Silk sutures

Silk (qv) suture is made from the threads spun by the silkworm Bombjx mori. The fiber is composed principally of the protein fibroin and has a natural coating composed of sericin gum. The gum is usually removed before braiding the silk yams to make sutures in a range of sizes. Fine silk sutures may be made by simply twisting the gum-coated silk yams to produce the desired diameter. White silk is undyed. Silk is either dyed black with logwood extract or blue with D C Blue No. 9. The suture may be uncoated or coated either with high molecular weight polydimethylsiloxane or with wax. 

D C Blue No. 9 (12) Indanthrene Blue Carbanthrene Blue Cl Vat Blue 6 [130-20-1] 69825 cotton and silk sutures (including those for ophthalmic use) only 2.5% (w/w) max dmgs in general... 

When suppurative wounds were treated with the widely used Vishnevsky ointment or synthomycin emulsion they soon became free from necrotic tissues to form rich granulations. Application of the l-(chloromethyl)silatrane ointment did not accelerate this process. The postoperatively silk-sutured wound healed at the proper time (7-10days). 

Kolb [203] describes a stepwise gas-extraction procedure called multiple headspace extraction (MHE). Using this method, Kolb found that the determination can be performed with only two extractions. The volume of the sample was compensated for by adding a similar volume of an inert material such as glass beads. Ethylene oxide in surgical silk sutures was determined by this procedure. The extrapolated total area (four steps) was nearly identical to the total area value obtained using the two-step MHE process, 184 versus 183, respectively. 

The cannula is then removed from the trachea, which is closed with silk suture thread. 

The trachea and lungs are dissected free from the heart and surrounding tissue and a sterile plastic catheter is inserted into the middle portion of the trachea and secured with silk suture. 

Sprague-Dawley rats weighing 150-200 g are anesthetized. Through a 6-cm midline incision in the abdominal wall the small bowel and cecum are lifted and placed on saline-soaked gauze sponges. The exposed right kidney is dissected from the retroperitoneal area and the vascular and ureteric pedicles are ligated with 2-0 silk sutures, transected, and the kidney is removed. The renal artery of the left kidney is dissected... 

Fig. 19 Nitroblue tetrazolium stained heart sections of rabbits with acute myocardial infarction treated with PL (left panel), saline placebo (middle panel) and IL (right panel). The sites of left circumflex coronary artery occlusion can be seen in the middle and right panels to be at the 4th slices by the presence of the silk sutures. Normal myocardium is stained purple or brown, whereas the infarcted regions remain as light colored regions.

A left thoracotomy is performed and the anterior descending coronary artery is occluded with a silk suture placed through the myocardium with an SH-needle. 

Postsurgical Adhesion Data at One Week with HA/Interleuken-4 (IL-4) Formulations and Placebos Using Sidewall Model with Silk Sutures... 

This study is designed to compare the effect of ftie gel-former selected in Section 13.3.4.2 on POA wifti a size 6-0 silk suture/saline, HA, and C-TA as basic barrier and positive controls, respectively. The adhesion formation was studied using a rat sidewall model. The abdominal cavity was entered into in female Sprague-Dawley rats through a small midline incision. A 1-cm2 area of peritoneal sidewall was excised wifti a scalpel blade. The 6-0 silk was then sutured aroimd the perimeter of ftie excised area with a square knot at each corner. Aliquots of either the gel-former (100 pL) or the controls (1 mL) were injected on tiie excised site. One week postoperative, the adhesion prevention score was recorded for the different formulations on a scale of 0 to 10. A score of 10 represents maximum adhesion whereas 0 reflects the absence of any adhesions. Adhesion rating criteria were based on the work by Bums et al. ... 

H.K. Soong, K.R. Kenyon, Adverse reactions to virgin silk sutures in cataract surgery. Ophthalmology 91 (1984) 479-483. 

Fig. la shows the surface of untreated silk suture, already containing many impurities. The filaments have no regular diameter and surface characteristics. It is also diflicult to distinguish the single filaments. They seem to stick to each other and stay as bundles. 

At the broken ends of silk suture the flattening of the filaments was observed before implantation. This contributes to the presence of lateral forces on loading (see Fig. 4). 

Figure 5. The fibrous tissue ci sule of the silk sutures after implantation [(a)stiaight form (0 USP) PCIO) (b)lmotted form (3/0 USP)]...

Figure 6. The broken ends of the silk sutures (0 USP) after tensile strength test post implantation (XI0)...

This study has analysed ftacture mechanisms of two non-absorbable sutures before and after 3 and 8 weeks implantation in rats. Scaiming Electron Microscope (SEM) and optical light microscope were used for analysis of fiacture mechanisms and sur ce changes of the sutures. A clear in vivo effect on the ftacture mechanism was seen for braided silk suture. Typical ductile fiacture for polyamide suture was observed. In terms of ftacture mechanism it was not affected by the implantation and the implantation time. In the knotted ftmn, the break was always l eath Ae knot and the knot was securely in place for silk suture. In polyamide suture, imdone knots were observed. While silk Woodhead Publishing Limited, 2010 435... 

Introduce a single stitch into the body wall on one side of the incision, and leave the silk suture in place. 

After each embryo has been injected, replace all the uterine swellings back into the abdominal cavity. Suture closed the muscle and skin layers separately. First, close the inner muscle wall using silk suture thread be sure that the fascial coverings of muscles do not slip into the abdominal cavity. Use interrupted sutures spaced about 1/4-3/8 in. apart. Similarly, suture closed the outer skin layer. 

All silks are not, however, chemically identical. Different silkworm species produce fibrous proteins that contain different sequences and proportions of amino acids. These compositional differences in turn influence the mechanical properties of the fibers. The most common form of sUk, produced by the silkworm Bombyx mori from which most silk sutures are made, has a predominant six-residue sequence Gly-Ser-Gly-Ala-Gly-Ala, which repeats itself for long distances along the chain. This sequence accounts for a large proportion of the amino acid residues that are present. 

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