Temporary Diaphragm Pacing for Patients at Risk of Prolonged Mechanical Ventilation After Extensive Open Aortic Surgery

Abstract

Respiratory failure after extensive aortic surgery (EAS), such as thoracoabdominal aortic aneurysm (TAAA) repair, is the most prevalent complication. It starts with the initiation of mechanical ventilation (MV), which results in diaphragm atrophy and contractile dysfunction, termed ventilator-dependent diaphragmatic dysfunction (VIDD), with attendant increases in morbidity and mortality. VIDD has been reported in ≤53% of patients after 24 hours of MV. Diaphragm pacing (DP) has been used for patients with VIDD, such as quadriplegia and diaphragm paralysis. We evaluated the feasibility of DP for patients with a high risk of prolonged MV after EAS. A retrospective review of prospectively collected data was conducted of patients who had undergone implantation of a Food and Drug Administration–approved DP system after EAS from June 2020 to March 2021. The DP electrodes were placed in the left diaphragm after diaphragm closure after TAAA repair or bilaterally after transperitoneal exposure. DP was instituted on arrival to the intensive care unit to prevent diaphragm atrophy and VIDD. The diaphragm electromyogram was analyzed before DP and daily. The key clinical outcome variables were recorded. Seven patients (four men; mean age, 70.1 years) had undergone DP implantation after TAAA repair (n = 6) or transperitoneal renal/visceral debranching (n = 1). The risk factors for respiratory failure and outcomes are listed in the Table. Pulmonary function could not be assessed in three patients owing to emergency nature of the operation. No patient died intraoperatively. No DP-related complications occurred. In all patients, significant improvement in the diaphragm electromyogram was noted with DP (Fig). The median total MV time, including operating time, was 32 hours (range, 16-73 hours). The median postoperative MV time was 22.1 hours (range, 8-63 hours). One patient had required reintubation because of pulmonary edema 29 hours after initial extubation, requiring 44 hours of additional MV. No patient had required prolonged MV (>3 days) or developed VIDD. The median intensive care unit length of stay was 5 days. DP was used for 2 to 6 days (median, 3.8 days). DP increased diaphragm muscular contractions and might mitigate prolonged MV and the development of VIDD after EAS. A further comparative study is warranted.TableRisk factors and outcomesPt. No.Age; sexRisk factorProcedureMV duration, hoursICU, daysFEV1, %EMG: right; leftPostoperativeTotalBaselineFollow-up160; MFormer smokerTAAA repair17.530.54NANA; weakNA; good276; MFormer smoker; sleep studies with poor oxygen saturationRuptured TAAA repair12206NANA; weakNA; good381; MFormer smoker; COPDMycotic TAAA repair16.525.52NANA; weakNA; good475; FFormer smoker; COPDRuptured TAAA repair816101.68NA; weakNA; good561; FActive smoker; COPDTAAA repair243651.55NA; nearly absentNA; good666; MActive smoker; COPDRVD19 + 4423 + 4462.38Nearly absent; nearly absentGood; good779; FFormer smokerTAAA repair637351.29NA; absentNA; weakCOPD, Chronic obstructive pulmonary disease; EMG, electromyogram; F, female; FEV1, forced expiratory volume in 1 second; ICU, intensive care unit; M, male; MV, mechanical ventilation; NA, not applicable; Pt. No., patient number; RVD, renal/visceral debranching; TAAA, thoracoabdominal aortic aneurysm. Open table in a new tab