoscopic suturing and knot tying are becoming integral parts of the skills that any laparoscopist must acquire. We report a new laparoscopic intracorporeal knot tying technique using a homemade suture ring that enables the introduction of the suture thread wrapped on the needle driver and ready for knot tying, simply by pulling on the ends of the thread. Our new technique avoids difficulty, saves time and is easy to apply and learn.
METHODS
We devised a homemade suture ring that when fitted to the needle driver, enables the introduction of the suture thread wrapped on the needle driver and ready for knot tying simply by pulling on the ends of the thread. Suture ring configuration. The suture ring is a plastic ring with 2 arms mimicking a shark mouth in configuration (fig. 1). The 13 and the 7 mm. arms arise from a plastic ring and function to maintain the suture material wrapped around the needle driver throughout the introductory and suturing phases. The ring arms are directed toward the needle driver extremity with the long arm on the upper and the short arm on the lower aspect of the needle driver. Two triangular notches in opposite directions are tailored distal on the ring arms with 1 each on the right aspect of the long arm and the left aspect of the short arm (fig. 1). These notches allow better maintenance of the suture material on the needle driver. The suture ring is easily configured from a 15 mm. segment of a 16Fr silicone Ne´laton feeding tube. Using a surgical blade, a V-shaped incision is made on each side of the tube segment. The tip of the V is located approximately 2 mm. away from the other end of the tube segment. At this stage a ring with 2 arms is configured. One arm is cut 7 mm. from its origin on the ring to serve as the short arm. A triangular notch is incised distally on the right aspect of the long arm and on the left aspect of the short arm approximately 1 mm. deep. The suture ring is then ready to use. It is fitted to the needle driver 2.5 cm. away from its tip. Knotting technique using the suture ring. A 20 cm. length of suture material is cut. Its tail is secured between the needle driver and the long arm of the suture ring. The suture material Accepted for publication February 23, 2001.
is then rolled twice on the needle driver as well as on the long arm of the suture ring counterclockwise before securing it between the short arm and needle driver. The triangular notch on the short arm helps to maintain the suture material in place (fig. 2). The number of turns of the suture material around the needle driver and long arm determines the configuration of the first half knot. With only 1 turn the first half knot is simple, while 2 turns provide a double half knot, 3 provide a triple half knot and so on. For the purpose of clarity we describe the formation of a surgeon knot. To transfer the suture into the operative field the suture material is grasped by the needle driver jaws proximal to the needle before being introduced through a 10 mm. port. To avoid suture damage, unwrapping of the suture around the needle driver and suture entanglement during passage through the valve mechanism of the port, it is advisable to shield the suture from the valve by a suture introducer. Once in the peritoneal cavity the needle is correctly loaded in the needle driver (fig. 3, A). After the needle passes through the tissues the suture thread is advanced and re-grasped by the needle driver at a short distance from the needle (fig. 3, B). Another needle driver grasps the end of the thread, that is the part secured between the long arm and needle driver (fig. 3, C). This second needle driver is called passive, while the needle driver fitted with the suture ring is called active. By pulling the 2 needle drivers in opposite directions the 2 suture edges are secured by a double half knot (fig. 3, D). Care must be taken to allow a sufficient length of suture material on the needle end to facilitate the subsequent steps.
FIG. 1. Suture ring is cut from 16Fr Ne´laton tube with triangular notches in opposite directions on long and short arms. 195
196
PRE-LOOPED INTRACORPOREAL KNOT
FIG. 2. Suture material is rolled around needle driver fitted with suture ring. Inset shows computer generated image indicating how suture material is rolled on needle driver and suture ring.
To create a second half knot, the needle end of the thread is grasped by the passive needle driver and slid between the long arm of the suture ring and the active needle driver. The triangular notch on the side of the long arm helps to secure the thread in this position (fig. 3, E). The active needle driver is then turned 360 degrees clockwise (fig. 3, F). A sufficient length of thread must have been allowed on the needle end to avoid any pulling on the first double half knot during this wrapping process because otherwise it becomes loose and accurate tissue approximation is jeopardized. The active needle driver is then used to pull on the nonneedle fitted end of the thread, while the passive needle driver pulls on its needle fitted end (fig. 3, G and H). A third flat half knot is tied by repeating the maneuvers used to create the second half knot. To tie a square knot the thread is rolled only once on the active needle driver before being secured on the short arm of the suture ring. The first half knot is single. Tying the second half knot is the same as tying a surgeon knot.
RESULTS
Our early experience with this technique has proved that it is easy and rapid to learn. The suture ring may be tailored rapidly by the surgeon or scrub nurse immediately preoperatively, a process that requires no more than 2 minutes.
DISCUSSION
Intracorporeal knots are instrument ties performed completely within the body cavity at the operative site. Although similar in many respects to instrument tied knots in open surgery, they require the same skills as in microsurgical knot tying since each involves a magnified field, restricted work space, absent normal binocular vision, limited degree of freedom and eye-to-hand coordination challenges due to disconnecting the visual and motor axes of the operator.1 In an experimental study involving intracorporeal knotting the task efficiency of experienced surgeons was decreased more than 50% when the exercise was performed via endoscopy using a television monitor in contrast to direct vision.2 By introducing the suture material pre-looped
FIG. 3. Steps of knot tying process aided by suture ring
around the needle driver a great economy of movement and time is realized at this critical step. Grasping and pulling the ends of the thread is an easy task for which 3-dimensional vision has no superiority over 2-dimensional vision. Slippery or stiff suture materials usually require the first half knot to be tripled or even quadrupled.1 These multiple half knots are also interesting in the approximation of tissue edges under mild tension. The contact surface and friction of the threads are thereby increased and the holding force of the initial half knot is enough to maintain the tissue edges approximated while the subsequent half knots are tied. This task involves rolling the suture material 3 or 4 times around the needle driver. When performed intracorporeally, it is difficult and demands a great deal of concentration and expertise. In our technique the suture material is rolled around the suturing instrument extracorporeally and it is as easy to tie a simple half as it is a triple or quadruple knot. In this respect our technique combines the sophistication of intracorporeal knot tying with the ease and simplicity of extracorporeal knotting. No further expertise is needed to tie an initial double, triple or even quadruple half knot. Introducing the suture material pre-looped and maintained by the suture ring prevents entanglement because the thread ends are not free from the time of introduction through the port site to the time that the first half knot is tied. Thus, much confusion and time wasted in reorganizing the surgical site due to thread entanglement are avoided. Although our technique may be applied with no modifications to laparoscopic needle holder design, we may suggest some
197
PRE-LOOPED INTRACORPOREAL KNOT
alterations to these instruments by incorporating the suture ring that we devised.
CONCLUSIONS
Our laparoscopic intracorporeal pre-looped knot technique renders intracorporeal knot tying an easy and rapid task. It is simple to apply and cost-free.
REFERENCES
1. Cushieri, A. and Szabo, Z.: Intracorporeal knots in endoscopic surgery. In: Tissue Approximation in Endoscopic Surgery. Oxford, United Kingdom: Isis Medical Media, chapt. 4, p. 42, 1995 2. Crosthwaite, G., Chung, T., Dunkley, P. et al: Comparison of direct vision and electronic two and three-dimensional display systems on surgical task efficiency in endoscopic surgery. Br J Surg, 82: 849, 1995
Vol. 166, 195–197, July 2001 Printed in U.S.A.
THE PRE-LOOPED INTRACORPOREAL KNOT: A NEW TECHNIQUE FOR KNOT TYING IN LAPAROSCOPIC SURGERY YASSINE NOUIRA
AND
ALI HORCHANI
From the Department of Urology, La Rabta Hospital, Tunis, Tunisia
ABSTRACT
Purpose: Intracorporeal knot tying in laparoscopic surgery is time-consuming and difficult to learn. We present a new technique, that we call the pre-looped intracorporeal knot technique, which obviates the difficulties and saves time. Materials and Methods: We devised a homemade suture ring that allows the introduction of the suture thread wrapped on the needle driver and ready for knot tying simply by pulling on both extremities of the thread. Results: Our experience with this technique proved it to be easy to apply and to learn. Conclusions: The prelooped intracorporeal knot technique allies the sophistication of intracorporeal knot tying to the easiness and simplicity of the extracorporeal classic suturing. It renders intracorporeal knotting an easy and rapid task to achieve. KEY WORDS: laparoscopy, suture techniques, endoscopy, sutures, equipment and supplies
With the increasing number of open surgical procedures shifting to laparoscopy, laparoscopic suturing and knot tying are becoming integral parts of the skills that any laparoscopist must acquire. We report a new laparoscopic intracorporeal knot tying technique using a homemade suture ring that enables the introduction of the suture thread wrapped on the needle driver and ready for knot tying, simply by pulling on the ends of the thread. Our new technique avoids difficulty, saves time and is easy to apply and learn.
METHODS
We devised a homemade suture ring that when fitted to the needle driver, enables the introduction of the suture thread wrapped on the needle driver and ready for knot tying simply by pulling on the ends of the thread. Suture ring configuration. The suture ring is a plastic ring with 2 arms mimicking a shark mouth in configuration (fig. 1). The 13 and the 7 mm. arms arise from a plastic ring and function to maintain the suture material wrapped around the needle driver throughout the introductory and suturing phases. The ring arms are directed toward the needle driver extremity with the long arm on the upper and the short arm on the lower aspect of the needle driver. Two triangular notches in opposite directions are tailored distal on the ring arms with 1 each on the right aspect of the long arm and the left aspect of the short arm (fig. 1). These notches allow better maintenance of the suture material on the needle driver. The suture ring is easily configured from a 15 mm. segment of a 16Fr silicone Ne´laton feeding tube. Using a surgical blade, a V-shaped incision is made on each side of the tube segment. The tip of the V is located approximately 2 mm. away from the other end of the tube segment. At this stage a ring with 2 arms is configured. One arm is cut 7 mm. from its origin on the ring to serve as the short arm. A triangular notch is incised distally on the right aspect of the long arm and on the left aspect of the short arm approximately 1 mm. deep. The suture ring is then ready to use. It is fitted to the needle driver 2.5 cm. away from its tip. Knotting technique using the suture ring. A 20 cm. length of suture material is cut. Its tail is secured between the needle driver and the long arm of the suture ring. The suture material Accepted for publication February 23, 2001.
is then rolled twice on the needle driver as well as on the long arm of the suture ring counterclockwise before securing it between the short arm and needle driver. The triangular notch on the short arm helps to maintain the suture material in place (fig. 2). The number of turns of the suture material around the needle driver and long arm determines the configuration of the first half knot. With only 1 turn the first half knot is simple, while 2 turns provide a double half knot, 3 provide a triple half knot and so on. For the purpose of clarity we describe the formation of a surgeon knot. To transfer the suture into the operative field the suture material is grasped by the needle driver jaws proximal to the needle before being introduced through a 10 mm. port. To avoid suture damage, unwrapping of the suture around the needle driver and suture entanglement during passage through the valve mechanism of the port, it is advisable to shield the suture from the valve by a suture introducer. Once in the peritoneal cavity the needle is correctly loaded in the needle driver (fig. 3, A). After the needle passes through the tissues the suture thread is advanced and re-grasped by the needle driver at a short distance from the needle (fig. 3, B). Another needle driver grasps the end of the thread, that is the part secured between the long arm and needle driver (fig. 3, C). This second needle driver is called passive, while the needle driver fitted with the suture ring is called active. By pulling the 2 needle drivers in opposite directions the 2 suture edges are secured by a double half knot (fig. 3, D). Care must be taken to allow a sufficient length of suture material on the needle end to facilitate the subsequent steps.
FIG. 1. Suture ring is cut from 16Fr Ne´laton tube with triangular notches in opposite directions on long and short arms. 195
196
PRE-LOOPED INTRACORPOREAL KNOT
FIG. 2. Suture material is rolled around needle driver fitted with suture ring. Inset shows computer generated image indicating how suture material is rolled on needle driver and suture ring.
To create a second half knot, the needle end of the thread is grasped by the passive needle driver and slid between the long arm of the suture ring and the active needle driver. The triangular notch on the side of the long arm helps to secure the thread in this position (fig. 3, E). The active needle driver is then turned 360 degrees clockwise (fig. 3, F). A sufficient length of thread must have been allowed on the needle end to avoid any pulling on the first double half knot during this wrapping process because otherwise it becomes loose and accurate tissue approximation is jeopardized. The active needle driver is then used to pull on the nonneedle fitted end of the thread, while the passive needle driver pulls on its needle fitted end (fig. 3, G and H). A third flat half knot is tied by repeating the maneuvers used to create the second half knot. To tie a square knot the thread is rolled only once on the active needle driver before being secured on the short arm of the suture ring. The first half knot is single. Tying the second half knot is the same as tying a surgeon knot.
RESULTS
Our early experience with this technique has proved that it is easy and rapid to learn. The suture ring may be tailored rapidly by the surgeon or scrub nurse immediately preoperatively, a process that requires no more than 2 minutes.
DISCUSSION
Intracorporeal knots are instrument ties performed completely within the body cavity at the operative site. Although similar in many respects to instrument tied knots in open surgery, they require the same skills as in microsurgical knot tying since each involves a magnified field, restricted work space, absent normal binocular vision, limited degree of freedom and eye-to-hand coordination challenges due to disconnecting the visual and motor axes of the operator.1 In an experimental study involving intracorporeal knotting the task efficiency of experienced surgeons was decreased more than 50% when the exercise was performed via endoscopy using a television monitor in contrast to direct vision.2 By introducing the suture material pre-looped
FIG. 3. Steps of knot tying process aided by suture ring
around the needle driver a great economy of movement and time is realized at this critical step. Grasping and pulling the ends of the thread is an easy task for which 3-dimensional vision has no superiority over 2-dimensional vision. Slippery or stiff suture materials usually require the first half knot to be tripled or even quadrupled.1 These multiple half knots are also interesting in the approximation of tissue edges under mild tension. The contact surface and friction of the threads are thereby increased and the holding force of the initial half knot is enough to maintain the tissue edges approximated while the subsequent half knots are tied. This task involves rolling the suture material 3 or 4 times around the needle driver. When performed intracorporeally, it is difficult and demands a great deal of concentration and expertise. In our technique the suture material is rolled around the suturing instrument extracorporeally and it is as easy to tie a simple half as it is a triple or quadruple knot. In this respect our technique combines the sophistication of intracorporeal knot tying with the ease and simplicity of extracorporeal knotting. No further expertise is needed to tie an initial double, triple or even quadruple half knot. Introducing the suture material pre-looped and maintained by the suture ring prevents entanglement because the thread ends are not free from the time of introduction through the port site to the time that the first half knot is tied. Thus, much confusion and time wasted in reorganizing the surgical site due to thread entanglement are avoided. Although our technique may be applied with no modifications to laparoscopic needle holder design, we may suggest some
197
PRE-LOOPED INTRACORPOREAL KNOT
alterations to these instruments by incorporating the suture ring that we devised.
CONCLUSIONS
Our laparoscopic intracorporeal pre-looped knot technique renders intracorporeal knot tying an easy and rapid task. It is simple to apply and cost-free.
REFERENCES
1. Cushieri, A. and Szabo, Z.: Intracorporeal knots in endoscopic surgery. In: Tissue Approximation in Endoscopic Surgery. Oxford, United Kingdom: Isis Medical Media, chapt. 4, p. 42, 1995 2. Crosthwaite, G., Chung, T., Dunkley, P. et al: Comparison of direct vision and electronic two and three-dimensional display systems on surgical task efficiency in endoscopic surgery. Br J Surg, 82: 849, 1995