Laparoscopic Knot Research Articles

A New Technique for Intracorporeal Knot Tying in Laparoscopic Surgery

Laparoscopic intracorporeal knot tying in minimally invasive surgery is an advanced skill. Mastering this skill is a difficult process with a long learning curve. Intracorporeal suturing is essential to advanced laparoscopy and is a rate-limiting step in many procedures. Many different instruments and methods have been described for laparoscopic suturing and knot tying. We have developed a new technique for laparoscopic knot tying. The long end of the suture is held with a left-hand instrument, and the instrument is rotated for 360 degrees in a clockwise direction to make a forward-direction loop. The end of the loop is grasped with the right-hand instrument, and the other end of the suture is grasped with the left-hand instrument. The suture end, held by the left hand, is pulled though the loop and tied, thus making a half-knot of a square knot. The second half-knot is made by using the right-hand instrument with the same technique. Laparoscopic suturing and knotting is difficult to perform, especially when the angle between the working instruments is narrow and working space is limited. In all these situations, knot tying using this technique makes knotting more simple and easy to perform, especially for those who have limited experience in intracorporeal suturing and knot tying. No special instrument is required to perform knot tying with this technique.

Laparoscopos csomózásr

Wound closure with sutures has been routinely used as a result of the technical and surgical development since the 20th Century. Knot tying in open surgery can be easily learned and performed; however, knot tying becomes challenging and frustrating when performed laparoscopically. Laparoscopic vessel ligation, suturing and performing anastomosis opened up a new horizon for laparoscopy. Laparoscopic knots can be performed extracorporally or intraabdominally. The most common intracorporal knots are the tumble square, Dundee, Aberdeen, midship and blood knots. Inherent disadvantages of intracorporal laparoscopic knot tying are decreased sensation of the tension applied to the tissues and the knot; and difficulty in knotting because of technical requirements and limited space. The most common extracorporal knots: Duncan, Roeder, modified 4-S Roeder, Tayside, Yanni and GEA knots. Extracorporally tied knots are obviously much easier to tie than intracorporal one;, but they can cause tissue trauma from pulling long lengths of suture through the needle tract, excessive tension on the tissue while pushing the knot into position, and loss of focus on the operative field during knotting. One kind of knot-pusher would not fit for all and we suggest to use different knot-pushers for different suture materials. In robotic assisted suturing the operative time decreased, the stability has increased and the skills can be developed in simulation labs.

Transfer validity of laparoscopic knot-tying training on a VR simulator to a realistic environment: A randomized controlled trial

Laparoscopic suturing is one of the most difficult tasks in endoscopic surgery, requiring extensive training. The aim of this study was to determine the transfer validity of knot-tying training on a virtual-reality (VR) simulator to a realistic laparoscopic environment. Twenty surgical trainees underwent basic eye-hand coordination training on a VR simulator (SIMENDO, DelltaTech, Delft, The Netherlands) until predefined performance criteria were met. Then, they were randomized into two groups. Group A (the experimental group) received additional training with the knot-tying module on the simulator, during which they had to tie a double laparoscopic knot ten times. Group B (controls) did not receive additional manual training. Within a week the participants tied a double knot in the abdominal cavity of an anaesthetized porcine model. Their performance was captured on digital video and coded. Objective analysis parameters were: time taken to tie the knot and number of predefined errors made. Subjective assessments were also made by two laparoscopic surgeons using a global rating list with a five-point Likert scale. Trainees in group A (n = 9) were significantly faster than the controls (n = 10), with a median of 262 versus 374 seconds (p = 0.034). Group A made a significantly lower number of errors than the controls (median of 24 versus 36 errors, p = 0.030). Subjective assessments by the laparoscopic experts did not show any significant differences in economy of movement and erroneous behavior between the two groups. Surgical trainees who received knot-tying training on the VR simulator were faster and made fewer errors than the controls. The VR module is a useful tool to train laparoscopic knot-tying. Opportunities arose to improve simulator-based instruction that might enhance future training.

Performance differences in laparoscopic surgical skills between true high-definition and three-chip CCD video systems

Laparoscopic surgery requires surgeons to rely on visual clues for discrimination among differing tissues and for depth of field on a two-dimensional screen. High definition (HD) provides a superior image. If there is a measurable advantage with HD television (TV), the increase in the cost of the technology would be justified. A digital three-chip CCD camera with a standard monitor (SD system) and a true HD camera (1,080 pixels) with a 16:9-ratio HD monitor (HD system) were compared in clinical and laboratory settings. Three experiments were performed: (1) subjective visual evaluation of the HD and SD systems during actual surgical cases, (2) subjective visual evaluation in a controlled laboratory surgical setting with simultaneous parallel recording, and (3) three laparoscopic surgical task evaluations in a laboratory setting, namely, task A (metric analysis of participants on the surgical simulator), task B (simple eye-hand coordination performance), and task C (knot tying). All 53 participants subjectively evaluated HD as superior to SD in the laboratory setting and during actual surgery. In task B, there was no significant difference between SD and HD (dominant hand: p = 0.19; nondominant hand: p = 0.07). In task C, the knot-tying time was significantly less when performed with HD (mean, 173 +/- 84 s vs 214 +/- 107 s; p = 0.003). Most importantly, subjects with less skill (more documented time required in the basic module on a surgical simulator) improved significantly in the knot-tying task with the HD system (R = 0.631; p = 0.005). All the participants preferred HD to SD. High definition significantly improved laparoscopic knot tying, which requires precise depth perception, proving that HD is more than just a pretty picture.

Video Trainers, Simulation and Virtual Reality: A New Paradigm for Surgical Training

William S. Halsted established an educational system of graded learning in which surgical postgraduate trainees would, over time, do more and more of an operation as their training progressed. The apprentice model has been in place ever since, but economic pressures and work hour limitations have competed to hurry training along. A popular surgical adage is “see one, do one, teach one”, and under this model, trainees after very limited experience would be empowered to perform procedures on patients. The apprentice model may no longer be working. The National Academy of Science in 1999 and its publication To Err is Human noted that approximately 98,000 deaths occur each year due to medical error.1 In fact, they identified error in the performance of an operation as one of the many causes of mortality. The Institution of Medicine further challenged that alternative methods of surgical training needed to be developed. The cost of training is not cheap. Bridges et al broke down the financial impact of teaching surgical residents in the operating room.2 In 9,733 cases with residents versus 4,719 cases without residents, they found that cases with residents took an additional 12 minutes per case. In their analysis, they charged US$4.29/minute and assumed 1,014 US residents. The cost to society was US$53 million per year to train surgical residents in the operating room. No wonder as we scrutinize costs in the operating room, the most expensive “instrument” seems to be operative time. Halsted’s apprentice model of graded learning seems to work with general surgery in that trainees begin by making the incision, tying a knot, tying a series of knots and then performing simple procedures and eventually complex operations. However, these “open” hand skills are not transferable to laparoscopic procedures. The master “open” general surgeon may not be able to perform the most basic of laparoscopic procedures safely. Laparoscopy uses fixed ports with elongated instruments. Laparoscopy lacks the same tactile feedback and often uses a twodimensional visual system. Tying a traditional two-handed knot does not mean that the surgeon can tie an intracorporeal laparoscopic knot. So simply waiting for a junior resident to become a senior resident does not mean that they would then have the ability to perform laparoscopic surgery. Learning these techniques in the operating room may also prove too costly to the hospital; therefore, new techniques and ideas about how to train surgeons had to evolve. The laparoscopic revolution began in 1987 with laparoscopic cholecystectomy. In the early 1990s, thousands of surgeons began to embark on this new field. Most surgeons would take a weekend course which included operating on a pig before bringing the new instruments into the operating theatre for their next case. Unfortunately, the rate of common bile duct injuries increased five-fold as surgeons not expert in these techniques took on new

How Reliable Is Intracorporeal Laparoscopic Knot Tying?

Are knots tied laparoscopically as reliable as those tied in open surgery? The aim of our study was to try to answer this question. Using a standardized technique, one senior laparoscopic surgeon tied 3 suture materials using 3 methods of knotting: hand, instrument, and laparoscopic (in a simulator). The tension in the knots was measured using a tension gauge at the time of knotting and 5 minutes later. The surgeon was blinded to the value. The experiment was repeated 4 times. The 36 sutures were then analyzed using a materials-testing machine. The force achieved prior to breakage, the extension, and the breaking points were recorded. The scientist performing the analysis was blinded as to the method of tying and tensions produced. There were no significant differences in tension at 5 minutes between suture materials or method of knot tying. The mean extension achieved prior to breakage for 33 sutures was 29.71 mm with a force of 16.09 N. In 3 sutures the knot slipped completely while tension was being increased, thus no measure of breakage force could be obtained. These 3 sutures were monofilament and tied laparoscopically. There were no significant changes in suture tension after 5 minutes regardless of material or method of knot tying. Three of the 12 knots tied laparoscopically came undone under strain testing. All 3 knots were monofilament suture. This may have important implications when choosing suture material. Further studies are planned to expand the analysis of different knotting techniques with different suture materials.

Evaluation of a novel knotless self-anchoring suture material for urinary tract reconstruction

Objectives To evaluate a novel prototype self-anchoring suture (SAS) material that incorporates unidirectional “barbs” designed to grip and approximate tissue without the need for suture ligation for urinary tract reconstructive procedures. Methods The in vitro failure strength of various porcine tissue approximations with SAS was compared with the strength of similar approximations with standard ligated suture. For in vivo analysis, 3 pigs underwent laparoscopic pyeloplasty with SAS on one side and 2-0 Vicryl suture on the contralateral side. Nine pigs underwent bladder neck anastomoses (BNA) performed with SAS (n = 3) and standard ligated interrupted suturing (n = 3) or standard ligated running suturing (n = 3). The operative times were compared. One week after surgery, the integrity of each anastomosis was evaluated radiographically and histopathologically. Results The in vitro analysis revealed no statistically different ( P = 0.22) failure forces between the approximations performed with SAS (13.2 ± 2.6 N) and standard suture (14.1 ± 3.1 N). The in vitro analysis revealed no difference in operative times for the pyeloplasties ( P = 0.72) or BNA ( P = 0.31). None of the 1-week postoperative radiographic studies revealed extravasation. The histopathologic analysis revealed more fibrotic reaction associated with the SAS BNA procedures ( P <0.01). Conclusions Self-anchoring suture secures tissue approximations at loads equivalent to tissue approximations with standard tied suture. Self-anchoring suture obviates the need for knot tying and provides a watertight anastomosis. With laparoscopic knot tying experience, anastomotic time with SAS and standard suture do not differ. Self-anchoring suture might induce more fibrosis. Long-term follow-up evaluation will be required before clinical application.

A groundbreaking new suturing device

Laparoscopic knot tying can be stressful. We reported two simple techniques, known as the Thumbs up! knot and the Tornado knot. We have further refined these procedures with the development of a new needle holder, called the Excalibur suturing needle holder. This forceps differ from most conventional forceps in that the hinge is designed to stick out. The large hinge is stored out of the way when the forceps are closed, to prevent the thread accidentally catching. The thread is hooked on the projected hinge, which resembles the heel of a high-heel shoe. By using this forceps, the laparoscopic knot tying becomes easier for not only well experienced but also less experienced surgeons. The Excalibur, with its high heel, can complete knots with simple straight-line motion, making knot tying easier. This forceps will help reduce the stresses associated with intra-corporeal knot tying.

The role of mental rotation and memory scanning on the performance of laparoscopic skills

The rotational angle of the laparoscopic image relative to the true horizon has an unknown influence on performance in laparoscopic procedures. This study evaluates the effect of increasing rotational angle on surgical performance. Surgical residents (group 1) (n = 6) and attending surgeons (group 2) (n = 4) were tested on two laparoscopic skills. The tasks consisted of passing a suture through an aperture, and laparoscopic knot tying. These tasks were assessed at 15 degrees intervals between 0 degrees and 90 degrees , on three consecutive repetitions. The participant's performance was evaluated based on the time required to complete the tasks and number of errors incurred. There was an increasing deterioration in suturing performance as the degree of image rotation was increased. Participants showed a statistically significant 20-120% progressive increase in time to completion of the tasks (p = 0.004), with error rates increasing from 10% to 30% (p = 0.04) as the angle increased from 0 degrees to 90 degrees. Knot-tying performance similarly showed a decrease in performance that was evident in the less experienced surgeons (p = 0.02) but with no obvious effect on the advanced laparoscopic surgeons. When evaluated independently and as a group, both novice and experienced laparoscopic surgeons showed significant prolongation to completion of suturing tasks with increased errors as the rotational angle increased. The knot-tying task shows that experienced surgeons may be able to overcome rotational effects to some extent. This is consistent with results from cognitive neuroscience research evaluating the processing of directional information in spatial motor tasks. It appears that these tasks utilize the time-consuming processes of mental rotation and memory scanning. Optimal performance during laparoscopic procedures requires that the rotation of the camera, and thus the image, be kept to a minimum to maintain a stable horizon. New technology that corrects the rotational angle may benefit the surgeon, decrease operating time, and help to prevent adverse outcomes.

Evaluation of a Novel Modified Suture Material Designed to Facilitate Intracorporeal Knot Tying during Laparoscopic Surgery

Laparoscopic intracorporeal knot tying in minimally invasive surgery is an advanced skill. Mastering this skill is an arduous process with a long learning curve. While recent advances in instrumentation have allowed easier suturing and tying, until now, no attempts have been made to modify the suture material in order to facilitate this process. We present an evaluation of a novel modified suture material designed to allow inexperienced surgical residents to tie intracorporeal knots laparoscopically using conventional laparoscopic needle drivers. Surgical residents with no prior experience in laparoscopic surgery were invited to take part in this investigation. Each of the 14 participants was given a 10-minute demonstration of laparoscopic intracorporeal knot tying and then allowed a mentored practice session of 10 minutes. In the first trial, they were then randomized to tie a laparoscopic knot with either a standard or a modified dry suture. Time and accuracy scores were recorded. They then performed the same task with the other type of suture. On the second trial, wet standard and modified sutures were used, and the order of the sutures used in the first trial was reversed. The average time taken to tie an intracorporeal knot laparoscopically was significantly less when the modified suture was used in both dry and wet conditions (162.71 +/- 10.79 seconds v 270.86 +/- 22.76 seconds; P = 0.0039, and 123.29 +/- 4.70 seconds v 247.57 +/- 23.17 seconds; P = 0.0032, respectively). No significant difference in accuracy scores was noted with the two sutures. Our modified suture design allowed inexperienced surgical residents to perform intracorporeal laparoscopic knot tying on average faster than the standard suture did. The concept of modifying suture design to facilitate laparoscopic suturing and knot tying deserves further investigation and development.

The effect of delayed visual feedback on telerobotic surgery

Telerobotic surgery is ideally suited for remote applications in which the instrument control console is stationed separately from the end-effectors at the patient's bedside. However, if the distance between the console and the patient is great enough, a lag effect or latency between end-effector manipulation and the depicted image leads to alterations in movement patterns. The purpose of this study was to determine the effect of visual delay on surgical task performance. At an endoscopic skill station, an analogue delay device was interposed between the surgical field and monitor to delay the transmission of visual information, thus mimicking the distance effect of data transmission. Three surgeons with similar laparoscopic experience participated in the laparoscopic knot tying portion of the study, and seven residents participated in the accuracy and dexterity tasks. The time to complete a single throw was recorded in seconds after adding consecutively increasingly time delay in 50 ms increments. Similar time delay increments were added for the accuracy and dexterity tasks, which involved passing a needle through two adjacent circles and passing a small cylinder through a larger one to reproduce two-handed coordination and spatial resolution. Data were presented as the median time to complete each task. For all three tasks, an incremental increase in time delay was associated with a significant (p < 0.001) increase in the time to complete the task. For dexterity, a statistically significant (p <or= 0.05) delay was identified at 0.25 s of delay from control values without delay. A move-and-wait strategy was gradually adopted up to 0.4 s of visual delay. Compensation for visually delayed image perception occurs on several levels. Initial adaptations include slower end-effector manipulation; late adaptive changes include a move-and-wait strategy. Increased time to perform surgical maneuvers as well as diminished accuracy, diminished dexterity, and increasing fatigue represent additional performance encumbrances evoked by visual time delay. The nuances of both human and digital compensatory mechanisms for visual time delay must be defined and enhanced to maximize the potential for telerobotic surgical applications.

The Relationship Between Five Kinds of Laparoscopic Knots and Five Types of Suture Materials and Histological Findings in Tissues

The aim of the current study was to examine the slipping and the tightening of laparoscopic knots with various kinds of sutures, as well as the histologic alterations in tissues. Fifty rabbits and five kinds of sutures were used-silk, polyglactine-910 (Vicryl), Polydioxanone (PDS), Polyglycol (Dexon), and cat-gut chromic-and five laparoscopic knots were used-Tayside, Roeder, Melzer, Cross, and Blood. The knots were performed extracorporeally and were used to ligate a part of the omentum. Sliding and tightening of the knots were evaluated. The omentum, the suture, and the knots were checked 10 days and 1 month after operation. Histologic examination was performed 1 month after surgery. Polyglactine-910 (Vicryl) and silk were the most qualitative sutures used in Tayside, Roeder, and Blood knots and the least harmful for the tissues. Catgut chromic and Polydioxanone (PDS) were the most defective sutures. The most efficient laparoscopic slipknots are Tayside, Roeder, and Blood, especially when constructed with silk and polyglactine-910 (Vicryl).

Laparoscopic myomectomy using a modified type of reusable laparoscopic Roeder knot pusher to enhance positioning and tightening of the Roeder knot

To describe the technique of laparoscopic reconstruction of the uterine wall defect after laparoscopic enucleation of intramural fibroid, using a modified type of reusable laparoscopic knot pusher which enhances precise positioning and adequate tightening of the Roeder knot.A stand‐alone one‐day surgery unit.Six patients having laparoscopic enucleation of an intramural fibroid.The defect in the uterine wall was reconstructed with open surgery sutures tied extracorporeally using a Roeder knot which was slid and tightened with the knot pusher.Since the Roeder knots were slid and tightened without blockage and the uterine wall was reconstructed without postoperative intramural haematoma in all patients, the impression is that the modified type of Roeder knot pusher used on standard sutures could be a low‐price alternative to endoscopic sutures.

Tension to breakage and tension to loosening of extracorporeal laparoscopic knots with different suture materials

Tension to breakage and tension to loosening of extracorporeal laparoscopic knots with different suture materials

Laparoscopic Instrumentation: Linear Cutters, Clip Appliers, and Staplers

Some of the most common forms of instrumentation and technology used laparoscopically include linear cutters, clip appliers, and staplers. The clip applier was the instrument that finally allowed the surgeon to be able to perform laparoscopic cholecystectomies. Staplers were developed quickly thereafter for tacking tissue together or for applying mesh for hernia repairs. Linear cutters became much more useful when the laparoscopic procedures became more advanced, and their application continues to expand. This report reviews the technology regarding these instruments and discusses clip appliers, linear cutter-staplers, and hernia staplers, which are currently available on the market. However, it should be noted that there remains a lack of peer-reviewed literature regarding the efficiency, efficacy, and cost of these instruments compared with that of laparoscopic suturing and knot tying.

Laparoscopic suturing evaluation among surgical residents.

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. 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. 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 +/- 64 s) than with the conventional instrument (206 +/- 107 s) or the Suture Assistant (151 +/- 70 s). Residents preferred the use of the Endo Stitch in all three categories for suturing, knot tying, and handling. The Endo Stitch enhanced laparoscopic skills and was the preferred instrument for laparoscopic knot tying and suturing among surgical residents.

A new direction in laparoscopic suturing and knot tying

An intracorporeal knot can be tied using instruments, employing a method that mimics the actions of the hooked index finger as used in the one‐handed, hand tie, of open surgery. The short end of the suture, when held in the instrument jaws, can be looped around the bite section of the suture. This rotation is facilitated by a spiral spur member, which is affixed to the instrument jaw, and which captures the bite. For maximum efficiency one uses paired left and right instruments, where the spiral spurs are directed clockwise and anticlockwise, respectively. Instrument rotation and minimal instrument transfers are required for this technique. The surgical half‐hitch can be created by two entirely different actions, the instrument‐ or the hand‐tied method. Each of these methods could be considered to be the converse of the other. Ergonomically designed instruments are essential for laparoscopic surgery. A role for instrument axial rotation is recognized and extended in this new method of laparoscopic knot tying. This novel technique contrasts with all known knotting methods.

The Effect of Knot Geometry on the Strength of Laparoscopic Slip Knots

The Effect of Knot Geometry on the Strength of Laparoscopic Slip Knots

Laparoscopic skills enhancement

Laparoscopy requires a unique subset of surgical skills that, for the inexperienced, can significantly delay the development of basic operative skills. We hypothesized that learning laparoscopic suturing and knot tying would improve laparoscopic skills. A laparoscopic training seminar for junior surgical residents was established to test this hypothesis. Emphasis was placed on laparoscopic knot tying and suturing. Skills were assessed at the beginning and the end of the course. All residents showed significant improvement. Dominant and nondominant hand skills improved by 30.2% and 26.9%, respectively. Two-handed skills improved by 58.6% and 30.1%. Overall scores improved by 28.9%. A structured laparoscopic skills course stressing knot tying and suturing is an effective way to develop dexterity and significantly improve the performance of laparoscopic tasks. These improvements can be accomplished in a cost-effective curriculum that should enhance the surgical education of residents and speed the acquisition of competent operative skills.

Manual laparoscopic suturing and knot tying made easy

Manual laparoscopic suturing can be a difficult and time-consuming procedure even in the hands of an experienced surgeon. Percutaneous introduction and removal of the suture through a vantage point not only helps in laparoscopic manipulation but also allows its extracorporeal manipulation, thereby making laparoscopic suturing and knot tying a much simpler procedure.