Free flow capacity of skeletonized versus pedicled internal thoracic artery grafts in coronary artery bypass grafts.

OBJECTIVE: The internal thoracic artery (ITA) is the ideal conduit for coronary artery bypass grafting (CABG). The skeletonization technique of this arterial conduit has been proposed to reduce chest wall trauma, increase graft length and facilitate construction of sequential anastomoses. Nevertheless, some surgeons decline this technique because of potentially increased trauma to the ITA with impairment of flow. In this investigation we compared the free flow of skeletonized with that of pedicled ITA grafts. METHODS: Two surgeons operated on 80 consecutive patients with coronary artery disease for elective CABG. In group I (n = 40), the left ITA was dissected using the skeletonization technique. In group II (n = 40), it was harvested as a pedicled graft. In 23 patients of group I both ITA's were dissected in skeletonized fashion for complete arterial revascularization. Diluted papaverine was instilled into the lumen of the ITA after distal transection of the vessel in both groups. Free flow of the ITA was registered before and 15 min after intraluminal application of diluted papaverine. Mean arterial pressure was maintained at 70 mmHg. RESULTS: Before the application of papaverine, free flow of skeletonized and pedicled ITA grafts was identical between the two groups. After treatment with papaverine maximum free flow was significantly higher in the skeletonized ITA's (group I 197.2 (+/-66.6) ml/min; group II 147.1 (+/-70.5) ml/min; P < 0.05). There was no significant difference between free flow after dilatation of the left and right ITA in group I (left 197.2 (+/-66.6) ml/min; right 198.9 (+/-61.8) ml/min). CONCLUSIONS: Preparation of the ITA with the skeletonization technique results in significantly, higher free flow capacity than in pedicled grafts. This may increase the safety of arterial revascularization by reducing the risk of ITA hypoperfusion syndrome.     

Changing pattern in beating heart operations: use of skeletonized internal thoracic artery

BACKGROUND: The use of skeletonized internal thoracic artery (ITA) was reported to be technically and hemodynamically beneficial in conventional coronary artery bypass grafting with cardiopulmonary bypass assistance. The purpose of this study is to evaluate the impact of changing from conventional to skeletonized ITA harvesting on early off-pump coronary artery bypass grafting outcome. METHODS: Between 1996 and 2001, 640 patients underwent systematic off-pump coronary artery bypass grafting (single surgeon experience). The ITA was pedicled (P) in the first consecutive 440 patients and skeletonized (S) in the subsequent 200 consecutive patients. Mean age, preoperative risk factors, sex, number of involved territories, and incidence of reoperations were similar in both groups. RESULTS: In group S, number of ITAs per patient (1.7 +/- 0.08 versus 1.2 +/- 0.05; p < 0.001), bilateral ITA (46% versus 27%; p < 0.001), ITA sequential grafts (27% versus 1%; p < 0.001), and T grafts (16% versus 3%; p < 0.001) were higher. Deep sternal infections were comparable in both groups (group S: 1%, group P: 1.2%; p = 0.38). Perioperative myocardial infarction, maximal creatinine kinase-MB level, and requirement for more than 24 hours of inotropic support were comparable in both groups. Thirty-day mortality was also similar (S: 1.7%, P: 1.6%). CONCLUSIONS: Changing to routine use of skeletonized ITA in off-pump coronary artery bypass grafting is a safe alternative to routine pedicled ITA. In our experience, this procedure has facilitated the use of ITA anastomosis without increasing sternal wound complications.     

Natural Y-grafting using internal thoracic artery branches for off-pump coronary artery bypass

The excellent long-term patency rates achieved utilizing the internal thoracic arteries (ITAs) have stimulated a variety of approaches to expand the use of these conduits in coronary revascularization. The ITA divides at the level of the fifth or sixth intercostal space into the superior epigastric and musculophrenic branches. If these terminal branches of the ITA are large and long enough for grafting, they can be used to construct a "Y" anastomosis to the coronary arteries. We experienced 2 patients who underwent multivessel off-pump coronary artery bypass (OPCAB) using these ITA branches. In both patients the bilateral ITAs and the right gastroepiploic artery were taken down using the skeletonization technique as in situ grafts. One patient had 5 grafts including the right ITA terminal branches which were used for the left anterior descending branch (LAD) and diagonal branch. Another patient had 6 grafts including the left ITA terminal branches which were used for the posterolateral branch (PL)1 and PL2. Postoperative angiography revealed widely patent grafts in both patients. We believe that one of the advantages of applying the off-pump technique when the ITA branches are used is that it might be easier to arrange the angle of constructing a natural "Y" configuration compared with conventional coronary artery bypass grafting (CABG). In conclusion, the terminal branches of the ITA, if of suitable size, should be considered for "Y" grafts to diseased coronary arteries when performing complete arterial revascularization with only in situ grafts.     

Internal thoracic arterial grafts evaluation by multislice CT scan: a preliminary study

BACKGROUND AND AIM: The internal thoracic artery (ITA) has a better long-term patency than saphenous veins, and anastomosis between ITA and the left anterior descending artery (LAD) represents the "gold-standard" of surgical myocardial revascularization. The aim of this study is to evaluate the multidetector multislice CT Scan (MCTS) as a means of postoperative evaluation of ITA coronary artery bypass grafts. METHODS: Twenty-eight patients having been operated on for coronary artery bypass with ITA during a 6-months period, benefited, 7 days after surgery, from a patency and anastomotic site control of ITA with a MCTS associated with cardiac gating (Light Speed, General Electric, USA). RESULTS: Internal thoracic artery bypasses are visualized perfectly on all their courses, with possibility of 3D reconstructions, showing the relationship between cardiac cavities and the arterial bypasses. The anastomotic site on the LAD was, in selected cases, perfectly visualized. Sequential bypasses with left ITA are well visualized as well as T or Y right-to-left ITA grafts. However, surgical clips create some image artefacts. CONCLUSIONS: The postoperative control of ITAs are possible by MCTS with a satisfactory resolution. This makes it possible to check the patency of ITAs, their course on the heart surface, and the location and quality of anastomosis with a noninvasive reproductive method.     

Effects of skeletonization on intraoperative flow and anastomosis diameter of internal thoracic arteries in coronary artery bypass grafting

BACKGROUND: We examined the hypothesis that complete skeletonization of an internal thoracic artery (ITA) results in increased diameter of the graft for anastomosis and therefore improves graft flow in coronary artery bypass grafting. METHODS: We studied 65 consecutive patients who underwent coronary artery bypass grafting, in which the left ITA was anastomosed to the left anterior descending artery. The first 20 consecutive ITA were harvested as a pedicle (group P) and later 45 consecutive ITAs were harvested as an ultrasonically skeletonized graft (group S). Intraoperative ITA graft mean flows were obtained with a transit-time flowmeter. Three diameters of the ITA graft were measured quantitatively in postoperative angiograms performed 14 +/- 5 days after the coronary artery bypass grafting; D1, at the origin from the subclavian artery; D2, at the level of the second intercostal space; and D3, just proximal to the anastomosis. RESULTS: Intraoperative mean flow was significantly greater in group S than in group P (S: 42.6 +/- 29.1 mL/min versus P: 26.4 +/- 16.1 mL/min, p = 0.03). Although the diameters D1 and D2 were not significantly different between groups, D3 was significantly larger in group S than in group p (S: 1.77 +/- 0.28 mm versus P: 1.57 +/- 0.17 mm, p = 0.02). CONCLUSIONS: Compared with pedicle harvesting, complete skeletonization of ITA may make it possible to anastomose an ITA with a larger diameter in coronary artery bypass grafting, which leads to increased graft flow by decreasing vascular resistance.     

Long-term follow-up of coronary artery bypass grafting in three-vessel disease using exclusively pedicled bilateral internal thoracic and right gastroepiploic arteries

BACKGROUND: Considerable data now exist that show that coronary artery bypass grafting with bilateral internal thoracic artery (ITA) grafts produce better outcomes than the use of a single ITA graft. The benefit of a third arterial graft has been less well established. Therefore this article describes the survival and cardiac-related event-free survival in patients having bilateral ITA and gastroepiploic artery (GEA) grafting for 3-vessel disease. METHODS: From November 1992 to May 2002, 201 patients (mean age 53 +/- 7 years) presented with 3-vessel disease and received exclusively bilateral internal thoracic (ITAs) and right gastroepiploic (GEA) arteries as pedicled grafts for coronary artery bypass procedure. Twenty-seven (13%) patients were not elective, 10 (5%) were reoperations, 115 (57%) had one or more myocardial infarction, 21 (10%) had diabetes. In total 733 anastomoses were constructed (3.7/patient), with sequential grafting in 124 (62%) patients. The clinical follow-up was complete. The patients were followed for up to 10 years (mean 6.4 +/- 2.7 years). RESULTS: Ten-year actuarial survival (including in-hospital death) was 87%. The actuarial freedom from angina pectoris, after hospital discharge, was 97% and 86% at 5 and 10 years respectively. None of the patients needed a repeat surgical revascularization after leaving the hospital, whereas 9 (5%) patients underwent a percutaneous transluminal coronary angioplasty. At 5 years 86% and at 10 years 69% of the patients remained free of any cardiac-related event. CONCLUSIONS: The results of this study clearly indicate that the exclusive and extensive use of pedicled bilateral ITA and GEA in coronary bypass grafting provides excellent 10-year patient survival and functional improvement in terms of freedom from return of angina pectoris and, more impressive, freedom from any cardiac-related event. Our findings clearly corroborate the concomitant use of bilateral ITA and GEA grafts in selected patients with 3-vessel disease.     

Coronary revascularization with bilateral internal thoracic artery grafts]

Thirty-two patients underwent coronary revascularization with bilateral internal thoracic artery (ITA) grafts. Each patient received 2.7 grafts in average including double ITA grafts. Seventeen patients had the right ITAs as free grafts. The other sixteen were treated with 13 autologous veins and 9 right gastroepiploic arteries in addition. Fifty-five grafts out of 56 (98.2%) were proved to be patent at the time of hospital discharge. The postoperative morbidity included three reoperations for bleeding and one perioperative inferior myocardial infarction. One patient died of colon perforation after surgery and another died of cerebral infarction late after surgery. These results exhibited that coronary artery bypass grafting with bilateral ITA grafts had relatively low risks and could contribute to complete revascularization in patients with diseased coronary arteries.     

Coronary-coronary bypass using the internal thoracic artery: a sparing procedure of the arterial conduit

BACKGROUND: The internal thoracic artery (ITA) is well known to be the best conduit for coronary artery bypass grafting. However, the bilateral use of ITAs remains limited because in situ right ITAs (RITAs) do not possess an adequate length to be directed to the posterolateral myocardium. We thus considered using free ITAs for conduits between the two segments of the same coronary artery. METHODS: From March 1997 to May 1999, 17 patients underwent coronary-coronary bypass grafting (C-CBG) using free ITAs. Early operative results were analyzed. C-CBG was indicated when the right ITA had an inadequate length or when a distal part of the ITA was left unused. RESULTS: No patient died after C-CBG and none have experienced angina since C-CBG (mean follow-up period 27.3 +/- 19.8 months). Postoperative angiography was performed in all subjects at discharge. Only one coronary-coronary bypass graft was occluded, the other grafts were patent, and there were no stenotic changes. Bilateral ITAs were used in 75% of the patients undergoing CABG during the period of this study. CONCLUSIONS: C-CBG can expand the use of bilateral ITAs and can provide an alternative method for revascularization of the posterolateral myocardium.     

In situ bilateral skeletonized internal thoracic arterial grafting for left-side myocardial revascularization using an off-pump technique

The aim of this study was to review the clinical and angiographic outcomes of in situ skeletonized bilateral internal thoracic artery (ITA) grafting for left coronary arterial revascularization using an off-pump technique in 144 consecutive patients. We also assessed the difference between left and right ITA grafting to the left anterior descending coronary artery (LAD). Arrangement of the bilateral ITAs (grafting of the left/right ITA to the LAD) was decided according to the coronary anatomy and quality of the grafts. Early postoperative angiograms were evaluated in 110 patients. The average numbers of anastomoses and bilateral ITA anastomoses per patient were 3.4 and 2.3, respectively. There were no surgical deaths or sternal infection. The left and right ITA were anastomosed to the LAD in 106 (73.6%) and 38 (26.4%) patients, respectively. There were no differences in preoperative conditions and postoperative complications between the left ITA and right ITA to LAD groups. The patencies of the left and right ITAs were 99.1 and 100%, respectively. In situ skeletonized bilateral ITA grafting for left-side revascularization using an off-pump technique was shown to be feasible, producing excellent early clinical and angiographic outcomes. Furthermore, arrangement of bilateral ITAs did not affect outcomes.     

Bilateral Thoracoscopic Minimally Invasive Direct Coronary Artery Bypass Grafting Using Internal Thoracic Arteries

Background. Single-vessel coronary artery bypass grafting of the left internal mammary artery (ITA) to the left anterior descending coronary artery using a minithoracotomy has been shown to produce excellent results with a very low mortality. However, this procedure cannot be used in patients with double- or triple-vessel disease. Our goal was to develop a minimally invasive direct coronary artery bypass grafting procedure without cardiopulmonary bypass for patients with multivessel disease.

Methods. Both ITAs were thoracoscopically harvested using video imaging. Limited bilateral anterior thoracotomies were performed in the fourth intercostal spaces, thus exposing the right coronary artery and the left anterior descending coronary artery. The right ITA–right coronary artery and ITA–left anterior descending coronary artery anastomoses were performed without cardiopulmonary bypass using 8-0 polypropylene sutures.

Results. This procedure was successfully performed in 3 patients. The patients were extubated in the operating room. Postoperative angiographic studies showed patent left ITA and right ITA grafts.

Conclusions. Bilateral thoracoscopic minimally invasive direct coronary artery bypass grafting can be used to treat patients with a proximally diseased left anterior descending coronary artery and right coronary artery. Bilateral thoracoscopic ITA harvesting is a less invasive surgical technique that may become an option for the management of multivessel coronary artery disease.     

Long-term results of bilateral internal thoracic artery grafting

Background. Little is known about the long-term results of the uniform group of patients who had bilateral internal thoracic artery (ITA) grafting with the method of left ITA-to-left anterior descending coronary artery and right ITA-to-circumflex artery.

Methods. Late follow-up study was performed in the first consecutive 203 patients (mean age, 62.6 ± 9.1 years) who underwent isolated coronary artery bypass grafting with the left ITA anastomosed to the left anterior descending coronary artery and the right ITA to major branches of the circumflex artery. The patients were grouped according to the patency of ITA grafts demonstrated by early postoperative angiography (Both patent (BP) group, 168 patients: both ITAs showed complete patency; Not patent (NP) group, 23 patients: at least one ITA was dysfunctional).

Results. Actuarial 7-year survival in all patients was 89.3% ± 3.1%. The cumulative probability of event-free survival for cardiac death, myocardial infarction, intervention, and angina at 7 years was 96.6% ± 1.8%, 98.0% ± 1.5%, 86.7% ± 3.2%, and 90.7% ± 2.9%, respectively. NP group had more myocardial infarction and angina than the BP group, but was not statistically significant. Because of failed grafts at the early angiography, intervention was performed more frequently in NP group (p < 0.01).

Conclusions. Our results of actuarial 7-year survival and the cumulative probability of event-free survival were at least comparable to the results of other similar studies using bilateral ITA. The freedom from angina appeared to be better than in the previous study. Overall our study supports the continued use of this method of ITA grafting.     

Late-term regression of stenosis at the kink site in the internal thoracic artery in two cases.

A kink in the internal thoracic artery (ITA) is a rare postoperative complication after coronary artery bypass surgery. The kink can be accompanied by significant stenosis and has been observed after the ITAs are harvested by the skeletonization method. In this report, we present two cases in which early postoperative angiography showed the kink accompanied by significant stenosis, and late angiography revealed regression of stenosis at the kink site. Immediate intervention is not always necessary even when the kink, accompanied by significant stenosis was observed on early postoperative angiography.     

Skeletonization of gastroepiploic artery graft in off-pump coronary artery bypass grafting: early clinical and angiographic assessment

BACKGROUND: Recently skeletonization has been recognized as an alternative to pedicle harvesting of the internal thoracic artery as a technique that increases the length and caliber size of the graft compared with pedicled internal thoracic artery grafts; however, this is not yet popular for harvesting the gastroepiploic artery (GEA). We report here our experience of skeletonized GEA grafting in off-pump coronary artery bypass grafting with early clinical and angiographic results. The purpose of this study was to evaluate skeletonization of GEA grafting in off-pump coronary artery bypass grafting with a large patient volume. METHODS: One hundred sixty-eight patients including 131 men and 37 women (mean age, 65 years; range, 45 to 87 years) underwent the skeletonized GEA grafting in off-pump coronary artery bypass grafting. These patients represent 41% (168 of 407 patients) of those who underwent off-pump coronary artery bypass grafting operations during the same period. We used the GEA graft of choice in patients with right coronary artery lesion. Skeletonization was performed in a unique manner we developed. RESULTS: There were no in-hospital deaths among the study patients. One patient had a perioperative myocardial infarction, which was considered a result of vasospasm of the GEA graft. None of the other patients had severe morbidity. The patency rate of the skeletonized GEA graft was 98.1% (151 of 154 distal anastomoses). CONCLUSIONS: This study suggests that skeletonization of the GEA graft can enlarge its caliber size and improve its flow capacity. In addition, the acceptable early clinical and angiographic outcome suggests that use of the skeletonized GEA graft in off-pump coronary artery bypass grafting surgery is safe and effective.     

Internal thoracic artery: to skeletonize or not to skeletonize?

The internal thoracic artery has been the most reliable graft material used in coronary artery bypass grafting with an excellent long-term patency rate. Complete myocardial revascularization with internal thoracic arteries improves long-term survival and decreases the rate of repeat operations compared with vein grafts. Adequate length of the graft in coronary artery bypass graft surgery is essential for providing complete arterial revascularization. In the last decade or so, technique of skeletonization of internal thoracic artery has been proposed to achieve extra length. Skeletonization of the internal thoracic artery allows the preparation of longer conduits with a superior free flow and can reduce the incidence of postoperative pulmonary and sternal complications. However, concerns about vasoreactivity of skeletonized internal thoracic artery grafts, the functional consequences of surgical trauma, the possible loss of innervation, and vasa vasorum perfusion in the skeletonized conduits have prevented this technique from being universally accepted. Presently available evidence from retrospective studies (level 3 evidence) suggests that skeletonization is a safe and effective technique for myocardial revascularization. However, there is a need for conducting multicenter, randomized controlled trials comparing the skeletonized and pedicled internal thoracic arteries with special emphasis on long-term patency to conclusively validate the safety and efficacy of skeletonization technique.     

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.     

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.     

Suitability and durability of multiple internal thoracic artery coronary artery bypasses.

OBJECTIVE: The authors evaluate operative and extended outcomes of coronary artery bypass surgery using the bilateral internal thoracic arteries (ITAs) as bypass grafts. The authors conclude that the procedure is viable and of long-term benefit to most patients. SUMMARY BACKGROUND DATA: Multiple ITA grafting was met with early enthusiasm by the surgical profession, but skepticism and controversy arose with reports of increased operative morbidity, insufficient graft blood flow, a high incidence of failure of the right ITA, and uncertainty about durability and long-term benefits. METHODS: To assess the actual incidence and impact of these complications and long-term results, the authors prospectively studied 500 consecutive patients with multiple ITA bypasses, constituting the closely observed and carefully documented experience of one surgeon over an 11-year period. RESULTS: Operative mortality in the series of 500 patients was 1.8%, perioperative myocardial infarction (new Q wave) rate was 0.6%, and deep sternal wound infection occurred in 1%. Six patients (1.2%) had strokes, and nine patients (1.8%) were returned to the operating room to control bleeding. One hundred ninety-eight patients who had abnormal stress test results before surgery were retested within 3 months of surgery. Ninety-four percent of these were normal, 3% were nondiagnostic, and 3% were abnormal. After a mean follow-up of 7.1 years (mode, 7.2 years), 87.5% of patients in the sample were alive, and 93.2% of this group have experienced continuing good clinical results (New York Heart Association class I or II). Eighty-nine patients who underwent an angiogram had 90.8% patency rates of ITA bypasses and 84.5% patency of vein grafts. Only two patients required repeat operations. CONCLUSIONS: The operative results did not support the contention that the coronary artery bypass using ITA procedure produces higher than acceptable mortality and morbidity rates. Multiple ITA bypasses can be performed without excessive morbidity, with low reoperation rates and long-term outcomes that should encourage skeptics to reconsider the procedure's clinical value.     

Feasibility and suitability of the routine use of bilateral internal thoracic arteries

BACKGROUND: It has been demonstrated that bilateral use of internal thoracic arteries (ITAs) confers better long-term results in patients than does unilateral use. However, routine use of bilateral ITAs has usually been avoided. METHODS: Since 1997, we have used bilateral ITAs extensively for patients who required multivessel bypasses. Recently, 243 consecutive patients, including 127 diabetic patients, were reviewed. RESULTS: Every patient received at least one ITA graft, and 200 patients (82%) received bilateral ITAs. The majority (93%) of ITA grafts were used as in situ grafts. The hospital mortality rate was 0.41%, and deep sternal infections were observed in 5 patients (2.0%). There was no difference in the incidence of chest wound infection between the group treated with bilateral ITA grafting and that treated by unilateral ITA grafting. CONCLUSIONS: These observations suggest that ITAs can be used bilaterally for treatment in the majority of patients who require multivessel bypass, with low mortality and morbidity.     

Intimal injury of ultrasonically skeletonized internal thoracic artery by a vessel clamp: morphological analysis

The skeletonized internal thoracic artery (ITA) has several advantages over a pedicled one in coronary artery bypass grafting. A skeletonized ITA, which lacks surrounding tissue, thus seems more susceptible to the mechanical force exerted by a vessel clamp than the pedicled ITA. The purpose of this study was to assess the detrimental effect of vessel clamps on the intimal integrity of the ultrasonically skeletonized ITA. We skeletonized twelve ITAs with an ultrasonic scalpel in patients who underwent coronary artery bypass grafting, and thereafter two types of clamp, namely a metal clamp and a fibrous jaw clamp, were applied to the terminal portion of the ITA for 30 min. The intimal integrity of the ITAs was morphologically assessed using scanning electron microscopy. A metal clamp can cause serious intimal injury which disrupts the internal elastic lamina, and thus should be avoided for the temporary clamping of the skeletonized ITA. A fibrous jay clamp, however, hardly ever causes intimal injury, and its clinical use for the temporary clamping of the ultrasonically skeletonized ITA is therefore recommended. Vessel clamps can cause intimal injury of the ultrasonically skeletonized ITA, and the degree of the injury depends on the type of the clamp used.     

The impact of chronic renal failure on atherosclerosis of the internal thoracic arteries

BACKGROUND: Little is known about the impact of renal failure on atherosclerotic changes in the internal thoracic artery (ITA). METHODS: A total of 20 consecutive patients on chronic dialysis who underwent coronary artery bypass grafting (CABG) during April 1998 through September 1999 were investigated. The 20 control patients were selected from the same interval to rigorously match risk factors. Atherosclerosis of the ITA collected from each patient was analyzed using the subjective evaluation proposed by Kay and colleagues. RESULTS: There were no cases of greater than 25% atherosclerotic luminal narrowing among a total of 35 ITA specimens from dialysis patients. The degree of atherosclerosis was not significantly different from that of the specimens from matched patients (p = 0.18). No calcification was found in ITA grafts either microscopically or macroscopically. The number of elastic lamellae, an index of the elasticity of the ITA graft, was not significantly different from those obtained from the matched patients. Analysis of preoperative coronary angiography revealed that coronary calcification was significantly more frequent in dialysis patients (15 patients, 75%) than in matched patients (p < 0.05). By analysis of postoperative angiography in dialysis patients, no evidence of atherosclerotic changes was found in 28 opacified ITAs. In addition, despite the presence of calcification in the native coronary, no calcification was evident along the entire length of the ITAs. CONCLUSIONS: This study revealed the minimal impact of chronic renal failure on atherosclerotic changes in the ITA. The results of this study support the continued use of ITA grafting in dialysis patients.