Knotting abilities of a new absorbable monofilament suture: poliglecaprone 25 (Monocryl).

OBJECTIVE: To study the mechanical knotting abilities of the new synthetic absorbable monofilament suture poliglecaprone 25 (Monocryl) compared with other absorbable suture materials. DESIGN: Experimental laboratory study. MATERIAL: Knotted loops (3/0 USP) of five synthetic absorbable sutures: Monocryl (poliglecaprone 25), PDS-2 (polydioxanone), Maxon (polyglyconate), Vicryl (polyglactin-910) and Dexon-Plus (polyglycolic acid). Three different knots were tested in a total of 150 experiments. MAIN OUTCOME MEASURES: Mean loop holding capacity (LHC) of 10 experiments, expressed in Newtons (N). RESULTS: Monofilament Maxon tied significantly more secure knots than the other sutures. Sliding knots of Monocryl (poliglecaprone 25) were similar to, and three-throw square knots were less secure than those tied with monofilament PDS-2. Braided Dexon-Plus was superior to Monocryl for sliding knots but comparable for square knots. Braided Vicryl did not differ significantly from Monocryl. CONCLUSION: The mechanical knot performance of Monocryl is identical to that of Vicryl, less than that of one other synthetic absorbable monofilament suture (Maxon) and comparable to or somewhat less than the other alternative (PDS-2). These findings, together with other characteristics such as degradation rate, should be used to define the application of Monocryl.

[Frequency and determinants of episiotomy in second-line obstetrics in The Netherlands]. / Frequentie en determinanten van episiotomie in de tweedelijnsverloskunde in Nederland.

OBJECTIVE: To study factors that influence the probability of episiotomy in Dutch gynaecologist-supervised deliveries. SETTING: Obstetric units of Dutch hospitals. DESIGN: Observational study. METHODS: Data of 65,313 gynaecologist-supervised, vaginal deliveries of live-born singletons registered in the Dutch National Obstetric Database of 1990, were used. Firstly, the effect of characteristics of the mother, the child, the pregnancy, and the delivery on the probability of episiotomy were assessed in univariate analyses. Subsequently logistic regression analysis was used to determine the effect of each variable, while adjusting for the other variables. RESULTS: The episiotomy rate in the total group of gynaecologist supervised deliveries was 39%. In the subgroup of vaginal deliveries of live born singletons, the rate was 46%. Besides the well-known risk factors such as parity, instrumental delivery and length of second stage of labour, ethnicity was also found to have an independent effect on the risk of an episiotomy. Mediterranean, Creole and Hindu women had a lower episiotomy risk than Dutch women (OR: 0.47 and 95% CI: 0.44-0.51). Gynaecologists more often performed episiotomy than midwives, after adjusting for possible confounding factors (OR: 1.54; 1.46-1.63). In University hospitals fewer episiotomies were performed than in large non-university hospitals (OR: 0.81; 0.76-0.87. CONCLUSION: The decision to perform episiotomy appears not to depend solely on factors related to perineal rupture or foetal complications. The probability of episiotomy is also influenced by attendant at delivery and type of hospital.

Episiotomies and the occurrence of severe perineal lacerations.

OBJECTIVE: To investigate the relation between the use of mediolateral episiotomy and the occurrence of severe (third degree) perineal tears in hospital deliveries in the Netherlands. DESIGN: An observational study. SUBJECTS: Data were derived from the Dutch National Obstetric Database (LVR) of 1990, from which 43,309 spontaneous, occipito-anterior, vaginal deliveries of live, singleton infants were investigated. INTERVENTION: Medio-lateral episiotomy. MAIN OUTCOME MEASURE: The occurrence of severe perineal tears. RESULTS: The severe tear rate was 1.4% in the total study group. Using multiple logistic regression to control for possible confounding variables, the use of mediolateral episiotomy was found to be associated with a more than fourfold decrease in risk of severe lacerations (odds ratio 0.22, 95% CI 0.17 to 0.29). Further, in a logistic model deliveries in hospitals with restrictive use of episiotomy (< 11%) were compared with those in hospitals with liberal use of episiotomy (> 50%). Liberal use of episiotomy was not associated with a lower frequency of severe perineal tears. CONCLUSION: Although a protective effect of mediolateral episiotomy on the occurrence of severe lacerations was found, liberal use of mediolateral episiotomy should be discouraged on the basis of our findings.

Hormone-dependent spinal leiomyoma.

A 43-year-old woman underwent subtotal removal of a cervical spinal leiomyoma in 1980 and 1981. When her (cyclic) symptoms recurred and tumor growth was demonstrated, she was treated with a synthetic anti-gonadotropic hormone (Danazol; Danatrol) until menopause, when medication could be discontinued without further recurrence of her symptoms or increase in size of the residual tumor.

Mechanical performance of square knots and sliding knots in surgery: comparative study.

Various square knots, sliding knots, and surgeon's knots in mono- and multifilament suture material of different diameters were tested with respect to knot strength and knot security. Loop holding capacity of knots varied from 37.2 to 149.8 N, depending on the kind of knot, knot configuration, kind of suture, suture structure, and suture dimension. On the whole, square knots proved to be more reliable than sliding knots. Knot performance of surgeon's knots was not better than that of square knots. Knot security of three-throw sliding knots and two-throw square knots and surgeon's knots was rather poor. These knots cannot be recommended for clinical use. In smaller diameter mono- and multifilament suture material, knot performance of sliding knots that contained one extra throw was identical to that of square knots. It is concluded that the outcome of the comparison of square knots and sliding knots depends on knot configuration, suture material, and suture size. The implications of these laboratory findings for clinical use are discussed.

Factors relating to the volume of surgical knots.

The suture's knot site represents the highest amount and density of foreign body material of a knotted suture loop. The volume of a knot is directly related to the total amount of inflammatory reaction surrounding the knot. We measured the volume of seven surgical knots frequently used in surgical practice. Two different suture materials and two different sizes were tested. Suture size was found to contribute significantly more to the volume of all knots tested than the number of throws of which the knots were composed. Knots made with coated multifilament polyglactin-910 were significantly larger than the knots made with monofilament nylon. Clinical implications of these findings are discussed. Surgical techniques keeping the volume of knots to a possible minimum, are encouraged.

Tissue reaction and surgical knots: the effect of suture size, knot configuration, and knot volume.

Tissue reaction surrounding surgical knots was assessed histologically using a semiquantitative scoring system in 40 male Wistar rats. We tested sizes 2/0 and 4/0 (United States Pharmacopeia [USP]) coated polyglycolic acid and coated polyglactin-910 sutures, and two different knots. In addition, we measured the volume of the different knots and the total volume of tissue reaction surrounding the knots. Multivariate analysis showed only suture material and suture size to be independent factors determining tissue reaction. An increase of suture size resulted in a more than four- to sixfold increase in knot volume and a more than two- to threefold increase in the amount of the tissue-reaction sheath; however, the addition of extra throws to the knot enlarged the knot body by a factor of ony 1.5 and the tissue-reaction sheath by a factor of 1.0-1.9. These findings suggest that the use of thick-gauge suture material adds much more to the total amount of foreign body and tissue reaction in the wound than the addition of extra throws to the knot and might, therefore, be deleterious to optimum wound healing.

Assessment of tissue reaction at suture knots; an adaptation of Sewell's scoring system.

From a theoretical point of view and from reported animal work the knot side should be considered the most relevant part of the suture loop for studying inflammatory foreign body reaction. In the present study a semi-quantitative histological assessment of inflammatory tissue reaction around the knots of implanted sutures is presented. To test the reliability of this method an animal model was used in which two suture materials with well-known differences in tissue reactivity were studied. Differences in tissue response around the knots between these materials proved to be highly significant statistically (tissue reactivity score (TRS) 44.17 vs. 58.71: p less than 0.001). No differences in TRS could be demonstrated between different localizations in the anterior abdominal wall of male Wistar rats. Implications of these findings with respect to future studies are discussed.

Performance of sliding knots in monofilament and multifilament suture material.

Three different sliding knots were tested using five recently developed monofilament and multifilament suture materials. The resorbable materials were polyglactin-910 (Vicryl), polyglycolic-acid (Dexon-Plus), polyglyconate (Maxon), and polydioxanone (PDS), and the nonresorbable material was polypropylene (Prolene). For each type of sliding knot, three or five throws of suture were tested. Knot strength was determined by the loop holding capacity, which was defined as the strength at which the knot broke, or at which slippage in the knot amounted to more than 2 mm. When the three kinds of sliding knots were compared, identical sliding knots with identical throws around a single suture were found to be the most unreliable. Nonidentical and parallel sliding knots differed little with respect to knot reliability. Five-throw knots were generally stronger than three-throw knots. However, the effect of adding two extra throws to three-throw sliding knots was only significant if monofilament suture material was used. Comparison of the different suture materials revealed major differences in knot holding ability. These findings indicate that knot strength is dependent on both the type of knot and the type of suture material, and surgeons should be cognizant of these variables.