Chimney Commando Procedure Reduces Operative Times in Single-Surgeon Study

A modified surgical approach known as the chimney Commando procedure significantly reduced operative duration in a retrospective single-surgeon series. Researchers evaluating early surgical outcomes found that patients undergoing this technical modification experienced shorter cardiopulmonary bypass and aortic cross-clamp times than those treated with the classical Commando technique. Across the evaluated cohort, no individuals receiving the chimney technique required a permanent pacemaker implantation following their operation.

The Commando procedure involves double valve replacement combined with annular enlargement. Historically, the classical operation has presented substantial technical challenges for surgical teams and has carried a documented association with elevated postoperative permanent pacemaker rates. The chimney modification may simplify the operation.

To evaluate the comparative performance of the technique, the investigators conducted a retrospective analysis of 58 consecutive Commando operations completed by a single surgeon. The study cohort comprised 15 patients managed with the classical Commando technique and 43 patients managed with the chimney modification. The investigative team evaluated several early clinical endpoints, focusing on operative durations, 30-day mortality, the incidence of postoperative permanent pacemaker implantation, and hemodynamic parameters obtained from predischarge echocardiography.

An examination of patient profiles revealed that most baseline characteristics were similar between the two operative groups, though several clinical differences were observed. Concomitant tricuspid procedures were performed significantly more often in the chimney cohort, accounting for 51 percent of cases compared with 13 percent in the classical group, yielding a statistically significant difference with a p-value of 0.014. Additionally, implanted mitral valve size differed significantly between cohorts, measuring a median of 27 millimeters in the chimney group versus 29 millimeters in the classical group, with a p-value of 0.002. Rates of active endocarditis were numerically higher among chimney patients at 21 percent compared with 6.7 percent in the classical group, and preoperative atrial fibrillation occurred in 56 percent versus 33 percent, respectively.

Procedural efficiency differed markedly between the two approaches, demonstrating significant time savings associated with the chimney modification. The median aortic cross-clamp time in the chimney group was 96 minutes, with an interquartile range of 83 to 116 minutes, compared to a median of 138 minutes, with an interquartile range of 104 to 152 minutes, in the classical group, establishing a statistically significant reduction with a p-value of 0.009. Total cardiopulmonary bypass duration was likewise significantly shorter for chimney procedures, recording a median of 164 minutes and an interquartile range of 148 to 184 minutes, compared with 215 minutes and an interquartile range of 163 to 235 minutes for classical procedures, yielding a p-value of 0.019.

Analysis of postoperative conduction outcomes showed that zero of the 43 patients in the chimney cohort required a permanent pacemaker implantation following surgery. In contrast, 6.7 percent of patients in the classical cohort, representing one of 15 individuals, required permanent pacemaker placement, a difference that did not reach statistical significance, with a p-value of 0.3. Early survival outcomes were comparable across both cohorts, with 30-day mortality recorded at 11.6 percent in the chimney group and 13.3 percent in the classical group, reflecting a non-significant difference with a p-value greater than 0.9.

Hemodynamic assessments conducted prior to hospital discharge confirmed consistent functional results across both surgical cohorts. Predischarge echocardiography demonstrated that aortic valve mean gradients and left ventricular ejection fraction were similar between patients treated with the chimney modification and those who underwent the classical procedure. Furthermore, the postoperative imaging examinations identified no occurrences of moderate or severe paravalvular leak in either patient cohort.

The study authors concluded that the chimney Commando procedure served as a safe and efficient alternative to the classical technique within their single-surgeon series, demonstrating reduced operative durations and an absence of pacemaker requirements. However, the researchers emphasized that the study design was a retrospective observational analysis originating from a single operator, noting that these preliminary clinical findings require further validation through larger, multicentre clinical investigations.

Subject of Research: Comparative early outcomes of classical versus chimney Commando double valve replacement procedures

Article Title: Transition from classical to chimney Commando procedure: improved operative efficiency and zero permanent pacemaker in the chimney cohort – a single-surgeon experience

Article References: Zhang, Y., Zhu, R., Yu, G., Hu, L., & Cao, Y. (2026). Transition from classical to chimney Commando procedure: improved operative efficiency and zero permanent pacemaker in the chimney cohort – a single-surgeon experience. BMC Cardiovascular Disorders. https://doi.org/10.1186/s12872-026-06857-8

Image Credits: AI Generated

DOI: 10.1186/s12872-026-06857-8

Keywords: chimney Commando procedure, classical Commando procedure, double valve replacement, annular enlargement, permanent pacemaker implantation, aortic cross-clamp time, cardiopulmonary bypass time, operative efficiency, active endocarditis, atrial fibrillation, concomitant tricuspid procedures, mitral valve size, 30-day mortality, predischarge echocardiography, aortic valve mean gradient, left ventricular ejection fraction, paravalvular leak, single-surgeon cohort