Comparing the tensile strength of square and reversing half-hitch alternating post knots.

BACKGROUND: Square knots are the gold standard in hand-tie wound closure, but are difficult to reproduce in deep cavities, inadvertently resulting in slipknots. The reversing half-hitch alternating post (RHAP) knot has been suggested as an alternative owing to its nonslip nature and reproducibility in limited spaces. We explored whether the RHAP knot is noninferior to the square knot by assessing tensile strength. METHODS: We conducted 10 trials for each baseline and knot configuration, using 3-0 silk and 3-0 polyglactin 910 sutures. We compared tensile strength between knot configurations at the point of knot failure between slippage and breakage. RESULTS: Maximal failure strength (mean ± SD) in square knots was reached with 4-throw in both silk (30 ± 1.5 N) and polyglactin 910 (39 ± 12 N). For RHAP knots, maximal failure strength was reached at 5-throw for both silk (31 ± 1.5 N) and polyglactin 910 (41 ± 13 N). In both sutures, there were no strength differences between 3-throw square and 4-throw RHAP, between 4-throw square and 5-throw RHAP, or between 5-throw square and 6-throw RHAP knots. Polyglactin 910 sutures, in all knot configurations, were more prone to slippage than silk sutures (p < 0.001). CONCLUSION: The difference in mean tensile strength could be attributed to the proportion of knot slippage versus breakage, which is material-dependent. Future studies can re-evaluate findings in monofilament sutures and objectively assess the reproducibility of square and RHAP knots in deep cavities. Our results indicate that RHAP knots composed of 1 extra throw provide equivalent strength to square knots and may be an alternative when performing hand-ties in limited cavities with either silk or polyglactin 910 sutures.

CONTEXTE: Les nœuds plats sont la norme en matière de points de suture manuels, mais ils sont difficiles à reproduire dans des cavités profondes et deviennent par inadvertance des nœuds coulants. Le nœud de type demi-clé inversée alternée a été proposé comme solution de rechange en raison de sa nature non glissante et de sa reproductibilité dans des espaces restreints. Nous avons voulu vérifier la non-infériorité de la demi-clé inversée alternée par rapport au nœud plat en évaluant sa résistance à la traction. MÉTHODES: Nous avons réalisé 10 essais de référence et autant d'essais pour chaque type de nœud, en utilisant des fils de soie de taille 3-0 et de polyglactine 910 de taille 3-0. Nous avons comparé la résistance à la traction des différentes configurations de nœuds, c'est-à-dire le point de défaillance entre le glissement du nœud et la rupture de celui-ci. RÉSULTATS: La résistance maximale à la traction (moyenne ± É.-T.) des nœuds plats a été atteinte avec 4 boucles, tant pour le fil de soie (30 ± 1,5 N) que le fil de polyglactine 910 (39 ± 12 N). Pour les demi-clés inversées alternées, la résistance maximale à la traction a été atteinte avec 5 boucles pour le fil de soie (31 ± 1,5 N) et de polyglactine 910 (41 ± 13 N). Dans les 2 types de sutures, on n'a noté aucune différence de résistance entre le nœud plat à 3 boucles et la demi-clé inversée alternée à 4 boucles, entre le nœud plat à 4 boucles et la demi-clé inversée alternée à 5 boucles, ni entre le nœud plat à 5 boucles et la demi-clé inversée alternée à 6 boucles. Dans tous les types de nœuds, les sutures de polyglactine 910 ont été plus sujettes au glissement que les sutures de soie (p < 0,001). CONCLUSION: La différence de résistance moyenne à la traction a pu être attribuée à la proportion de glissement c. la rupture des nœuds, qui dépend du matériau. D'autres études pourraient réévaluer les résultats obtenus avec des sutures monofilaments et mesurer objectivement la reproductibilité des nœuds plats et des demi-clés inversées alternées dans des cavités profondes. Selon nos résultats, les demi-clés inversées alternées comportant une boucle supplémentaire offrent une résistance équivalente à celle des nœuds plats et seraient une solution de rechange lors de sutures manuelles dans des cavités restreintes, avec la soie ou la polyglactine 910.

A prospective, randomized assessment of a spatial orientation device in natural orifice transluminal endoscopic surgery.

BACKGROUND: One of the challenges in natural orifice transluminal endoscopic surgery (NOTES) is spatial orientation. The Queen's NOTES group has devised a novel method of orientation by using a magnetic device that passes within an endoscope channel allowing for 3-dimensional imaging of the shape and orientation of the endoscope. OBJECTIVE: To assess the feasibility and utility of a novel orientation device. DESIGN: Randomized, controlled trial. SETTING: Animal research laboratory study on four 25-kg pigs. INTERVENTION: The device was tested by 6 endoscopists and 6 laparoscopic surgeons. Starting at the gastrotomy, the time to identify 4 targets was recorded. Participants were required to identify and touch the gallbladder, the fallopian tube, a clip on the abdominal wall, and the liver edge. Use of the orientation device was randomized for each session. MAIN OUTCOME MEASUREMENTS: Time to identify targets with and without the device. Secondary analysis assessed differences between medical specialties and level of training. RESULTS: The mean time to identify all 4 targets with the device was 75.08 ± 42.68 seconds versus 100.20 ± 60.70 seconds without the device (P <.001). The mean time to identify all 4 targets on the first attempt was 102.29 ± 61.36 seconds versus 72.99 ± 40.19 seconds on the second attempt (P <.001). No differences based on specialty or level of training were identified. LIMITATIONS: Small sample size and simplicity of tasks. CONCLUSION: Regardless of randomization order, both groups were faster with the device. These encouraging results warrant further study using more complex scenarios.

Patient perceptions of natural orifice translumenal surgery.

Natural orifice translumenal endoscopic surgery (NOTES) is on the forefront of surgical technique, but existing research has produced mixed results regarding factors associated with interest in the procedure. Our objective was to ascertain patient opinions at a Canadian centre regarding scarless surgery. A survey comprising demographic data (gender, age, body mass index [BMI]), interest in NOTES, impact of increased risk, as well as importance of further research and shorter recovery time was administered to volunteer patients at outpatient general surgery clinics. Nonparametric tests were utilized to examine difference in response by age, sex, BMI, and preexisting scars. Of the 335 participants (57% female, mean age of 54.5 ± 15.9 years, mean BMI of 28.7 ± 6.9), the majority (83%) showed some interest, but this dropped to 38% when additional risk was factored in. Generally, women, those under 50 years of age and those of healthy weight, were more interested than male, older, and/or heavier patients. Most felt that research into NOTES and reduced length of inpatient stay were important (80% and 95%, respectively). Further investigation into objective NOTES outcomes are needed to provide patients adequate data to make an informed choice regarding surgical route.

Treatment of esophageal achalasia with Heller myotomy: retrospective evaluation of patient satisfaction and disease-specific quality of life.

BACKGROUND: Prospective randomized studies have suggested that surgery palliates esophageal achalasia more effectively than pneumatic dilatation, but for some dilatation is still the procedure of choice for initial treatment. We decided to compare achalasia symptoms before and after Heller myotomy by means of postoperative questionnaires. METHODS: The study included 22 patients who underwent Heller myotomy for achalasia at the Hotel Dieu Hospital, Queen's University, Kingston, Ont., since July 1990; 5 of them required repeat myotomy for symptom recurrence, for a total of 9 open and 18 laparoscopic procedures. Median follow-up was 43 (range 6-109) months. Preoperative and postoperative data regarding dysphagia, regurgitation, chest pain and overall patient satisfaction were gathered. Symptom scores were calculated by adding severity (0 = none, 2 = mild, 4 = moderate, 6 = severe) to frequency (0 = never, 1 = occasionally, 2 = once a month, 3 = every week, 4 = twice a week, 5 = daily). Patients having a repeat procedure were instructed to evaluate symptoms with respect to their initial myotomy. RESULTS: Seventeen (77%) patients were successfully contacted, 4 of them had subsequent repeat myotomy for symptom recurrence. Initially, overall symptom scores decreased for all but 1 patient, with mean preoperative and postoperative values of 23.1 and 7.3 respectively (p < 0.001). The patient in whom symptoms did not improve is a candidate for a repeat procedure. Repeat myotomy was performed after a median of 38 (range 23-75) months, corresponding to an overall 3-year positive outcome in 13 (76%) of the 17 patients. Fifteen (88%) patients considered their myotomies a success and 16 (94%) would choose to have this procedure again given the outcome. CONCLUSION: Heller myotomy appears to be effective in alleviating the symptoms of achalasia. Repeat myotomy is occasionally required.

Risk of emergency admission while awaiting elective cholecystectomy.

BACKGROUND: There is uncertainty regarding the frequency of adverse events while on a surgical waiting list. We assess the relationship between the duration of wait for cholecystectomy and the risk of emergency admission. METHODS: We analyzed time to emergency admission in a group of 761 patients who underwent cholecystectomy after being seen in clinic for biliary colic and placed on waiting lists at 2 acute care centres in Ontario, from 1997 to 2000. RESULTS: Emergency admissions due to worsening symptoms occurred in 51 patients (6.7%) waiting for elective cholecystectomy. The weekly rate of emergency admission was low during the first 19 weeks on the list, but increased almost by a factor of 3 after 20 weeks (rate ratio 2.7; 95% confidence interval 2.0-3.7). Relative to the first 4 weeks on the list, the rate was 1.6 times higher after 20 weeks, 2 times higher after 28 weeks and 7 times higher after 40 weeks. INTERPRETATION: The probability that a patient on a waiting list will be admitted for emergency cholecystectomy consistently increases with the duration of wait, particularly after 20 weeks.