Skeletonization of bilateral internal thoracic artery grafts lowers the risk of sternal infection in patients with diabetes

OBJECTIVE

Deep sternal wound infection is a dreaded complication of coronary artery bypass surgery, particularly in patients with diabetes. This study determines whether skeletonization of internal thoracic artery conduits compared with pedicled harvesting reduces the risk of deep sternal wound infection in patients with diabetes undergoing bilateral internal thoracic artery grafting.

METHODS

We reviewed prospectively gathered data on all patients who have undergone coronary artery bypass grafting and received bilateral internal thoracic artery grafts at our institution since 1990. We compared patients with diabetes who received skeletonized (n = 79) versus conventional pedicled (n = 36) internal thoracic artery conduits.

RESULTS

The proportion of patients taking insulin (19.0% vs 14.0% for skeletonized vs conventional grafts, respectively, P =.6) or oral hypoglycemic agents (68.4% vs 69.4%, P =.9), as well as the prevalence of type I diabetes (2.5% vs 8.3%, P =.18), were similar in both groups. Patients who received skeletonized grafts were more likely to receive a free rather than an in situ right internal thoracic artery graft (93.7% vs 30.6%, P <.001). The prevalence of deep sternal wound infection was significantly lower in patients who received skeletonized grafts compared with patients who received conventional grafts (1.3% vs 11.1%, P =.03). Patients in the skeletonized group were also less likely to develop any (superficial or deep) sternal wound infection postoperatively (5.1% vs 22.2%, P =.03). There was no significant difference in the prevalence of deep sternal wound infection between patients with diabetes who received skeletonized internal thoracic arteries and patients without diabetes who underwent conventional internal thoracic artery grafting (n = 578) (1.2% vs 1.6%, respectively, P =.8).

CONCLUSIONS

Skeletonization of internal thoracic artery conduits lowers the risk of deep sternal wound infection in patients with diabetes undergoing bilateral internal thoracic artery grafting. We no longer consider diabetes a contraindication to bilateral internal thoracic artery grafting, provided the internal thoracic arteries are skeletonized.

Evaluation of flow characteristics of the left internal thoracic artery graft: perioperative color Doppler ultrasonography versus intraoperative free-bleeding technique

From October 2000 through April 2001, we prospectively evaluated the flow characteristics of the left internal thoracic artery (LITA) graft in a homogenous group of 44 men with isolated severe proximal left anterior descending coronary artery stenosis who underwent elective coronary artery bypass grafting with cardiopulmonary bypass. We performed transthoracic color Doppler ultrasonography preoperatively and repeated this examination in each patient between the 5th and 7th postoperative days, obtaining cross-sectional area, total flow volume, diastolic velocity, systolic velocity, mean velocity, pulsatility index, and resistance index. These results were compared with those of the intraoperative free-bleeding technique. Good-quality Doppler images of the LITA were easily obtained with a combined supraclavicular-parasternal approach. After surgery, systolic flow velocity, pulsatility index, and resistance index decreased significantly, but diastolic flow velocity and mean flow velocity increased significantly. The intraoperative flow volume obtained by the free-bleeding technique (32.42 +/- 12.33 mL/min) was significantly less than both pre- and postoperative ultrasonographic values (42.22 +/- 10.77 mL/min and 45.36 +/- 19.52 mL/min, respectively). No significant difference was found when changes in LITA values were compared between patients with (n=19) and without (n=25) normal anterior wall motion. We conclude that color Doppler ultrasonography is a reliable noninvasive technique for preoperative evaluation of the LITA as a graft and for postoperative long-term follow-up of graft function. However the intraoperative free-bleeding technique is not reliable for flow-volume measurement due to anesthesia-related hemodynamic changes and vasospasm. Color Doppler can prevent useless LITA harvesting and decrease the need for postoperative LITA angiography.

Usefulness of dipyridamole stress echocardiography for predicting graft patency after coronary artery bypass grafting

Noninvasive techniques often provide controversial results in patients who have coronary artery bypass grafts (CABGs). Vasodilator stress echocardiography allows semi-simultaneous imaging of CABG flow and segmental left ventricular wall motion. To assess the comparative and additive value of regional flow and function for noninvasive evaluation of graft patency status, we evaluated 110 consecutive patients who underwent CABG and who were scheduled for coronary angiography. All patients underwent stress echocardiography with dipyridamole (0.84 mg/kg) and atropine (1 mg), including wall motion analysis by 2-dimensional echocardiography and Doppler evaluation of flow reserve of each CABG. Echocardiographic findings were compared with angiographic data. Four patients had inadequate acoustic windows. The remaining 106 patients had 226 grafts performed. Stress echocardiography showed 67% sensitivity, 91% specificity, and 71% accuracy for identification of 50% to 100% stenosis in the graft or in the recipient coronary vessel. There was a fair agreement with angiography (kappa coefficient 0.60). Identification of impaired coronary bypass flow reserve (i.e., <1.9 for internal mammary grafts and <1.6 for saphenous vein grafts) by Doppler had 91% sensitivity, 88% specificity, and 89% accuracy for graft stenosis. There was good agreement with angiographic findings (kappa 0.77). The combination of the 2 techniques achieved 93% sensitivity, 93% specificity, and 93% accuracy, showing a very good agreement with the patency status of the grafts as evaluated at angiography (kappa 0.85). The combined assessment of wall motion and flow reserve in patients who underwent CABG is feasible and provides an accurate estimate of graft patency status by increasing sensitivity of stress echocardiography and specificity of Doppler flow reserve.

Transbrachial Coil Occlusion of the Large Branch of an Internal Mammary Artery Coronary Graft

Percutaneous transbrachial insertion of two complex coils into the intercostal branch of the left internal mammary artery resulted in the relief of severe angina in a 45-year-old man who had coronary artery bypass surgery 2 years before. The diagnosis of coronary artery steal was made clinically. This case illustrates the importance of recognizing coronary steal in patients who redevelop angina after coronary artery surgery with the use of an incompletely prepared left internal mammary artery as a conduit. Brachial or radial artery should be preferred to reach left internal mammary artery (LIMA) for cannulation easily. The preoperative angiographic imaging of LIMA is important to detect the side branches and their sizes. The patient was treated without the need for further surgery.

Does competitive flow reduce internal thoracic artery graft patency?

BACKGROUND

In coronary arteries with moderate stenosis, competitive flow may lead to internal thoracic artery (ITA) graft occlusion. The goals of this study were to determine if competitive flow reduces ITA patency, and if there is a degree of coronary stenosis below which ITAs should not be used.

METHODS

From 1972 to 1999, 50,278 patients underwent primary coronary artery bypass grafting (CABG). Of these, 2,002 had at least one ITA graft and postoperative angiography before coronary reintervention; 2,999 angiograms of 2,121 ITAs were made. Time-related ITA occlusion was modeled using longitudinal analysis to identify its risk factors while accounting for lack of independence introduced by repeated angiography and multiple ITA anastomoses per patient. Proximal coronary stenosis (maximum preoperative stenosis between ITA anastomosis and aorta) was the surrogate for competitive flow.

RESULTS

Unadjusted ITA patency was 93%, 89%, 90%, and 92% at 1, 5, 10, and 15 years after CABG. Risk factors associated with ITA occlusion were lesser degree of proximal coronary stenosis (p < 0.0001); longer time from CABG in grafts to non-left anterior descending coronary arteries (p < 0.0001); female sex (p = 0.0003); later date of CABG (p = 0.01); right ITA (p < 0.0001); and smoking (p < 0.0001). In all arteries, as preoperative proximal coronary stenosis decreased, ITA patency declined; however, at no degree of stenosis was there a sharp decline.

CONCLUSIONS

Internal thoracic artery patency decreases as coronary competitive flow increases. However, the nature of this relationship indicates ITAs should not be abandoned at moderate grades of stenosis.

[Subclavian-coronary steal syndrome following CABG--a case report]

A case of 47-year-old man with occlusion of the subclavian artery occurring few months after CABG with the left internal mammary artery grafting is presented. The patient developed a subclavian-coronary steal syndrome with retrograde blood flow from the coronary circulation to the subclavian artery through the left internal mammary artery. Clinical presentation consisted of vertigo and recurrence of chest pain. The increasing frequency of this syndrome and the preoperative preventive methods such as pressure gradient measurement between the left and right upper limb are discussed.

Radial artery patency: are aortocoronary conduits superior to composite grafting?

BACKGROUND

The radial artery (RA) can be used as either an aortocoronary (RA-Ao) or composite graft (T graft). Optimum use for the RA has yet to be established. We compared RA patency with these two techniques.

METHODS

Between October 1993 and June 2001, 1505 patients underwent coronary artery bypass grafting using the RA as either a composite (n = 1022) or RA-Ao graft (n = 483). Angiograms performed on 203 (13.5%) patients with signs or symptoms of ischemia at an average of 26.1 +/- 18.5 months postoperatively were reviewed.

RESULTS

Patients with RA-Ao grafts had a greater incidence of postoperative angiography versus patients with composite grafts (19% versus 11%; p < 0.01). Patients receiving T grafts had a greater number of anastomoses per patient (4.1 +/- 0.6 versus 3.0 +/- 1.0; p < 0.01) and a higher incidence of total arterial revascularization (100% versus 41%; p < 0.01). Regardless of grafting strategy, patency was significantly worse for targets of the right coronary artery (58% T graft; 67% RA-Ao; p < 0.01 for both) and for targets with less than or equal to 70% stenosis (59% T graft; 57% RA-Ao; p < 0.01 for both). The site of proximal anastomosis failed to effect RA patency (relative risk, 1.2; 95% confidence interval, 0.7 to 1.8; p = 0.50).

CONCLUSIONS

The site of the proximal anastomosis does not appear to influence patency. Both RA-Ao and composite conduits are sensitive to target location and stenosis. Advantages of composite grafting include greater conduit length and minimizing aortic manipulation at the expense of increased complexity and the potential for hypoperfusion. These factors should be considered when choosing an RA grafting strategy.

Discrepancy between myocardial ischemia and luminal stenosis in patients with left internal mammary artery grafting to left anterior descending coronary artery

BACKGROUND

Left internal mammary artery (LIMA) grafting to the left anterior descending artery (LAD) is known to have long-term patency. However, myocardial ischemia in the territories supplied by LIMA to LAD is still demonstrated. The aim of this study is to examine the relationships between the extent, location, and clinical outcome of myocardial ischemia in LAD territories (ILAD) by use of myocardial perfusion imaging (MPI) and angiographic characteristics of such a bypass conduit.

METHODS AND RESULTS

We studied 38 consecutive patients with prior coronary artery bypass grafting who showed stress-induced ischemia in LIMA to LAD territories by MPI single photon emission computed tomography between the years 1996-2000. All patients underwent quantitative coronary angiography within 6 months of the nuclear study. Single photon emission computed tomography parameters of ILAD were assessed by location (septum, apex, anterior, and anterolateral) and included extension score (1-4 per patient), severity score (0-3 per territory), and total sum score. LIMA to LAD quantitative coronary angiography parameters included minimal lumen diameter, lesion length, reference diameter, and diameter stenosis (percentage). LAD and LIMA diameters and ratio (in normal segments) were determined within 10 mm proximal and distal to the anastomotic site. The study group was compared with 18 control subjects without ischemia or stenosis treated with LIMA to LAD. The patients were followed up for cardiac death at an interval of 3.2 +/- 1.5 years from the time of MPI testing. The patients' mean age was 66 +/- 12 years (31 men and 7 women); the mean period after surgery was 6.2 +/- 1.5 years. The ILAD distribution was as follows: septum, 12 (32%); apex, 20 (52%); anterior, 24 (63%); and anterolateral, 18 (47%). The mean extension score was 1.9 +/- 1.0, and the mean total sum score was 3.4 +/- 2.3. Of 38 patients with ILAD, only 17 (45%) had greater than 50% luminal stenosis (2 LIMA and 15 anastomosis or distal). Among clinical variables during stress testing, the prevalence of angina was significantly higher in the luminal stenotic patients versus patients without stenosis (P =.04). A significant correlation was found between anterior wall ischemia and reference diameter (r = -0.7, P =.002) and between total sum score and minimal lumen diameter (r = -0.48, P =.05). Of note, the LAD-to-LIMA ratio was significantly lower in patients with ILAD and without luminal stenosis compared with the control group (0.73 +/- 0.16 vs 0.87 +/- 0.15, P =.004). Cardiac death occurred in 8 patients (21%), 5 patients with luminal stenosis versus 3 patients without stenosis (P = not significant).

CONCLUSIONS

In patients with LIMA to LAD anastomosis, myocardial ischemia could occur even without angiographic luminal stenosis and apparently reflects a mismatch between LAD and LIMA diameters at distal anastomotic sites. Regarding the similar prevalence of cardiacdeath, invasive evaluation and aggressive treatment are recommended in all patients with ischemia in LIMA/LAD territories.

In situ retrocaval skeletonized right internal thoracic artery anastomosed to the circumflex system via transverse sinus: Technical aspects and postoperative outcome

BACKGROUND

The aim of this study was to investigate whether, by using the in situ right internal thoracic artery via the transverse sinus (eventually retrocaval), both the proximal and distal major branches of the circumflex system could be grafted and to evaluate the early and late outcome in these patients.

METHODS

Between January 1997 and March 2002, 452 consecutive patients underwent grafting of the circumflex system with the in situ skeletonized right internal thoracic artery routed via the transverse sinus. The mean age was 62.4 +/- 10.3 years. A mean of 2.2 +/- 0.3 arterial grafts per patient were used, and 271 (60%) patients underwent total arterial myocardial revascularization. At 3 months after surgery, 86 patients (right Y or T graft) underwent echo color Doppler imaging before and after an adenosine provocative test. The mean follow-up was 27 +/- 8 months.

RESULTS

The success rate of skeletonized right internal thoracic artery grafting to the circumflex system branch was 100%. There were 15 (3.4%) hospital deaths. In 116 patients who underwent postoperative angiography, the total patency rates of the right and left internal thoracic arteries were 94% and 96.6%, respectively. Strong predictors for nonfunctional internal thoracic artery grafts were a small internal thoracic artery caliber (P <.001), recipient coronary artery diameter less than 1.5 mm (P =.012), stenotic lesions of less than 60% (P =.016), and diffuse stenotic lesions (P =.015) of the recipient coronary artery. In 86 patients who underwent postoperative echo color Doppler imaging, the flow reserves at the main stem of the left and right internal thoracic arteries were 2.24 +/- 0.5 and 2.48 +/- 0.6, respectively. Cumulative actuarial survival at 3 years was 96.3%, and event-free cumulative survival was 93%. The Cox model revealed a left ventricular ejection fraction of less than 35% (P =.016), age greater than 70 years (P =.025), New York Heart Association grade greater than III (P =.0019), nontotal arterial myocardial revascularization (P =.002), and the preoperative presence of more than 1 ischemic area (P <.001) as strong predictors for poor overall cumulative event-free survival.

CONCLUSIONS

The skeletonized right internal thoracic artery, placed via the transverse sinus and eventually retrocaval, can reach most branches of the circumflex system and is associated with an excellent patency rate. The predictors for poor overall event-free survival seem to be similar to those of the general population undergoing conventional coronary artery bypass grafting. Use of bilateral internal thoracic arteries and in situ right internal thoracic artery grafting via the transverse sinus offers the possibility of various configuration constructions, making possible total arterial myocardial revascularization with a minimum number of arterial conduits.

Non-invasive assessment of the composite radial artery and in situ left internal thoracic artery Y-graft for myocardial revascularization

BACKGROUND

It is controversial whether composite arterial grafts can provide adequate blood flow for myocardial revascularization. We assessed at transthoracic echography and myocardial scintigraphy the composite radial artery-in situ left internal thoracic artery Y-graft.

METHODS

In 32 of 36 consecutive patients who underwent myocardial revascularization using this composite arterial graft, successful postoperative transthoracic images of the main stem of the Y-graft were obtained at rest and early after standard exercise. The main stem diameter, cross-sectional area and blood flow velocity and volume were measured. The coronary flow reserve (CFR) was calculated. The patients were divided into three groups according to the number of coronary artery systems bypassed with the Y-graft: group I included 11 patients with one coronary system bypassed, group II 18 patients with two, and group III 3 patients with three coronary systems bypassed. In 14 patients myocardial scintigraphy was performed at rest and after stress.

RESULTS

After exercise, the diameter, cross-sectional area, and blood flow velocity and volume increased. The mean CFR in group III was greater than in group I (p = 0.00045) and in group II (p = 0.049). In 2 patients, the nuclear stress test was positive (reversible ischemia in the distribution area of the Y-graft) and the mean CFR was lower than in the patients with a negative nuclear stress test (p = 0.046).

CONCLUSIONS

This composite arterial graft is a compliant conduit, able to regulate its flow capacity to myocardial demand. Non-invasive assessment of this Y-graft using transthoracic echography is possible, and correlates with the results of myocardial scintigraphy.

Extended use of bilateral internal thoracic arteries for coronary artery bypass grafting in the elderly

OBJECTIVE

Internal thoracic artery (ITA) grafts provide better early and long-term patency than saphenous vein (SV) grafts. Furthermore, bilateral ITA grafting has recently demonstrated better long-term results than unilateral ITA grafting. However, its use in the elderly is controversial.

METHODS

From March 1991 through November 2001, 307 consecutive patients aged 65 years or over undergoing isolated coronary artery bypass grafting (CABG) were reviewed, and the influence of bilateral ITA grafting on the early and long-term results was evaluated. All ITA grafts were harvested as a pedicle, and almost all of which were used as in-situ grafts.

RESULTS

Operative mortality in 138 patients undergoing bilateral ITA grafting was 1.4%, and in 108 patients undergoing unilateral ITA grafting, the rate was 0.9%. Pre-discharge angiography conducted in 97% of the subjects showed that the patency rate of all the ITA grafts (98.9%) was superior (p < 0.0001) to that of all the SV grafts (93.6%). In comparisons of survival and freedom from cardiac events at 10 years after CABG, the bilateral use of ITA grafts was proved to be more beneficial than the unilateral use (p < 0.05).

CONCLUSIONS

It was demonstrated that bilateral ITA grafting could be performed with acceptable mortality and morbidity. Moreover, it offers better long-term survival and freedom from cardiac events than either unilateral ITA grafting or no ITA grafting. Bilateral ITA grafting thus can serve as a favorable procedure even in elderly patients.

Dopexamine increases internal mammary artery blood flow following coronary artery bypass grafting

OBJECTIVE

Vasoactive agents and inotropes influence conduit-coronary blood flow following coronary artery bypass grafting (CABG). It was hypothesized that dopexamine hydrochloride, a dopamine A-1 (DA-1) and beta(2) agonist would increase conduit-coronary blood flow. A prospective randomized double blind clinical trial was carried out to test this hypothesis. DA-1 receptors have previously been localized to human left ventricle.

METHODS

Twenty-six American Society of Anaesthesiology class 2-3 elective coronary artery bypass graft patients who did not require inotropic support on separation from cardiopulmonary bypass (CPB) were studied. According to a randomized allocation patients received either dopexamine (1 microg/kg per min) or placebo (saline) by intravenous infusion for 15 min. Immediately prior to and at 5,10 and 15 min of infusion, blood flow through the internal mammary and vein grafts (Transit time flow probes, Transonic Ltd.), heart rate, cardiac index, mean arterial pressure and pulmonary haemodynamics were noted. The data were analysed using multivariate analysis of variance.

RESULTS

Low-dose dopexamine (1 microg/kg per min) caused a significant increase in mammary graft blood flow compared to placebo at 15 min of infusion (P=0.028, dopexamine group left internal mammary artery (LIMA) flow of 43.3+/-14.2 ml/min, placebo group LIMA flow at 26.1+/-16.3 ml/min). Dopexamine recipients demonstrated a non-significant trend to increased saphenous vein graft flow (P=0.059). Increased heart rate was the only haemodynamic change induced by dopexamine (P=0.004, dopexamine group at 85.2+/-9.6 beats/min and placebo group at 71.1+/-7.6 beats/min after 15 min of infusion).

CONCLUSION

This study demonstrates that administration of dopexamine (1 microg/kg per min) was associated with a significant increase in internal mammary artery graft blood flow with mild increase in heart rate being the only haemodynamic change. Low-dose dopexamine may improve graft flow in the early post CABG period with minimal haemodynamic changes.

Assessment of flow velocity in a bypass graft of the gastroepiploic artery by contrast-enhanced transabdominal Doppler echocardiography: a case report

An 81-year-old man with effort angina pectoris underwent coronary artery bypass grafting operation using the bilateral internal thoracic arteries and the right gastroepiploic artery (GEA). Angiography after operation showed that the bilateral internal thoracic arteries were patent. Abdominal angiography showed severe ostial stenosis in the celiac trunk. The GEA was not opacified by the celiac trunk but by the superior mesenteric artery, by collaterals. GEA flow could be detected from the epigastric lesion by contrast-enhanced Doppler echocardiography, and moreover, the flow velocity reserve of the graft was 2.4. This case suggests that the GEA graft can provide sufficient blood flow to the coronary artery despite ostial stenosis of the celiac trunk.

Myocardial rewarming mirrors intraoperative mammary artery graft function

BACKGROUND

The internal mammary artery (IMA) bypass graft provides a satisfactorily long-lasting blood supply to the myocardium. However, its initial flow capacity can be insufficient with subsequent regional myocardial ischemia. We evaluated a method to assess the IMA graft function intraoperatively.

METHODS

Twenty-five patients with three-vessel coronary artery disease underwent coronary artery bypass grafting on cardiopulmonary bypass. The in situ IMA was grafted to the left anterior descending coronary artery (LAD) in combination with two saphenous vein grafts to the left circumflex and right coronary artery. Distal anastomoses were performed during cold intermittent blood cardioplegia. After unclamping of the aorta and of the grafted IMA, the temperature at the cardiac anterior and posterior side was measured during the first 5 minutes of warm reperfusion.

RESULTS

A sufficient IMA graft function was expressed by a typical rise in temperature: the cardiac anterior and posterior sides showed a parabolic and exponential course, respectively. The rewarming velocity expressed as the first derivative of temperature over time led to a sharp and early peak for the anterior side, and a smaller and delayed peak for the posterior side. Insufficient IMA graft function could be recognized by an atypical temperature course.

CONCLUSIONS

Temperature measurement of the heart during warm reperfusion after hypothermic cardioplegia can help to assess the effectiveness of the IMA-LAD graft function.

Mediastinitis after coronary artery bypass graft surgery: influence of the mammary grafting for diabetic patients

Mediastinitis is a severe complication of coronary artery bypass graft surgery (CABG) particularly when harvesting internal mammary arteries (IMA). CABG in diabetic patients often uses two IMA because the saphenous graft is damaged. To our knowledge this risk of mediastinitis has not previously been reported in diabetic patients. All consecutive diabetic patients undergoing CABG over a three-year period from 1998 to 2000 were included in the study. Data recorded were: age, sex, duration of stay, whether one or two IMA were used, diagnosis of mediastinitis. Calculation of relative risk and analysis of trends by chi2 trend tests was also performed. In total 256 diabetic patients were included in the cohort. The incidence of mediastinitis was 4.3% (11/256). The risk of mediastinitis was higher in patients with two IMA than in patients with one IMA (relative risk 5.97, 95 CI 1.63-21.93, P=0.004). Age and sex were not confounding factors. No patients with mediastinitis died. Bilateral IMA grafting is associated with higher risk of mediastinitis in diabetic patients. The authors suggest that the risk of mediastinitis in diabetic patients should be taken into consideration when cardiac surgeons choose unilateral or bilateral IMA harvesting for surgery.

Long-term patency of the right internal mammary artery used as a coronary bypass conduit and the effect of the recipient vessel

This study reviewed our experience with the long-term patency of the right internal mammary coronary artery (RIMA) bypass graft in 58 patients over 1 year. Thirty-one percent (n = 18) of patients had obstructive lesions in the RIMA. In vessels with any lesion, the percent stenosis was 85.5% (range 30% to 100%). Eleven of 38 patients (28%) with right-sided recipient vessels had significant stenosis, whereas 21% of left-sided recipient vessels had significant stenosis of the RIMA. When compared with left internal mammary artery grafting, the long-term patency of the RIMA was lower than expected and warrants larger prospective studies.

Arterial grafting results in reduced operative mortality and enhanced long-term quality of life in octogenarians

BACKGROUND

Despite well-established benefits of arterial (ART) grafting, surgeons have been reluctant to use this conduit in octogenarians. This study explores the influence of arterial revascularization on operative and long-term outcomes of coronary artery bypass grafting surgery.

METHODS

A retrospective analysis was conducted of 987 consecutive patients 80 years of age or older who underwent isolated coronary artery bypass grafting between January 1989 and November 2000. Patients with saphenous vein graft only (SVG; n = 574) were compared with those receiving arterial and saphenous vein grafts (ART+SVG; n = 413). Mean follow-up for SVG patients was 3.8 years (range, 4 months to 12.6 years) and 98.6% complete, and mean follow-up was 3.1 years for ART+SVG patients (range, 2 months to 11.2 years) and 97.3% complete.

RESULTS

Patients with SVG had a significantly higher (p = 0.009) operative mortality (11.1% versus 6.3%) and significantly longer postoperative length of stay (12.9 versus 10.7 days; p = 0.002) than ART+SVG recipients. More ART+SVG than SVG patients were free of all postoperative complications (290 of 413; 70.2% versus 372 of 574; 64.8%; p = 0.086). Multivariable analysis identified SVG as an independent predictor of operative mortality (p = 0.014) and late mortality (p = 0.040). When patients were matched by equivalent propensity scores to receive SVG only, operative mortality was higher for SVG patients in four of the five quintiles. At 10 years, 97.0% +/- 1.2% of SVG and 92.9% +/- 3.7% of ART+SVG current survivors were free of all late major adverse cardiac events (p = 0.565), and 95.5% of SVG patients and 97.5% of ART+SVG patients were in Canadian class 1 or 2 (p = 0.162). On the SF-36 quality-of-life assessment, ART+SVG patients scored significantly higher than both SVG patients and age-adjusted normal subjects. Physical health summary component scores were 36.8 +/- 11.0 for SVG and 41.0 +/- 10.3 for ART+SVG (p = 0.001). Mental health summary scores were comparable for the two groups.

CONCLUSIONS

Arterial grafting confers an operative survival benefit, and an enhanced long-term quality of life in elderly patients.

A comparison of bleeding and transfusion in patients who undergo coronary artery bypass grafting via sternotomy with and without cardiopulmonary bypass

OBJECTIVE

To determine whether there is a difference between on-pump cardiopulmonary bypass (CABG) and off-pump coronary artery bypass grafting (OPCAB) without heparin reversal with regard to bleeding, transfusion requirements, and incidence of surgical re-exploration of the mediastinum.

DESIGN

Retrospective chart review.

SETTING

A large academic medical center.

PARTICIPANTS

Two hundred adult patients undergoing cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One hundred CABG patients were compared with 100 OPCAB patients. Statistical significance was measured with P values of <or=0.05. The heparin was not reversed in the OPCAB patients. CABG patients received more intraoperative allogeneic red blood cells (median 250 mL v 0 mL, p = 0.002), intraoperative autotransfusion (IAT) (550 mL v 425 mL, p = 0.001), platelets (9% v 1%, p = 0.009), and less albumin (0 mL v 250 mL, p = 0.001) than OPCAB patients. Postoperatively, CABG patients were more likely to receive fresh-frozen plasma (19% v 8%, p = 0.03) and less likely to receive IAT than the OPCAB group. During the initial 4-hour postoperative period, OPCAB patients exhibited greater blood loss via chest tube (290 mL v 385 mL, p = 0.003); however, at 12 hours and 24 hours postoperatively, there was no statistical difference in blood loss between the 2 groups. There were no statistically significant differences in surgical re-exploration of the mediastinum between the CABG and OPCAB groups.

CONCLUSION

Despite not reversing the heparin at the end of the OPCAB surgery, OPCAB surgery was associated with an overall reduction in allogeneic transfusion requirements.

Off-pump long onlay bypass grafting using left internal mammary artery for diffusely diseased coronary artery

Surgical treatment of a diffusely diseased coronary artery has been considered a relative contraindication for off-pump coronary artery bypass grafting. To our knowledge, long onlay-patch grafting with off-pump coronary artery bypass grafting has not been described. Two sets of Octopus 3 tissue stabilizers were placed longitudinally along the target coronary artery. This allowed us to perform surgical angioplasty and bypass grafting without cardiopulmonary bypass support (double Octopus technique). We report our early experience with off-pump long onlay bypass grafting in patients with a diffusely diseased coronary artery using double Octopus tissue stabilizers. Diffusely diseased coronary artery; off-pump coronary artery bypass grafting; coronary artery reconstruction; coronary artery bypass grafting; onlay patch anastomosis

A prospective evaluation of hemodynamic instability during off-pump coronary artery bypass surgery

OBJECTIVE

Despite recognized hemodynamic derangements during cardiac displacement, most patients appear to tolerate the off-pump procedure well. However, some patients unpredictably become hemodynamically unstable requiring emergency cardiopulmonary bypass or intra-aortic balloon pump support. After an experience of 5306 multivessel off-pump coronary artery bypasses (OPCABs), this study was undertaken to determine the factors that would identify the patients who were at a higher risk for the procedure.

DESIGN

Prospective clinical investigation.

SETTING

Tertiary care academic cardiac care center.

PARTICIPANTS

Five hundred consecutive patients undergoing multivessel OPCAB from September to December 2001.

INTERVENTIONS

Various cardiac and extracardiac factors were charted in prespecified data-entry forms. Multiple logistic regression analysis was done to determine if any identifiable factors were predictors of a higher risk of unacceptable hemodynamic instability during OPCAB. Institution of IABP support or conversion to CPB were the endpoints of the study.

MEASUREMENTS AND MAIN RESULTS

Of the 500 patients studied, significant hemodynamic instability developed in 24 (4.8%) patients. IABP support was instituted in 16 (3.2%) patients, and 8 (1.6%) were converted to CPB. Stepwise logistic regression identified ejection fraction <25% (p < 0.001), myocardial infarction of <1-month duration (p = 0.009), congestive heart failure (p = 0.016), and preoperative hemodynamic instability (p = 0.057) as predictors of conversion during OPCAB.

CONCLUSIONS

Patients with low left ventricular ejection fraction <25%, myocardial infarction of <1-month duration, congestive heart failure, or preoperative hemodynamic instability constitute the high-risk group for OPCAB.

Phrenic nerve injury associated with high free right internal mammary artery harvesting

BACKGROUND

The right phrenic nerve is at risk of injury during high mobilization of the right internal mammary artery (RIMA). The incidence and implications of this injury have not been previously defined.

METHODS

Prospectively collected data on all patients who underwent RIMA harvesting between January 1995 and February 2002 were analyzed. Thirty-one patients with right phrenic nerve injury were identified and the medical charts reviewed. Phrenic nerve injury was diagnosed when a postoperative chest roentgenogram showed the right hemidiaphragm to be two or more intercostal spaces higher than the left, or transection of the nerve was seen intraoperatively. Investigations included fluoroscopy and spirometry in upright and supine positions. Diaphragm plication was offered for symptom control. Subsequent follow-up was undertaken to determine the incidence of spontaneous recovery of diaphragm function and the benefits of diaphragm plication.

RESULTS

Seven hundred and eighty-three patients underwent high mobilization of the RIMA with proximal detachment for use as a free graft. Thirty-one patients with right hemidiaphragm dysfunction were identified in the postoperative period providing an injury incidence of 4% (confidence interval, 2.6% to 5.3%). Of these, 12 patients underwent diaphragm plication (4 early and 8 late), 14 patients achieved spontaneous recovery, and 5 patients were lost to follow-up. The supine to upright forced vital capacity ratios at the time of phrenic nerve dysfunction, after diaphragm plication, and after spontaneous recovery were 0.79, 0.90, and 0.96 respectively.

CONCLUSIONS

The incidence of phrenic nerve injury associated with high RIMA harvesting was 4% but spontaneous recovery may be anticipated in two thirds (14 of 22) of patients in whom the injury is identified postoperatively. High RIMA harvesting should be used with caution in patients with preoperative pulmonary dysfunction in whom phrenic nerve injury would be poorly tolerated.

The effect of left internal mammary artery utilization on short-term outcomes after coronary revascularization

BACKGROUND

The purpose of this study was to determine whether use of the left internal mammary artery (LIMA) during coronary revascularization influences short-term morbidity in all patients undergoing revascularization, as well as in patients over the age of 75 years, female patients, and patients with diabetes. The study also explored variability in the utilization of LIMA grafts across an entire state.

METHODS

Using the Clinical Outcomes Assessment Program (COAP) of the state of Washington, procedural outcomes were compared for patients receiving and patients not receiving LIMA grafts as part of revascularization procedures from January 1, 1999 to December 31, 2000. Mortality and major complications were examined, both as unadjusted rates and after adjusting for baseline patient risk factors.

RESULTS

A total of 16 centers performed 8,797 nonemergent coronary artery revascularizations, including 81.7% with LIMA grafts. The use of a LIMA graft was associated with a significantly lower mortality (3.7% No LIMA vs 1.6% LIMA), as well as decreases in ventricular arrhythmias, need for postoperative dialysis, need for transfusions, ventilator dependence, and length of hospital stay. These trends were true for the population as a whole as well as for all subgroups analyzed, and they persisted after correcting for differences in comorbid conditions. In addition, there was wide variability in the use of LIMA grafts from center to center in the state.

CONCLUSIONS

The use of LIMA grafts for coronary revascularization is associated with decreased mortality and morbidity. Despite these advantages, there is great variability in its application across the state of Washington.

The VB-1 catheter: an improved catheter for difficult-to-engage internal mammary artery grafts

As patients with prior coronary artery bypass grafting age, internal mammary artery grafts are more frequently encountered in the cardiac catheterization laboratory. Angiography and interventions involving these grafts are often difficult, particularly in patients with tortuous subclavian anatomy and/or proximal internal mammary artery origins. We describe a new catheter shape, the Cordis Behar Internal Mammary, VB-1, which allows selective intubations of both right and left internal mammary arteries that are not possible with conventional catheters.