Egg envelopes of Armadillidium vulgare (Latreille, 1804) (Crustacea, Isopoda Oniscidea): Ultrastructure and lectins binding.

The ultrastructural study carried out on (a) oocytes of Armadillidium vulgare during vitellogenesis, (b) mature eggs taken from the ovaries during the parturial moult of the posterior half of the body, and (c) fertilized eggs collected within a few hours of their release into the brood pouch, has clearly demonstrated that before the fertilization the chorion is the only envelope present in the egg of oniscidean isopods. In the mature eggs, the chorion appears as a uniformly electron-dense lamina, about 0.4-0.5 µm thick, which does not show any specialized area. A second envelope, described by other authors as vitelline envelope, is formed above the oolemma only right after fertilization and appears separated from the chorion by a space full of liquid. The ways in which the genesis of this envelope is realized are not yet clear; it could be interpreted rather as a fertilization membrane. The investigations carried out with the aid of a battery of FITC-lectins have highlighted the presence at the chorion surface of unfertilized eggs of various saccharide residues distributed in uniform way. No significant change was observed in the pattern of lectins binding to the chorion of eggs taken from the brood pouch, thus demonstrating how, after the fertilization, no significant rearrangement in the distribution of saccharide residues present on the egg surface occurs in A. vulgare. The ways in which, therefore, the recognition, the binding and the entry of the peculiar sperm of oniscidean isopods into the egg occur, still remain all to be deciphered. Microsc. Res. Tech. 79:792-798, 2016. © 2016 Wiley Periodicals, Inc.

Testis follicles ultrastructure of three species of terrestrial isopods (Crustacea, Isopoda Oniscidea).

The aim of the research, carried out on three species of terrestrial isopods - Armadillidium granulatum, Halophiloscia hirsuta and Trichoniscus alexandrae - is to bring a first consistent contribution to the knowledge of the ultrastructural organization of the testis follicles. The testis follicles are seat of a remarkable dynamic activity of their cell components (somatic cells and germ cells) that results in a continuous variation, related to the trend of spermatogenesis, of their morphology, organization and of the relationships between the two cell populations. The somatic cells, known in literature as follicular cells, nurse cells or Sertoli cells, are arranged at the periphery of the follicle to form an epithelial layer of variable thickness resting on a thin basal lamina in turn surrounded by a discontinuous network of muscle cells. In A. granulatum and H. hirsuta, two types of Sertoli cells are present: a first type, the nurse cells, envelop the spermatids in cavities within their cytoplasm and through their secretion activity play a fundamental role in the formation of the spermatophores; moreover, they phagocytizes the residual cytoplasm of spermatids. A second type of Sertoli cells shows features that leave clearly identify its supporting role to the spermatophores in formation. In T. alexandrae, instead, only one type of Sertoli cells, the nurse cell, is present, whose features are widely superimposable to those observed in the other two species. Moreover, two septa of Sertoli cells depart from the periphery of the testis follicle to constitute an articulated compartmentalization of the follicle itself, probably targeted to realize at its inside a series of microenvironments functionally diversified in order to meets the needs of the different stages of the spermatogenic cycle.

Metallothioneins and heat shock proteins 70 in Armadillidium vulgare (Isopoda, Oniscidea) exposed to cadmium and lead.

The heavy metals bioaccumulation capability in Armadillidium vulgare feeded with chestnut leaves contaminated with various sublethal concentrations of Cd and Pb, was evaluated under laboratory conditions. The metal concentration found in the hepatopancreas of treated animals, as measured by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), affected the expression and localization of MT and HSP70 as shown by immunohistochemical and western blotting analysis. The Cd content of the animals treated with the various concentrations of the metal has been always higher than that of chestnut leaves contaminated. The accumulation of Pb was, instead, always modest compared to the content of the chestnut leaves. The immunohistochemical investigation in hepatopancreas tissue of animals treated with increasing concentrations of Cd and Pb, by using the anti-MT and anti-HSP70 antibodies, has provided a response clearly positive even if differentiated in relation to the metal and concentration tested. In particular, a positive response to anti-MT antibody was detected in B and S cells nuclei and S cells cytoplasm; the localization of HSP70 was particularly intense at the cell surface. Western blotting analysis showed significant up-regulation of the expression (about 2.6 fold) of HSP70 proteins in the hepatopancreas of animals exposed to highest Pb concentrations respect to control. Moreover, samples exposed to higher Cd and Pb concentrations showed a higher expression of MT (3.2 fold and 4 fold respectively) compared to control. In summary, our data beyond to clearly demonstrate for the first time the expression of MT in terrestrial isopods, suggest that A. vulgare would be a suitable organism for assessing Cd and Pb exposure in environments threatened by metal pollution as suggested by the modulation of the biomarkers MT and HSP70.

Bioaccumulation of cadmium and lead and its effects on hepatopancreas morphology in three terrestrial isopod crustacean species.

This study was designed to compare cadmium (Cd) and lead (Pb) bioaccumulation in three species of oniscidean isopods - Armadillidium granulatum Brandt, Armadillidium vulgare (Latreille) and Porcellio laevis Latreille which were exposed for three weeks to a contaminated diet, and to determine the morphological and ultrastructural changes in hepatopancreas. Metal accumulation, determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), was linearly associated with the exposed concentration and was a function of the metal and the species tested. All three species accumulated lower levels of Pb than Cd. A. vulgare accumulated the largest concentration of Pb, especially at the higher doses, whereas P. laevis showed the greatest Cd accumulation, and the highest Cd concentration was lethal for all exposed species. The highest concentrations of Pb and Cd induced significant changes both in the general morphology of tubules and in the ultrastructural organization of epithelial cells in hepatopancreas. Some Pb/Cd induced alterations include: brush border disorganization; reduction of the basal labyrinth formed by the plasma membrane; condensation of some cytoplasm areas and of chromatin; rough endoplasmic reticulum and mitochondrial alterations; increase of secondary lysosomes and of type B granules in S cells. Some of the ultrastructural changes observed overlap with those induced by prolonged starvation, whereas others can be useful biomarkers of heavy metal toxicity. This study has confirmed that in terrestrial isopods, the accumulation of the different metals occurs in a species-specific manner; therefore ecological monitoring and assessment studies should consider each species individually. The research has confirmed that in the terrestrial isopods the accumulation of the different metals occurs in a species-specific way; therefore each species should first be evaluated in view of its employ in biomonitoring programs.

Effects of heavy metal accumulation on some reproductive characters in Armadillidium granulatum Brandt (Crustacea, Isopoda, Oniscidea).

The impact of heavy metal bioaccumulation on reproduction of the isopod Armadillidium granulatum was studied by exposing the animals to food contaminated with various sub-lethal concentrations of cadmium, lead and zinc salts over a period of three weeks. The analysis carried out by atomic absorption spectrometry on whole body and on isolated female and male genital systems highlighted that, although metal's bioaccumulation was always concentration-dependent, it varies considerably depending on the metal (Cd>Zn>Pb) as pointed out by the respective values of the concentration factor. The heavy metals bioaccumulation has influenced in different ways the reproductive characters observed; while no significant difference was found with regard to the length of the incubation period and the number of broods--A. granulatum has an iteroparous reproductive strategy--the onset and the length of the reproductive season were negatively affected by the increase in concentration of the tested metals, in particular of Cd. The rate of gravid females, instead, was negatively affected by the bioaccumulation of Cd and Zn while in the groups treated with the highest concentrations of Pb all females produced at least one brood. The number of juveniles released from the brood pouch at the end of incubation resulted considerably higher and it was always positively correlated to the increase of the concentration of each metal, except for the highest Pb concentration. The explanation of this result, apparently anomalous, could be the object of a future research.

Presence of F-actin in sperm head of Armadillidium peraccae (Isopoda, Oniscidea).

Sperm of Armadillidium peraccae have been examined with cytochemical and immunocytochemical methods for fluorescence and electron microscopic visualization of cytoskeleton components. Sperm incubation in an antibody anti-ß-tubulin shows only the presence of two centrioles located in the cytoplasmic region above the nucleus; no other microtubules are present in the sperm head. Instead, fluorescence microscopy of sperm incubated in FITC-phalloidin allowed to detect the presence of a large amount of F-actin in the apical region of the sperm head. The incubation of ultrathin sections of sperm embedded in Lowicryl K4M with a phalloidin-gold complex allowed a more precise localization of F-actin in the amorphous part of the acrosome and in the cytoplasmic region between acrosome and nucleus; F-actin is also present in the thin cytoplasmic layer between plasma membrane and nuclear envelope at the apical portion of the nucleus. Although the sperm was always found completely devoid of motility, the discovery of the presence of an actin cytoskeleton leads us to hypothesize a possible acquisition of motility by the sperm at the time of its interaction with the female gamete. Such a hypothesis is supported by what is known for ostracods whose aflagellate sperm implement a type of amoeboid movement only at the time of their interaction with the female gamete.

Double subepicardial aneurysm after myocardial infarction.

The echocardiogram of 68-year old man, admitted with an acute myocardial re-infarction revealed the presence, in the middle-apical region of the lateral wall, of two little and contiguous subepicardial aneurysms.

Composite lengthened arterial conduits: long-term angiographic results of an uncommon surgical strategy.

BACKGROUND: We sought to evaluate the long-term patency rate of composite lengthened conduits. METHODS AND RESULTS: From December 1991 to April 2000, 43 patients had a composite lengthened arterial conduit. There was a mean of 2.83 +/- 1.23 anastomoses per patient. No 30-day mortality occurred. Five patients died from 3 to 84 months after the operation (mean, 38.6 +/- 34.6 months). After a mean follow-up of 57.0 +/- 32.3 months (range, 3-99 months), all the survivors are asymptomatic. The only cardiac major events recorded were 2 (4.6%) late acute myocardial infarctions in the patients who died. Eight-year survival and event-free survival were both 80.4% +/- 9.1% (range, 3%-93%). In the early period (13.5 +/- 4.8 days) in 26 patients, 26 arterial composite lengthened conduits and 37 distal anastomoses had postoperative angiographic control; all the anastomoses were rates as grade A, according to Fitzgibbon classification. In the late period (29 +/- 30 months) in 23 patients, 23 arterial composite lengthened conduits and 34 distal anastomoses were checked; the patency rate was 22 (95.6%) of 23 for the composite lengthened conduits and 33 (97%) of 34 for the distal anastomoses. CONCLUSIONS: In particular situations, when the length of an arterial conduit is not enough to allow a correct use of the graft, lengthening of an arterial conduit can be a safe and effective technique.

Radial artery for myocardial revascularization: long-term clinical and angiographic results.

BACKGROUND: To evaluate the long-term clinical and angiographic results of the radial artery (RA) as a graft in coronary artery bypass surgery. METHODS: One hundred sixty-four patients had a RA graft from July 1992 to July 1994. In 128 (group A) the RA was connected end to side (115) or end to end (13) to the left internal mammary artery. In 36 (group B) the proximal anastomosis was on the ascending aorta. RESULTS: Early mortality was 1.8% (group A 1.6% and group B 2.8%). Eight-year survival was 83.2%+/-3.2% (group A 82.1%+/-3.8% and group B 86.7%+/-6.2%, p = not significant [NS]), and event free survival was 80.1%+/-3.5% (group A 79.9%+/-4.4% and group B 80.2%+/-7.3%, p = NS). Sixty-one patients (37.2%) had an early angiography within 90 days from the operation. Patency rate of RA distal anastomoses were 98.9% (88 of 89), 98.7% in group A (77 of 78), 100% in group B (11 of 11; p = NS). After a mean of 48+/-27 months (6 to 96), 72 patients (51.1% of the survivors) had a new angiography. Patency rate of RA distal anastomoses was 95.6% (87 of 91), 93.8% in group A (61 of 65) and 100% in group B (26 of 26; p = NS). All the intermediate RA-LIMA anastomoses were patent at the early and late control. Patency rate for RA and IMAs was similar both early (88 of 89 versus 82 of 82; p = NS) and after 48+/-27 months (87 of 91 versus 93 of 93; p = NS). CONCLUSIONS: Long-term clinical results after RA grafting are satisfying. Angiographic patency rate, both early and after 48 months, is higher than 90% and is similar to that obtained with internal mammary arteries. The site of the proximal anastomosis does not influence early and late patency.

Mitral valve procedure in dilated cardiomyopathy: repair or replacement?

BACKGROUND: Mitral valve (MV) procedure for dilated cardiomyopathy is becoming popular. We analyzed the indications to MV repair or replacement according to our 10-year experience. METHODS: From January 1990 to May 2000, 49 patients with dilated cardiomyopathy (12 idiopathic and 37 ischemic) underwent MV operation, 29 repair and 20 replacement. Preoperative evaluation included measurement of MV coaptation depth (CD) as a mirror of the abnormalities of MV apparatus leading to functional mitral regurgitation. RESULTS: Thirty-day mortality was 4.2% (2 patients). One-, 3-, 5-, and 10-year actuarial survival was, respectively, 90%, 87%, 78%, and 73%. The possibility of survival with at least one New York Heart Association functional class improvement was 88%, 76%, 71%, and 65%. Return of functional mitral regurgitation after MV repair was nearly inevitable; however, using a scale from 0 to 4, mean postoperative functional mitral regurgitation was 1.2+/-0.8 when preoperative MVCD was 10 mm or less and 2.5+/-0.7 when preoperative MVCD was 11 mm or higher (p < 0.05). Globally, functional results were not influenced by the strategy of treatment (MV repair or replacement). CONCLUSIONS: Mitral valve operation can give satisfying survival and good palliation of dilated cardiomyopathy. The MVCD can be helpful in the choice of the surgical strategy on the MV.

Bilateral internal thoracic artery grafting: long-term clinical and angiographic results of in situ versus Y grafts.

BACKGROUND: We evaluated whether bilateral internal thoracic arteries provide the same long-term results when used as in situ grafts and as Y grafts. METHODS AND RESULTS: From October 1991 to February 2000, 1818 patients had bilateral internal thoracic arteries used as in situ (n = 1378, group A) or as Y grafts (n = 440, group B). The number of anastomoses per patient and the number of bilateral internal thoracic artery anastomoses per patient were higher in group B (3.1 +/- 0.9 and 2.7 +/- 0.9) than in group A (2.9 +/- 0.8 and 2.2 +/- 0.6) (both P <.001). The number of right internal thoracic artery anastomoses per patient rose from 1.0 +/- 0. 3 in group A to 1.4 +/- 0.6 in group B (P <.001), and the number of sequential anastomoses per right internal thoracic artery graft rose from 4.1% to 34.3% (P <.001). Thirty-day mortality was 2.0% in group A versus 2.5% in group B (P = not significant). No difference in postoperative course was detected. Eight-year survivals were 95.8% +/- 2.7% in group A versus 94.8% +/- 4.0% in group B (P = not significant), and event-free survivals were 95.2% +/- 2.9% in group A versus 93.6% +/- 4.4% in group B (P = not significant). Early angiograms were obtained in 295 patients (945 anastomoses, 863 distal and 82 proximal Y grafts), 213 patients (611) in group A and 82 patients (334) in group B. Patency rate was 98.8% in group A and 96.0% in group B (P = not significant), whereas grade A patency rate was 97.2% in group A and 96.4% in group B (P = not significant). Late angiograms were obtained in 88 patients (25 in group A and 63 in group B) at a mean of 17.5 +/- 18.4 months: patency rate was 100% in group A and 99.2 in group B (P = not significant), and grade A patency rate was 98.6% in group A and 98.8% in group B (P = not significant). No Y anastomosis was occluded or stenosed. COMMENT: Survival, incidence of cardiac events, and angiographic patency in the early and late phases are similar for bilateral internal thoracic arteries used either in situ or as Y grafts. However, Y grafting with bilateral internal thoracic arteries increases the number of anastomoses per bilateral thoracic artery, as well as the flexibility of the right internal thoracic artery.

Off-pump myocardial revascularization using arterial conduits without cardiopulmonary bypass.

OBJECTIVE: The feasibility of myocardial revascularization via a median sternotomy with arterial conduits, without and with cardiopulmonary bypass (CPB), was evaluated. MATERIAL AND RESULTS: From May 21, 1997, to November 30, 1999, 721 patients had myocardial revascularization without CPB via median sternotomy using at least two arterial conduits. The procedure was performed without CPB in 322 patients (Group A); the remaining 399 patients (Group B) underwent the same operation with the aid of CPB. Group A patients were older, with a higher ejection fraction and less redo than Group B. There was no early death in Group A versus nine (2.3%) patients in Group B (p < 0.02). Incidence of cerebrovascular accident (CVA) and acute myocardial infarction (AMI) were similar in both groups. Early major events incidences were 1.2% versus 8.0% (p < 0.001) in Groups A and B, respectively. Postoperative angiographic controls showed a cumulative patency rate of 98.4% and a perfect patency rate of 96.7%. After 30 months, Groups A and B showed an actuarial survival of 98.1 +/- 0.7 and 96.5 +/- 2.8 (p = ns) and an event-free survival of 96.6 +/- 1.0 and 96.5 +/- 2.8 (p = ns), respectively. CONCLUSION: Myocardial revascularization without CPB using arterial conduits can be accomplished with the same quality of results obtained with the use of CPB.

Current results in off pump surgery.

OBJECTIVE: We reviewed our experience with myocardial revascularization without cardiopulmonary by-pass (CPB) to evaluate early- and mid-term results compared with those obtained using CPB. METHODS: From May 21, 1997 to November 1998, 747 patients had isolated myocardial revascularization, 480 without CPB (Group A) and 267 with CPB (Group B). Exposure of the target vessels was obtained with four slings (two passed through the transverse sinus and two behind the inferior vena cava) and four deep pericardial sutures on the mobile pericardium around the left atrium (Lima stitches). The number of anastomoses/patient (when two or more conduits were used) was higher in Group B (3.1 +/- 1.0 vs 2.6 +/- 0.7, P < 0.001). More marginal branches were grafted in Group A (258 vs 239), but the percentage was higher in Group B (P < 0.001). Crude and risk adjusted mortality was similar in both groups, as well as cerebrovascular accident (CVA) and acute myocardial infarction incidences. Patients in Group A woke earlier, had less inotropes, lower creatinkinase myocardial band (CK-MB) peak, lower bleeding and less transfusion, shorter Intensive Care Unit (ICU) and postoperative stay in hospital than patients in Group B. 266 anastomoses were checked; of these 98.5% were patent and 97.0% were patent and not restrictive. CONCLUSIONS: Myocardial revascularization without CPB can provide good early- and mid-term results in selected patients. Primary endpoints (death and acute myocardial infarction) were similarly independent from the technique used. Some of the secondary endpoints were favorable in Group A: however their importance is minor. Even if we feel that some high risk patients with severe comorbidities can benefit from CPB surgery; this aspect is difficult to demonstrate scientifically.

Bilateral internal mammary artery grafting: midterm results of pedicled versus skeletonized conduits.

BACKGROUND: To increase the number of anastomoses per patient, bilateral internal mammary arteries (BIMAs) were harvested with a skeletonized approach instead of a pedicled one. METHODS: One thousand one hundred forty-six patients underwent isolated myocardial revascularization using BIMAs, 304 receiving pedicled grafts (group A, October 1991 through May 1994) and 842 receiving skeletonized conduits (group B, June 1994 through June 1998). Group B had a higher incidence of patients with diabetes (223 versus 40, p < 0.001). RESULTS: The number of BIMA anastomoses per patient was significantly higher in group B (2.4 +/- 0.3 versus 2.1 +/- 0.4, p < 0.001), as well as the number of sequential grafts (288 versus 42, p < 0.001). Twenty-three patients (2.0%) died in the first 30 days after surgery, 5 in group A (1.6%) and 18 in group B (2.1%) (not significant). Postoperative complications were similar in both groups; the incidence of sternal wound healing problems was higher as a whole and with regard to diabetic patients (4 of 40 [10%] versus 5 of 223 [2.2%], p < 0.05) in group A. Seventy-one patients in group A and 133 (15.8%) in group B underwent a postoperative angiography. Patency rate was similar, both early (100% in group A versus 98.6% in group B, not significant) and late (98.6% in group A versus 98.4% in group B, not significant). CONCLUSIONS: The use of skeletonized BIMA conduits allowed us to increase the number of BIMA anastomoses per patient with a lower rate of sternal wound complications and angiographic results similar to those obtained with pedicled BIMA conduits.

Multiple arterial conduits without cardiopulmonary bypass: early angiographic results.

BACKGROUND: Lack of angiographic results and technical difficulty in grafting the vessels in the lateral and posterior walls have reduced interest in myocardial revascularization without cardiopulmonary bypass (CPB). We describe our experience to demonstrate the feasibility of coronary surgical intervention without CPB in multivessel disease. METHODS: From May 21, 1997, through February 1998, 227 patients underwent revascularization with two or more arterial conduits as the first operation: 122 without CPB (group A) and 105 with CPB (group B). Group A included a greater number of high-risk patients. RESULTS: Mean +/- SD anastomoses per patient were 2.5 +/- 0.6 in group A and 2.8 +/- 0.8 in group B (p = NS). No patient died in group A, whereas 1 patient (0.9%) died in group B. The postoperative complication rate was low in both groups, but intensive care unit and in-hospital stays were shorter in group A than in group B (14.1 +/- 7.1 versus 27.3 +/- 36 hours, p < 0.001, and 4.1 +/- 1.6 versus 5.4 +/- 2.4 days, p < 0.001, respectively [group A versus group B]). Sixty-seven patients in Group A (54.9%) underwent postoperative angiography 33 +/- 35 days after operation. The patency rate was 98.9% (98.2% for the marginal branches). CONCLUSIONS: Arterial revascularization of the coronary arteries without CPB is feasible, with results similar to those obtained with CPB. The two techniques, in our opinion, are complementary, not antagonistic.

Minimally invasive mammary artery Doppler flow velocity evaluation in minimally invasive coronary operations.

BACKGROUND: Left internal mammary artery Doppler flow velocity assessment during the Azoulay maneuver (patient's legs are passively lifted up and actively maintained by the patient) can increase the information on the anastomosis quality after left internal mammary artery to left anterior descending coronary artery grafting after the left anterior, small thoracotomy operation. METHODS: One hundred patients had an early postoperative angiography and a Doppler flow velocity assessment at rest and during the Azoulay maneuver. Peak and mean systolic velocities, peak and mean diastolic velocities, and peak and mean diastolic to systolic velocity ratios were recorded in all patients. RESULTS: In 95 patients with no restrictive conduit or anastomosis, peak and mean diastolic to systolic velocity ratios increased during the Azoulay maneuver; all but 1 patient showed at least one ratio equal to or greater than 1. In 4 patients with restrictive conduit or anastomosis, peak and mean diastolic to systolic velocity ratios were always less than 1 during the Azoulay maneuver. In the patient with an occluded conduit these ratios were less than 0.6. CONCLUSIONS: Peak and mean diastolic to systolic velocity ratios less than 1 during the Azoulay maneuver are suggestive of conduit or anastomosis malfunction. If we limit the angiographic controls to these patients, it is very likely that a pathologic anastomosis or conduit will not be missed.

The LAST operation: techniques and results before and after the stabilization era.

BACKGROUND: Left anterior descending artery stabilization allows performance of left internal mammary artery grafting via a left anterior small thoracotomy on a beating heart. Our surgical experience was reviewed to assess if surgical results have improved as result of specialized instrumentation. METHODS: Of 545 patients who had the left anterior small thoracotomy operation, 261 underwent this procedure for single left anterior descending artery disease. Two groups were considered, before and after the use of specialized instrumentation: group A (n = 93), operated on from November 21, 1994, to April 20, 1996; and group B (n = 168), operated on from April 21, 1996, to December 1997. RESULTS: Early mortality was similar in the two groups. The further revascularization (operation or percutaneous transluminal coronary angioplasty) and the rate of occlusion of the conduit were higher in group A, whereas anastomotic or conduit malfunction was not. Cumulating angiography and Doppler flow evaluation, 92.5% of the anastomoses in group A and 98.8% in group B (p = 0.026) were patent, and 90.3% in group A and 97.6% in group B (p = 0.031) were patent and not restrictive. At 19 months, survival was similar, but the event-free survival was higher in group B. CONCLUSIONS: Both left anterior descending artery stabilization and safer left internal mammary artery harvesting contributed to improve angiographic and clinical results after the left anterior small thoracotomy operation.

Recent advances in multivessel coronary grafting without cardiopulmonary bypass.

BACKGROUND: Coronary artery bypass grafting (CABG) without the heart lung machine has been possible for easily accessible targets such as the anterior descending or proximal right coronary. Until now technical difficulty in reaching lateral and inferior wall targets imposed significant barriers to multivessel off-pump grafting. To expand the potential for off-pump CABG the authors have devised new exposure and stabilization techniques suitable for all target vessels. In this report we relate our experience with these new techniques and demonstrate that multivessel coronary bypass can be safely performed without cardiopulmonary bypass (CPB). METHODS: From February 8, 1993 to December 16, 1997 a total of 280 patients underwent myocardial revascularization on the beating heart via median sternotomy. Until May 20, 1997 only patients with high preoperative risk factors for CPB were considered for this approach (Group A; N = 122). After this date any patients with favorable anatomy were included (Group B; N = 158) and were subsequently compared with patients operated on using CPB during the same time interval (Group C; N = 114). In Group B patients lateral and/or inferior wall targets were exposed by means of 4 cloth slings (2 through the transverse sinus and 2 behind the inferior vena cava) and by positioning the patients in Trendelenburg with rightward rotation of the table. Regional stabilization of the target artery was obtained with a commercial stabilizing foot plate. RESULTS: Thirty day hospital mortality was only 2 patients (1.6%) in Group A, 3 patients (1.9%) in Group B, and 3 patients (2.6%) in Group C (NS). Postoperative complications were low in both Group A and B. When Group B was compared with a similar cohort in whom CPB was used (Group C), there were statistically significant improvements in ICU and hospital stay demonstrated when CPB was not used (16.8+/-10.7 vs 26.3+/-38.6 hours respectively; p = 0.007, and 4.1+/-1.5 vs 5.5+/-2.4 days respectively, p<0.001). Angiographic followup was available for 78 patients in Groups A and B with a global patency rate (all grafts) of 98.6%, including a patency rate of 96.7% for 60 grafts to obtuse marginal branches of the circumflex). CONCLUSIONS: Multivessel CABG without CPB is possible with results similar to those obtained with pump-oxygenator support using simple exposure and stabilization techniques.

Left anterior small thoracotomy (LAST): mid-term results in single vessel disease.

BACKGROUND: Left anterior descending artery grafting using the left internal mammary artery via a left anterior small thoracotomy (LAST) gained new popularity in 1994. We review our experience in 250 of 512 patients who underwent a LAST in single vessel left anterior descending artery disease from November 1994 to October 1997. METHODS: Left anterior descending artery stabilization was obtained pharmacologically and mechanically. Two patients (0.8%) had percutaneous transluminal coronary angioplasty at a mean of 23 +/- 5 days; 172 (68.8%) patients had early postoperative angiography. RESULTS: Eight conduits were occluded (patency rate 95.3%). There was only one late death. Cumulative angiography and Doppler flow evaluation showed that 96.8% of the anastomoses were patent and 95.6% were both patent and nonrestrictive. At a mean follow-up of 16.3 +/- 9.3 months, 9 (3.6%) patients had redo-surgery due to anastomotic/conduit failure and 249 (99.6%) patients were alive and asymptomatic. No patients had acute myocardial infarction. The 35-month actuarial survival rate was 99.6% +/- 0.4%, and the event-free survival rate for the entire experience was 93.7% +/- 1.3%. If only the last 157 patients are considered, at 18 months event-free survival was higher than in the entire group of patients (96.4% +/- 1.4% vs 93.7% +/- 1.3%, p = 0.05). CONCLUSIONS: New instrumentation has made the operation easier and has contributed to its spread, along with increased experience and the end of the learning curve. At the moment we consider the LAST a more anatomical and physiological surgical approach to single vessel coronary disease.