Duration of wound healing and tissue resistance as important criteria for selecting suture materials in colon surgery

The modern absorbable suture materials are well introduced in colonic surgery. Surgeon's intension is to reduce foreign body reactions by using small sized sutures and will be limited by the suture holding capacity of the tissue. Suture holding capacity of the human colon is about 9 +/- 2 N. Wound healing of colon anastomoses normally lasts 10 to 12 days. The braided absorbable suture materials Dexon, Dexon plus and Vicryl (size 3-0 USP) have a knot breaking strength of about 10 N after 12 days implantation in the human colon, the monofilament absorbable sutures PDS and Maxon have about 20 N resting strength after implantation. These results document that the size 3-0 USP (2-metric) should be the lowest limit for the braided absorbable suture materials used in colonic surgery.     

Evaluation of coated and uncoated synthetic absorbable sutures in rabbit limbal wounds

Polymer coatings have been applied to braided synthetic absorbable sutures to decrease tissue drag and improve knot tying characteristics. To examine the possibility that increased "slipperiness" would decrease knot security, coated (Dexon Plus) and uncoated (Dexon S) polyglycolic acid sutures were compared in rabbit limbal wounds. Both suture types had comparable knot security, tissue reaction, and absorption rates, while the coated sutures caused less tissue drag. Clinical trials of coated polyglycolic acid suture for limbal wounds are warranted.     

A comparison of the effect of pH on the biodegradation of two synthetic absorbable sutures.

The differences in hydrolytic degradation of two size 2-0 synthetic absorbable sutures, Polyglycolic acid (Dexon) and Poly(glycolide-lactide) (Vicryl), in the buffer media of three different pH levels ranging from 5.25 to 10.09, were compared in terms of the percentage retention of tensile strength. It was found that Vicryl sutures, in general, exhibited better retention of tensile strength than Dexon sutures within the studied pH range and extent of hydrolysis. When comparing Vicryl with Dexon sutures, the former was only slightly better than Dexon sutures, in the case of an acid environment. The former, however, retained better strength than the latter in a physiological pH (7.44) and under high-alkaline conditions (10.09). Among the three pH levels tested, Vicryl sutures retained the highest tensile strength in a physiological pH and showed a faster loss of tensile strength in both acidic and high-alkaline conditions. Dexon sutures, however, exhibited better retention of tensile strength in the acidic medium than in an alkaline medium. This pH dependent hydrolysis of Dexon and Vicryl sutures should command surgeons' attention in their selection of synthetic absorbable suture materials for particular needs.     

Evaluation of 10-0 polyglycolic acid and polyglactin suture in rabbit limbal wounds

Sutures of 10-0 polyglycolic acid (Dexon) or polyglactin (Vicryl) were used to close limbal incision in rabbits. When seven Dexon or Vicryl sutures were used alone wound disruption occurred in eight of twelve eyes. Sutures disappeared at 4-5 weeks. When three 10-0 nylon sutures were alternated with four 10-0 absorbable sutures, wound integrity was greatly improved. The handling properties of these sutures were excellent and inflammatory reactions were minimal. The 10-0 Dexon and Vicryl did not appear to differ in their properties, but they were insufficient for lasting would closure when used alone. It is suggested that these sutures not be used as the sole closure for limbal wounds.     

Sutures inserted into the gastric wall an experimental study

Thirty gastrotomies were performed in 15 dogs using 2/0 atraumatic needles. Various kinds of threads were used: Dexon as an absorbable suture, Black Perlon and Black Braided Silk as nonabsorbable sutures. Ten suture rows were made with each material. Single-row interrupted sutures were made with no suture in the mucosa. No suture insufficiency occurred. Dexon proved to be the most suitable material, although the nonabsorbable sutures did not cause complications, either.     

Effect of different absorbable sutures on healing of gastrointestinal anastomoses

Studies were performed in dogs to determine whether the newer absorbable sutures would be preferable to catgut in the gastrointestinal tract. Dissolution times of plain and chromic catgut were compared with those of polyglycolic acid (Dexon) and polyglactin 910 (Vicryl) sutures exposed to gastrointestinal contents in vitro and in vivo. Strength and healing of gastric, jejunal, and colonic anastomoses performed with each suture were compared in dogs. Catgut sutures proved susceptible to rapid proteolytic digestion throughout the gastrointestinal tract, whereas Dexon and Vicryl were invulnerable. Type of suture did not affect microscopic healing in the stomach, jejunum, or colon. However, gastric anastomoses of Dexon were stronger at four and seven days and jejunal anastomoses of Dexon and Vicryl were stronger at seven days than anastomoses of catgut. Dexon and Vicryl may be superior to catgut for use in gastrointestinal anastomoses.     

In-vivo comparison of four absorbable sutures: Vicryl, Dexon Plus, Maxon and PDS

Absorbable sutures are initially equal or superior to nonabsorbable sutures in terms of tensile strength but are absorbed at variable rates by the action of hydrolysis. This study demonstrated that the in-vivo half-life tensile strength of the braided absorbable sutures polyglycolic acid (Dexon Plus) and polyglactin 910 (Vicryl) is 2 weeks, whereas those of the monofilament absorbable sutures polyglyconate (Maxon) and polydioxanone (PDS) are 3 and 6 weeks respectively. The addition of a single hitch or six knots reduced the in-vitro tensile strength by 30% to 35%. Polyglyconate (Maxon) suture demonstrated the best in-vitro knot security.     

Polyglycolic acid mesh in surgery of the liver and spleen

Since 1987 absorbable PGA-mesh (Dexon) has been used as a pad for mattress sutures and as remaining tamponade in surgery of the liver and spleen. In 25 cases atypical resections of liver tumors have been performed using PGA-mesh to secure mattress sutures. Blood loss was below 500 cm3 in all cases, operating time was decreased and no infection was seen. Six times this technique was also used in cases with splenic trauma. In all patients the organ could be preserved. In 10 patients with severe trauma of the liver PGA-mesh was successfully used as a remaining tamponade. Also in these cases no infection occurred although 50 mesh had been implanted in one case.     

Enzymatic wound cleaning and absorbable sutures. An experimental study on Varidase and Dexon sutures

The effect of an enzymatic preparation for wound cleaning (Varidase) on the mechanical properties of absorbable sutures (Dexon) was studied in vitro and in vivo in a rat model. In vitro the sutures demonstrated a significant decrease in strength (breaking strength and energy absorption) and extensibility after 12 days of incubation in saline. Incubation in Varidase, however, further decreased the mechanical properties significantly. The stiffness of the sutures was independent of treatment and time. In vivo changes of mechanical properties of the sutures resemble those of the in vitro study, except for a decrease in stiffness of the sutures. The sutures in a primary closed wound had the same strength (energy absorption) as the sutures of an open wound treated by saline, while the sutures of an open wound treated by Varidase tended to have a decreased strength (p = 0.08). This study supports the hypothesis that an enzymatic process may be involved in the degradation of Dexon. The continuous use of Varidase in Dexon-sutured wounds for a period longer than a few days is, therefore, questioned.     

A new method for correction of urinary stress incontinence in women

Twenty-two patients with urinary stress incontinence confirmed by urodynamic recordings were operated on by using absorbable Dexon sutures combined with a two-component fibrin sealant, which induced fibrosis, for the fixation of the urethrovesical junction to the retropubic periostium. The postoperative observation period ranged from 12 to 30 months, and so far no relapses or complications have been observed.     

Knotting and handling characteristics of coated synthetic absorbable sutures

The purpose of this study was to evaluate the knotting and handling characteristics of the new coated synthetic absorbable sutures. When compared to the coated polyglactin 910 sutures, the coated polyglycolic acid sutures displayed a lower coefficient of friction, encountered less tissue drag forces, and exhibited less flexural rigidity. In the case of sizes O, 2-O, and 3-O coated polyglycolic sutures, knot security was achieved with one less throw than with similar sizes of coated polyglactin 910 sutures. On the basis of these comprehensive mechanical performance tests, the knotting and handling characteristics of the coated polyglycolic acid sutures were judged to be superior to that of the coated polyglactin 910 sutures.     

Polyglycolic acid synthetic absorable sutures

A laboratory study of the characteristics of a synthetic absorbable polyglycolic acid polymer suture (Dexon) is presented. The polyglycolic acid sutures were found to be well tolerated by the abdominal wall tissues in rabbits in both clean and infected wounds. Tissue reactivity and tensile strength of the experimental sutures compare favorably with silk, cotton, Dacron, and plain and chromic catgut sutures. The polyglycolic acid sutures handle with the ease of silk while being absorbed more completely than catgut.     

Absorbable suture in hernia repair

In a randomized, double-blind study, comparison was made between absorbable polyglycolic acid sutures (Dexon) and non-absorbable sutures (Dacron) in inguinal and femoral herniorrhaphies. The study comprised 58 patients with 61 hernias. Bassini repair was done in inguinal hernia and McVay repair in femoral hernia. The patients were evaluated at a follow-up examination six months after the operation. There was no wound dehiscence or infection during the primary admission. In one patient from each group there was recurrence of hernia during the observation period. No suture granuloma had developed in that time. These results warrant the use of absorbable sutures in inguinal and in femoral herniorrhaphy.     

Comparison of suture materials for intestinal anastomosis.

Ninety end-to-end entero-anastomoses were prepared in 45 dogs by inverted single row knotted sutures. Half of the anastomoses were carried out on the small intestine, the other half on the colon. Of the two non-absorbable materials that of the polyester type proved to be the best. Of the absorbable materials Dexon can be recommended for intestinal anastomoses, but on the colon Dexon is not reliable. Plain catgut is not recommended for this kind of anastomoses.     

Effect of polyglycolic acid microsuture on rat uterine anastomoses

In order to observe the effectiveness of polyglycolic acid microsutures (Dexon on rat uterine anastomoses, 40 Lewis rats were subjected to two-layer (including the mucosa) and one-layer (avoiding the mucosa) interrupted anastomoses of the freshly severed uteri using Dexon sutures. They were killed at days 7, 14, 21, 30, 60, 90, 180, 270, and 360. There was intensive inflammatory reaction during days 7-14 that gradually subsided, and the inflammatory reaction was limited to the suture sites by days 21-30. Sutures were still detectable at the end of 2 months, but they were no longer recognized at the end of 3 months. As the sutures were completely absorbed, giant cells and granulomatous reactions completely cleared. By days 180, 270, and 360, the rat uteri in both groups were indistinguishable from nonoperated ones. In this observation, it was noted that the use of absorbable microsutures with the mucosa inclusion in the rat uterine anastomoses was equally effective as those without the mucosa, and Dexon microsutures showed no residual effects on the uterine reanastomoses.     

Effects of physical configuration and chemical structure of suture materials on bacterial adhesion. A possible link to wound infection

The purpose of this study was to examine the effects of physical configuration and the chemical nature of suture materials on the preferential adherence of bacteria. Ten suture materials of 2-0 (chromic catgut, Dexon, Vicryl, PDS, Mersilene, Tycron, Ethibond, Surgilon, Ethilon, and Prolene) were used. The bacterial strains tested were Staph. aureus and E. coli. The level of bacterial adherence was determined quantitatively by radiolabelled cells and qualitatively by scanning electron microscopy. It was found that the amount of adhered bacteria depended on the type of suture material, the type of bacteria, and the duration of contact. In the group of absorbable sutures, the new PDS sutures exhibited the smallest affinity toward the adherence of both E. coli and Staph. aureus. Dexon sutures had the highest affinity toward these two bacteria. With nonabsorbable sutures, the physical configuration of the sutures contributed more to their ability to attract bacteria than the surface finish. The bacterial adherence on suture materials was also time dependent. Scanning electron microscope morphologic observation also indicated that Staph. aureus adhered on the suture surface in clusters whereas E. coli tended to adhere individually.     

An in vitro evaluation of the stability of mechanical properties of surgical suture materials in various pH conditions.

The effects of pH on the tensile properties of eight commonly used 2-0 suture materials--plain catgut, Dexon, Vicryl, silk, Nurolon, Ethilon, Mersilene, and Prolene--were examined. The pH level ranged from 3.0 to 10.0. In general, absorbable suture materials were more sensitive to pH than non-absorbable suture materials; within the same suture materials, a strong alkaline condition would have a more adverse effect on the strength of suture materials than physiologic and acidic pHs. Plain catgut sutures lost relatively significant amounts of strength at both acidic and alkaline conditions when compared with Dexon and Vicryl sutures; hence, precaution should be taken when they are used in closing tissues in contact with acidic environment like the stomach. Among the non-absorbable suture materials, silk and Nurolon exhibited the largest loss of strength in both alkaline and acidic environments after one month, while other sutures retained almost all of their original strength. Physical configuration of the suture materials seemed also to contribute to the sensitivity of suture materials toward pH. A comparison of Nurolon and Ethilon sutures demonstrated this point of view.     

Do absorbable mesh sutures cause less chronic pain than nonabsorbable sutures after Lichtenstein inguinal herniorraphy?

Chronic inguinal pain occurs in 20-30% of patients after hernia surgery. A prospective randomized study of 162 patients was undertaken to determine whether absorbable sutures cause less pain than continuous polypropylene fixation of the mesh in the Lichtenstein operation. All patients were operated on under local anesthesia by the same senior surgeon. One-half of the meshes were fixed with continuous 2-0 Dexon II sutures and one-half with continuous 2-0 Prolene sutures. The incidence of pain and recurrence was investigated after a mean follow-up of 2 years. Patient characteristics and operative outcome were similar in the two groups and statistically nonsignificant in both. The rate of significant wound hematomas (n = 3), infections (n = 1), and recurrences (n = 2) were low and not related to the type of sutures. In both study groups 24-26% of the patients felt some pain in follow-up, but over 90% were very satisfied with the operation. The absorbable suture material does not appear to cause less neuropathic pain after Lichtenstein operation than nonabsorbable sutures.     

A new method of reconstruction for chest wall resection

Sixteen patients who involved in chest wall disease underwent major chest wall resection between April 1995 and January 1999. The underlying diseases were 6 recurrence of breast cancers, 4 direct invasion by primary lung cancer, 2 metastatic chest wall tumor, one direct invasion by metastatic lung tumor, one direct invasion by metastatic mediastinal tumor, one radio-induced-necrosis of the chest wall, and one chest wall infection. In 9 patients, the thoracic cage reconstruction was performed using double sheets of absorbable mesh (Dexon mesh), cross string sutures and autologous ribs grafts. None of the patients had major respiratory failure and chest wall unstability. No late complications including infections, pains, recurrence and others related to reconstruction materials have been observed.     

New surgical procedure for management of Peyronie disease

Surgical excision of fibrotic plaques and replacement of the defect by grafts may be necessary in advanced Peyronie disease. Synthetic, absorbable mesh for grafting the defect was used in 6 mongrel dogs. An area of tunica albuginea 1.5 by 2.5 cm was removed from the corpus cavernosum, thus exposing the spongy cavernous tissue. A Dexon mesh of the same dimensions, woven in our laboratory from polyglycolic acid fibers of 308 denier thickness, was sutured to the defect by 3-0 Dexon sutures. The mesh caused hemostasis and the animals' postoperative course was uneventful. Posterection cavernosograms showed no curvature of the penis, bulging of the operative area, or obstruction of the corpora cavernosa. Histologic studies at three weeks, and two, four, and six months after surgery showed complete healing and gradual replacement of the Dexon mesh by fibrous connective tissue.