***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background — Observational studies suggest that skeletonization of the internal thoracic artery ( ITA ) can improve conduit flow and length and reduce deep sternal infections and postoperative pain . We performed a r and omized , double-blind , within-patient comparison of skeletonized and nonskeletonized ITAs in patients undergoing coronary surgery . Methods and Results — Patients ( n=48 ) undergoing bilateral ITA harvest were r and omized to receive 1 skeletonized and 1 nonskeletonized ITA . Intraoperatively , ITA flow was assessed directly and with a Doppler flow probe before and after topical application of papaverine . ITA harvest time and conduit length were recorded . A blinded assessment of pain ( visual analog scale ) and dysesthesia ( physical examination ) was performed at discharge , at 2 weeks , and at a 3-month follow-up . Sternal perfusion was assessed with nuclear imaging ( n=7 ) . Skeletonization required longer ITA harvest times ( 27±1 versus 24±1 minutes ; P=0.04 ) . There was a trend toward increased ITA length in the skeletonized group ( 18.2±0.3 versus 17.7±0.3 cm ; P=0.09 ) . In situ ITA flow was lower in skeletonized arteries ( 7.4±0.9 versus 10.1±1.0 mL/min ; P=0.01 ) and increased significantly after ITA division and papaverine application . Postanastomotic flows were similar between groups . Skeletonization was associated with decreased pain at the 3-month follow-up and a reduction in major sensory deficits at the 4-week and 3-month ( 17 % versus 50 % ; P=0.002 ) follow-ups . Baseline adjusted sternal perfusion was significantly greater by 17±6 % ( P=0.03 ) on the skeletonized side . Conclusions — Skeletonization results in reduced postoperative pain and dysesthesia and increased sternal perfusion at follow-up but does not produce increased conduit flow . ITA skeletonization may be a strategy for reducing morbidity after CABG BACKGROUND This study was conceived to evaluate the effect of internal thoracic artery ( ITA ) skeletonization on vessel wall integrity . METHODS Forty consecutive patients undergoing coronary artery bypass were r and omized to receive a skeletonized ( n = 22 ) or a pedicled ( n = 18 ) ITA graft . ITA harvesting was performed by 2 experienced surgeons using the same instrumentation and technique . Specimens were examined by light and electron microscope in order to assess vascular wall integrity . A specific immunohistochemical staining and a computerized method were used to quantify the degree of endothelial integrity after surgical preparation . RESULTS Morphologic analysis revealed 2 cases of limited subadventitial hemorrhage ( one for each group ) and no case of major arterial damage . Immunohistochemical staining demonstrated an extremely high degree of maintenance of the endothelial integrity in both groups ( 97.2 % + /- 1.9 % in the skeletonized and 96.8 % + /- 2.1 % in the pedicled one ; p = 0.53 ) . CONCLUSIONS Skeletonization does not affect ITA wall integrity in humans su bmi tted to coronary artery bypass procedures BACKGROUND The skeletonization of internal thoracic artery is postulated to improve graft length , early blood flow , sternal blood supply , and postoperative respiratory function . Concern exists that skeletonization may injure internal thoracic artery , precluding good results of surgery . Reports on endothelial function of skeletonized internal thoracic artery are lacking . METHODS A prospect i ve assessment of early clinical outcomes of 357 consecutive patients undergoing coronary artery bypass grafting was performed : 287 patients with nonskeletonized and 70 with skeletonized left internal thoracic artery ( LITA ) .  The lengths of LITA and of its discarded distal segment , as well as free LITA blood flow , were measured . The dose-effect relationship for relaxation to  acetylcholine  was studied in the organ bath . RESULTS Apart from a higher incidence of breaching the pleura with nonskeletonized LITA the clinical outcomes were comparable . The length of skeletonized LITA was 17.8+/-1.14 cm versus 20.3+/-0.52 cm skeletonized ( p = 0.11 ) . The length of discarded LITA was shorter in nonskeletonized artery ( 0.8+/-0.28 cm versus 2.6+/-0.49 cm ; p = 0.022 ) . The free LITA blood flow was 66.3+/-7.42 mL/min in nonskeletonized vessel versus 100.3+/-14.84 mL/min in skeletonized ( p = 0.048 ) . The acetylcholine-induced relaxation was similar in both groups ( maximal relaxation , 80.7%+/-5.95 % in nonskeletonized versus 72.9%+/-9.11 % in skeletonized ; not significant ; negative logarithm of half-maximal effect , 7.43+/-0.18 versus 7.1+/-0.10 , respectively ; p = 0.063 ) . CONCLUSIONS Skeletonization does not damage the endothelial function of the LITA . Higher free blood flow and available LITA length should encourage the use of skeletonized LITA in clinical practice BACKGROUND Skeletonization of the internal thoracic artery ( ITA ) has advantages , but the variation of ITA preparation may be traumatic for the arterial wall . We sought to compare intraoperative results and endothelial nitric oxide synthase ( e-NOS ) expression on the vessel wall after left ITA harvesting with skeletonization and the conventional technique . METHODS A prospect i ve evaluation of 84 consecutive patients undergoing coronary artery bypass grafting was performed : 40 patients with skeletonized and 44 patients with pedicled left ITA .  The lengths of ITA and free ITA blood flow were measured . Distal ITA segments were analyzed histopathologically and stained by antibodies against e-NOS . RESULTS In the skeletonized group , the length of the ITA were significantly longer than in the pedicled group ( 15.7 + /- 0.4 cm versus 19.0 + /- 0.6 cm ; P = .001 ) . Also , the free-flow capacity of the ITA was significantly higher than in the pedicled group ( 62.4 + /- 4.8 mL/min versus 88.6 + /- 6.9 mL/min ; P = .001 ) . e-NOS expressions on endothelial cells were similar between the groups . Dense e-NOS immunostaining was observed in vaso vasorum of the adventitia in the pedicled group . However , there was not any e-NOS immunostaining in vaso vasorum of the adventitia in the skeletonized group . CONCLUSIONS Although skeletonization of the ITA is a more technically dem and ing procedure , it provides some advantages such as increased available graft length and reduced sternal devascularization . This technique did not have any detrimental effects on the endothelial cell lining and e-NOS expressions on the endothelial layer . To reach a definitive judgment for using skeletonized ITA , we need information about the long-term angiographic patency rates OBJECTIVE To compare the free blood flow , caliber , and length of the left internal thoracic artery ( LITA ) , dissected in the pedicled ( P ) and skeletonized ( S ) manners , during surgery before and after topical vasodilator ( TV ) application . METHODS A r and omized , blind , clinical trial was carried out with 50 patients undergoing elective myocardial revascularization to assess the use of the LITA in situ in its pedicled or skeletonized form . The 25 patients in the pedicled group ( GP ) had NYHA class II or III angina , ejection fraction ( EF ) of 50.8+/-9.2 % , and 16 were of the male sex . The patients in the skeletonized group ( SG ) had NYHA class II angina , EF of 46.8+/-9.3 % , and 19 were of the male sex . The measurements were performed before extracorporeal circulation and divided into 2 phases : phase 1 ( before topical papaverine application ) and phase 2 ( 15 min after topical application of papaverine , 2.5 mg/mL , at 37 degrees C ) . During the measurements , mean blood pressure , central venous pressure , and heart rate were monitored . RESULTS The phase 1 and 2 results are as follows : 1 ) PG : blood flow , 46+/-16 and 77+/-28 mL/min ; caliber , 1.4+/-0.1 and 1.7+/-0.1 mm , respectively ; 2 ) SG : blood flow , 57+/-27 and 97+/-35 mL/min ; and caliber , 1.4+/-0.1 and 1.8+/-0.2 mm , respectively . No significant differences were observed in length . CONCLUSION The LITA in SG had a significant increase in blood flow and caliber after the use of TV compared with blood flow and caliber in PG ( P=0.03 and P=0.01 , respectively ) 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 BACKGROUND The preferential harvesting technique of the internal mammary artery has been periodically debated . This r and omized study evaluated the flow outcome of the skeletonized versus pedicled left internal mammary artery . METHODS Two hundred patients undergoing surgery for left anterior descending coronary artery revascularization were enrolled and r and omized to pedicled  ( n=100 ) or skeletonized  ( n=100 ) harvesting . Intraoperative baseline flow and post adenosine infusion into the left ventricle , hospital outcome , echocardiographic results , and troponin I leakage were analyzed . Noninvasive periodic evaluation of flow was carried out at rest and during intravenous adenosine infusion by transthoracic Doppler ultrasound , and was stratified according to the harvesting technique . Final angiographic evaluation was performed by 64-slice multidetector computed tomography . RESULTS Skeletonized left internal mammary arteries demonstrated better flow capacity at rest and during adenosine recruitment perioperatively and at all time points of follow-up . Troponin I leakage was significantly higher in the pedicled group ( 59 vs 42 , p=0.02 ) . Pedicled harvesting ( hazard ratio [ HR ] 3.6 , 95 % confidence interval [ CI ] 2.5 to 6.9 , p<0.001 ) ; indexed left ventricular mass greater than 150 g/m2 ( HR 4.6 , 95 % CI 3.1 to 7.5 , p<0.001 ) ; and baseline corrected thrombolysis in myocardial infa rct ion frame count greater than 30 ( HR 4.4 , 95 % CI , 3.8 to 7.2 , p<0.001 ) were the most powerful multivariable predictors of graft flow reserve less than 2.0 . Postoperative echocardiographic results and clinical and angiographic outcomes were comparable between the two groups . CONCLUSIONS Skeletonization of the left internal mammary artery , beyond traditional proven advantages , provided significantly higher flow capacity and better graft flow reserve 
    Output:
    
Meta-regression demonstrated some modulation influence by female gender , age and diabetes on the flow capacity of grafts .
In summary , in terms of flow capacity , a skeletonized ITA appears to be superior in comparison with a pedicled ITA during CABG