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* From the Departments of Pulmonary, Allergy, and Critical Care Medicine (Dr. Stoller) and Thoracic and Cardiovascular Surgery (Drs. Blackstone, Pettersson, and Mihaljevic), Cleveland Clinic, Cleveland, OH.
Correspondence to: James K. Stoller, MD, MS, FCCP, Department of Pulmonary, Allergy and Critical Care Medicine, A90, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195; e-mail: stollej{at}ccf.org
Abstract
Background: The reported experience is sparse for patients with prior pneumonectomy who are undergoing surgery for ischemic or valvular heart disease. Such surgery poses special technical challenges. To expand the experience with this challenging clinical intervention, we reviewed the reported patients with prior pneumonectomy who were undergoing cardiac surgery as well as the experience at the Cleveland Clinic.
Methods: A MEDLINE search of the literature for articles published in the English language from 1966 to August 2006 was conducted using the search terms "pneumonectomy" and "cardiac surgery." We included all available individually described patients and also reviewed the Cardiovascular Information Registry at the Cleveland Clinic from 1972 to 2006.
Results: A total of 19 individually described patients in 13 reports were available, 15 of which had previously been reported and 4 that were newly reported from our institution (1 of whom had undergone two operations separated by 8 years). Of the 20 operations performed in these 19 patients, coronary artery bypass grafting (CABG) alone was performed in 15 patients (75%), valve replacement or repair was performed in 4 patients (20%), and CABG with both aortic valve replacement and mitral valve repair was performed in 1 patient (5%). Most patients (13; 68%) had undergone left pneumonectomy. For these 19 patients, the postoperative mortality rate was 16%. Postoperative complications followed 10 of the operations (50%).
Conclusions: Although complications and postoperative deaths occurred more frequently than in other high-risk patient groups (eg, those with COPD undergoing cardiac surgery), this experience suggests that cardiac surgery can be undertaken with a reasonable likelihood of a favorable outcome in this challenging population, justifying the approach in appropriately selected and counseled patients.
Key Words: cardiac surgery • coronary artery bypass graft • outcomes • pneumonectomy • valve repair
Assessing candidacy for cardiac surgery typically includes evaluating the patient’s pulmonary status.123 For example, guidelines from the American College of Physicians3 recommend spirometry for patients with a history of smoking or dyspnea who are undergoing coronary bypass or upper abdominal surgery.
Although several authors have addressed simultaneous cardiac surgery and pneumonectomy456 and closure of atrial septal defects or patent foramen ovale after pneumonectomy,78 little attention has been given to the issue of surgery for ischemic or valvular heart disease after prior pneumonectomy. To review the available reported experience and to better assess the outcomes of such surgery, we reviewed both the Cleveland Clinic experience of cardiac surgery for revascularization and valve repair or replacement, alone or in combination, in patients with prior pneumonectomy and the available literature regarding this challenging clinical scenario. Our search identified four patients who had undergone operations at the Cleveland Clinic and 15 previously reported patients, whose surgical courses are the subject of this report.
Materials and Methods
The study was reviewed and approved by the Institutional Review Board of the Cleveland Clinic. Because the study was a chart review regarding standard medical treatment, informed consent was waived.
To assess comprehensively the reported experience with cardiac surgery in patients who had undergone prior pneumonectomy, we conducted a MEDLINE search from 1966 to August 2006 using the search terms "pneumonectomy" and "cardiac surgery." We also reviewed articles cited in the resultant references and interrogated the Cardiovascular Information Registry at the Cleveland Clinic regarding patients who had undergone pneumonectomy and then underwent coronary artery bypass grafting (CABG) and valve surgery, either alone or in combination, for the interval 1972 to August 2006.
Results
As reviewed in Table 1
,9101112131415161718192021 the search identified 13 articles reporting 16 patients (patients 1 to 16), of whom 1 was excluded (patient 3) because the cardiac operation was a modified Fontan procedure rather than CABG or a valve procedure. A review of the Cleveland Clinic Cardiovascular Information Registry identified four additional, previously unreported patients (patients 17 to 20), whose five operations are described in the text that follows and whose courses are summarized in Table 1. Notably, patient 18 underwent two operations 8 years apart, initially CABG, then mitral and tricuspid valve repair. Brief, selected comments about each Cleveland Clinic operation (Table 1) follow.
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Patient 18
The first operation was an emergency on-pump CABG with three vein grafts, which was performed through a median sternotomy. The postoperative course was complicated and prolonged (Table 1)
, but the patient ultimately recovered good functional status. Eight years after the first cardiac operation, he presented with shortness of breath, attributable to severe mitral regurgitation (MR) and tricuspid regurgitation (TR). Cardiac catheterization demonstrated patent vein grafts, and the patient remained well revascularized save for one anastomotic stenosis, which was dilated and stented before the reoperation. The second operation was performed through a resternotomy after axillary artery and femoral vein cannulation and the initiation of cardiopulmonary bypass. The dissection was extremely difficult and dense adhesions prevented aortic cross-clamping. The patient was cooled, and when the heart fibrillated the right atrium was opened, a superior vena cava cannula was placed, and the left atrium was drained. Prosthetic annuloplasty repair of the tricuspid valve was performed during cooling. A transseptal approach to the mitral valve gave poor exposure. The mitral valve was repaired with an edge-to-edge Alfieri stitch, connecting midportions of the anterior and posterior leaflets. There was 1 to 2+ residual MR and no TR. The patient’s second cardiac postoperative course was remarkably smooth.
Patient 19
This patient presented with severe MR and TR 9 years after undergoing a left pneumonectomy and subsequent mediastinal radiation; neither important coronary artery disease nor aortic calcification was found. The approach was through a median sternotomy, and pericardial adhesions were dense. Aortic and bicaval venous cannulation was used. The left atrium was entered behind the atrial septum. Exposure of the mitral valve was very difficult. Prosthetic annuloplasty repairs of both valves were performed. Residual MR required replacement of the mitral valve during a second period of aortic clamping. The postoperative course was complicated by renal failure (Table 1).
Patient 20
The patient presented with angina 37 years after undergoing left pneumonectomy and was found to have severe three-system coronary disease. A standard on-pump quadruple CABG operation using all veins was performed through a left thoracotomy in the sixth interspace. The choice of the sixth intercostal space approach was based on the plain chest radiographic position of the heart; in retrospect, an approach through the fifth intercostal space seems preferable, because it is easier to lift the heart than pull the aorta down. The operation and hospital course were uneventful.
Considered as a group, the mean age of these four patients (at the time of the initial operation in patient 18) was 62 years (age range, 48 to 74 years). Half of the patients were women, and all had undergone left pneumonectomy. Three patients underwent CABG, one patient underwent mitral replacement and tricuspid annuloplasty, and, as mentioned, one patient underwent both procedures during separate operations performed 8 years apart. Four operations were performed using cardiopulmonary bypass, and one operation was performed off-pump. The surgical approach was through a left thoracotomy in two patients, and through a median sternotomy in the other three patients. Two of the patients experienced postoperative complications, which were characterized (in patient 18) by hypoxemia requiring extracorporeal oxygenation after the first operation and atrial fibrillation after the second operation, and (in patient 19) by postoperative azotemia and atrial fibrillation. All patients survived the cardiac surgical hospitalization and were discharged from the hospital on mean postoperative day 14 (length of stay range, 5 to 26 days). One patient experienced a stroke at home 18 days after the undergoing the operation and died 4 days later in the hospital in the context of directives for comfort care. The other three patients are alive, with durations of postoperative follow-up of 1 month, 40 months, and 101 months (since the first operation in patient 18) as of September 2006.
Considering the entire reported experience of 20 operations (in 19 patients), the procedures were CABG alone in 15 patients (75%), valve surgery alone in 4 patients, all mitral valve replacement and tricuspid annuloplasty (20%), or both (specifically, patient 16 [Table 1] underwent CABG, aortic valve replacement, and mitral valve repair during the same operation [4%]). The surgical approach was through a median sternotomy in 17 operations (85%); three patients, one reported previously15 and two newly reported (patients 17 and 20), had undergone left thoracotomy, both in the context of prior left pneumonectomy. The operation was conducted off- pump in three instances (ie, patient 17 and the patients described in the studies by El-Hamamsy et al19 and Kumar et al20); all three patients had undergone CABG, and two patients had previously undergone left pneumonectomy. The mean (± SD) age of these 19 patients (considering the age of patient 18 at the time of the first operation) was 66 ± 7.4 years; 63% of patients (n = 12) were men. Of the 19 patients, most (68%; n = 13) had previously undergone left pneumonectomy, with an interval between the pneumonectomy and the first cardiac operation of between 9 months11 and 51 years.19
Measurements of percent predicted FEV1 were available preoperatively for 14 patients (mean FEV1, 47 ± 17% predicted; range, 21 to 75% predicted). Also, values of percent predicted FVC were available preoperatively for 13 patients (mean FVC, 48 ± 13% predicted; range, 32 to 77% predicted). Preoperative arterial blood gas levels were available for seven patients; the mean PaCO2 was 41 ± 4.6 mm Hg (range, 36 to 48 mm Hg). Postoperative complications were reported in 50% of the 20 operations (n = 10); most commonly, they were respiratory failure (n = 5), pneumothorax (n = 2), and mediastinitis (n = 1). The 30-day mortality rate was 16% (n = 3).
Discussion
The current series extends the available literature regarding coronary revascularization and/or valvular surgery in patients with prior pneumonectomy by contributing four new patients who had undergone five separate operations and by summarizing the aggregate experience of 20 reported operations in these 19 patients.9101112131415161718192021 Two prior reports1218 presented summaries of patients with prior pneumonectomy who had undergone cardiac surgery. Specifically, in 1994 Medalion et al12 conducted a survey of 118 surgeons who were members of the Society of Thoracic Surgeons, of whom 32 responded. Excluding the reported patients who had undergone postpneumonectomy closure of a patent foramen ovale or atrial septal defect for right-to-left shunt,8 they presented aggregate (but not individual) results for 27 patients who had undergone CABG or valve surgery, alone or in combination, after prior pneumonectomy. The mean age of these patients was 65 ± 7 years, and 78% of those whose gender was reported were men. Fifty-four percent of patients had previously undergone right pneumonectomy, and the operations performed included CABG in 81% and mitral valve replacement in 19%. Reported complications included early death in 7%, pneumothorax in 11%, postpericardiotomy syndrome in 4%, and reported difficulty in exposing the circumflex marginal branches in 7%.
In the second article presenting a review of earlier experience, Diab et al18 presented the results of a MEDLINE search conducted from 1966 to September 2000 that identified seven patients, five of whom had previously undergone left pneumonectomy and two of whom had undergone right pneumonectomy. All patients had undergone CABG. Forty-three percent of patients experienced postoperative complications (reintubation in two patients), and 14% of patients (one patient) died postoperatively. Notably, the current review includes the six patients (patients 1 and 4 to 8) cited in articles91112131415 reviewed by Diab et al18 and the one new patient described by Diab et al18 (patient 12). We extend earlier reviews by including nine previously reported by others (patients 2 and 9 to 16) and adding four newly described patients (patients 17 to 20).
As is widely recognized, prior pneumonectomy poses several special challenges and considerations in the approach to cardiac surgery, especially regarding exposure, line placement for cardiopulmonary bypass, attention to avoiding diaphragmatic dysfunction, and choice of bypassing conduit if CABG is to be performed. Regarding exposure, prior left pneumonectomy causes displacement of the heart into the left chest, thereby obscuring key structures behind the sternum and making exposure difficult. Thus, Soltanian et al15 based their surgical approach on a preoperative chest MRI scan showing that the left anterior descending artery was inaccessible by a median sternotomy, and that the left circumflex abutted the spine and was deemed inaccessible by any approach; therefore, they bypassed the left anterior descending artery through a left thoracotomy. A similar surgical approach was taken in patients 17 and 20, who underwent CABG through a left thoracotomy, one through the fourth interspace and the other through the sixth interspace, respectively, one off-pump and the other on-pump, respectively. These patients demonstrate the imperative to consider carefully the surgical approach based on the location of the heart, the probability of severe adhesions, and the condition of the aorta. In this context, we were surprised to find out how many of the previously reported CABG operations had been performed through a sternotomy.
The combination of MR in a patient who had previously undergone left pneumonectomy, as in patients 18 and 19 in this series, poses particular surgical challenges. First, the tolerance of MR is poor, and such patients often become symptomatic even with a moderate degree of MR. Also, as in these cases, the intraoperative exposure of the mitral valve may prove to be difficult because the heart is far away, shifted into the left chest, and adherent to the anterior chest wall. The base of the heart is displaced posteriorly, tilting the plane of the mitral valve parallel to the surgeon’s line of vision. Any approach, whether through the interatrial groove or transseptally, is difficult. From a right thoracotomy, the heart is even farther away. In these circumstances, our preferred approach is transseptal. The mobilization of the heart is really the only way to achieve better exposure but is especially difficult when adhesions are dense. In patient 18, our solution was to compromise, limiting the mitral repair to an Alfieri stitch, which reduced but did not eliminate the MR.
Whether the patient has previously undergone right pneumonectomy compared with left pneumonectomy may have other important implications for the surgical approach. For example, CABG seems technically easier to perform in patients with prior right pneumonectomy because of the position of the heart and because there are fewer adhesions around the left side of the heart. Our patient 18, who had previously undergone left pneumonectomy, demonstrated conditions for his second cardiac operation that we thought precluded surgical revascularization. Under the best of conditions, concomitant mitral valve surgery and CABG require a well-thought-out approach and strategy. The conditions of reoperation or prior radiation therapy are likely to provoke severe adhesions, as encountered in this patient, which caused us to defer concomitant CABG and valve surgery. Rather, our patient 18 was offered a hybrid approach in that he underwent percutaneous coronary intervention (ie, stenting of the circumflex artery with a bare metal stent) before his second cardiac operation. Notably, of the 20 CABG or valve operations performed in the 19 patients described in this series, only 1 patient (patient 16, described by Shanker et al21 [Table 1]) underwent concomitant CABG and valve surgery.
Regarding other cardiac surgical challenges in patients with prior pneumonectomy, Golbasi et al17 point out that percutaneous catheters should be placed on the side of the prior pneumonectomy to minimize the risk of pneumothorax of the remaining lung, and that topical cardiac hypothermia should be avoided to lessen the risk of diaphragmatic dysfunction that would complicate the operation.
Finally, Berrizbeitia et al11 advised against the use of the internal thoracic artery (ITA) as a bypass conduit in the setting of prior pneumonectomy. They caution that in patients with prior right pneumonectomy, the pedicled left ITA may not reach the target site over the hyperinflated left lung and the pedicled right ITA could kink over it. Furthermore, any decrement in lung function incurred by harvesting the ITA might be poorly tolerated. Despite this concern, the ITA was used in three of the cases reported in this series,91620 all without reported adverse short-term consequences. Our favorable experience with the ITA graft, either in situ or as a free graft, leads us to generally favor its use while also recognizing that the technical challenges in the context of a low left thoracotomy (eg, achieving adequate conduit length and difficulty in harvesting the graft) may sometimes weigh against its use.
Not surprisingly, the overall mortality rate in the current series was frequent (16%) and exceeded the frequency in patients with preserved lung function undergoing CABG or valve operations, alone or combined. Because pneumonectomy compromises lung function and causes decreased pulmonary reserve, outcomes in this series invite comparison with those in patients with pulmonary dysfunction. Indeed, although available instruments for assessing postoperative risk variably include COPD,22 the 16% mortality rate in this small series exceeds the 7% mortality rate observed in a series of 191 patients with COPD undergoing CABG23 and the 2.63% mortality rate described in a series of 51,351 patients undergoing CABG from 1999 to 2002.2224
An accurate understanding of specific risk factors here is hampered by the small number of patients in this series and by the fact that assignment of the cause of death was possible in only patient 20; this patient was discharged from the surgical admission on postoperative day 6 and was readmitted to the hospital with a new-onset stroke 12 days later; death ensued 4 days later (postoperative day 22) in the context of advance directives for comfort care only. In postmortem series of patients who have died after cardiac operations, death was attributable to pulmonary causes in 5 to 8% of cases252627; specific pulmonary postoperative complications23 included pneumonia in 0.78%, pulmonary edema or ARDS in 4.9%, and other respiratory complications in 3.0%. The occurrence of postoperative respiratory failure in 25% of the patients (5 of 19 patients) with prior pneumonectomy in this series suggests a higher risk in this patient group.
In summary, the current series extends the available experience by describing the preoperative and outcome features of 19 individuals with prior pneumonectomy who underwent 20 operations for ischemic or valvular heart disease, including 4 newly described individuals from the Cleveland Clinic. The surgical challenges encountered in the newly described patients were numerous and occasionally proved difficult, inviting compromises and hybrid procedures. Though the prevalence of postoperative complications and mortality was higher in this series than in less impaired patients, the experience suggests that cardiac operations can be undertaken with reasonable likelihood of a favorable outcome, justifying the approach in appropriately selected and counseled individuals.
Footnotes
Abbreviations: CABG = coronary artery bypass graft; ITA = internal thoracic artery; MR = mitral regurgitation; TR = tricuspid regurgitation
The authors have reported to the ACCP that no significant conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.
Received for publication October 17, 2006. Accepted for publication January 13, 2007.
References
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