Does gender influence resource utilization in patients undergoing off-pump coronary artery bypass surgery?

OBJECTIVE

The purpose of the present study was to examine if gender influences duration of tracheal intubation, blood transfusion needs, intensive care unit length of stay (ICULOS), postoperative length of stay (PLOS), and total length of stay (LOS) in patients undergoing off-pump coronary artery bypass (OPCAB) surgery.

DESIGN

Retrospective study of consecutive patients undergoing OPCAB surgery.

SETTING

University teaching hospital. Tertiary care referral center for cardiac surgery.

PARTICIPANTS

Three hundred seventy-two consecutive male and female patients undergoing OPCAB surgery. There were 110 women and 262 men.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Gender, duration of tracheal intubation, units of blood transfused, ICULOS, PLOS, and LOS were collected from the records of patients undergoing OPCAB surgery at the authors' institution over a period of 16 months. There were a total of 372 patients: 110 women and 262 men. Median intubation time was 4.5 hours for women and 4.0 hours for men (p = 0.749); 59.1% of women received red blood cells versus 31.3% of men (p < 0.001). Median ICU LOS was 1 day for women and 1 day for men (p = 0.597) Median PLOS was 4 days for women and 4 days for men. Median LOS was 8 days for women and 6 days for men (p = 0.001).

CONCLUSION

Female sex was a predictor of increased blood transfusion and longer PLOS and LOS in patients undergoing OPCAB surgery. The study implies that female sex does not predict increased duration of tracheal intubation and mechanical ventilation and ICULOS in this group of patients. Females undergoing OPCAB surgery require increased resource utilization as measured by increases in blood transfusion, PLOS, and LOS.

[Assessment of left internal thoracic artery grafts by atrial pacing]

The flow reactivity of a left internal thoracic artery graft (LITAG) in response to atrial pacing was evaluated in 14 patients who underwent coronary artery bypass grafting (CABG) with LITAG to left anterior descending artery (LAD). Systolic peak velocity and diastolic peak velocity were recorded using a duplex scanner of 7.5 MHz, and flow volumes in each phase and flow ratio were calculated. The external temporary atrial pacing was used to increase heart rates 25 and 50%. Diastolic peak velocity and flow volume increased predominantly on both pacing rates. In contrast, systolic peak velocity decreased when heart rate was raised 50%, and there was no significant difference between the pacing modes in systolic flow volumes. As a result, flow ratio increased predominantly on both pacing rates. Based on the present studies, there may be some advantages with atrial pacing to increase the LITAG flow in response to the myocardial oxygen demand.

Radial artery patency and clinical outcomes: five-year interim results of a randomized trial

OBJECTIVE

This study was undertaken to compare elective angiographic patency and cardiac event-free survival of the radial artery graft with that of the free right internal thoracic artery or saphenous vein during a 10-year period after primary coronary artery bypass surgery.

METHODS

This prospective, randomized, single-center trial was conducted on two groups of patients undergoing primary coronary artery bypass surgery. In a younger group (group 1, n = 285, <70 years), the radial artery was compared with the free right internal thoracic artery. In an older group (group 2, n = 153, >/=70 years), the radial artery was compared with the saphenous vein. The trial conduit was grafted to the largest available coronary artery other than the left anterior descending coronary artery. Angiography was scheduled at intervals between 0 and 10 years according to a second random assignment. Patients were followed up at yearly intervals to assess clinical outcomes. Clinical outcomes were analyzed on an intent-to-treat basis during the 10-year follow-up with time-related analyses. This interim study reports angiographic and clinical outcome results during the first 5 years.

RESULTS

Graft patency estimates were as follows: 0.95 (95% confidence interval 0.85-0.99) in 39 radial arteries versus 1.0 in 29 right internal thoracic arteries (P =.4) in group 1, and 0.86 (95% confidence interval 0.67-0.99) in 24 radial arteries versus 0.95 (95% confidence interval 0.83-0.99) in 22 saphenous veins (P =.5) in group 2. Cardiac event-free survival estimates were as follows: 0.91 (95% confidence interval 0.76-0.99) for the radial artery versus 0.82 (95% confidence interval 0.63-0.99) for the right internal thoracic artery (P =.7) in group 1, and 0.84 (95% confidence interval 0.64-0.99) for the radial artery versus 0.89 (95% confidence interval 0.72-0.99) for the saphenous vein (P =.9) in group 2.

CONCLUSION

The 5-year interim results do not support the hypothesis that the radial artery has superior patency to or is associated with fewer clinical events than free right internal thoracic artery or saphenous vein grafts.

Percutaneous transluminal coronary angioplasty for anastomotic stenosis after coronary arterial bypass grafting in Kawasaki disease

OBJECTIVES

We evaluated the efficacy of percutaneous transluminal coronary angioplasty for anastomotic stenosis after coronary arterial bypass grafting using the internal thoracic artery in patients with coronary arterial lesions due to Kawasaki disease.

SUBJECTS AND METHODS

From July 1997 to April 2000, four boys and one girl underwent percutaneous transluminal coronary angioplasty for 6 anastomotic lesions following coronary arterial bypass grafting using the left or right internal thoracic artery. Progressive severe stenosis of the grafts in the follow-up angiograms after grafting, and evidence of ischemia, were regarded as indications for percutaneous transluminal coronary angioplasty. Age at coronary angioplasty ranged from 4.2 to 16.7 years, with a median of 6.9 years, while the interval from operation ranged from 0.3 to 3.0 years, with a median of 1.1 years. The diameter of the balloon catheter employed varied from 1.5 to 2.5 mm, and the pressure of inflation ranged from 8 to 16 atmospheres.

RESULTS

The degree of stenosis decreased from 63 to 99%, with a median of 88%, to 0 to 40%, with a median of 17% immediately after angioplasty. A follow-up angiogram either 3 months or 1 year later revealed no restenosis in any patient.

CONCLUSION

Percutaneous transluminal coronary angioplasty is a feasible and useful procedure for treating anastomotic stenosis following coronary arterial bypass grafting using the internal thoracic artery in patients with coronary arterial lesions due to Kawasaki disease.

Percutaneous intervention on the LIMA: tackling the tortuosity

Percutaneous intervention on a tortuous left internal mammary artery (LIMA) graft is often challenging as the LIMA develops straightening and accordioning after the guidewire and dilatation balloon are placed in the graft, making angiographic assessment of the result impossible if there is no flow through the graft. We describe a new technique that overcomes this problem.

Supraclavicular control of patent internal thoracic artery graft flow during aortic valve replacement

BACKGROUND

The mortality and morbidity of aortic valve replacement (AVR) after prior coronary artery bypass surgery (CABG) with patent left internal thoracic artery (LITA) is significant. The risk of LITA injury and inadequate myocardial preservation during the cross-clamp period may cause myocardial pump failure.

METHODS

A total of 43 patients with a patent LITA graft underwent AVR. The patients were divided into the two groups. Group 1 included 19 patients who underwent AVR with deep hypothermia (20 degrees C) without LITA clamping. Group 2 included 24 patients in whom LITA flow was controlled through supraclavicular occlusion and AVR performed with moderate hypothermia (28 degrees C).

RESULTS

Average cardiopulmonary bypass time (CPB) time was 118.79 +/- 20.36 minutes in group 1 and 102.67 +/- 9.66 minutes in group 2 (p = 0.006). Average cross-clamp time was 53.79 +/- 7.26 minutes in group 1 and 49.63 +/- 6.7 minutes in group 2 (p = 0.022). Inotropic support was required in 12 patients in group 1 and 4 patients in group 2 (p = 0.002). Average intensive care unit stay was 4.68 +/- 2.24 days in group 1 and 2.29 +/- 0.46 days in group 2 (p < 0.001). Average hospital stay was 11.84 +/- 2.91 days in group 1 and 8.04 +/- 2.38 days in group 2 (p < 0.001). Mortality due to myocardial failure developed in 4 patients in group 1 but in none of the patients in group 2 (p = 0.02).

CONCLUSIONS

Proximal control of LITA flow by extrathoracic supraclavicular occlusion reduces the incidence of myocardial failure due to nonhomogenous cardioplegia delivery to the anterior wall of the heart, resulting in improved myocardial protection and the elimination of the need for deep hypothermia.

Technical aspects of composite arterial grafting with double skeletonized internal thoracic arteries

BACKGROUND

Complete myocardial revascularization with internal thoracic arteries (ITAs) improves long-term survival and decreases the rate of repeat operations, compared to vein grafts. Adequate length of the graft in coronary artery bypass graft (CABG) surgery is essential for providing complete arterial revascularization. Extra length can be obtained by skeletonization of both ITAs. In cases where the right ITA (RITA) is too short to bridge the distance to the target anastomotic site, it is used as a free graft in "composite" arterial grafting, a surgical technique in which free arterial conduits are proximally anastomosed end-to-side to an intact ITA.

OBJECTIVES

To describe alternative surgical procedures adapted to accommodate special anatomic requirements.

DESIGN

Retrospective study from April 1996 to April 1999.

PATIENTS

One thousand fifty patients underwent CABG surgery using bilateral skeletonized ITAs: 650 patients (482 men and 168 women; mean +/- SD age, 69 +/- 7 years) underwent composite arterial grafting. Two hundred sixteen patients (33.2%) were diabetics, 87 patients (13.4%) had severe left ventricular dysfunction (ejection fraction < 35%), and 27 patients (4.2%) underwent emergency operations.

INTERVENTIONS

The RITA was used as a free graft connected to the in situ left ITA (LITA) in 618 patients. A free LITA was attached to in situ RITA in 32 patients, and minicomposite grafts (free distal LITA on the LITA or free distal RITA on the RITA) were constructed in 38 patients. The average number of grafts was 3.2 per patient (range, 2 to 6 grafts per patient).

MEASUREMENTS AND RESULTS

Operative mortality was 2.9% (n = 19), and there were 11 sternal wound infections (1.7%). Early recatheterization was performed in 41 symptomatic patients. The patency rate was 95%. The mean follow-up was 25 months (range, 14 to 36 months), and the 3-year survival was 92.5%, with 97% of the surviving patients being angina free.

CONCLUSIONS

Planning CABG surgery using bilateral skeletonized ITAs as arterial conduits affords greater choice in grafting approaches, especially when a composite technique is feasible.

Does skeletonization compromise the integrity of internal thoracic artery grafts?

BACKGROUND

There are few reports that demonstrate the chronologic changes in the functional integrity of the internal thoracic artery (ITA) wall after skeletonization. We investigated the impact of skeletonization on ITA wall integrity by immunohistochemical analyses in acute and chronic phases.

METHODS

Nine mongrel dogs underwent bilateral ITA dissection with one skeletonized vessel and the other pedicled. The following studies were performed 1 week (acute phase, n = 3) and 12 weeks (chronic phase, n = 6) after ITA harvesting. All specimens of the ITAs were stained by antibodies against von Willebrand Factor (VWF), endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and proliferating cell nuclear antigen (PCNA). After observation with confocal laser scanning microscopy, quantitative analyses of the staining signal for VWF and eNOS expressed on endothelial cells were performed.

RESULTS

There were significantly more microvessels positive for VWF in the adventitia of skeletonized ITAs than in the adventitia of pedicled ITAs but the expression of PCNA in both groups was minimal, as in normal vessels. iNOS was not detected in any specimen. The intensity of VWF and eNOS expressed by endothelial cells had no significant differences between groups at either phase.

CONCLUSIONS

The functional integrity of skeletonized ITA was similar to that of pedicled ITA in both acute and chronic phases. Although skeletonization induced neovascularization in the adventitia it did not induce proliferation of smooth muscle cells in the media, which is supposed to be a feature of vascular remodeling.

Successful repair of a coronary artery to pulmonary artery fistula with saccular artery aneurysm and critical stenosis of the left anterior descending coronary artery

We report an infrequent case of an adult patient with a coronary artery to pulmonary artery fistula associated with a coronary artery aneurysm, a critical stenosis of the left anterior descending coronary artery (LAD) and a LAD dissection located distally to the stenosis. The fistula was successfully closed with direct sutures by opening the aneurysm under complete cardiopulmonary bypass. The excess aneurysm wall was excised and aneurysmorrhaphy was performed. Closure of the distal opening of the fistula was carried out without pulmonary arteriotomy and the operation was completed with a coronary artery bypass graft on the LAD with the left internal mammary artery used as "free graft". Postoperative angiographic evaluation demonstrated a normal artery distribution and the patient was asymptomatic without recurrence at 6 months after the operation.

The effect of pericardial restraint, atrial pacing, and increased heart rate on left ventricular systolic and diastolic function in patients undergoing cardiac surgery

Baseline measurements of systolic and diastolic function performed after the induction of anesthesia may be compared with subsequent measurements acquired under different physical conditions such as open pericardium and different heart rate or rhythm. We acquired data from 21 patients undergoing coronary artery surgery. Combined echocardiographic and pulmonary artery catheter measurements were performed before and after pericardial opening, atrial pacing at the native rate, and atrial pacing 30 bpm faster. Indices of systolic function included fractional area change, afterload corrected fractional area change, and myocardial performance index; diastolic function included mitral inflow and pulmonary vein Doppler profiles, color M-Mode Doppler flow propagation velocity, instantaneous end-diastolic stiffness, and isovolumetric relaxation time. Hemodynamic indices included cardiac index, mean arterial, right atrial, and pulmonary capillary wedge pressures, and systemic vascular resistance index. There were no changes in measurements after opening of the pericardium or with institution of atrial pacing. With increased heart rate, there were no changes in systolic function, but instantaneous end-diastolic stiffness increased. Propagation velocity showed a paradoxical improvement with increased heart rate opposite to other trends. Beat fusion occurs with increasing heart rate for mitral inflow Doppler. We recommend that serial measurements are performed at a similar heart rate.

IMPLICATIONS

Pericardial restraint or the institution of atrial pacing do not alter left ventricular function, as assessed by pulmonary artery catheter and transesophageal echocardiography measurements. Diastolic (but not systolic) measurements showed inconsistency with increased heart rate.

Extending the in situ right internal mammary artery graft with retrocaval positioning

Bilateral internal mammary artery grafting is associated with improved long-term patient outcomes. In situ right internal mammary artery grafting of the obtuse marginal artery, through the transverse sinus, is often limited by conduit length. We describe the technique of retrocaval positioning of the right internal mammary artery graft to extend its functional length for grafting of the circumflex territory. With careful surgical technique, this procedure can be performed safely during routine coronary bypass operations.

Spontaneous recanalization of functionally occluded bilateral internal thoracic artery T graft

Functional occlusion of the left internal thoracic artery T graft is reported. The patient underwent triple coronary artery bypass grafting with bilateral internal thoracic artery, anastomosing in situ to the left internal thoracic artery to the left anterior descending artery, free right internal thoracic artery to the obtuse marginal and posterolateral branch of the left circumflex artery. Early angiography showed occlusion of the in situ left internal thoracic artery to the moderately stenosed left anterior descending artery and patent side arm to circumflex. However, mid-term angiography revealed restoration of the left internal thoracic artery flow. A negative exercise stress test was noted throughout the postoperative period. Flow competition with a native coronary artery may be responsible for functional occlusion of the left internal thoracic artery.

[Combined use of internal mammary and right gastroepiploic arteries in myocardial revascularization with and without extracorporeal circulation]

Use of arterial grafts represent the new approach in coronary artery bypass grafting (CABG) surgery these days. This article represents our experience in use of two or more arterial grafts in combination (internal mammary artery--IMA and right gastroepiploic artery--RGEA). Between March 2000 February 2002, 10 patients underwent CABG with exclusive use of left or both IMAs and RGEA, with or without extracorporal circulation (ECC). In the group without ECC fast truck anesthesia was used. Post CABG catheterization was performed in three patients. There were no 30 day mortality or morbidity. Post CABG catheterization in two patients showed excellent graft patency. One patient continued to have chest pain and after the catheterization we found ostial narrowing of the celiac trunck which was successfully dilated. One of participants had abdominal hernia repair. Our opinion is that use of arterial grafts in CABG surgery has much lower risk, excellent patency and good long term prognosis.

Long-term results of coronary artery bypass grafting in patients with renal insufficiency

BACKGROUND

There are few published studies on coronary artery bypass grafting in patients with renal insufficiency who are not on maintenance dialysis. No details of long-term results have been published.

METHODS

This retrospective study focuses on 117 consecutive coronary artery bypass grafting patients with renal insufficiency, but who did not require dialysis (group B: preoperative serum creatinine level > or = 1.5 mg/dL). For comparison purposes, patients on maintenance dialysis (group C: 84 patients) and patients with normal renal function (group A: 794 patients; preoperative serum creatinine level < 1.0 mg/dL) were selected.

RESULTS

Hospital mortality was 11% (13 of 117) in group B, 5.9% (5 of 84) in group C, and 1.6% (13 of 794) in group A, and between groups A and B, p < 0.0001, and between groups B and C, p = 0.24. Actuarial survival rates at 10 years, including all deaths, were 87%, 32%, and 29% in groups A, B and C, respectively, and between groups A and B, p < 0.009 and between groups B and C, p = 0.63. In 23 patients in group B, the bilateral internal thoracic artery was used. No cardiac deaths were observed in these patients during the mean follow-up time of 42 months (range, 1 to 128 months). Cox model analysis revealed nonuse of arterial grafting (p = 0.03; Hazards ratio 1.7) to be a statistically significant factor, and renal insufficiency (p < 0.0001; Hazards ratio 3.3) and maintenance dialysis (p < 0.0001; Hazards ratio 5.6) to be major independent risk factors for actuarial survival.

CONCLUSIONS

Renal insufficiency was shown to be an independent risk factor for poor prognosis after coronary artery bypass grafting. However, aggressive use of arterial grafts, especially the internal thoracic artery, is recommended to improve late outcomes.

Briefly occlusive coronary anastomosis with tissue adhesive

OBJECTIVE

We assessed the feasibility of a facilitated, briefly occlusive, sutureless coronary anastomosis technique in which side-to-side preglued (octylcyanoacrylate adhesive) bounded walls were opened by a conventional arteriotomy.

METHODS

In low-flow (prothrombotic milieu, <or=15 mL/min, n = 8) and high-flow (approximately 50 mL/min, n = 8) porcine model of off-pump internal thoracic artery-left anterior descending coronary artery bypass, the anastomoses were evaluated intraoperatively (n = 16) and at 5 weeks (n = 14, with 2 evaluated at 2.5 weeks). The anastomoses were examined by flow measurement, angiography, and histologic studies.

RESULTS

Coronary occlusion lasted a median of 1.6 minutes (15th-85th percentile 1.4-1.8 minutes), and anastomosis construction required a median of 5.5 minutes (15th-85th percentile 4.2-6.5 minutes). At 5 weeks all anastomoses were fully patent (FitzGibbon grade A), with an angiographic appearance similar to an end-to-side anastomotic configuration.

CONCLUSIONS

The briefly occlusive adhesive anastomosis technique proved to be feasible in off-pump bypass surgery in the pig even under prothrombotic low bypass graft flow conditions (<or=15 mL/min). Further studies are warranted to investigate the applicability of this technique to endoscopic bypass surgery on the beating heart.

Internal thoracic artery grafts for the entire heart at a mean of 12 years

BACKGROUND

There is consensus today that the long-term results of bypassing the left anterior descending artery with an internal thoracic artery (ITA) graft are superior to those of a saphenous vein graft. Our hypothesis for this study was that three-vessel revascularization with only ITA grafts would also give excellent results.

METHODS

Using our previously described techniques to enhance the length of ITA grafts by skeletonization and high mediastinal mobilization, we were able to perform tension-free, three-vessel revascularization using only ITA grafts in 125 (83%) of a consecutive series of 150 patients with three-vessel occlusive coronary disease. We followed 100% of these 125 exclusive ITA graft patients (average of 3.9 anastomoses per patient) to their time of death (59; 47.2%) or current living status (66; 52.8%).

RESULTS

Combined intraoperative graft flows averaged 225 mL/min. Of the 125 patients in this study (average age, 63.5 years), 121 (96.8%) lived beyond 40 days. Of these 121 patients, 55 (45%) died at a mean of 7 years postoperatively and 66 (55%) are still living at a mean of 12.1 years. Of these 121 patients, 112 (93%) had angina at baseline. Of these 112, 92 (85%) were angina free at a mean of 9.1 years postoperatively. Freedom from infarction was 100% at 5 years and 97% at 10 years. Freedom from reintervention was 90% at a mean of 9.8 years.

CONCLUSIONS

Use of ITA grafts for three-vessel coronary revascularization provides excellent results and is both practical and appropriate for many patients.

Segmentation of the left internal thoracic artery: a new technique for maximal arterial grafting

The left internal thoracic artery lpa r;LITA) is the preferred graft with the best patency rate in coronary artery bypass grafting (CABG). To maximize its use, we developed a technique of grafting 2 distant coronary arteries with the LITA, using its distal portion segmented to construct a Y graft with either the in situ LITA or right internal thoracic artery (RITA). We applied this technique in 51 patients. The distal segment of the LITA was used to create a Y graft in 4 different configurations according to coronary pathology. Offpump grafting was performed in 11% of cases. The use of a distal segment of the LITA was thus extended not only to the left anterior descending artery and branches but also to the circumflex and right coronary artery territories.

Off-pump total arterial myocardial revascularization according to the right Y-graft configuration

OBJECTIVES

The aims of this study were as follows: 1) to evaluate the early outcome of the off-pump total arterial myocardial revascularization according to the right y-graft (lambda-graft) configuration and 2) to compare baseline flow and maximum flow between patients undergoing on-pump and off-pump right y-graft (RYG) construction.

METHODS

Between December 1998 and January 2001, 47 patients (Group I) and 20 patients (Group II) with three vessel disease underwent on-pump and off-pump coronary artery bypass graft (CABG) respectively according to the RYG configuration. The mean age was 55.5 +/- 4.7 years and 55 +/- 6.4 years in Groups I and II, respectively. The RYG was constructed employing both internal mammary arteries (IMAs) only, in 21 and 8 patients in Groups I and II, respectively, presenting proximal-middle third stenosis of the left anterior descending artery (LAD) and right coronary artery (RCA). The modified RYG configuration employing both IMAs and radial artery (RA) was performed in 26 and 12 patients in Groups I and II, respectively, presenting middle-distal third stenosis of the LAD and distal stenosis of the RCA or posterior descending artery stenosis. Postoperatively all patients underwent transthoracic echo color-Doppler (TTECD) contrast enhanced (by Levovist) before and after adenosine provocative testat one week and three months after operation.

RESULTS

There were no hospital deaths. The mean mechanical ventilation was significantly different in Group I versus Group II patients, 18 +/- 4.4 hours versus 13 +/- 5.7 hours, respectively (p = 0.041). The mean intensive care unit stay was 1.5 +/- 0.6 days in Group I and 1 +/- 0.4 days in Group II (p = 0.033). There were no differences between Groups I and II regarding the IMA diameter, mean velocity, and mean flow. At follow-up time, 6 +/- 2.4 months after the surgical procedure, all patients were alive and free of angina. The coronary flow reserve (CFR) at LIMA main stem was significantly higher at three months when compared to the values at one week after the surgical procedure within the same group, (LIMA)CFR (three months) = 2.37 +/- 0.6 versus (LIMA)CFR (one week) = 2.07 +/- 0.4 (p = 0.005) in Group I and (LIMA)CFR (three months) = 2.4 +/- 0.4 versus (LIMA)CFR (one week) = 2.06 +/- 0.3 (p = 0.004) in Group II. Similarly, the CFR at RIMA main stem were significantly higher at three months when compared to the values at one week after the surgical procedure: (RIMA)CFR (three months) = 2.47 +/- 0.7 versus (RIMA)CFR (one week) = 2.1 +/- 0.5 (p = 0.004) in Group I and (RIMA)CFR (three months) = 2.48 +/- 0.5 versus (RIMA)CFR (one week) = 2.08 +/- 0.4 (p = 0.008) in Group II.

CONCLUSION

The flow dynamic data, almost identical between patients undergoing off-pump and on-pump total arterial myocardial revascularization (TAMR) according to the RYG configuration, demonstrate that this technique can be applied with excellent results without the employment of cardiopulmonary bypass in selected coronary artery disease patients.