Construction of a computational mechanical model of bronchi for practical simulation of the optimal positive intrathoracic pressure conditions during general thoracic surgery

Abstract

BACKGROUND:

Thoracic CO₂ insufflation with positive intrathoracic pressure is usually effective during thoracoscopic surgery, however, lung collapse is sometimes insufficient. We hypothesized that inappropriate bronchial collapse might cause this unsuccessful lung collapse.

OBJECTIVE:

The objective of this study was to construct a computational mechanical model of bronchi for practical simulation to discover the optimal conditions of positive intrathoracic pressure during thoracoscopic surgery.

METHODS:

Micro-focus high-resolution X-ray computed tomography measurements of lungs from just-slaughtered swine were extracted, and the three-dimensional geometries of the bronchi under pressurized and depressurized conditions were measured accurately. The mechanical properties of the bronchus were also measured. Computational fluid dynamics (CFD) and computational structural mechanics (CSM) analyses were conducted.

RESULTS:

The CSM results indicated that the present structural model could simulate bronchial occlusion. The CFD results showed that airflows from pressed lung alveoli might cause low-internal-pressure regions when suddenly or heterogeneously pushed airflow was injected from a small branching bronchus to a large bronchus. A preliminary computational mechanical model of bronchi was constructed.

CONCLUSIONS:

We demonstrated the performance of the mechanical model of bronchi in rough simulations of bronchial occlusions. However, this model should be verified further using human data to facilitate its introduction to clinical use.

Keywords

Thoracoscopic surgery positive intrathoracic pressure computational fluid dynamics computational structural mechanics

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References

Ettinger

D.S.

Wood

D.E.

Aisner

D.L.

Akerley

Bauman

and Chirieac

L.R.

, Non-small cell lung cancer, Version 5.2017, NCCN clinical practice guidelines in oncology, J Natl Compr Canc Netw 15 (2017), 504–535.

Horswell

J.L.

, Anesthetic techniques for thoracoscopy, Ann Thorac Surg 56 (1993), 624–629.

Suda

, Subxiphoid uniportal video-assisted thoracoscopic surgery procedure, Thorac Surg Clin 27 (2017), 381–386.

Okamura

Takahashi

Dejima

Nakayama

Uehara

Matsutani

, Efficacy and hemodynamic response of pleural carbon dioxide insufflation during thoracoscopic surgery in a swine vessel injury model, Surg Today 46 (2016), 1464–1470.

Uehara

Yasuda

Kondo

and Kawamura

, Carbon dioxide insufflation and thoracoscopic ultrasonography image of pure ground-glass nodule, Interact Cardiovasc Thorac Surg 25 (2017), 836–838.

Timoshenko

S.P.

and Young

D.H.

, Elements of Strength of Materials, Fifth edn, D. Van Nostrand Company, 1968.

Hayashi

, Fundamental and applied studies of mechanical properties of cardiovascular tissues, Biorheology (1982).

J.T.

Armstrong

C.G.

and Mow

V.C.

, The effect of strain rate on mechanical properties of articular cartilage in tension, ASME Biomechanics Symposium (1983), 117–120.

Yokobori Jr

A.T.

and Yokobori

, The mechanical test method of cardiovascular and related biomaterials, Biomed Mater Eng 1 (1991), 25–43.

10.

Yokobori

Adachi

Yokobori

Abe

Nakayama

Takahashi

Time dependent and cyclic dependent behaviour of sintered silicon carbide and alumina ceramics, in: Proceedings of The 7th International Conference On Fracture (ICF7), 1989, pp. 2927–2936.

11.

Yokobori

A.T.

Adachi

and Yokobori

, Time-dependent mechanical behaviour of alumina ceramics, Eng Fract Mech 40 (1991), 863–870.

12.

Aratani

Egawa

Ohmi

and Yokobori

A.T.

, Fracture phenomena of float glass measured by the quasi-static method, Strength, Fract. Complex 13 (2020), 91–104.

13.

Wakayama

Suzuki

and Tanuma

, Effect of nasal obstruction on continuous positive airway pressure treatment: Computational fluid dynamics analyses, PLoS One 11 (2016), e0150951.

14.

Suzuki

and Tanuma

, The effect of nasal and oral breathing on airway collapsibility in patients with obstructive sleep apnea: Computational fluid dynamics analyses. Lee P-L, editor, PLoS One 15 (2020), e0231262.

15.

Tanuma

Nakagomi

and Nagumo

, Evaluations of steady and unsteady blood vessel wall stresses of artery with a cerebral aneurysm, in: Proc Bioeng Conf Annu Meet BED/JSME, 2013, pp. 551–552.

16.

Okada

Mimura

Ikegaki

Katoh

Itoh

and Tsubota

, A novel video-assisted anatomic segmentectomy technique: Selective segmental inflation via bronchofiberoptic jet followed by cautery cutting, J Thorac Cardiovasc Surg 133 (2007), 753–758.

17.

Yoshimoto

Nomori

Mori

Kobayashi

Ohba

Shibata

, Prediction of pulmonary function after lung lobectomy by subsegments counting, computed tomography, single photon emission computed tomography and computed tomography: A comparative study, Eur J Cardiothorac Surg 35 (2009), 408–413.