Vicryl Research Articles

Degradability of absorbable sutures in tendon grafts following anterior cruciate ligament reconstruction

Objective To observe the degradability of absorbable sutures in tendon grafts and the histology of tendon healing in a rabbit model.Methods Semitendinosus tendons were harvested from 15healthy adult New Zealand rabbits in this study. after two-band braiding, the semitendinosus tendons were sutured with the Vicryl Rapide absorbable surgical sutures. The anterior cruciate ligaments (ACL) of bilateral knees were reconstructed with the two-brand semitendinosus tendons in each rabbit. Specimens were collected at 2, 4, 8 weeks after surgery respectively for histological observation.Results Gross observation showed fine motion of the animal limbs and fine condition of the ACL reconstructed after surgery. The absorbable sutures inside the tendon grafts were not degraded and surround by a few inflammatory cells, but the sutures at the edge of tendon graft began to degrade and healing of the tendon grafts was observed at 2 weeks after implantation. The absorbable sutures inside the tendon grafts were partially degraded but newborn tissue was not observed in the degrading region at 4 weeks after implantation. The absorbable sutures were completely degraded and the degradation region was blank at 8 weeks after implantation.Conclusion The speed of degradation of absorbable sutures inside the tendon grafts trends to be stable and the speed of absorption is obviously prolonged. Key words: Anterior cruciate ligament; Transplantation; Rabbits; Sutures

Clinical application of primary bile duct closure improvement after choledochotomy

Objective To determine the value and reasonable application of slowly coated vicryl plus and albumin gel in primary suture after common BD exploration. Methods The operation was successfully performed in all 45 patients. The incision of common bile duct was directly sewed up by slowly coated vicryl plus and spurted by albumin gel after the exploration. Results There were no complications such as bile leakage and bile duct stricture etc.The mean payment of hospitalization was low 10.5%. Conclusion This method was safe,feasible and effective. Key words: Common bile duct exploration; Biliary surgery; Suture; Fibrin glue

Open extraperitoneal mesh repair for abdominal wall hernias in females.

To determine the outcome of treatment in terms of infection and recurrence using open extraperitoneal mesh repair technique. Quasi-experimental study. The department of General Surgery, Combined Military Hospital, Bahawal Nagar Cantonment, from February 2006 to November 2008. Female patients with abdominal wall hernias with defect of 4 cm or more were studied. A history of previous surgery along with clinical findings on examination like size of defect and previous scar were noted. At surgery, hernial sacs were carefully opened and omental and intestinal adhesions were carefully separated. Polypropylene mesh was placed over extraperitoneal space and secured with interrupted vicryl 2/0 sutures. Redivac drains were placed over the mesh and the fascial repair. The patients were discharged on the 3rd - 4th postoperative day and were followed-up at 3 monthly intervals for postoperative sequelae like seroma, haematoma, infection and recurrence. There were 32 cases with a mean age of 41.25 + or - 10.79 years. The mean follow-up period was 15.78 + or - 9.02 months. Previous abdominal surgical intervention was found in 16 (50%) cases. Out of those, 14 (43.7%) had defects through the previous scar. A history of multiple caesarean sections alone, or in combination with either hysterectomy or laparotomy in the last 5 years was present in 7 patients. There were 12 (37.5%) cases of paraumbilical hernia, 4 (12.5%) of a recurrent paraumbilical hernia, 5 (15.6%) epigastric hernia, 2 (6.2%) mix hernia, 7 (21.8%) incisional hernia and 1 (3.1%) each of Spigelian hernia and postlaparoscopic cholecystectomy portal (paraumbilical) hernia. The mean size of the defect was 4.9 cm in primary paraumbilical hernias and 7.2 cm in recurrent paraumbilical hernias. The mean size of the defect in incisional hernias was 9.4 cm, larger than all other types. Superficial wound infection was seen in only 1 morbidly obese (BMI > 30) patient. No case of seroma, haematoma, deep seated abscess or recurrence was noted in the follow-up period. Abdominal wall hernias are common in female patients, especially those with previous surgical intervention. Open extraperitoneal mesh repair with placement of redivac drains is an effective method for the management of abdominal wall hernias with a smaller complication rate and less recurrence.

Technical Notes and Tips: A Simple Tip for the Use of Staplers During Liver Surgery

The use of vascular staplers in liver resection is well established.1 An umbilical tape or sling is usually recommended to loop the portal or hepatic venous structures prior to stapling. However, these need to be removed before firing, or may be included in the fired stapler, and could cause the stapler to misfire. This results in lack of traction on the structure to be stapled, and a greater risk of the stapler being fired too close to the portal bifurcation or the inferior vena cava, respectively. This is particularly relevant in cases where hepatic veins are short and thick or exposure is poor (when cirrhotic or enlarged liver is present). We describe a simple, safe technique to loop the portal structures or hepatic veins, and recommend that the structure is encircled with a thread rather than a sling or umbilical tape (Fig. 1). The thread is not removed before firing and can be used to retract the patient side of the structure away from the stapler, so as to ensure that the stapler fires as close to the specimen as possible. The thread can be safely cut by the stapler without causing any disruption to the staple line. Figure 1 Transection of the right hepatic vein using a stapler, using a thread (Vicryl 2-0; Ethicon, Somerville, NY, USA) rather than a sling to loop the vein.

Video-assisted Thoracoscopic Surgery for Peritoneal Dialysis-related Hydrothorax

Objective: Peritoneal dialysis (PD)-related hydrothorax is a rare complication, which if not treated properly, will cause the patient to abandon PD. Methods: We started continuous ambulatory peritoneal dialysis (CAPD) treatment modality in 1991, and there have since been 400 consecutive patients receiving CAPD treatment (up to September 2007). Among them only 2 patients suffered from PD-related hydrothorax. In addition, the 2 patients who suffered from PD-related hydrothorax were referred from the other hospitals. Results: All the 4 patients were females, the mean age being 46 years old, and they presented with cough, dyspnea and inadequate outflow. Chest radiographs all showed massive effusion of the right thorax. The Tc99 shunt patency study was helpful in one case. All the 4 patients underwent VATS and one needed a limited thoracotomy due to failure of double lumen intubation. During the operation, all of them showed defects in the tendinous portion of the right side diaphragm which could be identified clearly after checking leakage. The defects were sutured continuously with 2-0 coated Vicryl. They resumed CAPD treatment 2~8 weeks after repair of the diaphragmatic defects. Conclusion: PD-related hydrothorax can be treated safely and successfully by VATS or limited thoracotomy.

Technical Notes and Tips: A Method for Improving Postoperative Analgesia in Patients Undergoing Saphenofemoral Ligation with ‘Strip’ of the Long Saphenous Vein

Antegrade stripping of the above-knee segment of the long saphenous vein (LSV) is a standard part of varicose vein surgery for saphenofemoral incompetence. Our unit uses a pin stripper to achieve satisfactory disruption of the above knee portion of the LSV. We describe a technique to improve pain control following a LSV strip. The LSV is stripped in the standard manner using a pinstripper that is tied to the proximal LSV using a 0 Vicryl™ (Ethicon, Edinburgh EH11 4HE, UK) tie. It is essential that the trailing length of tie be of sufficient distance to allow retrograde insertion of a size 7 umbilical catheter. Following removal of the pin stripper and LSV through a distal incision, the Vicryl tie is used to attach a size 7 umbilical catheter. Traction on the Vicryl tie from above allows the catheter to be drawn into the leg where the LSV has been stripped. Following this, 15 ml of 0.25% Chirocaine (Celltech, Cambridge CB4 4WE, UK) can be instilled as the catheter is removed, thus ensuring the bed of the LSV is adequately anaesthetised. We find this technique to be both simple and effective.

Technical Notes and Tips: The Use of a Polyglactin 910 Mesh to Obtain Haemostasis and Prevent Further Splitting in a Fractured Transplant Kidney

Technical Notes and Tips: The Use of a Polyglactin 910 Mesh to Obtain Haemostasis and Prevent Further Splitting in a Fractured Transplant Kidney

Avaliação de dois diferentes fios de sutura para colopexia incisional laparoscopia em cães: estudo experimental

Com o objetivo de descrever tecnica laparoscopica para a realizacao de colopexia em caes, comparando os resultados de dois distintos fios de sutura, os autores utilizaram 10 animais separados em dois grupos de igual numero (GV e GP). Nos do GV, a colopexia foi realizada com fio de poliglactina 910 3-0, enquanto no GP empregou-se polipropileno de igual espessura. Para o procedimento, os caninos foram posicionados em decubito dorsal e submetidos a pneumoperitonio com CO2 na pressao de 12mmHg. Foram introduzidos quatro trocartes, dois de 5mm e dois de 10mm, nas regioes umbilical, lateral direita e esquerda. O colon descendente foi apreendido com pinca Babcock e submetido a incisao seromuscular de 2,5cm na superficie antimesenterica. Procedeu-se a incisao semelhante no musculo transverso abdominal, paralelamente a linha alba. As margens correspondentes das feridas do intestino e da musculatura abdominal foram aposicionadas com suturas continuas simples. No 14o dia pos-operatorio, os caninos foram submetidos a laparoscopia para as avaliacoes da cavidade peritoneal e das aderencias produzidas, bem como para as coletas de biopsias. Constatou-se permanencia da colopexia em todos os animais e a fixacao do omento na regiao da sutura em 60% e 100% dos representantes do GV e do GP, respectivamente. Ambos os fios demonstraram adequabilidade; contudo, a sutura foi realizada mais facilmente com a poliglactina 910, gracas a sua menor memoria. Na histologia, observou-se que a deposicao de tecido conjuntivo foi semelhante entre os grupos, sendo que em todos os casos o colageno apresentava-se maturo. Pode-se concluir que a tecnica laparoscopica proposta e adequada para a realizacao de colopexias em caes.

Breast Reconstruction Using Tissue Expander Followed by Prosthesis after Mastectomy for Breast Cancer

Breast cancer is the leading cause of top ten cancers of female population in Taiwan. Breast reconstruction after mastectomy for breast cancer is necessary not only in the out-looking appearance but also in the personal psychological reason. The currently reconstructive modalities include autologous tissue reconstruction and alloplastic implants. We reported the method of tissue expander followed by permanent breast prosthesis implantation. The tissue expander is used to expand the residual native breast envelope and chest wall skin. After the end of expansion course, the tissue expander was replaced by the alloplastic implant. During this changing procedure, we could adjust the position and projection of the reconstructed breast. In the time of insertion of tissue expander, we dissected the pectoralis major muscle freely at inferior and lower medial origin, e.g. at the costal and lower sternal origin. We dissected the pectoralis major muscle at inferior and lower-medial origin to have the free space for implantation and expansion of the tissue expander. The free edge of the pectoralis major muscle is sutured with 4-0 Vicryl continuously to prevent cut through later. The margin is sutured to the skin through several stay sutures with 4-0 nylon and bolster of petroleum gauze. The expanded space was replaced by alloplastic breast prosthesis about 6 months later. The reconstructed breast preserved good shape, projection and symmetry. The surgical technique is easy and the operative time and the recovery period are short. Patients could participate in the course of treatment and the prosthesis would not interfere the breast cancer follow-up. Most of these patients are satisfactory. We provided this modality and focus on the method of elevation of pectoralis major muscle and the marginal continuous suture to prevent cut through.

Influence of Mesh Materials on Collagen Deposition in a Rat Model

Alterations of the extracellular matrix (ECM) with its major component collagen are increasingly discussed as possible risk factors implicated in the development of abdominal-wall herniation. Because of the widespread use of alloplastic meshes for the surgical repair of hernias, an animal study was performed to analyze the influence of various mesh materials on the quantity and quality of collagen deposition. In 60 male Sprague-Dawley rats an abdominal replacement was performed using three different kinds of mesh materials: polyester (PE), a pure polypropylene (PP), and a composite mesh made of polypropylene and polyglactin (PG). A simple fascia suture repair served as control. The count of fibroblasts, the collagen/protein ratio, the type I/III collagen ratio, and the ex-pression of basic fibroblast growth factor (b-FGF) at the interface were analyzed after 7, 21, and 90 days. The ratio of collagen to overall protein ( w g/mg) showed significant differences comparing different mesh materials (sham controls 38.44 - 16.33 w g/mg, PE 68.5 - 23.8 w g/mg, PP 101.6 - 32.3 w g/mg, PG 49.6 - 11.6 w g/mg at day 90). The ratio of collagen type I/III increased over time in all groups. However, 90 days after mesh implantation the ratio was always significantly lowered compared to the controls. No significant difference was found comparing different mesh materials. The alteration of the scar composition is closely connected to an increased b-FGF expression. b-FGF and count of fibroblasts highly correlated ( r = .95) and showed significant elevated levels compared to simple suture repair. The results of our study strongly support the notion that wound healing is affected by mesh implantation. The quality of the ECM deposition as determined by collagen type I/III ratio is impaired in general, whereas the quantity of ECM deposition is markedly influenced by the kind of mesh material.

USE OF NERVE CONDUITS IN PERIPHERAL NERVE REPAIR

Studies on nerve conduits for peripheral nerve regeneration have concentrated on the manipulation of various conduit materials to avoid sacrificing native nerve in the clinical situation. With the proliferation of available nerve growth-stimulating factors, the focus is shifting experimentally toward molecular biologic manipulation, with the addition of these materials as substrates within the conduit. The clinical use of conduits has concentrated on the use of autogenous tissue, with a few examples of polyglactin (PGA) mesh and silicone. Ultimately, as yet, conduit material does not seem to have a profound effect on outcome. Substrate manipulation has not yet had clinical application. An important problem that remains, both experimentally and clinically, is overriding the size of the maximal gap that can be bridged successfully, as well as obtaining good functional sensory and motor recovery, compared with the use of nerve grafts. Advances in molecular biology may reveal further details about the nerve growth phenomenon, the precise sequencing of the substrate materials that are effective in promoting nerve growth, and when they should be applied. Advances in chemical engineering may provide additional biologically stable materials that have the ability to integrate growth-enhancing agents or factors into the lumen of the conduit.

Kinetics of cell proliferation as a function of vascular graft material

Bioresorbable vascular grafts constructed for polyglactin 910 (PG910) and polydioxanone (PDS) and nonresorbable Dacron were interposed into the infrarenal abdominal aortas of New Zealand White rabbits. The prosthesis/tissue complexes were harvested after 2, 3, 4, 12, and 52 weeks. Seventeen, 9, and 1 h prior to sacrifice, animals received tritiated thymidine (0.5 mCi/kg/dose). All specimens were studied grossly and by light and transmission electron microscopy. Mitotic indices (MI's) were determined by autoradiography for inner capsule myofibroblasts at the proximal, mid, and distal segments of each prosthesis. There were no aortic-related deaths. All grafts were patent with no aneurysmal dilatation. At 4 weeks, PG910 resorption was evidenced by macrophage phagocytosis, less so in PDS while Dacron remained intact. At 12 weeks, the PG910 was completely resorbed while PDS resorption continued. The latter was completely resorbed by 52 weeks. There was no significant difference in MI's between proximal, mid, and distal regions for each graft type. The mitotic index paralleled the rate of prosthetic resorption in both PG910 and PDS groups, as high as 28.34 +/- 23.21 in the former 3 weeks after implantation and significantly higher at 4 weeks (7.58 +/- 2.02 and 7.50 +/- 2.66, respectively) than at 52 weeks (0.72 +/- 0.98 and 1.00 +/- 0.22, respectively) in both groups. The mitotic index in the Dacron group never surpassed 1.22 +/- 0.90. We conclude that higher levels of early cell proliferation in bioresorbable grafts closely parallel the kinetics of prosthetic resorption.

Long-term expression of a retrovirally introduced ?-galactosidase gene in rodent cells implanted in vivo using biodegradable polymer meshes

Grafts of various types of cells have been performed using bioresorbable polymer matrices. These synthetic fibers are degraded by hydrolysis into normal metabolic intermediates and induce a number of events that are conductive to healing and/or repair, the most important of which may be angiogenesis. The use of biodegradable meshes to deliver genetically altered cells was studied. A beta-galactosidase gene was inserted into Long-Evans rat bone marrow stromal (BMS) cells or fibroblasts derived from C57BL/6J mouse embryos using the retroviral vector LNL-SLX beta gal. Expression was monitored using X-gal staining. X-gal+ cells from monolayer cultures were seeded onto either polyglycolic acid (PGA) or polyglactin (PGL) biodegradable meshes and grown to confluence. Two types of grafts were performed: (1) embryonic C57BL/6J mouse fibroblasts (EMF) into either nude mice or adult C57BL/6J mice, and (2) Long-Evans rat BMS into Long-Evans rats. Beta-Galactosidase activity was found for up to 152 days for EMF in nude mice, 123 days for EMF in adult C57BL/6J mice, and 90 days for grafts of syngeneic BMS cells into Long-Evans rats. Noninfected cells grafted using the same methods did not stain with X-gal.

Effects of hypercholesterolemia on monokine-induced smooth muscle cell proliferation.

Macrophage/smooth muscle cell interactions play a role in atherogenesis and foreign body reactions to biomaterials. This study investigates the effect of a hypercholesterolemic diet on the ability of smooth muscle cells (SMCs) to respond to monokines which are produced in response to hypercholesterolemia, biomaterials or both. Peritoneal macrophages were harvested from rabbits fed either a normal (M phi NL) or a 2% cholesterol/6% peanut oil diet (M phi ATH) (plasma cholesterol 2840 vs 42.3 [p less than 0.005]). The macrophages were then cultured in the presence of either 1) polyglactin 910 (PG910), 2) Dacron, or 3) no biomaterial (control), and the media collected and pooled by week for the smooth muscle cell mitogenesis assays. Rabbit aortic smooth muscle cells were harvested and cultured from the same two groups of rabbits (SMCNL or SMCATH), quiesced in serum free media (48 h) followed by addition of the test media and 3H-TdR. The addition of either biomaterial to M phi NL-conditioned media increased 3H-TdR incorporation in both smooth muscle lines as compared to controls. PG910 resulted in significantly higher 3H-TdR incorporation than Dacron (weeks 3-5, p less than 0.005). The addition of either biomaterial to M phi ATH also increased 3H-TdR incorporation in both smooth muscle cell lines, however, the magnitude of the response was decreased as compared to the M phi NL-conditioned media in both cell lines (p less than 0.001 for either SMC line). In contrast to the M phi NL-conditioned media, the addition of Dacron to M phi ATH resulted in the highest level of 3H-TdR incorporation in both cell lines as compared to the media without biomaterial. The SMCNL had a higher response to both the monokines in conditioned media (2-fold) and to fetal bovine serum (3-fold) than the SMCATH (p less than 0.001). Although there is a generalized decrease in release of mitogens active on SMCs from M phi ATH, the M phi ATH exposed to Dacron release increased amounts of mitogenic factors, most active on the SMCATH cell line. A common mode of failure of small diameter Dacron grafts in man is pseudointimal hyperplasia, and it is inviting to postulate that the Dacron/macrophage/smooth muscle cell interactions in this atherosclerotic group of patients plays a role in the pathogenesis of this lesion.

Siyatik Sinirin Doku Yapıştırıcısı Ve Sütürle Epinoral Anastomunun Elektro Fizyolojik Olarak Karşılaştırılması

The Comparision of Epineural anastomosis of Sciatica nerve performed with fibrin glue and suture as electrophysiological ✓ 40 scitica nerves were performed the epineural anostomosis in 20 rats. Fibrin glue was used to first group. 8/0 vicryl was used to second group. At the end of the 45 days, the results were compared as electrophysiological and histological. We found that the latency and evoke voltage in to group that used fibrin glue were lower than other group and there was no significant difference between two groups as histopathological ✓ 20 Sicanda 40 siyatik sinir iki grup halinde epinoral anastomoz yapildi. Birinci grupta doku yapistiricisi, ikinci grupta 8/0 vicryl kullanildi. 45 gunun sonunda sonuclar elektrofizyolojik histolojik olarak karsilastirildi. Doku yapistiricisi (Tissel Kit) kullanilarak yapilan anostomozlu gruptaki latensi ve uyarilma voltaji diger gruba gore daha dusuktu. Histopatolojik olarak fark yoktu.

Effects of Hypercholesterolemia on Healing of Vascular Grafts

Small-diameter vascular grafts woven from bioresorbable lactide/glycolide copolymers have been successfully interposed into aortas of normal NZW rabbits. The current study examines the histologic and functional reactions to these bioresorbable grafts in severely hypercholesterolemic rabbits, a standard animal model of atherosclerosis. Sixty rabbits were placed on a 2% cholesterol, 6% peanut oil atherogenic diet. Baseline serum cholesterols and triglycerides were measured and repeated at operation 3 months later. Woven polyglactin 910 (PG910) grafts were interposed into infrarenal aortas. Fifty-two rabbits died on the diet or within 3 days of surgery and eight survived operation (normal NZW rabbit operative mortality is less than 10%). Cholesterol levels rose from 63 to 1989, p less than .001. Of the eight survivors, five died after 3 weeks, and one died after 2 1/2 months. Two were sacrificed at 2 and 4 months. Four aortic disruptions with retroperitoneal hematomas, one pseudoaneurysm, and one diffuse aneurysm were observed, greater than in normal rabbits, p less than .001. Inspection revealed severe atherosclerosis. Histologically, 3-week explants showed only small areas of neointima with myofibroblasts and endothelial cells; the outer capsules were infiltrated by lipid-laden macrophages. Graft material in 2- to 4-month explants was replaced by tissue with histologic atherosclerosis. More severe atherosclerosis was observed in native aortas at the perianastomotic areas than the more distant aortic segments. Abundant intracellular lipid was seen also in splenic histiocytes and hepatic cells with evidence of micronodular cirrhosis. Macrophages phagocytizing bioresorbable prostheses may release growth factors mediating the formation of a cellular tissue conduit. Severe hypercholesterolemia may alter monokine release from macrophages resulting in a weakened prosthesis/tissue complex.

Macrophage/biomaterial interactions: The stimulation of endothelialization

This current study analyzed macrophage/biomaterial interactions as modulators of endothelial cell proliferation. Rabbit peritoneal macrophages were harvested and seeded (1 × 106 cells/ml) into culture flasks with Dulbecco's modified Eagle medium and 10% platelet-poor, plasma-derived equine serum. Macrophages were identified by morphologic characteristics, nonspecific esterase, and Fc (immunoglobulin G) receptors on the cell membranes. Culture conditions were (1) no prosthetic material, (2) Dacron, or (3) Polyglactin 910 (PG910) (Ethicon, Inc., Somerville, N.J.). Both prosthetic materials were finely shredded into the media. After 5 weeks in culture, PG910 inclusions were seen within macrophage cytoplasm. No intracytoplasmic Dacron was observed. Conditioned media from all three groups were collected weekly from week 5 to week 10, centrifuged, filtered, and added in serial dilutions to cultured quiescent murine capillary lung endothelial cells. Quiescence was achieved by serum deprivation and verified by [3H] thymidine incorporation. Sixteen hours after addition of conditioned media, [3H] thymidine was measured in and expressed as percent increase above quiescent levels. Mitogenic activity in the PG910 group progressively increased from weeks 6 to 10. At week 10, the PG910 group (1:10 dilution) yielded a 620% increase in DNA synthesis. The Dacron group never varied from the control group (no prosthetic). The mean increases in [3H] thymidine incorporations over weeks 7 to 10 were PG910, 540% ± 65%; Dacron, 323% ± 65%, and control, 343% ± 26% (PG910 vs Dacron, p <- 0.004). These studies suggest macrophage activation by bioresorbable prostheses, yielding growth factor release with subsequent enhanced endothelial cell proliferation.

Macrophage/biomaterial interactions: The stimulation of endothelialization

This current study analyzed macrophage/biomaterial interactions as modulators of endothelial cell proliferation. Rabbit peritoneal macrophages were harvested and seeded (1 x 10(6) cells/ml) into culture flasks with Dulbecco's modified Eagle medium and 10% platelet-poor, plasma-derived equine serum. Macrophages were identified by morphologic characteristics, nonspecific esterase, and Fc (immunoglobulin G) receptors on the cell membranes. Culture conditions were (1) no prosthetic material, (2) Dacron, or (3) Polyglactin 910 (PG910) (Ethicon, Inc., Somerville, N.J.). Both prosthetic materials were finely shredded into the media. After 5 weeks in culture, PG910 inclusions were seen within macrophage cytoplasm. No intracytoplasmic Dacron was observed. Conditioned media from all three groups were collected weekly from week 5 to week 10, centrifuged, filtered, and added in serial dilutions to cultured quiescent murine capillary lung endothelial cells. Quiescence was achieved by serum deprivation and verified by [3H]thymidine incorporation. Sixteen hours after addition of conditioned media, [3H]thymidine was measured in and expressed as percent increase above quiescent levels. Mitogenic activity in the PG910 group progressively increased from weeks 6 to 10. At week 10, the PG910 group (1:10 dilution) yielded a 620% increase in DNA synthesis. The Dacron group never varied from the control group (no prosthetic). The mean increases in [3H]thymidine incorporations over weeks 7 to 10 were PG910, 540% +/- 65%; Dacron, 323% +/- 65%, and control, 343% +/- 26% (PG910 vs Dacron, p less than or equal to 0.004). These studies suggest macrophage activation by bioresorbable prostheses, yielding growth factor release with subsequent enhanced endothelial cell proliferation.

Polyglactin 910/polydioxanone bicomponent totally resorbable vascular prostheses.

Previous studies from our laboratory have shown that bioresorbable vascular prostheses woven from lactide-glycolide copolymers and implanted into arteries of several animal models become replaced by cellular tissues; the rate of replacement parallels the kinetics of prosthetic resorption. This study evaluates the efficacy of bicomponent resorbable prostheses as a method of augmenting resistance to dilatation during the resorption period of the more rapidly resorbed component. Bicomponent prostheses (n = 37) were woven from compound yarns containing 74% polyglactin 910 (PG910) and 26% polydioxanone (PDS) and were interposed into adult white New Zealand rabbit infrarenal aortas. Resultant prosthesis-tissue complexes were harvested after 2 weeks to 12 months. Specimens were photographed and sectioned for light, scanning, and transmission electron microscopy. Randomly selected fresh explants at 1 and 3 months and control aortic segments from the same rabbits were simultaneously perfused with culture media (37 degrees C, 100/80 mm Hg, 60 ml/min) and perfusates assayed by means of tritiated radioimmunoassay techniques for the stable prostacyclin metabolite 6-keto-PGF1 alpha before and after the addition of sodium arachidonate (10 micrograms/ml) to the media. Results showed 100% patency, no aneurysms, and stenosis in 1 of 37 prostheses (3%). PG910 was totally resorbed by 2 months and PDS by 6 months. By 1 month inner capsule thickness was 303 +/- 30 microns. In contrast to previous reports this was significantly thicker than that within 100% PDS (230 +/- 40 microns) and significantly less thick than in 100% PG910 (530 +/- 62 microns). Inner capsules in all three groups stabilized at similar thicknesses (417 to 502 microns).(ABSTRACT TRUNCATED AT 250 WORDS)

Polyglactin 910/ polydioxanone bicomponent totally resorbable vascular prostheses

Previous studies from our laboratory have shown that bioresorbable vascular prostheses woven from lactide-glycolide copolymers and implanted into arteries of several animal models become replaced by cellular tissues; the rate of replacement parallels the kinetics of prosthetic resorption. This study evaluates the efficacy of bicomponent resorbable prostheses as a method of augmenting resistance to dilatation during the resorption period of the more rapidly resorbed component. Bicomponent prostheses (n = 37) were woven from compound yarns containing 74% polyglactin 910 (PG910) and 26% polydioxanone (PDS) and were interposed into adult white New Zealand rabbit infrarenal aortas. Resultant prosthesis-tissue complexes were harvested after 2 weeks to 12 months. Specimens were photographed and sectioned for light, scanning, and transmission electron microscopy. Randomly selected fresh explants at 1 and 3 months and control aortic segments from the same rabbits were simultaneously perfused with culture media (37°C, 10080 mm Hg, 60 ml/min) and perfusates assayed by means of tritiated radioimmunoassay techniques for the stable prostacyclin metabolite 6-keto-PGF1α before and after the addition of sodium arachidonate (10 μg/ml) to the media. Results showed 100% patency, no aneurysms, and stenosis in 1 of 37 prostheses (3%). PG910 was totally resorbed by 2 months and PDS by 6 months. By 1 month inner capsule thickness was 303 ± 30 μm. In contrast to previous reports this was significantly thicker than that within 100% PDS (230 ± 40 μm) and significantly less thick than in 100% PG910 (530 ± 62 μm). Inner capsules in all three groups stabilized at similar thicknesses (417 to 502 μm). Regenerated tissues contained oriented myofibroblasts and collagen beneath endothelial-like blood-contacting surfaces. These surfaces metabolized sodium arachidonate to 6-keto-PGF1α in a similar fashion to control aortic surfaces. Although these data suggest possible clinical efficacy in multicomponent totally absorbable vascular prostheses, further work is needed to elucidate fully the mechanisms of arterial regenerative activity.