Esophagotomy Closure in the Dog A Comparison of a Double-Layer Appositional and Two Single-Layer Appositional Techniques

Esophagotomies were performed on 36 dogs and closed with 3-0 polydioxanone in double-layer simple interrupted, single-layer simple interrupted, or single-layer simple continuous patterns. The operative time was shortest for single-layer simple continuous closure, followed by single-layer simple interrupted and double-layer simple interrupted, respectively. Three dogs with each suture pattern were euthanatized at hours 0 and 1, and days 4 and 28 after surgery. The esophagotomy incisions were subjected to bursting strength testing and examined microscopically. The bursting wall tension was higher for all three suture pattern groups at 28 days than at 0 and 1 hour. The double-layer closure had higher bursting wall tension than the single-layer closures at 0 hour and 4 days. Single-layer simple continuous closure had the lowest bursting wall tension for each time period. Single-layer simple interrupted closure had the highest bursting wall tension at 28 days. Microscopic examination revealed close approximation of tissue planes for the double-layer closure and mucosal ever-sion for the simple interrupted and simple continuous single-layer closures. Healing was superior histologically with the double-layer closure.     

Partial Maxillectomy in the Dog Comparison of Suture Materials and Closure Techniques

This study compares the healing of oronasal defects created by partial maxillectomy when closed using two different suture materials and two different suture patterns. In experiment 1, 24 dogs were divided into four equal groups. Partial maxillectomy was performed on each dog and was closed using either a two-layer simple interrupted suture pattern (12 dogs) or a modified Mayo mattress pattern (12 dogs) with either polyglactin 910 (12 dogs) or polypropylene (12 dogs) sutures. On the seventh postoperative day, the dogs were euthanized, suture line bursting pressures were measured, and wound healing was evaluated grossly and histopathologically. Suture line dehiscence occurred in one dog from each of the four groups. These were the only dogs in which electrocoagulation had been used. The healing of suture lines closed with the two-layer simple interrupted pattern was superior to that of those closed with the modified Mayo mattress pattern based on the degree of gross oral ulceration, suppurative inflammation, fibrosis and oral epithelial covering at the suture line, and the number of necrotic sites in the adjacent tissue. The healing of suture lines closed with polypropylene was superior to that of those closed with polyglactin 910 based on suture line bursting pressures and the degree of suppurative inflammation and tissue necrosis at the suture sites. In Experiment 2, partial maxillectomies were performed on four dogs, and closure was achieved using a two-layer simple interrupted suture pattern with either polyglactin 910 (two dogs) or polypropylene (two dogs). On the 30th postoperative day, the dogs were euthanized, and wound healing was evaluated grossly and histopathologically. All suture lines were well healed. All polyglactin 910 oral sutures were absent, while all polypropylene oral sutures were still present.     

Strength Characteristics and Failure Modes of Suture Patterns in Severed Goat Tendons

The load-to-gap formation, maximum load, gap present at maximum load, and failure mode were compared among four suture patterns: Bunnell-Mayer, modified Kessler, Mason-Allen, and simple interrupted. Sixty-four goat tendons were sutured with 2-0 monofilament polypropylene in one of the patterns and distracted at 92 cm/min with an electrohydraulic materials testing system. All tests were filmed at 40 frames/sec with an intermittent pin registered camera. The load-to-gap formation was not significantly different among the Bunnell (13.3 +/- 1.5 newtons [N]), Kessler (12.8 +/- 1.3 N), and simple interrupted (11.7 +/- 1.7 N) patterns. The Mason-Allen pattern was significantly different )8.2 +/- 0.5 N). The Bunnell-Mayer had the highest mean maximum load to failure (43.0 +/- 1.6 N) followed by the modified Kessler (34.1 +/- 1.9 N). There was no difference between the Mason-Allen (22.9 +/- 1.4 N) and simple interrupted (21.2 +/- 1.4 N). All of the patterns permitted at least a 1 cm gap to form when the maximum load was applied. The Bunnell pattern caused severe constriction of the tendon and failed by suture material disruption. The modified Kessler caused some focal constriction, but the suture material pulled out before breaking and sliced the tendon in the process. The Mason-Allen and the simple interrupted patterns sliced the tendon as the suture pulled out of the tendon.     

Strength Characteristics and Failure Modes of Locking-Loop and Three-Loop Pulley Suture Patterns in Equine Tendons

Size 3-0 polydioxanone was used as a single strand, single braid (3 strands), or double braid (6 strands) to create six suture material-pattern combinations for equine tenorrhaphy: single-strand locking loop, single-braid locking loop, double-braid locking loop, single-strand three-loop pulley, single-braid three-loop pulley, and double-braid three-loop pulley. Maximum load to failure for the single-strand locking loop (46.1 +/- 2.9 newtons [N]) was less than for all other sutures (range, 103-155 N). The load required to form a 2 mm gap between tendon ends was greater for the single-braid three-loop pulley (66.7 +/- 6.9 N) and double-braid three-loop pulley (85.4 +/- 17.7 N) than any other sutures. The load required to produce a 10 mm gap was least for the single-strand locking loop (34.3 +/- 3.9 N) and greatest for the double-braid three-loop pulley (131.5 +/- 27.5 N). Gap between tendon ends at maximum load was greater for the single-braid (18.1 +/- 0.9 mm) and double-braid (19.2 +/- 2.2 mm) locking loops than for any other sutures. Suture material broke in 53% of the locking-loop tests but in only 17% of the three-loop pulley tests. Tendon matrix disruption accounted for 43% of the locking-loop failures and 77% of the three-loop pulley failures. The three-loop pulley pattern provided more support, less tendon distraction, and less tendon matrix constriction and distortion than the locking-loop pattern.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of Stainless Steel Fascial Staples and Polypropylene Suture Material for Closure of the Linea Alba in Dogs

Five centimeter segments of the linea alba in mature, female, mixed breed dogs were incised and then approximated with either stainless steel fascial staples or size 0 polypropylene suture material. Breaking strength of the linea alba closures was determined at 0 (Phase I, 18 dogs) and at 7,14, and 31 days (Phase II, 18 dogs). Histology and videointeractive planar morphometry were used to evaluate healing of the linea alba. Breaking strength and histologic and morphometric variables were analyzed statistically using analysis of variance in a split plot design. In a clinical trial, 20 cm linea alba incisions were approximated with stainless steel fascial staples after elective ovariohysterectomy in mature, female, mixed breed dogs (Phase III, eight dogs). The dogs were evaluated at 1, 2, 7,14, 31, 90, and 180 days. Linea alba incisions approximated with polypropylene suture material were significantly stronger than linea alba incisions approximated with stainless steel fascial staples on day 0. There was no significant difference between breaking strength values, histologic, and morphometric appearance of linea alba incisions closed with stainless steel fascial staples or polypropylene suture material when compared 7,14, and 31 days after surgery. All of the dogs in the clinical trial appeared to be normal at all evaluation times. Approximation of linea alba incisions with stainless steel fascial staples compares favorably to closure with a simple continuous pattern of polypropylene suture material with regard to breaking strength, clinical, histologic, and morphometric appearance.     

Closure of Abdominal Incisions Using A Continuous Polypropylene Suture: Clinical Experience in 550 Dogs and Cats

Closure of midline abdominal wall incisions in 469 dogs and 81 cats following various intraabdominal procedures was accomplished by using a single layer, simple continuous pattern with monofilament polypropylene. Skin was closed using simple interrupted nonabsorbable sutures. Weight of the patients ranged from 1 kg to 80 kg. Length of the incision ranged from 3 cm to 55 cm. There was one dehiscence (0.18%) and no incisional hernias. Results indicate the technique is a dependable, time saving method of abdominal closure.     

A Comparison of Simple Continuous Versus Simple Interrupted Suture Patterns for Tracheal Anastomosis After Large-Segment Tracheal Resection in Dogs

Two suture techniques for tracheal anastomosis after large-segment tracheal resection were compared. Eight cartilages were resected from the trachea of each of 12 dogs; anastomoses with 4-0 polydioxanone suture were created using a simple continuous suture technique in six dogs and a simple interrupted suture technique in six dogs. Surgical time was shorter but apposition of tracheal segments at the time of surgery was less precise with the simple continuous suture technique. The dogs were evaluated for 150 days after surgery. Clinical abnormalities after tracheal resection and anastomosis were not observed. Percent dorsoventral luminal stenosis was calculated by measuring the tracheal lumen diameter on lateral cervical radiographs. Percent luminal stenosis was calculated planimetrically using a computerized digitizing tablet. Anastomotic stenosis was mild in all dogs; however, the mean percent luminal stenosis determined planimetrically was significantly greater for dogs that had the simple continuous suture technique. Planimetric measurements of cross-sectional area made before and after formalin fixation were not significantly different. Radiographic determination of percent dorsoventral luminal stenosis was a poor predictor of diminution of cross-sectional area determined planimetrically.     

In Vitro Comparison of the Three Loop Pulley and Locking Loop Suture Patterns for Repair of Canine Weightbearing Tendons and Collateral Ligaments

Both triceps tendons and the medial collateral ligaments of both stifles of 10 freshly euthanized dogs were sharply transected. One tendon and one ligament of each dog were sutured with a three loop pulley pattern, and the opposite tendons and ligaments were sutured with a locking loop pattern. The tendons and ligaments were harvested with their muscular and bony attachments. The anastomoses were slowly tested in tension until failure occurred. The amount of tensile load required to produce failure of the anastomosis, the amount of distraction of the sutured ends prior to failure, and the modes of failure were recorded. In both tendons and ligaments, the three loop pulley pattern provided significantly greater tensile strength (p < 0.01) and allowed significantly less distraction between the sutured ends (p < 0.01) than the locking loop pattern. In tendons, disruption of the suture material was the most common mode of failure with both patterns. In ligaments, both patterns failed most commonly by pulling free from the tissue.     

Comparison of a Biofragmentable Intestinal Anastomosis Ring With Appositional Suturing for Subtotal Colectomy in Normal Cats

A subtotal colectomy was performed on 12 normal adult cats using an interrupted apposing suture pattern of monofilament polyglyconate (n = 6) or a biofragmentable intestinal anastomosis ring (Valtrac, Davis and Geek Company, Danbury, CT) (n = 6) composed of polyglycolic acid and barium sulfate. Abdominal radiographs were made daily, beginning 10 days after surgery, to determine fragmentation rates of the anastomosis ring. The cats were euthanatized 30 days after surgery, and a gross and histopathological evaluation of anastomotic healing and stricture formation was performed. The technique for implantation of the anastomosis ring was easy to learn and required only two purse string sutures to complete. Intraoperative complications associated with the anastomosis ring were minor, and included problems with purse string suture placement, small serosal tears, and spasms of the colon that reduced the lumenal diameter. There were no intraoperative complications in the cats with sutured anastomoses. Postoperative recovery was uneventful in all cats. The anastomosis rings fragmented 12.2 ± 1.1 days (mean ± standard deviation [SD]) after implantation and passed in the stool 3.8 ± 1.9 days later without clinical signs in five of six cats. There were no statistically significant differences between the time required to perform the anastomosis ( P = .348), postmortem gross anastomosis grades ( P = .088), or percent of lumenal stricture ( P = .178) between the two groups. Histologically, the only significant differences were an increased muscular inversion in the anastomoses performed using the fragmentable ring ( P = .039) and an increased muscular eversion in the sutured anastomoses ( P < .001) compared with normal colonic architecture.     

A Study of the Biomechanical Properties of the Adult Equine Linea Alba: Relationship of Tissue Bite Size and Suture Material to Breaking Strength

The purposes of this study were to mechanically determine the optimal tissue bite size and to evaluate seven suture materials at their largest commercially available size for breaking strength and stiffness using cadaveric adult equine linea alba. Soft tissues were removed from the abdominal fascia of 16 adult horses. Individual test sections were created from the entire linea alba and labeled (1 through 6) starting at the umbilicus and extending craniad. A single biomechanical test was performed on each test section. Tissue bite size (3, 6, 9, 12, 15, 18, and 21 mm) significantly altered breaking strength directly in a logarithmic fashion (P < .0001; R²= 0.94). Tissue bite size accounted for 44% and linea alba thickness for 24% of the variability in breaking strength of the equine linea alba. The optimal tissue bite size for adult horses was 15 mm from the edge of the linea alba based on lack of significant gain in breaking strength. There were no differences in breaking strength among horses, horses weight, or left and right test sections. Test sections taken from near or at the umbilicus had greater breaking strength (P < .005) and thicker linea alba (P < .001) when compared with more cranial test sections. Linea alba thickness alone accounted for 34% of the variability in breaking strength associated with test section position. There were no differences in linea alba stiffness among tissue bite sizes. All suture loops failed before complete fascial disruption, and 52 of 56 (93%) suture loops failed at the knot. Suture breaking strength and stiffness were significantly affected by the type of suture material examined (P < .0001). Size 5 polyester had a greater breaking strength and stiffness compared with the other suture materials tested. The next strongest suture materials were size 3 polyglactin 910 and size 2 polyglycolic acid, which were similar in breaking strengths and stiffness. Size 2 nylon was significantly weaker in breaking strength when compared with the other suture materials.     

Mechanical Properties of Four Suture Patterns for Transected Equine Tendon Repair

Thirty-six superficial digital flexor tendons from nine fresh equine cadavers were transected and sutured with size 2 monofilament nylon. Nine tendons were repaired with each of four suture patterns: single-locking loop, double-locking loop, triple-locking loop, or three-loop pulley. The times required for application, tensile strengths, resistance to distraction (gap), and modes of failure were analyzed. The mean times required were: single-locking loop, 3 mins, 15 secs; double-locking loop, 4 mins, 15 secs; triple-locking loop, 10 mins, 50 secs; and three-loop pulley, 4 mins. The double-locking loop, triple-locking loop, and three-loop pulley suture patterns were stronger than the single-locking loop. The triple-locking loop and three-loop pulley patterns were close in strength and only the triple-locking loop was stronger than the double-locking loop. The three-loop pulley had the greatest resistance to gap formation and its mode of failure was different from the others. The three-locking loop suture patterns failed by suture breakage but the three-loop pulley failed first by suture pull-out and then by suture breakage.     

Effect of Fascial Closure Technique on Strength of Healing Abdominal Incisions in the Dog A Biomechanical Study

Load-deformation data were used to determine the strength of healing abdominal incisions in dogs at 7, 14, and 21 days after wounding. The breaking energy of paramedian incisions closed by suturing the internal and external leaves of the sheath of the rectus abdominis muscle vs. incisions closed by suturing the external leaf only was similar in the 12 dogs studied. Closure of abdominal incisions by suturing only the external leaf of the rectus sheath provided wound strength comparable to the traditional method.     

Comparison of the Thinking Patterns between Chinese and Western Countries

This thesis focuses on different thinking patterns between Chinese and western countries, and discusses the impacts on intercultural communication, and at last provides some ideas to overcome the negative influences caused by these differences.