The Treatment of Multiple Coronary Occlusions by Internal Mammary Artery Implantation and Omental Graft: Report on Two Human Cases

The importance of triple coronary artery disease was evident in 125 patients undergoing internal mammary artery implantation, when some patients died from right coronary artery occlusion. This occurred even when the internal mammary artery was patent and revascularizing the left ventricle.In 1961 the free omental graft operation was developed to revascularize both right and left ventricles. In animals this operation has proved most effective in preventing death after application of Ameroid constrictors to all three coronary arteries. Arteriolar or larger-sized vessels rapidly formed between the aorta and omentum and the pericardium and omentum and the heart and omentum.Two patients with triple coronary artery disease underwent internal mammary artery implantation and free omental graft early in December 1962. Postoperative convalescence was uneventful. They have returned home and appear to be improved. Wrapping the entire heart with the free omental graft has produced little reaction, suggesting that, as in the animal, the grafts are surviving.     

Perforator flap breast reconstruction using internal mammary perforator branches as a recipient site: an anatomical and clinical analysis

A variety of useful recipient sites exist for breast reconstruction with free flaps, and correct selection remains a significant decision for the surgeon. Among the main pedicles, the disadvantages of the internal mammary vessels are the necessity of costal cartilage resection and the impairment of future cardiac bypass. This study was designed to reduce morbidity and to seek alternative recipient vessels. In the anatomical part of the study, 32 parasternal regions from 16 fresh cadavers were used. The locations and components of internal mammary perforator branches were measured and a histomorphometric analysis was performed. In the clinical part of the study, 36 patients underwent 38 deep inferior epigastric perforator (DIEP) flap and two superior gluteal artery perforator flap breast reconstructions (31 immediate and four bilateral). The recipient vessels were evaluated. In the anatomical study, there were 22 perforating vessels, with 14 (63.6 percent) on the second intercostal space and 11 (50 percent) with one artery and vein. The average (+/-SD) internal and external perforator artery diameters were 598.48 +/- 176.68 microm and 848.97 +/- 276.68 microm, respectively. In the clinical study, 13 successful anastomoses (32.5 percent) were performed at the internal mammary perforator branches (second and third intercostal spaces) with 12 DIEP flaps and one superior gluteal artery perforator flap (all performed as immediate reconstructions). One case of intraoperative vein thrombosis and one case of pedicle avulsion during flap molding were observed. The anatomic and clinical studies demonstrated that the internal mammary perforator branch as a recipient site is a further refinement to free flap breast reconstruction. However, it is neither a reproducible technique nor potentially applicable in all patients. Preoperative planning between the general surgeon and the plastic surgeon is crucial to preserve the main perforator branches during mastectomy. The procedure was not demonstrable in late reconstructions. The main advantages of internal mammary perforator branches used as recipient sites are sparing of the internal mammary vessels for a possible future cardiac surgery, prevention of thoracic deformities, and reduction of the operative time by limited dissection. Despite this, limited surgical exposure, caliber incompatibility, and technical difficulties have to be considered as the main restrictions.     

Reconstruction of mandibular defects with revascularized free rib grafts.

Two cases of hemimandibular reconstructions with revascularized free rib grafts are presented. The viability of the transplants was confirmed by bone scans and biopsy, even though the main nutrient vessels providing the intramedullary blood flow were not included in these grafts (and only the periosteal circulation was utilized). The removal of a rib graft without the nutrient vessel eliminates the need for a complicated posterior dissection, close to the costovertebral joint. Revascularized free bone grafts have a greater chance of survival, provide more rapid healing, offer less risk of absorption, and are more resistant to infection than conventional bone grafts.     

Combined Internal Mammary Artery Implantation and Free Omental Graft Operation: A Highly Effective Revascularization Procedure: (A Study of 17 Cases)

One hundred and forty patients with coronary artery disease treated by internal mammary artery implantation were followed up from six months to 13 years. The mortality rate was 3%; improvement was obtained in 70%. Occlusive disease of all three major coronary arteries, however, requires more blood than can be supplied by the implant procedure, and the free omental graft operation was developed for the management of selected patients with this condition. Normally in animals triple coronary artery ameroid constriction results in 100% mortality. When the free omental graft operation, with or without internal mammary artery implantation, was performed, 80% of such animals survived. The free omental graft forms capillary anastomoses in three days and arteriolar vessels in eight days, which leave the base of the aorta, enter the omentum, thence to the myocardium. A combined internal mammary artery implantation and free omental graft operation was performed in 17 patients with triple coronary artery disease as shown by cine coronary arteriography. There was no operative mortality, and 12 of the patients are free of pain and have returned to work.     

The Continuity of Right and Left Ventricular Myocardial Sinusoidal Spaces and its Relation to Right Ventricular Implants

Evidence is presented which indicates that blood leaving side branches of an internal mammary artery implanted into the anterior wall of the right ventricle flows from the tunnel in which it lies through myocardial sinusoidal spaces of the anterior right ventricular wall across the midline to fill corresponding spaces in the anterior wall of the left ventricle and thence is carried to the left coronary sinus. The myocardial sinusoidal spaces of right and left ventricles have been well outlined, using injections of polyvinyl acetate and the technique of digestion casts. We have been able to show that there is no barrier between the myocardial sinusoids of the right circulation and those related to the anterior descending branch of the left coronary artery. In structure, these myocardial sinusoidal spaces are quite different from the intramyocardial coronary arteriolar zones which, in 93% of human hearts, are separated from one another without collateral communication.The continuity of the right and left ventricular myocardial sinusoids explains why implantation of a right internal mammary artery into the anterior wall of the right ventricle combined with a corresponding left implant, epicardiectomy and free omental graft, has been so effective in our hands in the treatment of far-advanced human coronary artery insufficiency.     

Thoracodorsal vessels as recipient vessels for the free TRAM flap in delayed breast reconstruction.

The internal mammary vessels have been recommended as the first choice recipient vessels for delayed breast reconstruction with the free TRAM flap. This approach has avoided surgery in the previously operated axilla, has required a shorter pedicle length, and has allowed for more medial placement of the TRAM tissue. Frequency of nonusable axillary vessels has been reported at 11 percent, with a 6 percent incidence of flap loss in the delayed reconstructive setting. We reviewed our experience with the thoracodorsal vessels as recipient vessels in delayed free TRAM breast reconstruction to assess more accurately the adequacy of these potential recipient vessels. All patients undergoing delayed TRAM reconstruction were reviewed. Forty-seven of 300 consecutive TRAM procedures were for planned delayed free reconstruction. In seven of the patients (15 percent), the thoracodorsal vessels were found to be inadequate for free reconstruction. A supercharged pedicled TRAM was used for reconstruction in each of these seven patients. Average operating room time was 7 hours. Mean follow-up time was 38 months. Nineteen percent of all patients developed at least one complication. Twelve percent of free TRAM patients developed a complication, whereas 57 percent of supercharged patients developed a postoperative complication. The difference in complication rates was statistically significant. The thoracodorsal vessels have provided an adequate recipient vessel in 85 percent of delayed free TRAM reconstructions, comparable to previous reports. Pedicling and supercharging the flap, in those situations in which the thoracodorsal vessels were inadequate, were associated with an increased incidence of postoperative complications. This suggests that in the delayed reconstructive setting, higher-risk patients benefit from free reconstruction over supercharged reconstructions. A second recipient vessel should be used when the thoracodorsal vessels are inadequate for planned free TRAM reconstruction. In these circumstances, we would recommend the use of the internal mammary vessels followed by the thoracoacromial vessels as reliable alternative recipient sites for delayed free TRAM reconstruction.     

Choice of recipient vessels in delayed TRAM flap breast reconstruction after radiotherapy

This study compared the use of the internal mammary and thoracodorsal recipient vessels in a uniform group of patients who underwent delayed TRAM flap reconstruction after radiotherapy, focusing on usability rates and outcomes. The authors identified 123 delayed TRAM flap patients who had undergone postmastectomy radiotherapy from a prospective database (1990 to 2001). Recipient vessel unusability rates were calculated on the basis of reports of inspection of a vessel, either by direct intraoperative dissection or by findings from color Doppler examination (internal mammary vessels only). Charts were reviewed for outcomes including flap loss, vascular complications, fat necrosis, and lymphedema; t-test and chi-square analyses were performed to compare outcomes and unusability rates, and multiple regression analysis was performed to determine factors influencing outcome. Of the 123 planned free TRAM flaps, 106 were completed as free flaps and 17 were performed as pedicled flaps because of unusable recipient vessels. Of the free flaps, 45 were anastomosed to the internal mammary vessels, 55 to the thoracodorsal vessels, and six to other vessels. The internal mammary and thoracodorsal groups did not differ significantly in body mass index, abdominal scars, smoking history, time delay between irradiation and TRAM flap reconstruction, or flap ischemia time. Radiation doses to the axilla (thoracodorsal), internal mammary chain, and supraclavicular fossa were similar between the groups. The internal mammary vessels were rejected in 11 (20 percent) of 56 cases, and the thoracodorsal vessels were rejected in 19 (26 percent) of 74 cases (p = 0.42). In cases with unusable internal mammary vessels, 46 percent (n = 5) had inadequate veins, 27 percent (n = 3) had inadequate arteries, and in 27 percent (n = 3) both vessels were inadequate. In the 19 cases with unusable thoracodorsal vessels, 84 percent (n = 16) were excessively scarred, 11 percent (n = 2) had inadequate vessels, and 5 percent (n = 1) were absent. Outcomes were similar regardless of recipient vessels used (internal mammary versus thoracodorsal): total flap loss, 0 percent versus 4 percent (p = 0.20); vascular complications, 6.7 percent versus 11 percent (p = 0.46); arm lymphedema, 4.4 percent versus 9 percent (p = 0.37); partial flap loss, 9 percent versus 6 percent (p = 0.54); and fat necrosis, 18 percent versus 15 percent (p = 0.69). Multivariate analysis revealed a trend for higher complication rates in smokers and with the use of the thoracodorsal vessels as the recipients. Overall, no discernible unusability or outcome differences were detected between the internal mammary and thoracodorsal groups.     

The temporalis myo-osseous flap: an experimental study

The present paper investigates the anatomy and vascularization of the temporalis myo-osseous flap. This is a calvarial bone flap that employs temporalis muscle and its distal pericranial extension as a pedicle. In six human cadavers the flap was raised as an island on the anterior deep temporal artery after transecting the zygomatic arch and coronoid process. Maximal mobilization was thus obtained, allowing rotation of the flap into the mouth for intraoral reconstruction. The arc of rotation and potential surgical applications were noted. A comparative study of the temporalis myo-osseous flap and free calvarial bone graft was then conducted in a rabbit model. Vascularization of the calvarial bone flap was confirmed by technetium scintigraphy performed on the first postoperative day. The uptake of fluorochrome labels immediately after transfer verified the adequacy of the periosteal circulation in maintaining viability and new osteoid formation throughout the full thickness of calvarial bone. The transplantation of free calvarial bone grafts was followed by necrosis of most cellular elements. This was demonstrated by an absence of fluorochrome uptake up to 19 days postoperatively and a predominance of empty lacunae and nonviable marrow.     

Deltopectoral skin flap as a free skin flap revisited: further refinement in flap design, fabrication, and clinical usage

The deltopectoral skin flap is an axial flap; therefore, it can be fashioned as a free skin flap. Although color and texture of the skin are well suited for facial resurfacing, the structural features of inconsistent thickness of the skin, a short vascular pedicle, a minute caliber of the nutrient vessel, and donor site morbidity often preclude the use of this flap for this purpose. The deltopectoral skin flap fabricated as a free skin flap transferred by means of a microsurgical technique was used in 27 patients between 1985 and 1998 at our hospital. The anterior perforating branches of the internal mammary vessels were the primary nutrient vessels of the flap in seven instances. The external caliber of this artery varied between 0.6 mm and 1.2 mm, with an average size of 0.9 mm. The size of the accompanying vein varied between 1.5 mm and 3.2 mm, with an average of 2.3 mm. Coaptation of these vessels with those in the recipient site was technically difficult. Thrombosis occurred at the anastomotic site in three patients, requiring reoperation. Two flaps were saved. The flap failure was drastically reduced in the remaining 20 patients by including a segment of the internal mammary vessel when fabricating the vascular pedicle. The size of the internal mammary arterial segment averaged 2.1 mm, and the average size of the accompanying vein was 2.9 mm. The problem of a bulky flap was managed by surgical defatting/thinning of the flap at the time of flap fabrication and transfer. A V-to-Y skin flap advancement technique of wound closure was used in eight individuals. The flap donor-site morbidities were minimized with this method of wound closure.     

Implantation of the Right and Left Internal Mammary Arteries with Epicardiectomy and Free Omental Graft: A Preliminary Experimental Report

In animal experiments the right internal mammary artery was implanted into the outflow tract of the right ventricle during performance of left mammary artery implantation with epicardiectomy and free omental graft. The effect of double mammary artery implantation operation was tested by triple coronary artery ameroid constriction in 24 animals. In 20 animals studied both implanted arteries remained open and had commenced to bud and branch at the time of examination. The double implant operation is still an experimental procedure.     

Right Internal Mammary Artery Implantation into Right Ventricular Myocardium for Revascularization of the Entire Heart: Experimental Data and Preliminary Report

The left internal mammary artery implant combined with epicardiectomy and free omental graft provides three extra-coronary sources of blood. This operation tested in dogs with 92% main-stem occlusion of three coronary arteries protected 75% of the animals. Applied clinically in over 100 patients, the operation resulted in 90% improvement. To obtain complete myocardial revascularization, the right internal mammary artery has been used as a fourth source of extra-coronary blood. In 57 animals, the right internal mammary arteries were implanted into the anterior walls of the right ventricle; in 80% this vessel formed anastomoses with the right coronary tree, and in 65% with the right and left coronary arteriolar systems. Six patients are described who underwent right internal mammary artery implantation; five of these in addition had the combined operation of left internal mammary artery implant, epicardiectomy and free omental graft. All patients had completely blocked right coronary arteries; in addition, five had advanced disease of the left coronary arterial tree.     

The "double barrel" free vascularized fibular bone graft

A further modification of the free vascularized fibular bone graft is described in which a transverse osteotomy is made from the anterolateral aspect of the fibular shaft just distal to the entry of the nutrient artery. This produces two vascularized bone struts that may be folded parallel to each other but that remain connected by the periosteum and muscle cuff surrounding the peroneal artery and vein. The proximal strut is vascularized by both a periosteal and an endosteal blood supply, whereas the distal strut is vascularized by a periosteal blood supply alone. This so-called "double barrel" free vascularized fibular graft has been employed in three patients with segmental bone defects of the distal femur and in one patient with adjacent bony defects of the radius and ulna.     

Criteria for Internal Mammary Artery Implantation Based on Cine Coronary Arteriography

Preoperative coronary arteriograms were correlated, in a group of 50 patients, with left internal mammary angiograms obtained from 11 to 32 months, with a mean of 17 months, after mammary artery implantation. In all patients in whom the internal mammary artery was patent and considered functional with good angiographic opacification of the anterior descending coronary artery, the preoperative coronary angiogram showed total or subtotal obstruction of the latter vessel, with indirect evidence of decreased flow and pressure distal to the obstruction. This evidence was provided by the presence of a collateral circulation or, in a few cases of subtotal obstruction, delayed opacification of the vessel distal to the obstruction.In patients in whom the internal mammary artery was patent but showed no anastomotic connection with the anterior descending coronary artery or only opacification of small coronary branches, the degree of coronary obstruction was, in most cases, less than 90% of the lumen of the coronary artery in the absence of any collateral circulation or delayed opacification of the vessel distal to the obstruction.Occlusion of the internal mammary artery was seen as often in the presence of total or subtotal obstructions as with lesser degrees of anterior descending coronary artery obstruction, and is believed unrelated to the degree of pre-existing coronary artery disease.Successful internal mammary artery implantation can be related to specific coronary angiographic patterns recognizable before operation; these may serve as reliable criteria for the selection of patients.     

An outcome analysis comparing the thoracodorsal and internal mammary vessels as recipient sites for microvascular breast reconstruction: a prospective study of 100 patients

The thoracodorsal vessels have been the standard recipient vessels for the majority of surgeons performing free transverse rectus abdominis musculocutaneous (TRAM) flap reconstructions. Recently, the internal mammary vessels have been recommended as the first-choice recipient vessels for microvascular breast reconstruction. This approach requires a shorter pedicle length, allows for central placement of flap tissue, and avoids axillary scarring. The use of the internal mammary vessels may provide for a shorter operative time and a higher-quality aesthetic reconstruction. The authors performed a prospective trial examining the differences in operative and aesthetic outcomes between each recipient site. A prospective trial of 108 consecutive free-tissue transfers was conducted in 100 patients. The first 60 TRAM flap patients were randomized so that 30 flaps were anastomosed to the internal mammary vessels and 30 were anastomosed to the thoracodorsal vessels, whereas the recipient vessels for the remaining 40 patients were left to the discretion of the surgeon. Of the 40 nonrandomized patients, 10 patients underwent reconstruction using the internal mammary vessels and 30 patients underwent reconstruction using the thoracodorsal vessels. The patients' medical history and hospital course were noted. To evaluate aesthetic outcome, a group of five blinded nonmedical observers and three blinded plastic surgeons graded the reconstructions in the 60 TRAM flap patients for symmetry and overall aesthetic result on a scale of 1 to 5. Blinded practitioners administered postoperative questionnaires to patients regarding recovery time and satisfaction with the aesthetic result. Forty-three flaps were transferred to the internal mammary vessels and 65 were transferred to the thoracodorsal vessels. No significant differences existed between groups with regard to age of preoperative risk factors. Average operative time was 6 hours in each group. Average hospital stay was 5.8 days in each group. Conversion from initial recipient vessel to a secondary recipient site occurred in 12.5 percent of internal mammary reconstructions and 7 percent of thoracodorsal reconstructions. All converted internal mammary cases occurred in left-sided reconstructions and were attributable to problems with the veins. Overall, 20 percent of left-sided internal mammary reconstructions were found to have an inadequate recipient vein. Unusable thoracodorsal vessels were found only in delayed reconstructions, at a rate of 15 percent in the delayed setting. All flaps from converted procedures survived without complications. Average follow-up was 20 months, during which time there was one flap loss in the thoracodorsal group. There were no significant differences in complication rates between groups. Average aesthetic grade was 3.6 in each group. Postoperative recovery time and overall patient satisfaction were not significantly different between groups. Either recipient site can provide for a safe and acceptable result; however, surgeons should be aware of conversion rates and plan appropriately if recipient vessels appear unusable for free-tissue transfer.     

Blood supply of the rat amygdala.

The cerebral vessels of the rat were filled with inks of different colours. The topography of the vessels of the amygdala were reconstructed from serial sections. The circulation of the individual amygdaloid nuclei was studied in detail. The arteries of the amygdala arise from the deep and cortical branches of the internal carotid and middle cerebral arteries. Eight major arteries were found to supply blood to the amygdala. All amygdaloid nuclei receive branches from both arterial trunks. The vast majority of the veins are collected by the middle cerebral and basal veins. Only a small fraction drains into the hippocampal vein. Of particular importance are the veins ending in the basal vein and those cortical ones that run in the rhinal sulcus. All amygdaloid nuclei have a multidirectional drainage.     

Superoxide dismutase activity and expression in human venous and arterial bypass graft vessels.

Venous bypass grafts are more prone to accelerated atherosclerosis than arterial grafts, which is partly related to increased oxidative stress and diminished nitric oxide bioavailability. In veins superoxide production is dependent primarily on nox2 NAD(P)H oxidase expression, while in arteries nox4 appears to play an important role. This may in part explain differences in susceptibility to graft failure. Net levels of oxidative stress are however determined in parallel by the production as well as by degradation of free radicals (eg. by superoxide dismutases, catalases, thioredoxins etc). The differences in superoxide dismutase (SOD) expression and activity in human bypass conduit vessels remain unclear. Accordingly, we aimed to compare SOD activity and protein levels as well as its functional effects on superoxide production in segments of human internal mammary arteries (IMA) and saphenous veins (HSV) from patients undergoing bypass graft surgery (n=24). SOD activity was assessed by inhibition of pyrogallol autoxidation, Cu-Zn SOD and Mn SOD protein levels were studied by immunoblotting. Basal superoxide release was detected by lucigenin (5 microM) enhanced chemiluminescence. Total SOD activity did not differ significantly between HSV and IMA. Similarly, no difference was observed in SOD activity in the presence of KCN (Mn-SOD). Human bypass conduit vessels show amounts of Cu-Zn SOD or Mn-SOD protein levels. In both HSV and IMA segments superoxide production was more than doubled in the presence of SOD inhibitor-DETC. CONCLUSIONS: These studies suggest that the differences in oxidative stress between human arteries and veins are unlikely to be caused by SOD activity. However SOD plays and important role in amelioration of oxidative stress in both types of vessels.     

Collateral sources of costal and crural diaphragmatic blood flow

We measured the contribution of aortic, internal mammary, and intercostal arteries to the blood flow to the costal and crural segments of the diaphragm and other respiratory muscles in seven dogs breathing against a fixed inspiratory elastic load. We used radiolabeled microspheres to measure the blood flow with control circulation, occlusion of the aorta distal to the left subclavian artery, combined occlusion of the aorta and both internal mammary arteries, and occlusion of internal mammary arteries alone. With occlusion of the aorta distal to the left subclavian artery, blood flow to the crural diaphragm decreased from 40.3 to 23.5 ml . min-1 X 100 g-1, whereas costal flow did not change significantly (from 41.7 to 38.1 ml . min-1 . 100 g-1). Blood flows to the sternomastoid and scalene muscles (above the occlusion) increased by 200 and 340%, respectively, whereas flows to the other respiratory muscles did not change significantly. Blood flows to organs above the occlusion either remained unchanged or increased, whereas flows to those below the occlusion all decreased. When the internal mammary artery was also occluded, flows to the crural segment decreased further to 12.1 and costal flow decreased to 20.4 ml X min-1 X 100 g-1. Internal mammary arterial occlusion alone in two dogs had no effect on diaphragmatic flow. In conclusion, intercostal collateral vessels are capable of supplying a significant proportion of blood flow to both segments of the diaphragm but the costal segment is better served than the crural segment.     

Sectorial angioarchitecture of the human tibia.

The blood supply of the periosteum of the human tibia was investigated by anatomical dissection of 12 lower extremities which were filled with injection mass. By division of the tibia into 4 segments (proximal and distal fifths; proximal and distal diaphysis) a general supplying system of the periosteum was found. The proximal fifth of the tibial periosteum is nourished by branches of the arteriae recurrentes tibiales anterior et posterior and the aa. inferiores medialis et lateralis genus. At the proximal diaphysis (next three tenths of the tibia) periosteal branches arise from the aa. tibialis anterior and posterior, whereas the distal diaphysis is nourished exclusively by semicircular vessels of the a. tibialis anterior which twine around the bone and merge with each other at the facies medialis. Concerning the periosteal blood supply of the distal fifth of the tibia, two different types were found. In two thirds of the cases the lateral side was nourished by branches of the a. tibialis anterior, which are supported by vessels from the a. fibularis. In one third the latter branch was absent so that the rami periostales arising from the a. tibialis anterior nourished the lateral aspect of the distal tibia alone. The dorsal region was supplied in all cases by rami of the a. fibularis and a. tibialis posterior. On the medial side the periosteal nourishment is ensured only by anastomosis. Branches of the a. tibialis anterior supply the facies lateralis and facies posterior where it is supported by vessels of the a. tibialis posterior and in a minor region of rami of the a. fibularis (distal) and a. poplitea (proximal).(ABSTRACT TRUNCATED AT 250 WORDS)     

ACE2 and AT4R are present in diseased human blood vessels

A growing body of evidence suggests that the angiotensin II fragments, Ang(1-7) and Ang(3-8), have a vasoactive role, however ACE2, the enzyme that produces Ang(1-7), or AT4R, the receptor that binds Ang (3-8), have yet been simultaneously localised in both normal and diseased human conduit blood vessels. We sought to determine the immunohistochemical distribution of ACE2 and the AT4R in human internal mammary and radial arteries from patients undergoing coronary artery bypass surgery. We found that ACE2 positive cells were abundant in both normal and diseased vessels, being present in neo-intima and in media. ACE2 positive immunoreactivity was not present in the endothelial layer of the conduit vessels, but was clearly evident in small newly formed angiogenic vessels as well as the vaso vasorum. Endothelial AT4R immunoreactivity were rarely observed in either normal and diseased arteries, but AT4R positive cells were observed adjacent to the internal elastic lamine in the internal mammary artery, in the neo-intima of radial arteries, as well as in the media of both internal mammary artery and radial artery. AT4R was abundant in vaso vasorum and within small angiogenic vessels. Both AT4R and ACE2 co-localised with smooth muscle cell alpha actin. This study identifies smooth muscle cell alpha actin positive ACE2 and AT4R in human blood vessels as well as in angiogenic vessels, indicating a possible role for these enzymes in pathological disease.     

Traumatic ostial stenosis of internal mammary coronary graft

Because of the extensive use of arterial conduits for coronary surgery there is a growing interest in percutaneous intervention in these conduits. This kind of intervention presents a challenge for the interventional cardiologist owing to the anatomic and functional characteristics of this graft. In most cases significant internal mammary artery disease occurs at the distal anastomosis. Ostial stenoses are rare and their pathology uncertain. The authors report a case of an ostial graft lesion, most probably caused by repetitive ostial engagement of the left internal mammary artery in combination with atherosclerosis in the subclavian artery affecting the internal mammary artery.