Ileosigmoid Knot

Ileosigmoid knotting, also known as compound volvulus or double Volvulus, is a rare cause of acute intestinal obstruction. In this condition the ileum wraps around the base of the sigmoid colon and forms a knot. The condition is serious, generally progressing rapidly to gangrene of both ileum and sigmoid colon. Ileosigmoid knotting is an unusual entity in the West, but is comparatively common in certain African, Asian and Middle Eastern nations. Awareness of the condition is essential for prompt diagnosis and optimal management. This article will focus on the etiopathogenesis, presentation, diagnostic modalities, surgical interventions and outcome with review of articles and case reports published till date.     

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.     

The HU Knot: A New Sliding Knot for Arthroscopic Surgery

Sliding knots are commonly used in arthroscopic knot tying. The Surgical knot as a hand-tied knot is very secure. We found that the Surgical knot could be used as a sliding knot. We have modified the Surgical knot to include a self-locking loop. A new sliding knot for arthroscopic surgery, the HU knot, is described. By tensioning the loop strand, the self-locking loop creates a snug knot without sliding backward. The HU knot provides great security.     

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.     

Knot strength of nylon-band cerclage

Nylon bands of five sizes were tested to failure using a splint circular jaw mounted on a tensile testing machine. Four treatment groups of each of the five sizes were tested: as supplied by the manufacturer, ethylene oxide sterilized, autoclave sterilized, and saline-soaked. Comparisons were made between groups and to previously reported results of similar testing of stainless steel wire of three sizes. All the bands failed at the lock mechanism. Knot strength increased with increased size of nylon band. There was no difference between untreated and ethylene oxide sterilized bands, whereas bands subjected to autoclaving or saline soaking failed at less force. The knot strength of all the treatment groups in the three smaller sizes of bands was less than twist-knotted 0.8-mm wire cerclage; and when soaked in saline for 24 hours, the knot strength of the two largest size bands dropped to less than 1.2-mm twist-knotted wire.     

Knot strength of nylon-band cerclage

Nylon bands of five sizes were tested to failure using a splint circular jaw mounted on a tensile testing machine. Four treatment groups of each of the five sizes were tested: as supplied by the manufacturer, ethylene oxide sterilized, autoclave sterilized, and saline-soaked. Comparisons were made between groups and to previously reported results of similar testing of stainless steel wire of three sizes. All the bands failed at the lock mechanism. Knot strength increased with increased size of nylon band. There was no difference between untreated and ethylene oxide sterilized bands, whereas bands subjected to autoclaving or saline soaking failed at less force. The knot strength of all the treatment groups in the three smaller sizes of bands was less than twist-knotted 0.8-mm wire cerclage; and when soaked in saline for 24 hours, the knot strength of the two largest size bands dropped to less than 1.2-mm twist-knotted wire.     

Towards a Better Laparoscopic Knot: Using Knot Quality Scores to Evaluate Three Laparoscopic Knot-Tying Techniques

Objective:

In the past, knot-tying techniques have been evaluated and compared, but there has been a scarcity of objective scoring systems in these comparison studies. Using an objective scoring system, we aimed to compare 3 types of knots: intracorporeal flat-square knots, intracorporeal slip-square knots, and extracorporeal square-knots for their Knot Quality Scores (KQS) and their rates of slippage.

Materials and Methods:

Three surgeons tied 100 knots in the 3 knot categories. The knots tied were evenly distributed amongst the 3 surgeons with each surgeon contributing at least 30 knots. These knots were tied in a nonrandomized fashion. Forces were measured using a tensiometer and an objective scoring system, the Knot Quality Score (KQS), which is used to compare the knot''s strength and rates of slippage.

Results:

Median KQS scores of the 3 groups were not all the same. The median KQS and variance for the extracorporeal square knot group was 0.32 and 0.0079, respectively. For the intracorporeal slip-square knot group, the median KQS and variance was 0.28 and 0.00017, respectively. Lastly, for the intracorporeal flat-square knot group, the median KQS and variance was 0.33 and 0.0075, respectively. Follow-up analysis revealed that the KQS medians (0.32 versus 0.28) of the extracorporeal square-knots and intracorporeal slip-square knot groups were significantly different (P<0.0001). The medians of the intracorporeal slip-knot and intracorporeal flat-square knot groups (0.28 versus 0.33) were also statistically significantly different (P<0.0001). There was no statistically significant difference in KQS scores between extracorporeal square-knots and intracorporeal flat-square knots.

Conclusion:

Extracorporeal square-knots and intracorporeal flat-square knots can tolerate better distraction forces and thus have higher median KQS scores compared with intracorporeal slip-square knots.     

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.     

Knot in a thoracic epidural catheter

We report a case of impossible injection into a thoracic epidural catheter associated with a difficult withdrawal of this catheter after its introduction on the T3-T4 level. Thanks to a gentle and continuous traction, the catheter was finally successfully removed without being broken, but presented a simple knot at 13 mm from its end. No neurological complication was observed later on. This complication happened during the introduction of the catheter at the thoracic level where anatomic conditions are less favorable for this kind of complication to happen than at the lumbar level. We have been probably confronted with a catheter taking an abnormal direction due to an anatomic structure. This case shows us that knots in an epidural catheter are also possible on the high thoracic level and that its ascent within the epidural space must happen without any resistance.     

Knot strength of cerclage bands and wires

I compared the knot strength of loop- and twist-knotted cerclage wires, and Parham and CPC bands, using a knot-slip resistance test. Two twist-knot devices and one loop-knot device were used to apply cerclage wires, and a band clamp was used to apply bands to a 5-cm-diameter split circular jaw mounted on a tensile testing machine. For all the wire sizes tested, the twisted knot provided greater resistance to knot failure than did the loop knot. Knot resistance increased with increase in wire size for all the devices tested. Neither band produced knot-slip resistance as great as 1.2-mm twist-knotted wire.     

A New Knot Technique for Vessel Ligatures

A new technique for ligating vessels and similar structures that offers more security is described. The aim of the study was to test whether this hypothesis was correct. Six different types of knots, including the one described in this article were compared by a strength-testing study. The knots were tied on a silicon tube through which a constant air flow of 795.10 mmHg of pressure circulated. Tension of 2 kg was then applied to both loose ends of the suture filament (polyglyconate n°1 gauge) for 25 seconds. Then, 15 seconds after the tension was released an overpressure of 2250.31 mmHg was applied to the system. Two computerized pressure sensors were applied to both ends of the tube. The newly described knot reached the highest strangulating force (997.63 mmHg) and had the highest resistance to slippage. From these results, we conclude that the new knot is far more secure for vessel and duct ligature and that it represents a new and useful tool for surgeons in both open and laparoscopic surgery.     

Knot strength of cerclage bands and wires

I compared the knot strength of loop-and twist-knotted cerclage wires, and Parham and CPC bands, using a knot-slip resistance test. Two twist-knot devices and one loop-knot device were used to apply cerclage wires, and a band clamp was used to apply bands to a 5-cm-diameter split circular jaw mounted on a tensile testing machine. For all the wire sizes tested, the twisted knot provided greater resistance to knot failure than did the loop knot. Knot resistance increased with increase in wire size for all the devices tested. Neither band produced knot-slip resistance as great as 1.2-mm twist-knotted wire.     

棉针织服装扎染工艺

阐述了棉针织服装扎染的基本原理，并在反复试验的基础上，探索出棉针织服装的扎结方法，染色过程和后整理等扎染工艺。