Outcome of Unilateral Pulmonary Edema after Minimal-Invasive Mitral Valve Surgery: 10-Year Follow-Up

Abstract

The study was approved by the institutional review board (IRB) at the University Medical Center Campus Kiel, Kiel, Germany (reference number: AZ D 559/18) and registered at the German Clinical Trials Register (reference number: DRKS00022222). Objective. Unilateral pulmonary edema (UPE) is a complication after minimally invasive mitral valve surgery (MIMVS). We analyzed the impact of this complication on the short- and long-term outcome over a 10-year period. Methods. We retrospectively observed 393 MIMVS patients between 01/2009 and 12/2019. The primary endpoint was a radiographically and clinically defined UPE within the first postoperative 24 h, secondary endpoints were 30-day and long-term mortality and the percentage of patients requiring ECLS. Risk factors for UPE incidence were evaluated by logistic regression, and risk factors for mortality in the follow-up period were assessed by Cox regression. Results. Median EuroSCORE II reached 0.98% in the complete MIMVS group. Combined 30-day and in-hospital mortality after MIMVS was 2.0% with a 95, 93 and 77% survival rate after 1, 3 and 10 years. Seventy-two (18.3%) of 393 patients developed a UPE 24 h after surgery. Six patients (8.3%) with UPE required an extracorporeal life-support system. Logistic regression analysis identified a higher creatinine level, a worse LV function, pulmonary hypertension, intraoperative transfusion and a longer aortic clamp time as predictors for UPE. Combined in hospital mortality and 30-day mortality was slightly but not significantly higher in the UPE group (4.2 vs. 1.6%; p = 0.17). Predictors for mortality during follow-up were age ≥ 70 years, impaired RVF, COPD, drainage loss ≥ 800 mL and length of ventilation ≥ 48 h. During a median follow-up of 4.6 years, comparable survival between UPE and non-UPE patients was seen in our analysis after 5 years (89 vs. 88%; p = 0.98). Conclusions. In-hospital outcome with UPE after MIMVS was not significantly worse compared to non-UPE patients, and no differences were observed in the long-term follow-up. However, prolonged aortic clamp time, worse renal and left ventricular function, pulmonary hypertension and transfusion are associated with UPE.

Unilateral pulmonary edema following minimally invasive cardiac surgery: keeping both eyes maximally open

“…Over the last decades, advances in minimally invasive cardiac surgery (MICS) have opened up newer avenues for achieving an enhanced recovery by optimizing the cost-benefit ratio in the cardiac surgical arena. This paradigm shift resonates well with the overall aim of an improved quality of care, patient satisfaction and reduction in postoperative stay, favorably modulating the perioperative morbidity [ 1 – 3 ]. While the advantages generally outweigh the risks involved, MICS does however present challenges previously unheard of in similar conventional surgical cohorts [ 1 , 4 ].…”

“…This paradigm shift resonates well with the overall aim of an improved quality of care, patient satisfaction and reduction in postoperative stay, favorably modulating the perioperative morbidity [ 1 – 3 ]. While the advantages generally outweigh the risks involved, MICS does however present challenges previously unheard of in similar conventional surgical cohorts [ 1 , 4 ]. These include: challenged surgical field visualization, requirement of alternate cannulation sites for cardio pulmonary bypass (CPB) and one lung ventilation (OLV).…”

“…These include: challenged surgical field visualization, requirement of alternate cannulation sites for cardio pulmonary bypass (CPB) and one lung ventilation (OLV). This can potentially translate as increased concerns surrounding perioperative neurological and respiratory complications such as stroke and unilateral pulmonary edema (UPE), respectively [ 1 , 4 , 5 ].…”

“…More importantly, the pathophysiological basis of UPE to date remains unclear, with various suggested mechanisms. These include direct insults from atelectasis and hydrostatic forces leading to an alveolar-capillary barrier disruption, compounded by an indirect injury following ischemia-reperfusion, mediated by oxidative free radicals and chemo-toxic inflammatory cells [ 1 , 4 , 5 ].…”

“…[ 4 , 6 ]. Echocardiographic findings such as pulmonary hypertension, left ventricular ejection fraction < 50%, significant right ventricular dysfunction and a pathological right pulmonary vein Doppler profile are additionally associated with UPE [ 1 , 4 – 6 ]. A study by Khalil et al .…”