The mammary loop: How to do an adjustable “Y” graft with the left internal thoracic artery

We present a technique that permits the grafting of two vessels with the left internal thoracic artery when a sequential graft cannot be performed. The left internal mammary artery is anastomosed to itself resulting in a loop that will be cut open at the time of the coronary anastomosis.

Accelerated graft disease in a composite saphenous vein with internal thoracic artery in a chronic renal dialysis patient

A 59-year-old man with 18-year history of renal dialysis due to chronic nephritis suffered coronary artery disease, which was complete occlusion of the right coronary artery and diffuse 90% stenosis of the proximal left anterior descending artery. Off-pump coronary artery bypass grafting was performed. Saphenous vein (SV) was anastomosed with left internal thoracic artery (ITA) as a T-graft. Left ITA was anastomosed to the left anterior descending artery. The end of SV was sewn on the posterior descending artery. Coronary and graft angiography performed 2 weeks after the operation showed good patency with good distal run-off of both left ITA and SV. Three months after the operation, he was admitted with unstable angina. Angiography revealed accelerated SV graft stenosis without any change of prior coronary disease. However, angiography 7 months after the operation revealed complete obstruction of the SV graft when he was admitted because of recurrent anginal pain.

Native matrix metalloproteinase characteristics may influence early stenosis of venous versus arterial coronary artery bypass grafting conduits

PURPOSE

Stenosis and occlusion rates of internal mammary artery (IMA) and saphenous vein (SV) coronary artery bypass grafts (CABGs) are markedly different, which result from respective disparities in vascular remodeling. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) regulate vascular structure and may have important influence on graft patency. However, the MMP milieu and expression profile of the IMA and SV have not been contrasted. Therefore, the aim of this study was to assess and compare the native MMP systems in IMA vs SV conduits.

METHODS

IMA (n = 10) and SV (n = 10) specimens were obtained from patients undergoing CABG surgery. Protein levels of MMP-1, MMP-2, and MMP-9, TIMP-1, a membrane-bound MMP activator (MT1-MMP), and an extracellular MMP inducer protein (EMMPRIN) were determined by immunoblotting and quantified by densitometric analysis. MMP-2 and MMP-9 activity was determined by gelatin zymography.

RESULTS

MMP-2 levels were significantly higher in SV (2,218 +/- 351 pixels) vs IMA (1,012 +/- 213 pixels) specimens (mean +/- SEM]). There were no significant differences in MMP-1, MMP-9, or TIMP-1 content; however, MT1-MMP and EMMPRIN levels were significantly lower in SV (847 +/- 190 pixels, 1,742 +/- 461 pixels) vs IMA conduits (2,590 + 403 pixels, 5,606 + 678 pixels), respectively (p < 0.05). MMP-9 activity was similar while MMP-2 activity was significantly increased in SV vs IMA specimens.

CONCLUSIONS

SV and IMA conduits harbor the same MMP molecular constituents. However, MMP-2 levels and activity are significantly more abundant in the SV compared to the IMA. These differences may contribute to the early pathologic remodeling of the SV vs IMA conduit following CABG surgery.

The Radial Artery in Reoperative Coronary Bypass Surgery:. A 5-Year Experience

BACKGROUND

Failure of saphenous vein grafts (SVG) is a significant cause for coronary reoperation (redo CABG). The radial artery (RA) because of its availability, and versatility is well suited to use (together with internal thoracic arteries (ITA) in redo CABG, especially to replace failed SVG. We evaluated our experience where the RA was a major conduit in redo CABG over the past 5 years.

METHODS

From July 1996 to June 2002, 590 consecutive patients underwent redo CABG where one or both RA(s) were used, together with LITA or RITA. The mean age was 67.3 years, 82% were male, and 19% diabetic, 419 (71%) had Class III or IV angina, 135 (23%) had left main stenosis, and 210 (36%) had an LVEF < 0.50. There were a total of 877 RA conduits (303 single, 287 bilateral), 518 new LITA or RITA. A mean of 2.8 new distal anastomoses constructed 92% (2.6 per patient)of the arterial grafts. Follow-up was at 1 month, 3 months, and then yearly. The results were compared with 6466 primary CABG performed in the same time frame, and with a prior cohort of 741 consecutive patients having redo CABG without an RA in which identical operative techniques had otherwise been used.

RESULTS

The 30-day mortality was 3.9% (23 patients). Morbidity was low. Perioperative myocardial infarction occurred in 16 (2.7%) patients, stroke in 10 (1.7%), sternal infection in 10 (1.7%), donor site infection in 2 (0.3%), and IABP use in 23 patients (3.9%)-including 10 preoperatively. The results were better when compared to a prior cohort of 741 patients with redo CABG (1991 to 1996) without use of the RA. The results were inferior to that of the contemporary primary CABG. Operative mortality was 3.9% versus 0.9%, p = 0.002, myocardial infarction 2.7% versus 0.8%, p = 0.03.

CONCLUSION

The use of the RA (together with ITA) in redo CABG achieved total arterial revascularization in 92% of cases and is associated with excellent results, at least equal to or superior to those achieved previously.

["Mammary loop" technique--new method of multiple coronary revascularization using internal mammary arteries]

The internal mammary arteries are "the gold standard" conduits for coronary by-pass because their' s patency is superior to the saphenous graft. There are some surgical techniques which allow to use the entire length of the mammary arteries: the Y graft, the T graft and the pi graft. We describe recently the "mammary loop" technique that allows to make a Y graft using only one internal mammary artery. This technique also simplifies the construction of a pi graft. In this article we present the variants of this technique and discuss the indications and our early experience results.

Should the internal thoracic artery be skeletonized?

Traditionally, the internal thoracic artery is harvested as a pedicle. In contemporary cardiac surgical practice, however, certain surgeons practice the internal thoracic artery-skeletonization technique. A systematic review of clinical studies reporting on the use of skeletonized internal thoracic arteries (SKT-ITA) has not yet been performed. The primary aim of this review article is to examine comprehensively the entire body of evidence regarding the use of SKT-ITA. In particular, we aimed to analyze the effects of skeletonization on sternal blood supply, wall damage and blood flow in the harvested vessel, postoperative graft patency, and clinical outcome. Advantages and disadvantages of the skeletonization technique are highlighted and discussed.

Pharmacological assessment of composite arterial conduits using angiography early in the postoperative period

OBJECTIVES

Muscular arteries are vulnerable to vasospasm unlike elastic arteries. Having developed experimental models of composite arterial grafts, we assessed and compared the responses of the grafts with different pharmacological agents using angiography early in the postoperative period.

SUBJECTS AND METHODS

We harvested the internal thoracic artery (ITA) and brachial-median artery (BMA) from 10 sheep. BMA was used as an alternative to the radial artery. Each vessel was assessed histologically and morphologically. Then, a serial composite graft was constructed so that BMA was interposed. On postoperative day one or two, angiography was performed on the composite graft to measure the diameter of each vessel in response to phenylephrine (alpha-adrenergic receptor agonist), nitroglycerin+phenylephrine, and milrinone+phenylephrine.

RESULTS

The BMA had a wide media layer which consisted of abundant smooth muscle cells. The combined intima and media were thicker in BMA than in ITA (p<0.01). After injection of phenylephrine, the BMA diameter decreased (2.5+/-0.4 mm to 1.9+/-0.3 mm, p<0.01), while the ITA diameter remained unchanged (3.7+/-0.2 mm to 3.6+/-0.2 mm). Continuous infusion of nitroglycerin or milrinone prevented phenylephrine-induced vasoconstriction of the BMA (p<0.05).

CONCLUSIONS

These results suggest that muscular arteries have a more pronounced vasoconstrictive response to alpha-adrenergic receptor agonists than the elastic arteries. To avoid potential decrease in graft flow of muscular artery, it is advisable to use a vasodilator nitroglycerin or milrinone early in the postoperative period.

Rationale for off-pump coronary revascularization to small branches—angiographic study of 1,283 anastomoses in 408 patients

BACKGROUND

Off-pump coronary artery bypass grafting (OPCAB) has gained wide acceptance in tandem with the development of the stabilizer and associated operative techniques. However bypass grafting to the small branches of a beating heart is technically demanding and remains controversial. In the present study we evaluated the graft patency and quality of anastomoses to small coronary arteries by early postoperative angiography.

METHODS

Between March 2000 and December 2002 a total of 1,328 anastomosed sites to coronary branches were studied angiographically in 404 patients representing 88.6% of all cases who underwent OPCAB in this period. The coronary artery branches were categorized as large (>1.5 mm, group L: 1,028 anastomoses sites) or small (< 1.5 mm, group S: 300 sites) by intraoperative measurement. As in situ grafts the internal thoracic artery (ITA) and the gastroepiploic artery (GEA) were used at 504 and 28 distal anastomosis sites respectively. The radial artery (RA) was used as a composite graft for 739 distal anastomosis sites. Sequential bypass grafting was performed at 388 anastomosis sites in side-to-side fashion. Arterial grafts were used in 96.1% of total bypass grafting.

RESULTS

The percentage of male gender was 78.3% in group S and 87.2% in group L (p = 0.025). The ITA was used in 43.7% of group L and 18.3% of group S (p < 0.0001). The RA was used in 49.4% of group L and 77% of group S (p < 0.0001). The overall patency and stenosis free rates (FitzGibbon Type A) were 97.2% and 96.2%. Graft patency and stenosis free rates in group S (96.7% and 93.3%) were as good as those in group L (97.5% and 97.1%). In group S, the patency and stenosis free rates of SV grafts were 71.4% and 57.1%. On the other hand, those of ITA grafts were 100% and 98.3% (p = 0.53 vs. saphenous vein graft [SVG]) and RA grafts were 95.8% and 92.1% (p = 0.61 vs. SVG) respectively. In group S, the graft patency and stenosis free rates of bypass to the obtuse marginal (OM) (93.7% and 87.5%) were slightly lower than those to other implantation sites left anterior descending (LAD: 100% and 97.3%; PL: 96.5% and 92.3%; DI: 98.0% and 96%; PDA: 97.0% and 97.0%; right coronary artery [RCA]: 100% and 100%) although there was no statistical significance. The graft patency and stenosis free rates were slightly better with side-to-side anastomosis than with end-to-side anastomosis (side-to-side: 98.1% and 95.8% vs. end-to-side 96.3% and 86.3%) in group S.

CONCLUSIONS

OPCAB to small coronary artery branches with arterial grafts provided satisfactory graft patency and stenosis free rates.

Single versus bilateral internal thoracic artery grafts with concomitant saphenous vein grafts for multivessel coronary artery bypass grafting: effects on mortality and event-free survival

BACKGROUND

The issue of superiority of single internal thoracic artery grafting versus bilateral internal thoracic artery grafting remains unresolved. The aim of this study was to compare the long-term outcome of single and bilateral internal thoracic artery grafting with concomitant saphenous vein grafting for multivessel coronary artery bypass grafting.

METHODS

Between March 1985 and April 1995, 6650 patients underwent primary isolated coronary artery bypass grafting with internal thoracic artery grafts, including 4382 patients with multivessel bypass grafting requiring at least 3 grafts. Outcomes of patients undergoing single internal thoracic artery plus saphenous vein grafting (n = 2547) and bilateral internal thoracic artery plus saphenous vein grafting (n = 1835) were obtained at a mean follow-up of 11 +/- 3 years.

RESULTS

Patients with bilateral internal thoracic artery grafting were younger, were mostly male, and had less diabetes, hypertension, unstable angina, and recent myocardial infarction than patients undergoing single internal thoracic artery grafting. Thirty-day mortality was 2.3% for the group undergoing single internal thoracic artery grafting versus 1.2% for those undergoing bilateral internal thoracic artery grafting (P =.007). Survival probability at 10 years was 88% for the single-graft group compared with 93% for the bilateral-graft group (P <.001). Multivariate analysis with propensity scoring showed that bilateral internal thoracic artery grafting decreased the risk of death (hazard ratio, 0.74; 95% confidence interval, 0.60-0.90), myocardial infarction (hazard ratio, 0.79; 95% confidence interval, 0.67-0.93), and coronary reoperation (hazard ratio, 0.41; 95% confidence interval, 0.21-0.80) throughout the follow-up period. Other significant predictors of death were diabetes, prior myocardial infarction, need for intra-aortic balloon pump, chronic heart failure, and peripheral vascular disease.

CONCLUSION

Patients undergoing bilateral internal thoracic plus saphenous vein grafting appear to have a significantly better long-term clinical outcome than patients undergoing single internal thoracic artery plus saphenous vein grafting for multivessel coronary artery bypass grafting.

Early and mid-term angiographic assessment of internal thoracic artery grafts anastomosed to non-stenotic left anterior descending coronary arteries

BACKGROUND

Mild to moderately stenotic coronary arteries present a major problem as the progression of atherosclerosis is unpredictable. In addition, residual flow from the native coronary artery has been proposed as a mechanism that reduces blood flow in bypass grafts resulting in failure of the graft.

PATIENTS AND METHODS

The internal thoracic artery was anastomosed to the left anterior descending coronary artery for different reasons in three patients who underwent coronary arterial surgery, with stenosis of this coronary artery changing from none to 30%. Patients were monitored by coronary arteriography at different intervals postoperatively (from 6 days to 25 months) to assess the patency of the internal thoracic artery graft.

RESULTS

Internal thoracic artery grafts were found to be patent in all coronary arteriographies during the follow-up period. Twenty-five months after surgery, one patient showed total occlusion of the native coronary artery which was previously normal.

CONCLUSIONS

Competitive flow from the native coronary artery does not seem to influence internal thoracic artery patency when grafted to a normal or mildly stenotic left anterior descending coronary artery. This information could be of help in some patients undergoing coronary artery bypass surgery with non-critical stenosis of this coronary artery. If the non-critical lesion is located proximally and if the patient has additional risk factors for coronary artery disease progression, prophylactic grafting of the left anterior descending coronary artery to the internal thoracic artery should be considered to prevent any future cardiac event, keeping in mind that this procedure may accelerate the progression of the native coronary artery disease.

Fourier transform infrared spectroscopy application to vascular biology: comparative analysis of human internal mammary artery and saphenous vein wall

Saphenous vein (SV) and internal mammary artery (IMA) are used for aorto-coronary bypass grafting. IMA is considered to be the graft of choice for coronary revascularization having a long-term patency compared to SV. The aim of this study is to investigate the structure of vascular wall using a new technical approach. We analysed the chemical composition of vessel wall layers (total lipid, lipid ester and protein) of 25 vascular segments (19 SV and 6 IMA) using Fourier transform infrared spectroscopy (FTIR). FTIR analysis showed that in intima layer lipid ester and protein concentration (expressed as arbitrary units) was significantly higher in SV (lipid ester = 0.020 +/- 0.002; protein = 0.449 +/- 0.022) than in IMA (lipid ester = 0.014 +/- 0.002; protein = 0.342 +/- 0.032). Moreover, the percentage of lipid ester on total lipid was significantly higher in SV (intima = 54.7 +/- 2.9%; media = 78.4 +/- 4.9%; adventitia = 83.9 +/- 8.3%) wall layers compared to IMA ones (intima = 37.3 +/- 4.9%; media = 45.4 +/- 3.8; adventitia = 57.1 +/- 4.8). These data suggest that a different chemical composition of wall layers could also be responsible for the morphological modifications observed in SV after grafting.

Skeletonization does not influence internal thoracic artery innervation

BACKGROUND

This study was designed to compare the effect of surgical harvesting on internal thoracic artery innervation and to assess the eventual presence of denervation supersensitivity in skeletonized grafts.

METHODS

Nineteen patients who underwent primary isolated coronary artery bypass grafting were randomly assigned to receive a skeletonized (n = 9) or pedicled (n = 10) internal thoracic artery graft. Immunohistochemical nerve localization using anti-S-100 protein, anti-160-kd neurofilament polypeptide and anti-tyrosine hydroxylase antibodies was performed on distal specimens of arteries to study vascular innervation. Moreover, endovascular vasoactive challenges using serotonin and methylergometrine were performed at early angiographic control to evaluate the eventual presence of denervation supersensitivity.

RESULTS

Quantitative analysis of immunohistochemical specimens revealed lack of difference in the number of positive cells between skeletonized and pedicled arteries for all the antibodies used. No difference in the reaction to serotonin and methylergometrine was found between skeletonized and pedicled arteries.

CONCLUSIONS

Skeletonization does not influence internal thoracic artery innervation.

Diltiazem provides higher internal mammary artery flow than nitroglycerin during coronary artery bypass grafting surgery

OBJECTIVES

Perioperative internal mammary artery (IMA) vasospasm in patients undergoing coronary artery bypass grafting (CABG) surgery may lead to morbidity and mortality. Surgical stimulus is one of the common causes of IMA vasospasm. Preventive measures, beside treatment should be taken into consideration to obtain vasospasm free IMA. The effect of a pharmacologic agent on IMA flow when it is administered before harvesting the artery has not been documented. We designed a prospective randomized clinical study to compare the IMA free blood flows in patients receiving either diltiazem or nitroglycerin, starting infusion of study drugs before a surgical stimulus was applied to the IMA region and continuing throughout the isolation period.

METHODS

Sixty patients undergoing elective CABG surgery with the left IMA received diltiazem (n=30, 0.05-0.1 mg/kg per hour) or nitroglycerin (n=30, 0.25-2.5 microg/kg per minute) in a randomized manner. Infusions of study drugs were started before applying a surgical stimulus to the IMA region and continued throughout the harvesting period. The first free flow was measured after IMA was cut above its bifurcation and the second after its distal segment was resected. Heart rate, temperature, mean arterial and central venous pressures were recorded. Data were analyzed with Student's t-test and Fischer's exact test.

RESULTS

Preoperative and hemodynamic data were similar between the groups. The means of first and second IMA flows in patients treated with diltiazem (53.8+/-30.1 and 72.3+/-35.4 ml/min) were significantly higher than in those treated with nitroglycerin (25.7+/-16.2 and 48.9+/-23.8 ml/min; P=0.000, 0.004, respectively). IMA flows significantly increased after distal segment resection both in diltiazem (34%) and nitroglycerin groups (90%; P= 0.000, 0.000, respectively).

CONCLUSIONS

Diltiazem infusion which started prior to harvesting provided higher IMA blood flow compared to nitroglycerin infusion. Considering the percentage of increases in flows after resection of distal segment, the most prone part to vasospasm, we assume that a certain amount of spasm occurred in IMA in spite of infusion of study drugs, such that less with diltiazem and more with nitroglycerin. Diltiazem plays more important role than nitroglycerin in the prevention of vasospasm.

Robotic skeletonizing of the internal thoracic artery: is it safe?

BACKGROUND

The advantages of internal thoracic artery skeletonization include early high blood flow, a longer conduit, and less bleeding than pedicle internal thoracic artery grafts. Longer conduits are needed for complete endoscopic arterial revascularization. Therefore this study was designed to determine the feasibility and safety of internal thoracic artery skeletonization using the da Vinci robotic system (Intuitive Surgical, Sunnyvale, CA).

METHODS

Nine dogs underwent bilateral robotic internal thoracic artery harvesting through three ports placed in the left chest. One internal thoracic artery was harvested as a pedicle in each dog, and the other was skeletonized. Internal thoracic artery blood flow was measured in each graft, and comparative endothelial histologic studies were performed. Data are mean +/- the standard error of the mean.

RESULTS

All 18 internal thoracic arteries were harvested successfully. Skeletonized internal thoracic artery harvests required more time (48.0 minutes +/- 1.8) than pedicle internal thoracic artery harvests (39.0 minutes +/- 1.4; p < 0.05). Internal thoracic artery flows during the final intervals were similar (skeletonized = 30.0 mL/min +/- 2.4 vs pedicle = 31.5 mL/min +/- 1.8; p = 0.9). Free internal thoracic artery bleeding flow was similar in both groups (skeletonized = 162.0 mL/min +/- 3.0 vs pedicle = 189.0 mL/min +/- 2.4; p = 0.4). Histologically, both groups were similar with minimal endothelial damage.

CONCLUSIONS

Robotically skeletonized harvesting is safe, but it requires more time (48.0 minutes +/- 1.8) than pedicle internal thoracic artery harvesting. Despite muted tactile feedback with robotics, neither technique was associated with histologic or functional damage. These encouraging results may represent an advantage for complete arterial revascularization in robotic coronary bypass patients.

Analysis of Y-graft blood flow and flow reserve in conditions of increased myocardial oxygen consumption

BACKGROUND

It is not well established whether early following surgery the blood flow of arterial composite Y-grafts may efficiently meet the flow demand of the coronary system. The aim of this study was to evaluate whether early after surgery arterial composite Y-grafts may increase the blood flow in response to an increase in myocardial oxygen consumption (MVO2).

METHODS

Twenty-seven patients who received complete arterial myocardial revascularization using the left internal thoracic artery (LITA) and the radial artery (RA) as composite Y-graft gave their consent to a pre-discharge coronary angiography and intravascular flow velocity measurements using a Doppler guidewire. Flow measurements were performed in the LITA main stem, the distal LITA and the RA, both at rest and during atrial pacing at 85% of the patient age-predicted maximum heart rate. The heart rate-systolic blood pressure product was considered as an indirect index of MVO2. Hyperemic flow was determined after injection of adenosine. The flow reserve was defined as the ratio of blood flow during maximal hyperemia (Qmax) to baseline flow (Qbasal).

RESULTS

Atrial pacing significantly increased MVO2 (p < 0.000). None of the patients developed ischemic ST-segment modifications or complained of chest pain. Qbasal increased significantly in the LITA main stem (p = 0.001), distal LITA (p = 0.041) and RA (p = 0.004) while Qmax did not change significantly. As a consequence the flow reserve decreased in the LITA main stem (p = 0.002), distal LITA (p = 0.000) and RA (p = 0.000) but was not completely exhausted.

CONCLUSIONS

Early after surgery arterial composite Y-grafts may significantly increase blood flow in response to conditions of increased MVO2 and maintain a normal myocardial oxygen supply-to-demand ratio.

Autologous patch angioplasty of the left main coronary artery in a pediatric patient: 7-year follow-up

We present a patient who developed ischemia after an arterial switch procedure for transposition of the great vessels secondary to left coronary artery stenosis. The excellent intermediate-term result of patch angioplasty of the left main coronary artery with the use of an internal thoracic artery patch is outlined.

Determinants of successful endoscopic internal thoracic artery harvesting: a prospective analysis

OBJECTIVE

Endoscopic internal thoracic artery (ITA) harvesting is employed during minimal-access coronary artery bypass grafting. To improve case selection, we prospectively analyzed our entire experience to identify variables that predict intraoperative conversion to sternotomy.

METHODS

We performed a prospective study from September 1999 to November 2003 of 100 consecutive patients with an endoscopically harvested left ITA (LITA). Success was defined as an endoscopic dissection of the LITA sufficient to reach the anastomosis. Multivariate logistic regression analysis was performed to identify independent preoperative and procedural predictors of success.

RESULTS

The measured parameters (mean +/- SD) were age (62 +/- 9 years), height (174 +/- 9 cm), weight (81 +/- 14 kg), and logistic Euroscore (2.0 +/- 1.7). Patients comprised 8 (8%) women, 17 (17%) with urgent operations, 42 (42%) with multiple vessel disease, 17 (17%) with a left ventricular ejection fraction <50%, 2 (2%) redo procedures, and 3 (3%) with pleural disease. The Zeus robot was used in 17 patients (17%). Eight-eight (88%) of the LITA were successfully harvested endoscopically. Among the 12 patients who underwent conversions, pleural adhesions were the most common finding (n = 4, 33%). One LITA was unusable. In the final multivariate model, lung disease was a negative predictor of successful endoscopic harvest (odds ratio, 0.13; 95% confidence interval, 0.02-0.63; P =.012). The variables of age, sex, left ventricular function, logistic Euroscore, operative priority, and use of the Zeus robot did not achieve statistical significance.

CONCLUSIONS

Acceptable conversion rates and low conduit wastage are achievable during a unit's initial experience. Lung disease is associated with increased conversion frequency, and surgeons embarking on endoscopic harvesting should consider excluding these patients to improve their chances of success. Pleural adhesions increase the technical difficulty of surgery.

Repeat Median Sternotomy After Prior Ante‐Aortic Crossover Right Internal Thoracic Artery Grafting

BACKGROUND

In situ bilateral internal thoracic artery (ITA), with ante-aortic crossover right ITA (RITA) is gaining popularity. However, the retrosternal position of the crossover RITA has raised concerns with regard to its compromise during subsequent resternotomy.

METHODS

Ten patients underwent repeat median sternotomy after prior ante-aortic crossover RITA grafting. Specific RITA routing and fixation had been performed in the initial operation. Preoperative imaging, including computed tomography (CT) angiography, was performed to confirm RITA position in relation to the sternum and assess feasibility.

RESULTS

Resternotomy was performed 4-48 months after the initial operation (median, 22 months). Nine crossover RITA grafts were functioning at the time of resternotomy. CT angiography was performed in four patients in whom the premarked RITA could not be localized on the plain chest radiograph. The feasibility of conducting a nonmodified resternotomy was determined based on preoperative imaging. All RITA grafts resumed their original position and none was injured during reentry. There was no early mortality, perioperative stroke, or reexploration for bleeding. One patient sustained myocardial infarction, however, not in a RITA-related distribution. CT angiography was predictive in confirming a free retrosternal space.

CONCLUSIONS

Resternotomy after prior ante-aortic crossover RITA grafting can be performed at acceptable risk. Confirmation of a free retrosternal space by preoperative imaging may contribute to the safety of the procedure. Maneuvers performed during the first operation are useful in preventing RITA adherence to the sternum.

Endothelial integrity of ultrasonically skeletonized internal thoracic artery: morphological analysis with scanning electron microscopy

OBJECTIVE

The skeletonized internal thoracic artery (ITA) has several advantages over a pedicled one in coronary artery bypass grafting (CABG). An ultrasonic scalpel makes ITA skeletonization easy and speedy, however, the ultrasonic energy that is transmitted to the artery itself can occasionally injure the endothelium. Therefore, the endothelial integrity of the ultrasonically skeletonized ITA is a major concern related to this technique. The purpose of this study is to assess the endothelial integrity of the ultrasonically skeletonized ITA.

METHODS

We skeletonized the left ITA with an ultrasonic scalpel in nine patients who underwent CABG, and thereafter the terminal portion of this artery was subjected to a morphological study. The endothelial integrity of this artery was morphologically assessed using scanning electron microscopy, and the results were compared to that of the left ITA skeletonized with fine scissors.

RESULTS

All ITA specimens showed a completely confluent endothelium, and no endothelial injury was observed by the scanning electron microscopic study.

CONCLUSIONS

The skeletonization of the ITA with an ultrasonic scalpel had no deleterious effect on the endothelium. This morphological study confirmed the safety and the reliability of this technique, and we therefore recommend its clinical use in the skeletonization of the ITA for CABG.