The threshold for air leak: stapled versus sutured human bronchi, and experimental study

Area of Science:

• Thoracic surgery
• Surgical techniques
• Biomechanical testing

Background:

• Limited data exists on bronchial staple-closure integrity under immediate post-operative mechanical stress.
• Mechanical strength of stapled bronchial closure requires further investigation compared to manual suturing.
• Understanding bronchial closure tolerance to air and fluid leaks is crucial.

Purpose of the Study:

• To compare the mechanical strength and air leak threshold of stapled versus hand-sutured bronchial closures.
• To evaluate the integrity of bronchial staple-closures under increasing inflation pressures.
• To assess the tolerance of different bronchial closure methods to mechanical stress.

Main Methods:

• Forty intact cadaveric tracheobronchial trees (55-70 years old, 60% male) were divided into two groups.
• Group A: 20 left bronchi closed with a bronchial stapler; Group B: 20 bronchi closed with simple interrupted sutures.
• Specimens were submerged in water and inflated to detect air leaks, with pressure increased until leakage occurred.

Main Results:

• No air leaks were observed at 40 mmHg in either group.
• Median leakage pressure was significantly higher for hand-sutured bronchi (200 mmHg) than stapled bronchi (105 mmHg).
• 50% of stapled closures leaked from multiple sites, compared to single-site leaks in sutured closures (P < 0.001).

Conclusions:

• Hand-sutured bronchi exhibit greater tolerance to high inflation pressures before air leakage compared to stapled closures.
• Air leakage can occur in stapled bronchial closures even when staples appear intact radiologically.
• Suturing may offer superior mechanical integrity for bronchial closure in specific clinical scenarios.