Minimally invasive direct coronary bypass surgery via distal mini-sternotomy : Promising clinical results with anaortic, multivessel, all-arterial technique.

BACKGROUND: Minimally invasive direct coronary artery bypass grafting (MIDCAB) was developed to decrease perioperative morbidity, some of which may be related to the use of cardiopulmonary bypass and to cross-clamping of the aorta. We report our initial experience with multivessel MIDCAB via distal mini-sternotomy (DIMS). DIMS is performed to gain access to the left and right internal thoracic arteries and to reach the left anterior descending coronary artery (LAD), diagonal branches, and right coronary artery (RCA). METHODS: Between January 2016 and January 2017, 12 patients with significant coronary artery disease of the LAD and the RCA underwent multivessel, all-arterial MIDCAB through a distal midline skin incision from the fourth intercostal space to the xyphoid process, with L­ or T­shaped division of the sternum. The mean age of the patients was 61.5 ± 5.2 years (range: 52-71 years). RESULTS: We performed all-arterial revascularization using the left internal mammary artery in 12 patients, the radial artery in ten, and the right internal mammary artery in two patients. The mean number of grafts per patient was 2.08 ± 0.4 (range: 2-3). The mean length of the skin incision was 8.5 ± 1.3 cm (range: 7-11 cm). There was no perioperative ischemia, postoperative bleeding, or arrhythmia events. No postoperative cognitive dysfunction occurred. The mean hospital stay was 5.6 days. No major adverse cardiac events (MACE) occurred at the 12-month follow-up. At follow-up, all patients were in New York Heart Association class I and there were no wound complications. CONCLUSION: Although MIDCAB-DIMS is technically more demanding than conventional procedures and our experience is limited, we conclude that this technique can be used safely in selected patients, with promising 12-month follow-up results.

Surgical treatment of the isolated left ostial stenosis.

AIM: Conventional grafting for left main coronary artery (LMCA) stenosis provides a retrograde perfusion to extensive myocardial area, leads prospectively to totally occlusion of the LMCA and to competitive flow of the non-occluded coronaries thus consuming the grafts. Surgical reconstruction of the LMCA with patch-angioplasty is an alternative method that eliminates these drawbacks. METHODS: Between February 1997 and August 2009, 45 patients with isolated LMCA stenosis were referred for surgical ostial reconstruction. In 32 patients (71%) surgical angioplasties have been performed. All patients were followed-up clinically and with transesophageal echocardiography (TEE) and coronary angiography when required. RESULTS: In 13 patients (29%) a LMCA stenosis could not be confirmed. There were no early mortality or perioperative myocardial infarctions. The postoperative course was uneventful in all patients. In 30 patients, TEE demonstrated a wide open main stem flow pattern one to six months after reconstruction of the left main coronary artery with one patch mild aneurysmal dilated. CONCLUSION: The results after surgical reconstruction with patch-angioplasty are good and comparable with those after CABG. The endarterectomy and reconstruction should be avoided in the case of distal stenosis of LMCA and excessive calcification. Almost one third of the study group had no really LMCA stenosis. These patients have benefited of the plan to perform a reconstruction: antegrade flow pattern remained sustained and the arterial grafts have been spared.

Detection of vein graft disease using 4-row computed tomography. Evaluation of coronary bypass graft patency and correlation with the Ca-score.

BACKGROUND: Multi-row computed tomography (MDCT) is a promising non-invasive technique and capable of rapid imaging of cardiac structures, including coronary arteries and bypass grafts during a single held breath. In this study, we evaluated coronary artery bypass graft (CABG) patency by comparing 4-slice computed tomography with conventional contrast angiography. One disadvantage of MDCT is the limited diagnostic accuracy with + increased calcification of the grafts. Therefore, the correlation between Ca-grading and diagnostic accuracy was examined. METHODS: We examined 30 patients with 104 bypass grafts with a 4-row MDCT scanner. On the basis of the Ca-score, patients were divided into 3 groups. RESULTS: It was possible to assess the exact degree of stenosis in 25 of 32 > 50% stenoses with 4-row MDCT, 7 stenoses were underestimated. All occlusions in 21 patients were identified correctly, 33 graft segments were underestimated in MDCT, of which 28 were in the group with a Ca-score of > 800. CONCLUSIONS: MDCT allows non-invasive angiographic evaluation of coronary bypass grafts with a high diagnostic accuracy. However, the method strongly depends on the degree of vascular calcification and underrates the degree of stenosis subject to the Ca-score. This is a distinct limitation in distal vascular segments of small calibre which cannot be validly displayed. In patients with low or moderate Ca-score values, MDCT coronary angiography is promising new technique with a high diagnostic accuracy for the detection of graft stenosis or occlusions.

Assessment of the distal anastomosis of coronary artery bypass grafts with a 2D T2-weighted turbo spin echo sequence and correlation to conventional coronary angiography.

OBJECTIVE: The aim of the study was to evaluate the patency of the distal anastomoses of coronary artery bypass grafts and to detect graft stenoses and occlusions with a magnetic resonance (MR) spin echo sequence. PATIENTS AND METHODS: One hundred and eighty-five patients with 481 distal anastomoses were examined with a 1.5 T MR scanner and coronary angiography. A 2-dimensional T2-weighted breath-hold half-Fourier acquisition single-shot turbo spin echo sequence (Haste) was performed. All images were evaluated independently by a radiologist and cardiologist and compared to the conventional coronary angiography. The observers were blinded to the coronary angiography findings, but informed in regard to the surgical graft anastomosis. RESULTS: With the Haste sequence, 76% of the distal anastomoses were recognized (368/481). Forty-five of 52 (87%) stenoses and all occlusions were identified. The sensitivity and specificity for the evaluation of the distal anastomosis with the spin echo sequence was 87% and 96%. Twenty-four percent of the distal anastomoses were not identified due to a poor image quality or motion artefacts. CONCLUSION: Using the Haste sequence, a reliable assessment of graft patency of the distal anastomosis is possible. Further improvements of the spatial resolution and the image quality are necessary to recommend this MR technique for routine clinical use.

High-field MR angiography on an in vitro stenosis model determination of the spatial resolution on 1.5 and 3T in correlation to flow velocity and contrast medium concentration.

Since the first description of coronary magnetic angiography (MRA) in the early of 1990, this method seems to be shaped us a promising noninvasive modality to view the coronary arteries. Since several years dedicated high-field MR systems up to 4T are available for human use. The aim of the study was the evaluation of an in vitro vessel model with defined stenoses on 1.5T and 3T. For imaging at 3T, we used a 3d gradient-echo-sequence (fast SPGR). Furthermore, we examined the influence of the flow velocity and the contrast medium concentration on the spatial resolution. The accurate detection of in vitro stenoses was possible in segments up to 0.6 mm at 3T, the best results were obtained at a flow velocity of 40 ml/min and a contrast medium concentration of 0.2 mmol/l. The influence of the contrast medium concentration was statistically not significant. These results show that the spatial resolution can be increased by the use of a high-field MR scanner. Further in vivo studies are necessary to eliminate the method's limitation in visualizing small distal vessel segments.

Repair of recurrent coarctation using an ascending aortic autograft.

Results of aortic arch repair for interrupted aortic arch or aortic coarctation have considerably improved. However, re-stenosis or aneurysm formation is a common complication requiring complex re-interventions or even extra-anatomic bypass grafting. In two patients with recurrent coarctation, the use of cardiopulmonary bypass was mandatory, in one due to the concomitant repair of the intra-cardiac defect, in the other due to the small aortic arch, the long segment aortic coarctation and the small diameter of the supra-aortic vessels. In both patients a segment of the ascending aorta was interposed between the distal aortic arch and the proximal descending aorta with uneventful postoperative courses and freedom from pathological findings at 1 year and 6 months follow-up. In patients undergoing complex congenital heart surgery involving the ascending aorta, a segment of the autologous ascending aorta may be used to repair recurrent isthmic stenosis, avoiding the use of any foreign material.

Aortic valve replacement with the Cryolife-O'Brien stentless aortic bioprosthesis: five-year experience.

AIM: Improved hemodynamics with stentless bioprosthesis compared to stented valves have been well documented. It has been suggested that a simplified implant model, the Cryolife-O'Brien, offers less satisfactory outcomes compared with standard stentless models. This study was conducted to prospectively evaluate the midterm results after aortic valve replacement with the Cryolife-O'Brien stentless bioprosthesis. METHODS: In 1996, the prospective clinical trial using different stentless valves was initiated in our center. From September 1996 through August 2001, 132 consecutive patients with a mean age of 72.5 years underwent aortic valve replacement with the Cryolife-O'Brien porcine stentless bioprosthesis by the same surgeon. The predominant aortic valve lesion was stenosis in 110 cases and insufficiency in 22 cases. Patients have been followed-up from 2 to 60 months, mean 28 months. Echocardiography was performed by the same echocardiographer preoperatively, intraoperatively, postoperatively at discharge, 2 to 6 months later and annually thereafter. RESULTS: Sixty-five percent of patients received a valve 25 mm in diameter or larger, 42% had concomitant coronary bypass grafting. The 30-day operative mortality rate was 6.8 %. Nine late deaths, none related to the valve, have occurred. Severe aortic insufficiency caused by oversizing led to early reoperation in 3 patients. The peak and mean systolic gradients decreased significantly during the first 12 months after implantation (p<0.001) and the effective valve areas increased significantly during this time interval (p<0.001). Eleven patients have aortic insufficiency, trivial in 7 and mild in 4. The actuarial survival at 5 years was 86+/-3%. The rate for freedom from endocarditis was 100% and for freedom from thromboembolic events 92%. CONCLUSIONS: The Cryolife-OBrien stentless bioprosthesis has superior hemodynamics and a low rate of valve-related complications thus representing a very good alternative to conventional stented bioprosthesis. The midterm results are encouraging but further follow-up is needed to determine the valve's durability.

Expression of cyclooxygenase-2 in fine-needle aspirates from breast carcinoma and benign breast diseases.

Numerous studies have demonstrated that the levels of cyclooxygenase (COX), the enzyme that catalyzes the conversion of arachidonic acid to prostaglandin H(2), and of prostaglandins are higher in various tumors and cells during inflammation than in normal tissues. The aim of the present study was to analyze whether COX-2 isoform expression was noticeably higher in fine-needle aspirates (FNA) from breast carcinoma than in FNA from fibroadenoma and fibrocystic breast tissue. COX-2 expression was detected by immunocytochemical (IC) staining and was analyzed by microscopic scoring and computer gray-scale analysis. Evaluation of COX-2 IC positivity in FNA from three groups of patients (nine with breast carcinoma, nine with fibroadenoma, eight with fibrocystic breasts) revealed high COX-2 IC positivity in the majority of patients with breast carcinoma and low or absent COX-2 IC positivity in patients with fibrocystic breast changes. In addition, low or medium COX-2 IC positivity was found in the majority of patients with fibroadenoma, only three of these patients having high COX-2 IC positivity.

STR polymorphisms in the population of the island of Hvar.

The aim of this study is to analyze short tandem repeat (STR) variation using data on 9 loci (D3S1358, VWA, FGA, THO1, TPOX, CSF1PO, D5S818, D13S317, D7S820) from the subpopulations of 6 villages on the island of Hvar, Croatia. The STR data help us to analyze the genetic structure of Hvar. The analysis of STR data in this study indicated genetic homogeneity among the village subpopulations on Hvar and the lack of the so-called east-west dichotomy, which had been indicated by some previous multidisciplinary anthropological studies. The observed value of GST (0.030) is most probably a consequence of high STR mutation rates, which produce a high level of within-group (village) diversity relative to total diversity of the population. The validity of STR markers in assessing genetic structure of small populations and especially in determining the relationships among closely related and reproductively isolated groups remains to be further evaluated.

VNTR DNA variation in the population of the island of Hvar, Croatia.

The aim of this study was to investigate hypervariable DNA polymorphisms in the Croatian population. Two VNTR loci, D7S22 and D12S11, were studied in a sample of 68 inhabitants of the western and eastern regions of the island of Hvar. Binned allele frequencies and heterozygosity were calculated for the two regions and measures of genetic kinship and genetic distance were computed between the two regions and between each of these regions and nine world populations. The relatively large genetic distance between the two regions of the island of Hvar (0.0353) may reflect historical immigrations from the mainland and interesting peculiarities of the populations that arrived from the Balkan peninsula.

HLA class II gene and haplotype diversity in the population of the island of Hvar, Croatia.

The DRB1, DRB3, DRB5, DQA1 and DQB1 allele polymorphisms were analysed in 3 western and 3 eastern villages of the island of Hvar using PCR-SSOP method and 12th International Workshop primers and probes. Three DQB1 alleles (*0304, *0305, *0607) detected in the population of the island of Hvar (HP) have not yet been observed in general Croatian population (GCP). Significant differences were observed between two regions of Hvar for: a) DRB1*0701 allele (p < 0.001), b) DQA1*0201 allele (p < 0.01), and c) DRB1*0101-DQA1*0101-DQB1*0501 haplotypic association (p < 0.05). Two unusual haplotypic associations, which have not yet been described in general Croatian population (GCP), DRB1*0101-DQA1*0102-DQB1*0501 and DRB1*1501-DQA1 *0102-DQB1*0604 were observed in the population from the island of Hvar (HP). Measures of genetic kinship and genetic distances revealed isolation and clusterization which coincides with the known ethnohistorical, as well as biological and biocultural data obtained from a series of previous investigations. The five studied village subpopulations formed two clusters (East-West) to which the far eastern village (with the highest rii of 0.0407) joined later, thus indicating possible impact of historical immigrations from the mainland.

Application of HLA class II polymorphism analysis to the study of the population structure of the Island of Krk, Croatia.

The population structure of the northern Adriatic island of Krk, Croatia, was studied using PCR methodology and nonradioactive oligonucleotide hybridization for the analysis of HLA-DRB1, DRB3, DRB4, DRB5, DQA1, and DQB1 polymorphisms. Allele frequencies, genetic kinship (R), and genetic distances (E2) were computed, and correlations between distance (genetic, linguistic, geographic) and kinship (migration) matrices were examined. The results, reflecting past (micro-) evolutionary processes, indicate that ethnohistorical and sociocultural events rather than geographic distances are the primary determinants of today's population structure of the island.

Reconstituted basement membrane (Matrigel) promotes the survival and influences the growth of murine tumors.

The effects of reconstituted basement membrane (Matrigel) on in vivo survival and growth of several murine tumors were studied. Survival of tumor cells was enhanced in all experiments which resulted in increased incidence and/or in increased tumor mass. While basement membrane enhanced the in vivo growth of B16F6 melanoma cells, survival of these mice was prolonged. Basement membrane increased the incidence but reduced the growth of Ehrlich ascites tumor. Walker-256 hypercalcemic breast carcinosarcoma growth was enhanced and glandular-like structures were observed when grown on Matrigel. The results indicate that the enhanced survival of tumor cells in the presence of basement membrane is not unequivocally linked with increased malignancy.