Double-Gloving Impairs the Quality of Surgical Knot Tying: A Randomised Controlled Trial

Background

Double-gloving is endorsed by a number of healthcare authorities worldwide, on the basis that it promotes patient and surgeon safety; adoption of this practice amongst surgeons remains limited, based upon anecdotal reporting that double-gloving may compromise surgical technique due to impaired dexterity and sensation. The aim of this study is to formally investigate and demonstrate the effect of double-gloving upon the quality of knot tying, an essential surgical skill.

Methods

An international cohort of practising general surgeons hand tied surgical knots, under both single-gloved and double-gloved conditions, using monofilament and braided sutures, at two different gauges. Half of the participants tied single-gloved first. The mechanical strength of the knots was determined by tensile testing, and each knot was given a knot quality score (KQS), a validated assessment of knot quality.

Results and conclusions

1466 knots were tested. Double-gloving was shown to reduce KQS for all suture types, compared to knots tied under single-gloved conditions (p = 0.001). There was no difference in the KQS of the double-gloved ties between those who routinely double-gloved and those who did not (p = 0.640). The OR showed that double-gloving reduced the KQS by 24 % overall, with the effect being much more prominent when the finer 4.0 suture was used, as knot quality was reduced by almost 50 % (95 % CI 13–93 %). Double-gloving impairs the quality of knot tying, and therefore, surgeons should consider other precautions to ensure patient and surgeon safety. These findings also question the validity of recommendations that surgeons should double-glove as a routine.

     

Extracorporeal Versus Intracorporeal Anastomosis for Laparoscopic Right Hemicolectomy

Background:

During laparoscopic right hemicolectomy, the anastomosis can be created intra- or extracorporeally. This study aimed to determine whether a difference exists in short-term outcomes between these techniques.

Methods:

Prospectively collected data of 80 consecutive patients who underwent laparoscopic right hemicolectomies since 2004 were reviewed retrospectively. An intracorporeal anastomosis was performed in 23 patients, an extracorporeal anastomosis in 57.

Results:

There were no significant differences in median length of stay (4 days), number of removed lymph nodes, estimated blood loss, operative time (190 minutes intracorporeal vs. 180 minutes) and postoperative ileus (22% intracorporeal vs. 16%). The incision length was significantly shorter in the intracorporeal group (4cm vs. 5cm; P=0.004). Complications related to the anastomosis including twisting of the mesentery (n=2), anastomotic volvulus (n=1), or leak (n=1) occurred in 4 patients in the extracorporeal group compared with one minor anastomotic leak in the intracorporeal group. Major complication rates were similar between the 2 groups (4.3% intracorporeal vs. 5.3% extracorporeal).

Conclusion:

The type of anastomosis does not influence short-term outcomes after laparoscopic right hemicolectomy. An intracorporeal anastomosis results in shorter incision length and may decrease wound-related complications.     

The ultimate Aberdeen knot

INTRODUCTION

The Aberdeen knot has been shown to be stronger and more secure than a surgeon''s knot for ending a suture line. No data exist as to the ideal configuration of the Aberdeen knot. The Royal College of Surgeons of England in their Basic Surgical Skills Course, 2002 recommended six throws. The aim of this experiment is to find the ideal combination of throws and turns.

MATERIALS AND METHODS

Aberdeen knots of various configurations were tied in O-PDS suture (Ethicon, Johnson and Johnson). Each configuration was tied 10 times. A materials testing machine was used to test the knots to destruction in a standardised manner.

RESULTS

The knots were seen to behave in two ways. They either slipped and unravelled, or broke. Knots tied with fewer than three throws were unreliable. Knots tied with three throws and two turns appear to be the strongest configuration. Adding further throws and turns does not increase the strength of an Aberdeen knot.

CONCLUSIONS

An Aberdeen knot tied with three throws and two turns is the ultimate Aberdeen knot.     

Locking sliding knots in laboratory model of thoracoscopic repair of esophageal atresia

Aim

The study aimed to assess feasibility and strength of locking sliding knots, in comparison to intracorporeal square knots, in a thoracoscopic model of esophageal atresia (EA).

Methods

A simple thoracoscopic model of EA was created, and inside this model, 26 sliding knots were used to suture a soft drain together. In all cases, ten 5-0 monofilament sutures were used for this “anastomosis.” The drain is then mounted on a motorized digital tensometer, and the knots with the best tension profile were retested 4 more times to obtain an average. The tensometer measured the knots' strength by producing a constant and increasing weight on the sutured EA model and continuous readings were taken by integrated computer software. The point, at which either the knot slipped, broke, or the drain disrupted, was taken as the maximum load tolerated by the sliding knots. Knot pushers were not required for any of these knots.

Results

Of the 26 sliding knots, only locking sliding knots tolerated reasonably high tensions. However, when comparing these knots to the standard square knot, only Giant and Field knots had similar tension readings. Field knot was found to be very complex and therefore impractical with 5-0 suture material, leaving Giant knot as the only knot with favorable results.

Conclusions

Locking sliding knots and particularly Giant knot could have an enormous impact in minimally invasive surgery of neonatal conditions and can potentially replace intracorporeal knots. Giant knot is faster to tie and thus could reduce surgeon's fatigue during complex procedures.     

Knot integrity using different suture types and different knot-tying techniques for reconstructive pelvic floor procedures

Introduction and hypothesis

Surgeons use a variety of sutures and knot-tying methods during pelvic reconstructive procedures. We hypothesized that knot-strength integrity will be similar with regards to type of knot, type of suture, and the knot-tying process.

Methods

Using six different suture materials, flat square knots and slip knots were tied robotically and by hand by two surgeons. Knot integrity was evaluated using an Instron 5544 machine. We measured force and elongation at suture failure or knot slippage (whichever came first) as well as force at 3-mm displacement.

Results

Four hundred and thirty-two knots were tie; one unraveled before the analysis, and 431 were tested. Three hundred and ninety-two knots reached or surpassed tensile strength of 30 N, the force at which tissue itself will fail. Knots tied with polyglyconate suture achieved the greatest tensile strength and those with OO-polydioxanone had the lowest. Hand-tied knots, regardless of technique and suture material, had greater tensile strength but greater elongation than robotically tied knots. Slip knots and flat square knots have similar integrity regardless of the tying technique.

Conclusion

Hand-tied knots had greater tensile strength than robotic knots, but the strength to break all knots required supraphysiological conditions. The decision to use a specific type of suture based on strength is not supported by our results, suggesting that surgeons may choose sutures based on other characteristics and personal comfort.

     

Laparoscopic Pyeloplasty in the Animal Model

Purpose:

Laparoscopic pyeloplasty has been associated with long operative times. This study proposed to evaluate the feasibility of two different laparoscopic techniques for the performance of pyeloplasty repair of secondary ureteropelvic junction (UPJ) obstruction.

Materials and Methods:

Sixteen female Yucatan mini-pigs underwent general anesthesia for cystoscopy, retrograde pyelography, urine culture and a baseline renal scan. Unilateral UPJ obstruction was created by ligating the UPJ over a 5F catheter. Six weeks later a laparoscopic pyeloplasty was performed utilizing an intracorporeal suturing technique and the Lapra-Ty suture clip or the Endostitch device with intracorporeal knot tying. Four control animals underwent only cystoscopy and in/out ureteral catheterization. In the study animals the ureteral stent was maintained for six weeks and at six weeks, three months and six months post-pyeloplasty the animals underwent the previously mentioned studies. At six months post-pyeloplasty the animals were euthanized and the UPJ was calibrated. Histopathology was obtained on the ureter below the anastomosis, at the anastomosis, above the anastomosis and on a renal biopsy.

Results:

All planned laparoscopic pyeloplasties were completed. However, the stricture model was too severe in that most animals developed 40-45% decrease in renal function in the kidney following ipsilateral UPJ ligation. There was no significant difference between the two pyeloplasty techniques with respect to operative time to perform the pyeloplasty (mean of 40 minutes), post-pyeloplasty ureteral caliber (7.5-8.0 F), serum creatinine or healing scores at, above or below the anastomosis.

Conclusion:

Laparoscopic pyeloplasty can be performed equally successfully with the Endostitch device and intracorporeal knot tying or with the intracorporeal suturing technique and Lapra-Ty clips. The resultant pyeloplasty is also equivalent for the two techniques.     

Intracorporeal Knot-Tying and Suturing Techniques in Laparoscopic Surgery: Technical Details

Background:

Intracorporeal suturing and knot-tying in laparoscopic surgery require great manual dexterity; these techniques must absolutely be mastered by every surgeon who is interested in pursuing the minimally invasive approach.

Method:

The initial and final knot of a laparoscopic continuous suture can be accomplished in several ways and with easy technical solutions that are fully illustrated in the present study.

Conclusion:

We think it is better to perform a continuous suture than an interrupted one. It is advisable, moreover, to use traditional suture materials (not specially created for laparoscopy) that cost less than the more sophisticated ones.     

Optimization of the Racking Hitch Knot: How Many Half Hitches and Which Suture Material Provide the Greatest Security?

Background

Reliable methods of fixation of soft tissue and bone are of utmost importance in reconstructive shoulder surgery and in many orthopaedic applications. Current methods of securing lesser tuberosity osteotomies performed during shoulder arthroplasty and tuberosity fixation performed during repair of proximal humeral fractures often rely on alternating half hitches or surgeon’s knots regardless of the suture configuration used passing through the tissue (eg, Mason-Allen, Krackow). The racking hitch knot in contrast to half hitches allows sequential tightening, even under tension, with minimal risk of knot slippage or premature locking. These knot characteristics allow the surgeon to stepwise improve their reduction before committing and locking a construct, preventing hanging knots or under-tensioned repairs. However, little data exist to support the use the racking hitch knot to guide decision making regarding how to back up the knot or to explain the effect of suture material on security and strength.

Questions/purposes

The objectives of our study were (1) to identify the optimal number of half hitches necessary to maintain knot security for a single knot; (2) to evaluate if a difference exists in the relative behavior of racking hitch knots when tied using different suture materials; and (3) to define the biomechanical differences between the racking hitch and two other knot configurations commonly used in shoulder surgery (Weston and square knots).

Methods

Using an Instron device we tested the effect of adding supplemental half hitches (from one to four) to the racking hitch. Additionally, a selection of commercially available braided nonabsorbable polyethylene sutures and different knot configurations (racking hitch, Weston knot, and square knot) also were tested. Data were compared using ANOVA.

Results

Increasing the number of half hitches improved knot performance in peak load testing and cyclic testing, revealing a significant difference between the racking hitch supplemented with one and four half hitches (199.2 N versus 428.8 N, p < 0.05). Force Fiber™ #2 (359.6 N) and FiberWire^® #2 (302 N) showed increased loads to failure compared with Ethibond Excel™ #2 or Force Fiber™ #3/4, whereas Ethibond Excel™ had the least amount of slippage during cyclic testing (0.09 mm). The racking hitch knot had considerably higher loads to failure (359.6 N) than the Weston (145.2 N) or square (77 N) knots.

Conclusions

The racking hitch knot exhibited significantly higher loads to failure and comparable knot slippage (elongation during cyclic testing) when compared with other commonly used knots. According to the biomechanical data, the addition of four half hitches to supplement the racking hitch and the choice of FiberWire^® #2 or Force Fiber™ #2 suture resulted in increased knot security.

Clinical Relevance

This knot adds a tool to the arsenal for surgeons best suited for repairs requiring a high degree of knot security and reliable tissue tensioning.

Electronic supplementary material

The online version of this article (doi:10.1007/s11999-014-3478-0) contains supplementary material, which is available to authorized users.     

Objective Evidence for Optimum Knot Configuration

BACKGROUND: The knot configurations used in clinical practice often are based on tradition and previous training. This study was designed to test the hypothesis that knot quality improves with the addition of a single throw in two-throw and three-throw knots. We tested this hypothesis by using commonly used knot configurations and suture materials. METHODS: Three suture materials, SURGIPRO, BIOSYN and POLYSORB, of 3-0 caliber were used. The break force and integrated force of each material, a single-hitch throw on each material, and 2160 knots of six configurations were measured by using tensiometry. The knot quality scores (KQS) of the different knot configurations were compared by using nonparametric tests. RESULTS: A single-hitch throw on the suture material reduced the break force by up to 40%. The addition of an extra throw improved KQS in 2 x 1 x 1, 2 x 2, and 2 x 2 x 1 knots. The four-throw knot configurations resulted in high KQS and low slippage rates. The 2 x 2 knots were most likely to slip and had the lowest KQS. CONCLUSIONS: If a double-hitch throw is used in the first throw, two to three further throws are recommended. The four-throw knot configurations have the best knot qualities and should generally be used.     

Facilitating Intracorporeal Colorectal Anastomoses

Background and Objectives:

An experimental study was undertaken to evaluate whether a previously described technique for laparoscopic sigmoid resection with intracorporeal resection-anastomosis and specimen removal via a suprapubic incision could be facilitated and applied to the rectum.

Methods:

Ten domestic pigs (median weight 41 kg) underwent low anterior resection of the rectum, which was transected with an articulating endoscopic stapler. Pursestring sutures were fashioned intracorporeally with a laparoscopic pursestring clamp. The anvil of a circular stapler was inserted through a 33 mm port into the colon and pursestring tied intracorporeally. A circular gun with a spike fixed to its shaft was introduced per anum and a double-stapled anastomosis performed.

Results:

Complete doughnuts were obtained in all cases and anastomoses were all methylene blue tight. All porcine subjects had an uneventful 5-week postoperative course. The median anastomotic level from the anal verge was 5.2 cm. Histology of colorectal anastomoses revealed healing mucosa.

Conclusions:

The use of articulating endoscopic stapler, laparoscopic pursestring clamp, and circular stapler with a spike fixed to its shaft seems to facilitate a previously described intracorporeal approach to sigmoid resection which was safely applied to the rectum in a porcine model.     

Influence of instrument size on endoscopic task performance in pediatric intracorporeal knot tying

Background The widespread availability of adult minimal access surgical (MAS) equipment together with resource constraints have led pediatric surgeons to adopt the adult setup. This study examined the influence of instrument size on task outcome and physical impact on the surgeon in pediatric endoscopic intracorporeal knot tying. Methods Sixteen surgeons participated in this study in which they had to tie surgeon’s knots inside a neonatal simulator box with an endoscopic field of 40 mm. All surgeons tied 20 knots using paired pediatric needle-holders and 20 knots using paired adult needle-holders in a randomized order. Knot quality score (KQS) and wrap length were used as indices of knot quality and wrap tightness. Electromyographic (EMG) recordings of the upper limb muscle groups were used to indicate muscular recruitment. A questionnaire on discomfort and instrument preference was also completed by the surgeons. Results A total of 640 knots were analyzed. Median time was shorter for pediatric needle-holders than for adult needle-holders (94 s vs. 103 s; p < 0.001); however, KQS (0.271 vs. 0.260; p = 0.509) and the tightness around the tube (86 mm vs. 86 mm; p = 0.255) were not significantly different. The proportion of knots that completely slipped was also similar for both needle-holders (19% vs. 22%; p = 0.322). The normalized EMG values when using adult needle-holders were significantly higher than when using pediatric needle-holders in all upper limb muscle groups with the exception of left forearm extensors (p = 0.460). The surgeons reported less discomfort with the pediatric needle-holders in the right forearm and hand, and 13 surgeons expressed overall preference for the smaller instruments. Conclusion Endoscopic knot tying was performed faster in the neonatal simulator box using pediatric needle-holders while maintaining knot quality. Upper limb muscular recruitment was reduced resulting in less discomfort for the surgeon. Presented at the 10th World Congress of Endoscopic Surgery incorporating the 14th International Congress of the European Association for Endoscopic Surgery (EAES), Berlin, Germany, 13-16 September 2006 Preliminary data of this study were presented at the British Association of Paediatric Surgeons Annual Conference, Stockholm, Sweden, 20 July 2006     

Rocker handle for endoscopic needle drivers

Background: The design of the handle on instruments for endoscopic surgery determines comfort and efficiency of use by the surgeon. This applies particularly to needle drivers. Methods: A novel rocker handle was designed to provide holding comfort and intuitive function. This rocker handle was compared with a finger-loop handle in a study involving 10 surgeons who tied a total of 360 intracorporeal surgeons' knots in a random sequence. The end points in this study were the execution time, knot quality, and motion analysis parameters of the surgeon's elbow and shoulder joints. Results: Intracorporeal surgeon's knots tied with the rocker-handle driver exhibited a better knot quality, although this was not significant (p= 0.097). A significant improvement in the knot quality score (KQS) was observed between the first and the second sessions (p= 0.045) with the rocker handle, whereas no significant learning effect was observed for the finger-loop handle. During intracorporeal knot tying, the angular velocity at the elbow and shoulder joints was consistently lower with the rocker handle, suggesting that more controlled movements are enacted by the surgeon with this handle. Discomfort from finger-loop pressure on the thumb was reported by 3 of 10 surgeons with the finger-loop handle, whereas no discomfort was reported for the rocker handle. Conclusions: The new rocker handle improves the quality of task performance by eliminating discomfort and reducing angular velocities at the shoulder and elbow joints during use. Received: 26 May 1998/Accepted: 12 January 1999     

The Laparoscopic Approach for Repair of Morgagni Hernias

Background and Objectives:

Morgagni hernias are unusual congenital diaphragmatic hernias that are generally asymptomatic and discovered incidentally. Surgical treatment is indicated once the diagnosis is made. These hernias have traditionally been repaired by the open abdominal or thoracic approaches. We report a case of Morgagni hernia repaired successfully via the laparoscopic approach.

Methods and Results:

The patient was noted to have a large anteromedial diaphragmatic hernia by chest radiograph and CT imaging. He underwent laparoscopy, during which the hernia was reduced and the defect repaired with mesh placement. We used intracorporeal suture placement to anchor the mesh. The patient recovered uneventfully after a short hospitalization.

Conclusions:

The laparoscopic approach for repair of Morgagni hernias offers diagnostic advantages as well as the potential for reduced morbidity when compared to laparotomy. We report intracorporeal knot-tying for fixation of the mesh to be a secure and satisfactory means to achieve the laparoscopic repair.     

Laparoscopic Anterior Resection: New Anastomosis Technique in a Pig Model

Background and Objectives:

Bowel anastomosis after anterior resection is one of the most difficult tasks to perform during laparoscopic colorectal surgery. This study aims to evaluate a new feasible and safe intracorporeal anastomosis technique after laparoscopic left-sided colon or rectum resection in a pig model.

Methods:

The technique was evaluated in 5 pigs. The OrVil device (Covidien, Mansfield, Massachusetts) was inserted into the anus and advanced proximally to the rectum. A 0.5-cm incision was made in the sigmoid colon, and the 2 sutures attached to its delivery tube were cut. After the delivery tube was evacuated through the anus, the tip of the anvil was removed through the perforation. The sigmoid colon was transected just distal to the perforation with an endoscopic linear stapler. The rectosigmoid segment to be resected was removed through the anus with a grasper, and distal transection was performed. A 25-mm circular stapler was inserted and combined with the anvil, and end-to-side intracorporeal anastomosis was then performed.

Results:

We performed the technique in 5 pigs. Anastomosis required an average of 12 minutes. We observed that the proximal and distal donuts were completely removed in all pigs. No anastomotic air leakage was observed in any of the animals.

Conclusion:

This study shows the efficacy and safety of intracorporeal anastomosis with the OrVil device after laparoscopic anterior resection.     

The Triad Knot: A New Sliding Self-Locking Knot

Tying secure knots is essential in arthroscopic surgery. A new slip knot for arthroscopic shoulder surgery is described. Locking of the knot is accomplished by pulling the post strand. Knot tying is simple and a low-profile, secure knot is produced.     

Laparoscopic Cholecystectomy in Elderly Patients

Background and Objective:

In this study, we investigated whether laparoscopic cholecystectomy, a minimally invasive procedure, is advantageous in elderly patients.

Methods:

Data from 595 patients who underwent laparoscopic cholecystectomy between January 2003 and December 2007 were prospectively collected in a database. The patients were separated into 2 groups; patients >70 years of age (group A), and patients <70 years of age (group B). Group A was further divided into 3 subgroups, ages 70 to 74, 75 to 79, and 80 and above. Comparison between the groups was made with Mann-Whitney U and chi-square tests where appropriate.

Results:

ASA scores increased in conjunction with increased age (P<0.001). Of patients with an operative time longer than one hour, 26 patients aged 70 or older, and 152 patients aged 69 or younger had no difference with respect to PaCO₂ and pH measurements (P>0.05). In patients aged 80 or older, the rates of acute cholecystitis, conversion to open surgery, and postoperative complications were significantly higher than in other groups (P>0.05).

Conclusion:

We believe that in elderly patients, laparoscopic surgery can be applied safely without further increasing the surgical risks. The complications can be minimized by carefully selecting the patients aged 80 or older and by experienced teams with high technical capabilities operating on such patients.     

Knot security in laparoscopic surgery

Background: Few comparative studies have evaluated conventional and laparoscopic knots. The objective of this study was to evaluate laparoscopic knot reliability and identify which type of knot is most secure. Methods: Seven types of knots were compared; each one was conventionally tied with four and six throws and similarly by laparoscopy. Dinsmore nomenclature for knots was used. A tension meter was used to evaluate knot reliability, using the loop method, and percentage of failure by slipping and tensile strength was calculated for each group. Results: When S=S=S=S and S=S=S=S=S=S geometry are excluded, there was no difference between laparoscopic and conventional knot. A significant difference between four- and six-throw knots was shown. Excluding S=S=S=S=S=S geometry, all knots in the conventional six-throw group were secure. Intracorporeal 2X1X1X1X1 and 1X1X1X1X1X1 and extracorporeal SXS#SXS#SXS six-throw laparoscopic group knots were secure. Conclusions: Laparoscopic knots are as secure as conventional knots. All knots must be made with six throws because security is maximized.     

Laparoscopic and open partial nephrectomy: complication comparison using the Clavien system

Background and Objectives:

To compare postoperative complications in patients undergoing laparoscopic and open partial nephrectomy using a standardized complication-reporting system and a standardized tumor-scoring system.

Methods:

We conducted a retrospective analysis of 189 consecutive patients with nephrometry scores available who underwent elective partial nephrectomy for renal masses. Demographic, perioperative, and complication data were recorded. By using the modified Clavien scale, we graded 30- and 90-day complication rates.

Results:

107 patients underwent laparoscopic partial nephrectomy and 82 underwent open partial nephrectomy (N=189). Open partial nephrectomy patients had higher nephrometry scores than laparoscopic patients had (7.1±2.4 vs. 5.6±1.8, P<.001). Surgical and hospitalization times were shorter, and estimated blood loss was lower in the laparoscopic group (P<.001). At 30 days, there were more overall complications in the open group, but more major complications in the laparoscopic group (P>.05). After multivariable logistic regression analysis, only higher body mass index and higher estimated blood loss were predictors of more overall complications.

Conclusions:

Laparoscopic partial nephrectomy has the advantages of decreased operative time, lower blood loss, and shorter hospital stay. The complication rate in the laparoscopic group is similar to that in the open group, despite favorable tumor characteristics in the laparoscopic group.     

Laparoscopic supracervical hysterectomy versus laparoscopic-assisted vaginal hysterectomy

Objectives:

To compare the incidence of perioperative complications and postoperative healthcare utilization and costs in laparoscopic supracervical hysterectomy (LSH) versus laparoscopic-assisted vaginal hysterectomy (LAVH) patients.

Methods:

Women ≥18 years with LSH or LAVH were extracted using a large national commercial claims database from 1/1/2007 through 9/30/2008. Outcome was perioperative complications and gynecologic-related postoperative resource use and costs. Multivariate analysis was performed to compare postsurgical outcomes between the cohorts.

Results:

The final sample consisted of 6,198 LSH patients and 14,181 LAVH patients. LSH patients were significantly more likely to have dysfunctional uterine bleeding and leiomyomas and less likely to have endometriosis and prolapse as the primary diagnosis, and also significantly more likely to have a uterus that weighed >250 grams than LAVH patients. Compared with LAVH patients, LSH patients had significantly lower overall infection rates (7.4% versus 6.2%, P=.002) and lower total gynecologic-related postoperative costs ($252 versus $385, P<.001, within 30 days of follow-up and $350 versus $569, P<.001, within 180 days of follow-up). Significant cost differences remained following multivariate adjustment for patient characteristics.

Conclusions:

LSH patients demonstrated fewer perioperative complications and lower GYN-related postoperative costs compared to LAVH patients.