Comparison of leak pressures for single-layer simple continuous suture pattern for cystotomy closure using barbed and monofilament suture material in an ex vivo canine model*

Feasibility of laparoscopic stapled partial cystectomy in canine cadavers

OBJECTIVE

To describe a technique for laparoscopic partial cystectomy and evaluate sealing of canine urinary bladder tissue with an endoscopic stapler.

STUDY DESIGN

Prospective, cadaveric study.

SAMPLE POPULATION

Eleven canine cadavers.

METHODS

Laparoscopic partial cystectomy was performed with an endoscopic gastrointestinal anastomosis (GIA) stapler. Leak testing and urodynamic evaluation was performed to measure intravesical pressure at initial leakage and catastrophic failure or the maximum pressure at which intravesical pressure plateaued. Surgical time, complications, and site of leakage were also recorded.

RESULTS

Laparoscopic partial cystectomy was successfully performed in 10 of 11 cadavers. Median procedure time was 13.6 min (10.1-15.2 min). Median intravesical pressure at initial leakage was 31 mmHg (28-56 mmHg) with a median increase from initial pressure of 15 mmHg (11-37 mmHg). No catastrophic failure of the cystectomy site was observed during leak testing. Intravesical pressure plateaued at a median of 52 mmHg (39-73 mmHg), which was a median of 13 mmHg (8-23 mmHg) higher than intravesical pressure at initial leakage. The median total volume infused at the time of plateau of intravesical pressure was 89 mL (58-133 mL).

CONCLUSION

Laparoscopic stapled partial cystectomy was feasible in canine cadavers. Endoscopic GIA staplers appear to seal the canine urinary bladder with minimal leakage.

CLINICAL SIGNIFICANCE

Use of an endoscopic GIA stapler may provide a minimally invasive option for partial cystectomy in dogs. Further evaluation for application to clinical cases is warranted.

Influence of preconstructed effector loop location using a barbed unidirectional suture on leakage pressures following canine enterotomy closure

OBJECTIVE

To evaluate the influence of preconstructed effector loop location using a barbed unidirectional suture on leakage pressures following canine enterotomy closure.

STUDY DESIGN

Randomized, experimental, cadaveric.

ANIMALS OR SAMPLE POPULATION

Grossly normal jejunal segments from three canine cadavers.

METHODS

Jejunal segments were harvested and randomly assigned based upon effector loop location from the beginning of the incisional line. Groups (n = 12/group) included 0 mm, 5 mm, 10 mm, 15 mm, and intact controls (n = 6/group), repaired using a 3-0 unidirectional barbed suture in a simple continuous pattern. Initial leakage pressure (ILP), maximum intraluminal pressure (MIP), repair time, and leakage location were recorded.

RESULTS

Mean ILP for 0 mm group (24.42 ± 8.43 mmHg) was lower (p ≤ .001) compared to all experimental groups with ILP ~40% lower. There was no difference in MIP among experimental groups (p = .239). Repair time increased (p < .0001) as the distance of the effector loop increased ≥5 mm from the beginning of the incisional line. Leakage location differed among groups (p < .001) with leakage in the 0 mm group from the incisional line (75%), compared to leakage from predominantly from the suture holes in other groups, respectively.

CONCLUSION

Effector loop location influenced ILP and leakage location. Effector loops placed at the beginning of the incisional line (0 mm) decreased ILP compared to loops placed at 5, 10, and 15 mm.

CLINICAL SIGNIFICANCE

Effector loop location using a unidirectional barbed suture should be placed ≥5 mm from beginning of the incisional line for enterotomy closure. Further in vivo studies are necessary to determine the clinical significance of these findings.

Evaluation of barbed suture for celiorrhaphy and subcutaneous closure in bitches with pyometra submitted to ovariohysterectomy

Purpose

To evaluate the use of barbed sutures over the surgical time, the leukogram, the tissue thickness in which the sutures were employed (ultrasonography), the costs, and the possible complications in bitches with pyometra submitted to ovariohysterectomy (OH).

Methods

Convectional 2.0 polyglyconate suture was used in the control group (CG n = 10) and 2.0 barbed polyglyconate suture in the barbed group (BG n = 10) to perform celiorrhaphy (simple continuous pattern) and subcutaneous closure (continuous intradermal pattern). Data were assessed using paired (leukogram between 24 and 48 h within the same group) and unpaired (leukogram, surgical time, tissue thickness, and costs) Student’s t-test. The Fisher exact test was used to assess the occurrence of seroma between groups (p < 0.05). Results are shown as mean ± standard error of mean.

Results

The time spent to perform the celiorrhaphy (195.30 ± 17.37 s vs. 204 ± 16.00 s), subcutaneous closure (174.0 ± 15.86 s vs. 198.0 ± 15.62 s), and the total surgical time (24.30 ± 1.44 min vs. 23.00 ± 1.30 min) did not differ between BG and CG, respectively (p > 0.05). Leukogram at 48 h post-surgery did not differ between groups (p = 0.20). No differences were observed in the subcutaneous and the abdominal wall thickness (cm) assessed by ultrasonography at 48 h in BG (0.31 ± 0.04, 0.80 ± 0.05) and CG (0.34 ± 0.03, 0.72 ± 0.06), respectively. Similarly, 15 days post-surgery the same structures did not differ between BG (0.26 ± 0.02, 0.74 ± 0.08) and CG (0.26 ± 0.03, 0.64 ± 0.05) (p > 0.05). In one bitch from each group, a mild seroma was observed on one side of the surgical wound 48 h after surgery (p = 1.00). The procedures in which barbed sutures were used had an average additional cost of R$ 200.00 ± 11.66 (p < 0.0001).

Conclusions

Barbed suture has proven to be efficient and safe for abdominal and subcutaneous closure. However, considering its current high cost in addition thatthe surgical time of bitches with pyometra undergone OH was not reduced, no advantages were observed with theuse of barbed sutures for this type of surgery.

Cadaveric Evaluation of Load to Failure in Canine Gingiva Apposed With Varied Suture Patterns Using Poliglecaprone 25

The purpose of the study was to determine the effect of suture pattern and repair length on the load to failure in an ex vivo canine gingival model. Healthy mandibular gingiva and mucosa were harvested from fresh cadavers euthanized for purposes unrelated to the study. Samples were randomly assigned by length and pattern. Lingual and buccal free gingival margins were apposed using a simple interrupted (SI), cruciate (XT), simple continuous (SC), or unidirectional knotless continuous barbed suture (SF) closure technique with USP 4-0 poliglecaprone 25^{i, ii} applied over 2 lengths (3 cm and 6 cm). A custom template was used to ensure uniform suture bite application. Surgical time was recorded. Using a soft tissue mechanical testing frame, samples were tensioned to failure. Testing was video recorded and reviewed in conjunction with the tension trace data for tension at initial failure (T_fail) and maximum tension sustained (T_max). Two factor ANOVA by length and pattern was performed followed by individual one way T-tests. Statistically significant findings were XT-SC-SF patterns were quicker to perform than SI. SF was more likely to fail by suture breakage than tissue tearing, and SF withstood less tension at the 3 cm length than SI-XT-SC. No significant difference was detected in T_max or T_fail between SI and SC or XT. The study demonstrates that SC and XT are comparable to SI in tension resistance and faster to perform suggesting that SC and XT could replace SI for extraction site closure although further in vivo testing is required.

Biomechanical properties of canine staphylectomies closed with barbed or smooth suture

OBJECTIVE

To compare the duration of closure and biomechanical properties of staphylectomies closed with absorbable bidirectional barbed suture or smooth monofilament suture in a simple continuous or interrupted pattern STUDY DESIGN: Ex vivo study SAMPLE POPULATION: Soft palates (n = 60) harvested from mesaticephalic canine cadavers METHODS: One centimeter of tissue was excised from the caudal border of each soft palate, and the oral and nasopharyngeal mucosal surfaces were apposed with 2-0 bidirectional Quill Monoderm knotless closure device barbed suture (Q), 3-0 Monocryl in a simple continuous (MC) pattern, or 3-0 Monocryl in a simple interrupted (MI) pattern (n = 20 per group). Duration of closure was compared between groups. Tissues were tested under tension to failure, and mode of failure data were collected by video capture.

RESULTS

Closure time was longer for MI closures than for Q and MC closures, with means of 259.9, 215.4, and 196.7 seconds, respectively (P < .0001). No difference was detected in yield force, force to first tissue rupture, maximum force, and energy required for yield and maximum force between groups. Energy to yield was 190.0, 167.8, and 188.95 N-mm for MI, Q, and MC closures, respectively.

CONCLUSION

Biomechanical properties of staphylectomies closed with barbed or smooth sutures did not differ in this cadaveric model.

CLINICAL SIGNIFICANCE

Barbed suture can be considered as an alternative for closure of canine staphylectomies. These results provide evidence to justify additional research to evaluate clinical outcomes in dogs undergoing staphylectomy.

Bidirectional knotless barbed versus conventional smooth suture for closure of surgical wounds in inguinal castration in horses

Background

Castration of the stallion is one of the most frequently performed surgical procedures in the horse. Recently barbed suture materials for surgical wound closure were introduced to the market with manufacturers claiming that these sutures enhance speed and security as they eliminate the need to tie knots. Recently, it has been suggested that this type of suture may increase postoperative complications. This study aimed at investigating and comparing a bidirectional absorbable knotless barbed suture (KBS) to a conventional smooth suture (SS) for wound closure of inguinal castrations in the horse. This was done by evaluating short-term and post-discharge complications and by comparing the time spent on suturing the surgical wounds after bilateral inguinal castration, which was performed on 45 horses undergoing castration at The Large Animal Teaching Hospital at University of Copenhagen from September 2017 to May 2019.

Results

Short-term complications were few; at 24 h minor swelling occurred in 29 and 33% of horses sutured with KBS and SS respectively and cutaneous dehiscence during recovery occurred in two horses of each group. Post-discharge follow-up revealed that three horses needed veterinary attention for treatment of complications (scrotal swelling (n = 1, KBS); wound exudation (n = 1, SS) and wound dehiscence after return to pasture (n = 1, SS)). Wound closure was achieved 6 min faster with KBS than with SS (P < 0.0001).

Conclusions

Use of the KBS suture did not result in increased occurrence of postoperative complications. Wound closure was faster with KBS than with SS in equine bilateral inguinal castration. Our results show that KBS can safely be used in the horse following bilateral inguinal castrations without adverse effects and with a reduction in suturing time.

Use of a bipolar sealing device to seal partial cystectomy with and without augmentation with a single-layer simple continuous suture pattern in an ex vivo canine model

OBJECTIVE

To evaluate the ability of a bipolar sealing device (BSD) to seal canine bladder tissue and to determine the influence of suture augmentation on resistance to leakage of sealed partial cystectomies.

STUDY DESIGN

Ex vivo, simple randomized study.

SAMPLE POPULATION

Urinary bladders harvested from canine cadavers (n = 23).

METHODS

Partial cystectomy of the cranial third of each bladder was performed with a BSD. This seal was augmented with a simple continuous pattern of 4-0 polydioxanone in half of the specimens. A pressure transducer inserted through the ureter measured intraluminal pressure at initial leakage and catastrophic failure as dyed saline was infused via a catheter inserted through the urethra. Initial leakage pressure and pressure at catastrophic failure were compared between sutured and nonsutured sealed partial cystectomies.

RESULTS

Sutured sealed cystectomies showed initial leakage at lower pressures compared to non-sutured cystectomies (8.6 vs. 17.7 mm Hg; P = .0365) but were able to sustain greater pressures at catastrophic failure (34.3 vs. 21.8 mm Hg; P = .007). Catastrophic failure occurred along the seam of all nonsutured sealed cystectomies and at the suture holes in 10 of the 12 sutured bladders.

CONCLUSION

Partial cystectomies were effectively sealed with a BSD in this canine cadaveric bladder model. Augmentation with a simple continuous suture pattern increased the pressure at which catastrophic leakage occurred but lowered initial leak pressure.

CLINICAL SIGNIFICANCE

This study provides evidence supporting the evaluation of BSD use for partial cystectomy in live animals.

Effect of presurgical storage conditions on leakage pressures of enterotomy sites closed with unidirectional barbed suture material in fresh, chilled, and frozen-thawed cadaveric canine jejunal specimens

OBJECTIVE

To evaluate the effect of presurgical storage conditions on leakage pressures of enterotomy sites closed with unidirectional barbed suture material in fresh, chilled, and frozen-thawed cadaveric canine jejunal specimens.

SAMPLE

36 grossly normal jejunal segments obtained from 4 dog cadavers.

PROCEDURES

9 jejunal segments were harvested immediately from each euthanized dog and randomly assigned to be tested within 4 hours after collection (fresh segments), stored at 4°C for 24 hours before testing (chilled segments), or stored at -20°C for 7 days and thawed at 21°C for 6 hours before testing (frozen-thawed segments). For leakage pressure testing, a 3-cm-long antimesenteric enterotomy was performed and repaired with 3-0 unidirectional barbed suture material in a simple continuous pattern in each segment. Time to complete the enterotomy, initial leakage pressure, maximum intraluminal pressure, and leakage location were recorded for each segment.

RESULTS

Mean ± SD initial leakage pressure for fresh, chilled, and frozen-thawed segments was 52.8 ± 14.9 mm Hg, 51.8 ± 11.9 mm Hg, and 33.3 ± 7.7 mm Hg, respectively. Frozen-thawed segments had significantly lower mean initial leakage pressure, compared with findings for fresh or chilled segments. Time to complete the enterotomy, maximum intraluminal pressure, and leakage location did not differ among groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Leak pressure testing of cadaveric jejunal segments that are fresh or chilled at 4°C for 24 hours is recommended for enterotomy studies involving barbed suture material in dogs. Freezing and thawing of cadaveric jejunal tissues prior to investigative use is not recommended because leak pressure data may be falsely low.

Partial cystectomy with a bipolar sealing device in seven dogs with naturally occurring bladder tumors

OBJECTIVE

To describe the use of a bipolar sealing device (BSD) for partial cystectomy in dogs undergoing excision of bladder tumors.

STUDY DESIGN

Multicenter, prospective, clinical pilot study.

SAMPLE POPULATION

Seven client-owned dogs with nontrigonal urinary bladder lesions.

METHODS

Dogs underwent a sealed partial cystectomy with a BSD, with or without cystoscopic guidance of the resection. The sealed cystectomy site was oversewn with a single-layer simple continuous pattern with monofilament absorbable suture.

RESULTS

Sealed partial cystectomy was successfully performed in all dogs, with a median surgical duration of 69 minutes (range, 50-120). Lesions were located at the apex in six dogs and on the ventral midbody of the bladder in one dog. No urine leakage from the BSD luminal seal was visible prior to suture closure in three dogs, while varying amounts of urine leaked from the sealed site in four dogs. Suture was placed over the seal in grossly normal bladder tissue in six dogs and in the BSD peripheral thermal effect zone in one dog; in this latter dog, revision cystorrhaphy was required 3 days later because of uroabdomen. The other six dogs had no clinical evidence of urinary bladder healing complications.

CONCLUSION

The integrity of the seal generated by the BSD tested here on partial cystectomies varied between dogs and was unpredictable.

CLINICAL SIGNIFICANCE

Sealed partial cystectomy with a BSD may reduce exposure of urinary bladder luminal contents to the surgical site. However, the placement of sutures over the seal and through grossly normal bladder tissue is recommended to prevent postoperative uroabdomen.

Influence of barbed suture on leak pressures after double-layer inverting closure of cystotomy sites in sheep

OBJECTIVE

To determine the influence of barbed suture on double-layer inverting closure of cystotomy sites in sheep.

STUDY DESIGN

Ex vivo study.

SAMPLE POPULATION

Urinary bladders harvested from ovine (n = 26) cadaveric specimens.

METHODS

After collection and specimen preparation, a 3-cm-long incision was created on the ventral aspect of the urinary bladder. The cystotomy was repaired with barbed (n = 13) or nonbarbed analogous monofilament absorbable suture (n = 13) in a double-layer inverting suture pattern. Time required for closure in seconds was recorded for each test. Each bladder was connected to a pressure transducer to monitor intraluminal pressure during infusion with dyed Hartmann's solution until leakage occurred. Intraluminal pressure at time of initial leakage and leakage site were also recorded. Two-sample t tests were used to compare initial leakage pressure and closure time between the 2 types of suture (P = .05).

RESULTS

The mean ( ± SD) leakage pressure of ovine urinary bladder incisions did not differ between closures with barbed sutures (42.3 ± 21.7 mmHg) and nonbarbed closures (32.5 ± 14.4 mmHg, P = .187). Cystorrhaphies were performed faster with barbed suture (307 ± 50 seconds) than with nonbarbed suture (390 ± 62 seconds, P = .001).

CONCLUSION

The use of barbed suture did not affect mean leakage pressure of ovine urinary bladder incisions but decreased the time required to complete cystorrhaphies in this model.

CLINICAL SIGNIFICANCE

This study provides evidence to support the use of knotless barbed suture for open ovine cystorrhaphies. Use of such suture for laparoscopic and laparoscopic-assisted procedures in sheep warrants caution until cyclic and in vivo testing is performed with appropriate laparoscopic instrumentation.