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Laparoscopic Suturing Evaluation among Surgical Residents
Journal of Surgical Research 93, 133–136 (2000) doi:10.1006/jsre.2000.5969, available online at http://www.idealibrary.com on
Laparoscopic Suturing Evaluation among Surgical Residents Ninh T. Nguyen, M.D., 1 Kathrin L. Mayer, M.D., Richard J. Bold, M.D., Mike Larson, B.S., Samia Foster, M.D., Hung S. Ho, M.D., and Bruce M. Wolfe, M.D. Department of Surgery, University of California, Davis, Health System, Sacramento, California 95817 Submitted for publication March 20, 2000
Background. Laparoscopic suturing is an integral part of advanced laparoscopic surgery training. The objective of this study was to evaluate the performance and preference of surgical residents performing intracorporeal and extracorporeal knot-tying techniques using conventional and Endo Stitch instruments. The residents were also evaluated on their suturing techniques using conventional instruments, the Endo Stitch, and the Suture Assistant. Methods. Using an inanimate laparoscopic trainer model, 39 residents were evaluated as they performed laparoscopic knot tying exercises. Endpoints of the study were execution time and subjective preference of surgical residents with respect to the type of instrument used for knot tying. Forty-three residents were evaluated as they performed laparoscopic suturing exercises with three different types of suturing instruments using the same endpoints. Results. The intracorporeal technique was the preferred (89%) method of knot tying among surgical residents. The time for completion of laparoscopic suturing was significantly (P < 0.05) shorter with the Endo Stitch (114 ⴞ 64 s) than with the conventional instrument (206 ⴞ 107 s) or the Suture Assistant (151 ⴞ 70 s). Residents preferred the use of the Endo Stitch in all three categories for suturing, knot tying, and handling. Conclusion. The Endo Stitch enhanced laparoscopic skills and was the preferred instrument for laparoscopic knot tying and suturing among surgical residents. © 2000 Academic Press Presented in part at the Annual Meeting of the Association for Academic Surgery, Philadelphia, Pennsylvania, November 18 –20, 1999. 1 To whom reprint requests and correspondence should be addressed: Ninh T. Nguyen, M.D., Division of Gastrointestinal Surgery, Department of Surgery, 2221 Stockton Boulevard, Third Floor, Sacramento, CA 95817-1418. Fax: (916) 734-3951. E-mail: [email protected].
Key Words: laparoscopic surgery; education; resident training; surgical skills. INTRODUCTION
Laparoscopic suturing is an important technical skill needed for advanced laparoscopic surgery training. This skill is required to perform all complex laparoscopic operations. The two components of laparoscopic suturing are tissue penetration with the needle and knot tying. Laparoscopic suturing has been commonly performed using the conventional laparoscopic instrument (needle holder and grasper) [1– 4], but its use by inexperienced laparoscopists or surgical residents is limited by the difficulty in handling of tissue, the precise control of the needle, and the time-consuming knot-tying task. Advances in minimally invasive surgery with introduction of new instrumentation for laparoscopic suturing can possibly simplify suturing and reduce suturing time. The Endo Stitch (United States Surgical Corp., Norwalk, CT) and Suture Assistant (Ethicon Endosurgery, Cincinnati, OH) were designed to facilitate laparoscopic suturing. The Endo Stitch has the ability to transfer a straight needle from one arm of the device to the second arm and therefore facilitates knot tying. In addition, the needle is directly mounted onto the tip of the instrument and therefore reduces the need for needle positioning. The Suture Assistant consists of a ski needle and suture attached to a pretied knot. Its use requires conventional needle positioning and approximation of the tissue, but the knot-tying task is performed by deploying a pretied Duraknot equivalent to five alternating half-hitches. The Endo Stitch and Suture Assistant can theoretically enhance laparoscopic suturing by reducing the technical difficulty in positioning of the needle, help with tissue suturing, and facilitate knot tying. These instruments compared to
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0022-4804/00 $35.00 Copyright © 2000 by Academic Press All rights of reproduction in any form reserved.
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JOURNAL OF SURGICAL RESEARCH: VOL. 93, NO. 1, SEPTEMBER 2000
conventional instruments, can potentially improve laparoscopic suturing time. The goal of this study was to evaluate the performance and preference among surgical residents for knot tying and suturing using three different types of instrumentation.
METHODS
Surgical residents attended two inanimate laboratory sessions for training in laparoscopic suturing. Session 1 consisted of a 20-min introduction to laparoscopic knot tying. Proper use of the Endo Stitch and proper use of the conventional laparoscopic needle holder were the two techniques taught. Both intracorporeal and extracorporeal knot-tying techniques were examined. In session 2, a 20-min introduction to laparoscopic suturing technique was presented. Residents were instructed in the proper use of the Endo Stitch, Suture Assistant, and laparoscopic needle holder. A faculty member demonstrated laparoscopic suturing techniques using all three different instruments. Residents were allowed 1 h of practice time during each session. Residents worked in pairs at four inanimate stations, taking turns practicing with the three types of laparoscopic suturing instruments. Faculty assistance was available at each inanimate station. An evaluation was performed at the conclusion of each session. Session 1: Laparoscopic knot-tying drill. Thirty-nine surgical residents were evaluated as they performed a laparoscopic knot-tying drill. There were 24 junior (postgraduate years 1 and 2) and 15 senior (postgraduate years 3– 6) residents. The knot-tying task involved needle penetration of the tissue and tying four knots using intracorporeal or extracorporeal techniques. The tasks were recorded in seconds. Residents were then asked to rate their preferred technique of knot tying: the conventional laparoscopic needle holder or the Endo Stitch. The Suture Assistant was not evaluated in this session because this instrument deploys a pretied Duraknot and does not require knot tying skills. Extracorporeal knots were tied outside the trainer box and secured with a knot pusher. Knot-tying time was recorded on tissue penetration of the needle and ended on completion of four knots. The time for positioning of the needle in the needle driver was not recorded. Surgical residents were asked to record their preference of knot tying technique (intracorporeal vs extracorporeal) and instrument used for knot tying (conventional vs Endo Stitch). Session 2: Laparoscopic suturing drill. Forty-three surgical residents participated in the laparoscopic suturing exercise drill 1 month after session 1. There were 26 junior and 17 senior residents. Laparoscopic suturing was performed using three different types of laparoscopic suturing instruments: conventional, Endo Stitch, and Suture Assistant. Laparoscopic suturing consisted of needle positioning, tissue penetration of the needle, and creation of four intracorporeal knots. The length of time to perform the laparoscopic suturing task was recorded in seconds on insertion of the laparoscopic suturing instrument into the cannula and ended on completion of four intracorporeal knots. At the end of the laboratory session, residents were asked to record their preference among the three instruments with respect to suturing, knot tying, and handling of instruments, as well as overall instrument preference. Preferences were recorded as a single multiple choice among three options. Statistical analysis. Data were reported as means ⫾ SD. The performance times of groups were compared using the Kruskal– Wallis test, followed by pairwise Mann–Whitney U tests. Statistical analysis was performed using standardized biomedical software (Statview, SAS Institute Inc., Cary, NC). A P value less than 0.05 was considered significant.
FIG. 1. Performance time for extracorporeal (Extr) and intracorporeal (Intr) knot-tying among surgical residents using conventional instrument (Conv) or the Endo Stitch (Endo).
RESULTS
Comparison of Laparoscopic Knot-Tying Techniques The mean execution time for extracorporeal knot tying was significantly (P ⬍ 0.05) shorter (102 ⫾ 35 s) than the mean execution time for intracorporeal knot tying using the conventional instrument (185 ⫾ 84 s) and the Endo Stitch instrument (76 ⫾ 22 s vs 107 ⫾ 49 s, respectively) (Fig. 1). Senior residents performed the knot-tying task significantly (P ⬍ 0.05) faster than junior residents on three of four different types of laparoscopic knot-tying techniques (conventional/ intracorporeal, Endo Stitch/intracorporeal, Endo Stitch/extracorporeal). The senior and junior surgical residents preferred the intracorporeal technique (89%) and the Endo Stitch (83%) as the method and instrument of choice, respectively, for laparoscopic knot tying. Comparison of Laparoscopic Suturing Instruments The mean execution time for the laparoscopic suturing exercise was significantly (P ⬍ 0.05) less when using the Endo Stitch (114 ⫾ 64 s) than when using the conventional instrument (206 ⫾ 107 s) or the Suture Assistant (151 ⫾ 70 s). Senior residents performed the laparoscopic suturing task significantly faster than junior residents using the conventional instrument (133 ⫾ 52 s for senior residents vs 253 ⫾ 107 s for junior residents, P ⬍ 0.05) and the Endo Stitch (80 ⫾ 33 s for senior residents vs 137 ⫾ 70 s for junior residents, P ⬍ 0.05). There was no significant difference in performance time between senior and junior surgical residents using the Suture Assistant (135 ⫾ 76 s for senior residents vs 161 ⫾ 64 s for junior residents). The majority of residents chose the Endo Stitch as the instrument of choice for all three catego-
NGUYEN ET AL.: LAPAROSCOPIC SUTURING EVALUATION
FIG. 2. Comparison of instrumentation preference for laparoscopic suturing among residents in four categories (suturing task, knot-tying task, handling, and overall preference).
ries of suturing (70%), knot tying (61%), and handling (81%). Overall, 90% of the residents (39 of 43) preferred the Endo Stitch, 5% preferred the conventional, and 5% preferred the Suture Assistant (Fig. 2). DISCUSSION
Training in laparoscopic surgery has become an integral part of general surgical resident curriculum. The optimal methods for acquisition and assessment of skills remain in question [5– 6]. Advanced laparoscopic surgery requires a unique set of surgical skills such as two-handed surgical dissection techniques, vascular control and ligation techniques, and suturing skills. Laparoscopic suturing skill is an important aspect of all advanced laparoscopic operations but it can be difficult and time consuming to learn. Many centers have incorporated suturing drills into their laparoscopic training programs. Chung and Sackier [7] identified that appropriate needle positioning was the most difficult and time-consuming maneuver in laparoscopic suturing. Mori and colleagues [8] reported that needle mounting and knot-tying skills improved steadily with hands-on training. Hanna and colleagues [9] evaluated laparoscopic suturing models with different display locations and found that performance time improves when the monitor is placed in front of the operator and below the level of the head. Most of the results of these studies are based on an inanimate training model. In our study, we also used an inanimate model for evaluation of laparoscopic suturing skills. This model is inexpensive, reusable, and readily available at most institutions. In addition, the performance of suturing skills in an in vitro laparoscopic simulator was found by Fried et al. to correlate well with performance in an animal model [10]. In our first laparoscopic laboratory session, we evaluated two different types of knot-tying techniques (intracorporeal vs extracorporeal). Although the perfor-
135
mance time for the extracorporeal knot-tying technique was less than that for the intracorporeal technique, the preferred method of knot-tying among surgical residents was the intracorporeal approach. Extracorporeal technique required the use of a knot pusher and was considered by residents to be cumbersome. The extracorporeal knot-tying technique also reduced the surgeon’s ability to accurately place the knots, and it placed significant tension on the tissue during approximation of the knots. The Endo Stitch facilitated intracorporeal knot-tying. A unique feature of this device is the ability to transfer the needle from one arm of the instrument to the other arm by the use of a toggle switch. This maneuver enables the surgeon to create an intracorporeal knot rapidly using the dominant hand, as in the open knot-tying technique. Surgical residents performed intracorporeal knot-tying faster using the Endo Stitch than when using the conventional laparoscopic instrument (Fig. 1). In the second laboratory session, we evaluated laparoscopic intracorporeal suturing technique with three different instruments (conventional, Endo Stitch, and Suture Assistant). This drill takes into account both needle mounting and knot-tying skills. The performance time for completion of laparoscopic suturing was less when using the Endo Stitch than when using a conventional instrument or the Suture Assistant. The Endo Stitch has the needle directly mounted at the tip of the instrument and therefore eliminates the difficulty of positioning the needle onto the needle driver, which has been identified as a difficult maneuver [8]. The performance time for laparoscopic suturing, as expected, was shorter when performed by senior residents than when performed by junior residents; however, there were no differences in performance time between senior and junior residents using the Suture Assistant device. The Suture Assistant instrument was designed to specifically facilitate knot-tying. This instrument is controlled in the nondominant hand and the attached needle (ski needle) is passed through the tissue and then through a preformed loop. A pretied knot is deployed and creates five half-hitch knots. The Suture Assistant instrument eliminates the necessary skill required to perform conventional knot-tying, which explains the similar performance time between senior and junior residents. The majority of surgical residents (90%) preferred the Endo Stitch as the overall instrument of choice to use in laparoscopic suturing. Residents preferred the Endo Stitch for its design, which incorporates the needle directly into the tip of the instrument. This particular design eliminates the need for laparoscopic handling and positioning of the needle. The Endo Stitch also has the unique ability to transfer the needle from one arm of the device to the other, which facilitates knot-tying. The conventional instrument was the pre-
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ferred instrument of choice for 5% of residents. The advantage of the conventional instrument is that it replicates open surgical suturing, uses basic needle and sutures, and is readily available at most institutions. The disadvantages of the conventional instrument are the time-consuming task of correctly mounting the needle on a needle driver and the difficult technical skill required for knot-tying. The Suture Assistant was also preferred by only 5% of residents. The Suture Assistant instrument still requires the technical skill for mounting the needle onto a conventional needle driver and performing tissue suturing. The Suture Assistant only eliminates the technical skill required for knot-tying by passing the needle through a preformed loop and deploying a pretied knot. Surgical residents considered the Suture Assistant to be difficult to handle. In summary, the Endo Stitch enhances the performance of laparoscopic knot-tying and suturing skills. Although subjective, the Endo Stitch was overwhelmingly chosen as the instrument of choice among surgical residents for laparoscopic suturing. Residents preferred the Endo Stitch for ease of handling, easier ability to perform tissue suturing, and its unique ability to create intracorporeal knots. The Endo Stitch instrument should be used as an additional instrument along with the conventional laparoscopic needle holder and grasper in training surgical residents in laparoscopic suturing.
REFERENCES 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Derossis, A. M., Bothwell, J., Sigman, H. H., and Fried, G. M. The effect of practice on performance in a laparoscopic simulator. Surg. Endosc. 12: 1117, 1998. Derossis, A. M., Fried, G. M., Abrahamowicz, M., Sigman, H. H., Barkun, J. S., and Meakins, J. L. Development of a model for training and evaluation of laparoscopic skills. Am. J. Surg. 175: 482, 1998. Rosser, J. C., Jr., Rosser, L. E., and Savalgi, R. S. Objective evaluation of a laparoscopic surgical skill program for residents and senior surgeons. Arch. Surg. 133: 657, 1998. Szabo, Z., and Berce, G. Extracorporeal and intracorporeal knotting and suturing techniques. Laparosc. Cholecystect. Surg. Endosc. 3: 367, 1993. Royston, C. M., Lansdown, M. R., and Brough, W. A. Teaching laparoscopic surgery: the need for guidelines. Br. Med. J. 308: 1023, 1994. Champion, J. K., Hunter, J., Trus, T., and Laycock, W. Teaching basic video skills as an aid in laparoscopic suturing. Surg. Endosc. 10: 23, 1996. Chung, J. Y., and Sackier, J. M. A method of objectively evaluating improvements in laparoscopic skills. Surg. Endosc. 12: 1111, 1998. Mori, T., Hatano, N., Maruyama, S., and Atomi, Y. Significance of “hands-on training” in laparoscopic surgery. Surg. Endosc. 12: 256, 1998. Hanna, G. B., Shimi, S. M., and Cuschieri, A. Task performance in endoscopic surgery is influenced by location of the image display. Am. Surg. 227: 481, 1998. Fried, G. M., Derossis, A. M., Bothwell, J., and Sigman, H. H. Comparison of laparoscopic performance in vivo with performance measured in a laparoscopic simulator. Surg. Endosc. 13: 1077, 1999.
Laparoscopic Suturing Evaluation among Surgical Residents Ninh T. Nguyen, M.D., 1 Kathrin L. Mayer, M.D., Richard J. Bold, M.D., Mike Larson, B.S., Samia Foster, M.D., Hung S. Ho, M.D., and Bruce M. Wolfe, M.D. Department of Surgery, University of California, Davis, Health System, Sacramento, California 95817 Submitted for publication March 20, 2000
Background. Laparoscopic suturing is an integral part of advanced laparoscopic surgery training. The objective of this study was to evaluate the performance and preference of surgical residents performing intracorporeal and extracorporeal knot-tying techniques using conventional and Endo Stitch instruments. The residents were also evaluated on their suturing techniques using conventional instruments, the Endo Stitch, and the Suture Assistant. Methods. Using an inanimate laparoscopic trainer model, 39 residents were evaluated as they performed laparoscopic knot tying exercises. Endpoints of the study were execution time and subjective preference of surgical residents with respect to the type of instrument used for knot tying. Forty-three residents were evaluated as they performed laparoscopic suturing exercises with three different types of suturing instruments using the same endpoints. Results. The intracorporeal technique was the preferred (89%) method of knot tying among surgical residents. The time for completion of laparoscopic suturing was significantly (P < 0.05) shorter with the Endo Stitch (114 ⴞ 64 s) than with the conventional instrument (206 ⴞ 107 s) or the Suture Assistant (151 ⴞ 70 s). Residents preferred the use of the Endo Stitch in all three categories for suturing, knot tying, and handling. Conclusion. The Endo Stitch enhanced laparoscopic skills and was the preferred instrument for laparoscopic knot tying and suturing among surgical residents. © 2000 Academic Press Presented in part at the Annual Meeting of the Association for Academic Surgery, Philadelphia, Pennsylvania, November 18 –20, 1999. 1 To whom reprint requests and correspondence should be addressed: Ninh T. Nguyen, M.D., Division of Gastrointestinal Surgery, Department of Surgery, 2221 Stockton Boulevard, Third Floor, Sacramento, CA 95817-1418. Fax: (916) 734-3951. E-mail: [email protected].
Key Words: laparoscopic surgery; education; resident training; surgical skills. INTRODUCTION
Laparoscopic suturing is an important technical skill needed for advanced laparoscopic surgery training. This skill is required to perform all complex laparoscopic operations. The two components of laparoscopic suturing are tissue penetration with the needle and knot tying. Laparoscopic suturing has been commonly performed using the conventional laparoscopic instrument (needle holder and grasper) [1– 4], but its use by inexperienced laparoscopists or surgical residents is limited by the difficulty in handling of tissue, the precise control of the needle, and the time-consuming knot-tying task. Advances in minimally invasive surgery with introduction of new instrumentation for laparoscopic suturing can possibly simplify suturing and reduce suturing time. The Endo Stitch (United States Surgical Corp., Norwalk, CT) and Suture Assistant (Ethicon Endosurgery, Cincinnati, OH) were designed to facilitate laparoscopic suturing. The Endo Stitch has the ability to transfer a straight needle from one arm of the device to the second arm and therefore facilitates knot tying. In addition, the needle is directly mounted onto the tip of the instrument and therefore reduces the need for needle positioning. The Suture Assistant consists of a ski needle and suture attached to a pretied knot. Its use requires conventional needle positioning and approximation of the tissue, but the knot-tying task is performed by deploying a pretied Duraknot equivalent to five alternating half-hitches. The Endo Stitch and Suture Assistant can theoretically enhance laparoscopic suturing by reducing the technical difficulty in positioning of the needle, help with tissue suturing, and facilitate knot tying. These instruments compared to
133
0022-4804/00 $35.00 Copyright © 2000 by Academic Press All rights of reproduction in any form reserved.
134
JOURNAL OF SURGICAL RESEARCH: VOL. 93, NO. 1, SEPTEMBER 2000
conventional instruments, can potentially improve laparoscopic suturing time. The goal of this study was to evaluate the performance and preference among surgical residents for knot tying and suturing using three different types of instrumentation.
METHODS
Surgical residents attended two inanimate laboratory sessions for training in laparoscopic suturing. Session 1 consisted of a 20-min introduction to laparoscopic knot tying. Proper use of the Endo Stitch and proper use of the conventional laparoscopic needle holder were the two techniques taught. Both intracorporeal and extracorporeal knot-tying techniques were examined. In session 2, a 20-min introduction to laparoscopic suturing technique was presented. Residents were instructed in the proper use of the Endo Stitch, Suture Assistant, and laparoscopic needle holder. A faculty member demonstrated laparoscopic suturing techniques using all three different instruments. Residents were allowed 1 h of practice time during each session. Residents worked in pairs at four inanimate stations, taking turns practicing with the three types of laparoscopic suturing instruments. Faculty assistance was available at each inanimate station. An evaluation was performed at the conclusion of each session. Session 1: Laparoscopic knot-tying drill. Thirty-nine surgical residents were evaluated as they performed a laparoscopic knot-tying drill. There were 24 junior (postgraduate years 1 and 2) and 15 senior (postgraduate years 3– 6) residents. The knot-tying task involved needle penetration of the tissue and tying four knots using intracorporeal or extracorporeal techniques. The tasks were recorded in seconds. Residents were then asked to rate their preferred technique of knot tying: the conventional laparoscopic needle holder or the Endo Stitch. The Suture Assistant was not evaluated in this session because this instrument deploys a pretied Duraknot and does not require knot tying skills. Extracorporeal knots were tied outside the trainer box and secured with a knot pusher. Knot-tying time was recorded on tissue penetration of the needle and ended on completion of four knots. The time for positioning of the needle in the needle driver was not recorded. Surgical residents were asked to record their preference of knot tying technique (intracorporeal vs extracorporeal) and instrument used for knot tying (conventional vs Endo Stitch). Session 2: Laparoscopic suturing drill. Forty-three surgical residents participated in the laparoscopic suturing exercise drill 1 month after session 1. There were 26 junior and 17 senior residents. Laparoscopic suturing was performed using three different types of laparoscopic suturing instruments: conventional, Endo Stitch, and Suture Assistant. Laparoscopic suturing consisted of needle positioning, tissue penetration of the needle, and creation of four intracorporeal knots. The length of time to perform the laparoscopic suturing task was recorded in seconds on insertion of the laparoscopic suturing instrument into the cannula and ended on completion of four intracorporeal knots. At the end of the laboratory session, residents were asked to record their preference among the three instruments with respect to suturing, knot tying, and handling of instruments, as well as overall instrument preference. Preferences were recorded as a single multiple choice among three options. Statistical analysis. Data were reported as means ⫾ SD. The performance times of groups were compared using the Kruskal– Wallis test, followed by pairwise Mann–Whitney U tests. Statistical analysis was performed using standardized biomedical software (Statview, SAS Institute Inc., Cary, NC). A P value less than 0.05 was considered significant.
FIG. 1. Performance time for extracorporeal (Extr) and intracorporeal (Intr) knot-tying among surgical residents using conventional instrument (Conv) or the Endo Stitch (Endo).
RESULTS
Comparison of Laparoscopic Knot-Tying Techniques The mean execution time for extracorporeal knot tying was significantly (P ⬍ 0.05) shorter (102 ⫾ 35 s) than the mean execution time for intracorporeal knot tying using the conventional instrument (185 ⫾ 84 s) and the Endo Stitch instrument (76 ⫾ 22 s vs 107 ⫾ 49 s, respectively) (Fig. 1). Senior residents performed the knot-tying task significantly (P ⬍ 0.05) faster than junior residents on three of four different types of laparoscopic knot-tying techniques (conventional/ intracorporeal, Endo Stitch/intracorporeal, Endo Stitch/extracorporeal). The senior and junior surgical residents preferred the intracorporeal technique (89%) and the Endo Stitch (83%) as the method and instrument of choice, respectively, for laparoscopic knot tying. Comparison of Laparoscopic Suturing Instruments The mean execution time for the laparoscopic suturing exercise was significantly (P ⬍ 0.05) less when using the Endo Stitch (114 ⫾ 64 s) than when using the conventional instrument (206 ⫾ 107 s) or the Suture Assistant (151 ⫾ 70 s). Senior residents performed the laparoscopic suturing task significantly faster than junior residents using the conventional instrument (133 ⫾ 52 s for senior residents vs 253 ⫾ 107 s for junior residents, P ⬍ 0.05) and the Endo Stitch (80 ⫾ 33 s for senior residents vs 137 ⫾ 70 s for junior residents, P ⬍ 0.05). There was no significant difference in performance time between senior and junior surgical residents using the Suture Assistant (135 ⫾ 76 s for senior residents vs 161 ⫾ 64 s for junior residents). The majority of residents chose the Endo Stitch as the instrument of choice for all three catego-
NGUYEN ET AL.: LAPAROSCOPIC SUTURING EVALUATION
FIG. 2. Comparison of instrumentation preference for laparoscopic suturing among residents in four categories (suturing task, knot-tying task, handling, and overall preference).
ries of suturing (70%), knot tying (61%), and handling (81%). Overall, 90% of the residents (39 of 43) preferred the Endo Stitch, 5% preferred the conventional, and 5% preferred the Suture Assistant (Fig. 2). DISCUSSION
Training in laparoscopic surgery has become an integral part of general surgical resident curriculum. The optimal methods for acquisition and assessment of skills remain in question [5– 6]. Advanced laparoscopic surgery requires a unique set of surgical skills such as two-handed surgical dissection techniques, vascular control and ligation techniques, and suturing skills. Laparoscopic suturing skill is an important aspect of all advanced laparoscopic operations but it can be difficult and time consuming to learn. Many centers have incorporated suturing drills into their laparoscopic training programs. Chung and Sackier [7] identified that appropriate needle positioning was the most difficult and time-consuming maneuver in laparoscopic suturing. Mori and colleagues [8] reported that needle mounting and knot-tying skills improved steadily with hands-on training. Hanna and colleagues [9] evaluated laparoscopic suturing models with different display locations and found that performance time improves when the monitor is placed in front of the operator and below the level of the head. Most of the results of these studies are based on an inanimate training model. In our study, we also used an inanimate model for evaluation of laparoscopic suturing skills. This model is inexpensive, reusable, and readily available at most institutions. In addition, the performance of suturing skills in an in vitro laparoscopic simulator was found by Fried et al. to correlate well with performance in an animal model [10]. In our first laparoscopic laboratory session, we evaluated two different types of knot-tying techniques (intracorporeal vs extracorporeal). Although the perfor-
135
mance time for the extracorporeal knot-tying technique was less than that for the intracorporeal technique, the preferred method of knot-tying among surgical residents was the intracorporeal approach. Extracorporeal technique required the use of a knot pusher and was considered by residents to be cumbersome. The extracorporeal knot-tying technique also reduced the surgeon’s ability to accurately place the knots, and it placed significant tension on the tissue during approximation of the knots. The Endo Stitch facilitated intracorporeal knot-tying. A unique feature of this device is the ability to transfer the needle from one arm of the instrument to the other arm by the use of a toggle switch. This maneuver enables the surgeon to create an intracorporeal knot rapidly using the dominant hand, as in the open knot-tying technique. Surgical residents performed intracorporeal knot-tying faster using the Endo Stitch than when using the conventional laparoscopic instrument (Fig. 1). In the second laboratory session, we evaluated laparoscopic intracorporeal suturing technique with three different instruments (conventional, Endo Stitch, and Suture Assistant). This drill takes into account both needle mounting and knot-tying skills. The performance time for completion of laparoscopic suturing was less when using the Endo Stitch than when using a conventional instrument or the Suture Assistant. The Endo Stitch has the needle directly mounted at the tip of the instrument and therefore eliminates the difficulty of positioning the needle onto the needle driver, which has been identified as a difficult maneuver [8]. The performance time for laparoscopic suturing, as expected, was shorter when performed by senior residents than when performed by junior residents; however, there were no differences in performance time between senior and junior residents using the Suture Assistant device. The Suture Assistant instrument was designed to specifically facilitate knot-tying. This instrument is controlled in the nondominant hand and the attached needle (ski needle) is passed through the tissue and then through a preformed loop. A pretied knot is deployed and creates five half-hitch knots. The Suture Assistant instrument eliminates the necessary skill required to perform conventional knot-tying, which explains the similar performance time between senior and junior residents. The majority of surgical residents (90%) preferred the Endo Stitch as the overall instrument of choice to use in laparoscopic suturing. Residents preferred the Endo Stitch for its design, which incorporates the needle directly into the tip of the instrument. This particular design eliminates the need for laparoscopic handling and positioning of the needle. The Endo Stitch also has the unique ability to transfer the needle from one arm of the device to the other, which facilitates knot-tying. The conventional instrument was the pre-
136
JOURNAL OF SURGICAL RESEARCH: VOL. 93, NO. 1, SEPTEMBER 2000
ferred instrument of choice for 5% of residents. The advantage of the conventional instrument is that it replicates open surgical suturing, uses basic needle and sutures, and is readily available at most institutions. The disadvantages of the conventional instrument are the time-consuming task of correctly mounting the needle on a needle driver and the difficult technical skill required for knot-tying. The Suture Assistant was also preferred by only 5% of residents. The Suture Assistant instrument still requires the technical skill for mounting the needle onto a conventional needle driver and performing tissue suturing. The Suture Assistant only eliminates the technical skill required for knot-tying by passing the needle through a preformed loop and deploying a pretied knot. Surgical residents considered the Suture Assistant to be difficult to handle. In summary, the Endo Stitch enhances the performance of laparoscopic knot-tying and suturing skills. Although subjective, the Endo Stitch was overwhelmingly chosen as the instrument of choice among surgical residents for laparoscopic suturing. Residents preferred the Endo Stitch for ease of handling, easier ability to perform tissue suturing, and its unique ability to create intracorporeal knots. The Endo Stitch instrument should be used as an additional instrument along with the conventional laparoscopic needle holder and grasper in training surgical residents in laparoscopic suturing.
REFERENCES 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Derossis, A. M., Bothwell, J., Sigman, H. H., and Fried, G. M. The effect of practice on performance in a laparoscopic simulator. Surg. Endosc. 12: 1117, 1998. Derossis, A. M., Fried, G. M., Abrahamowicz, M., Sigman, H. H., Barkun, J. S., and Meakins, J. L. Development of a model for training and evaluation of laparoscopic skills. Am. J. Surg. 175: 482, 1998. Rosser, J. C., Jr., Rosser, L. E., and Savalgi, R. S. Objective evaluation of a laparoscopic surgical skill program for residents and senior surgeons. Arch. Surg. 133: 657, 1998. Szabo, Z., and Berce, G. Extracorporeal and intracorporeal knotting and suturing techniques. Laparosc. Cholecystect. Surg. Endosc. 3: 367, 1993. Royston, C. M., Lansdown, M. R., and Brough, W. A. Teaching laparoscopic surgery: the need for guidelines. Br. Med. J. 308: 1023, 1994. Champion, J. K., Hunter, J., Trus, T., and Laycock, W. Teaching basic video skills as an aid in laparoscopic suturing. Surg. Endosc. 10: 23, 1996. Chung, J. Y., and Sackier, J. M. A method of objectively evaluating improvements in laparoscopic skills. Surg. Endosc. 12: 1111, 1998. Mori, T., Hatano, N., Maruyama, S., and Atomi, Y. Significance of “hands-on training” in laparoscopic surgery. Surg. Endosc. 12: 256, 1998. Hanna, G. B., Shimi, S. M., and Cuschieri, A. Task performance in endoscopic surgery is influenced by location of the image display. Am. Surg. 227: 481, 1998. Fried, G. M., Derossis, A. M., Bothwell, J., and Sigman, H. H. Comparison of laparoscopic performance in vivo with performance measured in a laparoscopic simulator. Surg. Endosc. 13: 1077, 1999.