The effect of cartilaginous reinforcing sutures on initial tracheal anastomotic strength: a cadaver study

Despite the Effects of Tension and Intraluminal Pressure, Which Suture Technique Is the Most Appropriate for Prevention of Air Leakage or Anastomotic Dehiscence in Tracheal Anastomoses in the Short Term? An Experimental Research on Ex Vivo Model

Purpose: We performed an experimental study comparing different suture techniques in trachea anastomoses using the ex vivo sheep model, which deals with the parameters that suture tension, air leakage, intraluminal pressure, and tension at which the anastomosis will rupture. We aimed to find an answer to “Which suture technique should be used in tracheal anastomoses?”

Methods: In all, 45 sheep tracheas were randomly divided into three groups (each n = 15) differing in suture technique for anastomoses: single stitches, mixed, and continuous suture. The anastomoses were evaluated for air leakage under normal (25 mbar) and high (70 mbar) intraluminal pressures without tension. Then, air leakage was followed under high intraluminal pressure with tensile stress. Tension levels of dehiscence were also recorded. Data were statistically evaluated.

Results: No air leakage was observed at 25 mbar intraluminal pressure. At 70 mbar pressure without tension, no statistically significant difference was found among the groups (p >0.05). However, single-stitch technique was the best in terms of air leakage tension and rupture tension levels (p <0.05).

Conclusion: The most reliable and advantageous is single-stitch technique for a tracheal anastomosis in short-term results. Further studies are needed to analyze longer ventilation periods in terms of other serious complications as ischemic dehiscence and stenosis.

[The possibilities for the prevention of incompetent tracheorrhaphy]

The present review of the literature is focused on the methods designed for the prevention of incompetent tracheorrhaphy. The main cause that dictates the necessity of strengthening the sutures is the risk of the development of the complications during the postoperative period following the surgical interventions. The incompetence of the tracheal anastomoses is known to occur in 3.6-26.3% of the patients which leads to the development of such complications as neck phlegmon, mediastinitis, and pleural empyema. The mortality rate amounts to 18.2%. The authors describe the methods employed for the prevention of incompetent tracheorrhaphy following the circular resections and suturing of the linear traumatic defects. The advantages and disadvantages of individual methods are discussed.

Outcomes from Cyanoacrylate Use in Tracheal Anastomosis in a Rat Model

OBJECTIVES

We aimed to investigate the histologic effects of N-butyl-2-cyanoacrylate (NBCA) and metacryloxisulfolane (MS) comonomer on tracheal anastomosis in vivo on a rat model of tracheal resection and end-to-end anastomosis.

STUDY DESIGN

Animal experiment. Rat model of tracheal resection and end-to-end anastomosis.

SETTING

Animal laboratory.

SUBJECTS AND METHODS

Tracheal resection and end-to-end anastomosis were performed in 28 Wistar albino rats. Rats were randomly divided into 2 groups: control (n = 14), in which anastomoses were performed with 8/0 Vicryl, and study (n = 14), in which NBCA and MS comonomer was used in addition to 8/0 Vicryl to perform anastomosis. Seven rats from each group were sacrificed on day 7 and the remaining on day 28 for gross and histologic examination.

RESULTS

Indurations at the site of anastomoses were detected in all rats of study group. Slight narrowing at the site of anastomosis was observed in 8 rats of the study group and in only 1 of the control group. The difference was significant on day 28 (P = .021). The inflammatory cell infiltration was significantly increased in the study group on day 28 (P = .022). Epithelial regeneration was found to be worse in the study group on day 28 (P = .022).

CONCLUSIONS

The use of NBCA and MS comonomer increased the inflammation in rat tracheal anastomosis with respect to inflammatory cell count and epithelial regeneration. So the use of NBCA and MS comonomer in tracheal surgery cannot be recommended yet in the light of our data.

Effect of n-butyl-2-cyanoacrylate on the tensile strength and pressure resistance of tracheal anastomoses ex vivo

OBJECTIVES

To investigate the effects of n-butyl-2-cyanoacrylate on tracheal anastomoses in terms of increased tension and intraluminal pressure ex vivo.

STUDY DESIGN

Ex vivo experimental study.

SETTING

Tertiary referral center (Department of Otolaryngology).

SUBJECTS AND METHODS

Thirty sheep tracheas were used. Four cartilage rings were resected from the tracheas that were 20 cm in length. End-to-end anastomoses were performed by using Vicryl only (group 1), Vicryl and n-butyl-2-cyanoacrylate (group 2), and n-butyl-2-cyanoacrylate only (group 3). The amount of force to break off the anastomosis and the amount of intraluminal pressure to arouse air leakage through the anastomosis were measured.

RESULTS

The mean force required to break off was 171.9 ± 29.7 N in group 1, 164.8 ± 26 N in group 2, and 13.52 ± 2 N in group 3. The mean force required to break off in group 3 was significantly lower than those in groups 1 and 2 (P = .008 and P = .008, respectively). The mean pressure required to cause air leakage was 49.6 ± 9.1 mm Hg in group 1, 113 ± 14.4 mm Hg in group 2, and 15 ± 4.2 mm Hg in group 3. Group 2 was found to be more resistant to intraluminal pressure than groups 1 and 3 (P = .008 and P = .008, respectively).

CONCLUSION

n-Butyl-2-cyanoacrylate had no significant effect on tensile strength. However, its application on the suture line provided extra pressure resistance ex vivo. We believe that further studies need to be conducted to investigate its long-term effects and histological impact on tracheal anastomoses in vivo.