Impact of the Lumbar Arteries on Aneurysm Diameter and Type 2 Endoleak after Endovascular Aneurysm Repair

BACKGROUND

Prophylactic embolization of the inferior mesenteric artery (IMA) during endovascular aneurysm repair (EVAR) is recommended to prevent type 2 endoleak (T2EL). However, the impact of patent lumbar arteries (LAs) on T2ELs and aneurysm diameter has not been elucidated.

METHODS

Fifty-seven consecutive patients who underwent EVAR at our institution between January 2013 and September 2022 and whose IMA had been occluded preoperatively or newly occluded postoperatively were included in the study. Predictive factors for aneurysm sac enlargement, sac shrinkage, and T2EL were investigated.

RESULTS

T2ELs occurred in 22.8% of the patients. The 4-year cumulative incidence rates of sac enlargement and shrinkage were 6.7% and 64.6%, respectively. The number of postoperative patent LAs was identified as a risk factor for T2ELs (95% confidence interval [CI]: 1.54-12.7, P = 0.0065). The number of postoperative patent LAs was found to be a significant predictor of sac enlargement (adjusted hazard ratio [AHR] 3.15, 95% CI: 1.43-6.96, P = 0.0045) and shrinkage (AHR 0.63, 95% CI: 0.43-0.91, P = 0.014).

CONCLUSIONS

The current study demonstrated that the number of postoperative patent LAs had a significant impact on the development of T2ELs and the change in aneurysm diameter in patients in whom the IMA was occluded after EVAR.

Life Expectancy of Patients With Severe Aortic Stenosis in Relation to Age and Surgical Risk Score

BACKGROUND

There is a paucity of data regarding shorter life expectancy after aortic valve replacement (AVR) in patients with severe aortic stenosis (AS).

METHODS

Among 3815 patients with severe AS enrolled in the CURRENT AS (Contemporary outcomes after sURgery and medical tREatmeNT in patients with severe Aortic Stenosis) registry, there were 1469 patients (initial AVR: n = 647; conservative strategy: n = 822) with low surgical risk, 1642 patients (initial AVR: n = 433; conservative strategy: n = 1209) with intermediate surgical risk, and 704 patients (initial AVR: n = 117; conservative strategy: n = 587) with high surgical risk. Among 1163 patients who actually underwent surgical AVR as the initial strategy, patients were divided into 4 groups according to age <65 years (n = 185), 65 to 74 (n = 394), 75 to 80 (n = 345), and >80 (n = 239). The expected survival of the general Japanese population was obtained from the Statistics Bureau of Japan. The surgical risk was estimated using The Society of Thoracic Surgery (STS) score.

RESULTS

The median follow-up was 3.7 years. The cumulative incidences of all-cause death were significantly lower in the initial AVR strategy than in the initial conservative strategy across the 3 STS groups. Shorter life expectancy after surgical AVR was seen especially in younger patients. The observed mortality in low-risk patients was comparable to the expected mortality across all the age-groups, while intermediate-risk patients aged <75 years, and high-risk patients across all age-groups had higher mortality compared with the expected mortality.

CONCLUSIONS

The risk stratification according to age and STS score might be useful to estimate shorter life expectancy after AVR, and these findings have implications for decision making in the choice of surgical or transcatheter AVR.

Percutaneous coronary intervention using new-generation drug-eluting stents versus coronary arterial bypass grafting in stable patients with multi-vessel coronary artery disease: From the CREDO-Kyoto PCI/CABG registry Cohort-3

Aims

There is a scarcity of studies comparing percutaneous coronary intervention (PCI) using new-generation drug-eluting stents (DES) with coronary artery bypass grafting (CABG) in patients with multi-vessel coronary artery disease.

Methods and results

The CREDO-Kyoto PCI/CABG registry Cohort-3 enrolled 14927 consecutive patients who underwent first coronary revascularization with PCI or isolated CABG between January 2011 and December 2013. The current study population consisted of 2464 patients who underwent multi-vessel coronary revascularization including revascularization of left anterior descending coronary artery (LAD) either with PCI using new-generation DES (N = 1565), or with CABG (N = 899). Patients in the PCI group were older and more often had severe frailty, but had less complex coronary anatomy, and less complete revascularization than those in the CABG group. Cumulative 5-year incidence of a composite of all-cause death, myocardial infarction or stroke was not significantly different between the 2 groups (25.0% versus 21.5%, P = 0.15). However, after adjusting confounders, the excess risk of PCI relative to CABG turned to be significant for the composite endpoint (HR 1.27, 95%CI 1.04–1.55, P = 0.02). PCI as compared with CABG was associated with comparable adjusted risk for all-cause death (HR 1.22, 95%CI 0.96–1.55, P = 0.11), and stroke (HR 1.17, 95%CI 0.79–1.73, P = 0.44), but with excess adjusted risk for myocardial infarction (HR 1.58, 95%CI 1.05–2.39, P = 0.03), and any coronary revascularization (HR 2.66, 95%CI 2.06–3.43, P<0.0001).

Conclusions

In this observational study, PCI with new-generation DES as compared with CABG was associated with excess long-term risk for major cardiovascular events in patients who underwent multi-vessel coronary revascularization including LAD.

Modifiers of the Risk of Diabetes for Long-Term Outcomes After Coronary Revascularization: CREDO-Kyoto PCI/CABG Registry

BACKGROUND

Diabetes is a well-known risk factor for adverse outcomes after coronary revascularization.

OBJECTIVES

This study sought to determine high-risk subgroups in whom the excess risks of diabetes relative to nondiabetes are particularly prominent and thus may benefit from more aggressive interventions.

METHODS

The study population consisted of 39,427 patients (diabetes: n = 15,561; nondiabetes: n = 23,866) who underwent first percutaneous coronary intervention (n = 33,144) or coronary artery bypass graft (n = 6,283) in the pooled CREDO-Kyoto PCI/CABG (Coronary Revascularization Demonstrating Outcome Study in Kyoto Percutaneous Coronary Intervention/Coronary Artery Bypass Graft) registry. The primary outcome measure was major adverse cardiovascular and cerebral endpoints (MACCE), which was defined as a composite of all-cause death, myocardial infarction, and stroke.

RESULTS

With median follow-up of 5.6 years, diabetes was associated with significantly higher adjusted risks for MACCE. The excess adjusted risks of diabetes relative to nondiabetes for MACCE increased with younger age (≤64 years: adjusted HR: 1.30; 95% CI: 1.19-1.41; P < 0.001; 64-73 years: adjusted HR: 1.24; 95% CI: 1.16-1.33; P < 0.001; >73 years: adjusted HR: 1.17; 95% CI: 1.10-1.23; P < 0.001; P _interaction < 0.001), mainly driven by greater excess adjusted mortality risk of diabetes relative to nondiabetes in younger tertile. No significant interaction was observed between adjusted risk of diabetes relative to nondiabetes for MACCE and other subgroups such as sex, mode of revascularization, and clinical presentation of acute myocardial infarction.

CONCLUSIONS

The excess risk of diabetes relative to nondiabetes for MACCE was profound in the younger population. This observation suggests more aggressive interventions for secondary prevention in patients with diabetes might be particularly relevant in younger patients.

Inhaled nitric oxide improves pulmonary hypertension and organ functions after adult heart valve surgeries

OBJECTIVES

Pulmonary hypertension during cardiac surgery is associated with increased morbidity and mortality. Inhaled nitric oxide serves as a selective pulmonary vasodilator and has other potential extrapulmonary protective roles. Its effects on pulmonary hypertension and organ functions after adult valve surgeries were evaluated.

METHODS

From April 2017 to March 2000, 30 patients received inhaled nitric oxide therapy for pulmonary hypertension during weaning from cardiopulmonary bypass in valvular surgery (iNO group). The group was compared with a control group of 65 patients who developed pulmonary hypertension during weaning from cardiopulmonary bypass in valvular surgery and received conventional therapy from April 2014 to March 2017. Intraoperative hemodynamic changes and postoperative Sequential Organ Failure Assessment (SOFA) score were evaluated.

RESULTS

The inhalation of nitric oxide lowered the pulmonary-to-systemic pressure ratio (Pp/Ps) (p < 0.0001) in the iNO group, and this ratio after the inhalation was significantly lower than that in the control group (p = 0.015). Moreover, norepinephrine requirement was lower in the iNO group than in the control group (p = 0.0060). The SOFA total scores, respiratory scores, coagulation scores, and the increase of renal scores within postoperative 2 days were lower in the iNO group than in the control group (p < 0.0001, p = 0.0002, p = 0.0013, and p = 0.037).

CONCLUSIONS

Inhaled nitric oxide therapy ameliorated pulmonary hypertension and improved postoperative respiratory, coagulation, and renal functions in adult valve surgeries.

Comparison of Outcomes of Percutaneous Coronary Intervention Versus Coronary Artery Bypass Grafting Among Patients With Three-Vessel Coronary Artery Disease in the New-Generation Drug-Eluting Stents Era (From CREDO-Kyoto PCI/CABG Registry Cohort-3)

There is a scarcity of data comparing long-term clinical outcomes between percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in patients with three-vessel coronary artery disease (3VD) in the new-generation drug-eluting stents era. CREDO-Kyoto PCI/CABG registry Cohort-3 enrolled 14927 consecutive patients who had undergone first coronary revascularization with PCI or isolated CABG between January 2011 and December 2013. We identified 2525 patients with 3VD (PCI: n = 1747 [69%], and CABG: n = 778 [31%]). The primary outcome measure was all-cause death. Median follow-up duration was 5.7 (interquartile range: 4.4 to 6.6) years. The cumulative 5-year incidence of all-cause death was significantly higher in the PCI group than in the CABG group (19.8% vs 13.2%, log-rank p = 0.001). After adjusting confounders, the excess risk of PCI relative to CABG for all-cause death remained significant (HR, 1.45; 95% CI, 1.14 to 1.86; p = 0.003), which was mainly driven by the excess risk for non-cardiovascular death (HR, 1.88; 95% CI, 1.30 to 2.79; p = 0.001), while there was no excess risk for cardiovascular death between PCI and CABG (HR, 1.19; 95% CI, 0.87 to 1.64; p = 0.29). There was significant excess risk of PCI relative to CABG for myocardial infarction (HR, 1.77; 95% CI, 1.19 to 2.69; p = 0.006), whereas there was no excess risk of PCI relative to CABG for stroke (HR, 1.24; 95% CI, 0.83 to 1.88; p = 0.30). In conclusion, in the present study population reflecting real-world clinical practice in Japan, PCI compared with CABG was associated with significantly higher risk for all-cause death, while there was no excess risk for cardiovascular death between PCI and CABG.

Clinical Outcomes of the David V Valve-Sparing Root Replacement Compared With Bioprosthetic Valve-Conduits for Aortic Root Aneurysms

BACKGROUND

Valve-sparing root replacement (VSRR) is an established therapy for aortic root pathology. Limited insight exists when the results of VSRR are compared with those of conventional root replacement with use of a bioprosthetic composite conduit (BIO). This study compares the operative and midterm results of VSRR and BIO.

METHODS

A retrospective review from 2002 to 2015 at a United States academic center identified 282 patients who underwent VSRR and 425 patients who underwent BIO. Propensity-score matching was performed based on 20 preoperative characteristics, and 123 matched pairs were identified.

RESULTS

The mean age (VSRR 53.5 ± 11.1, BIO 53.0 ± 13.0; p = 0.74) and left ventricular ejection fraction (VSRR 54.5 ± 9.2%, BIO 54.4 ± 9.4%; p = 0.99) were equivalent in both groups. The incidence of bicuspid valves (VSRR 26.0%, BIO 27.6%; p = 0.77), Marfan syndrome (VSRR 6.5%, BIO 4.9%; p = 0.58), type A dissection (VSRR 13.0%, BIO 13.0%; p = 0.99), reoperation (VSRR 15.4%, BIO 20.3%; p = 0.32) and arch replacement (VSRR 60.2%, BIO 63.4%; p = 0.60) were similar between the groups. Operative mortality was 5.7% in VSRR and 0.8% in BIO (p = 0.07). There were no significant differences in postoperative renal failure (VSRR 0.8%, BIO 0.0%; p = 0.99) or stroke (VSRR 3.3%, BIO 0.8%; p = 0.37) between the groups. The 7-year survival (VSSR 82.4%, BIO 83.0%; p = 0.53), 7-year freedom from reoperation (VSRR 97.4%, BIO 95.8%; p = 0.48), and 7-year freedom from greater than moderate aortic insufficiency (AI) (VSRR 98.1%, BIO 100.0%; p = 0.47) were similar between groups.

CONCLUSIONS

VSRR and BIO result in equivalent operative mortality and morbidity with similar midterm survival and valve durability. VSRR is an effective alternative to BIO for aortic root pathologic conditions; however, careful patient selection is paramount.

The David V Valve-Sparing Root Replacement Provides Improved Survival Compared With Mechanical Valve-conduits in the Treatment of Young Patients With Aortic Root Pathology

BACKGROUND

Valve-sparing root replacement (VSRR) is an attractive therapy for aortic root aneurysms; however, there is a paucity of data comparing VSRR with conventional root replacement using a mechanical valve-conduit (MECH). This study evaluates and compares outcomes of VSRR and MECH.

METHODS

A retrospective review from 2002 to 2015 at a US academic center identified 444 patients who underwent VSRR (282 patients) or MECH (162 patients). Propensity score matching was performed, based on 22 preoperative and intraoperative characteristics, and 87 matched pairs were identified.

RESULTS

There was no difference in mean age between the groups (VSRR 45.0 years, MECH 44.2 years, p = 0.59). The incidence of Marfan syndrome (VSRR 10.3%, MECH 12.6%, p = 0.63), type A acute aortic dissection (VSRR 25.3%, MECH 27.6%, p = 0.73), reoperation (VSRR 23.0%, MECH 21.8%, p = 0.86), and arch replacement (VSRR 54.0%, MECH 52.9%, p = 0.88) were similar in both groups. Ejection fraction was similar (VSRR 52.8% ± 10.9%, MECH 52.4% ± 11.7%, p = 0.83). Operative mortality was 2.3% with VSRR and 8.0% with MECH (p = 0.10). There were no significant differences in renal failure requiring dialysis (VSRR 1.1%, MECH 4.6%, p = 0.24), permanent neurologic dysfunction (VSRR 2.3%, MECH 6.9%, p = 0.16), and pacemaker implantation (VSRR 1.1%, MECH 1.1%, p = 0.99) between the groups. Survival at 7 years was significantly improved in patients who underwent VSSR (VSRR 85.5%, MECH 73.6%, p = 0.03).

CONCLUSIONS

In comparison with patients undergoing MECH, there is improved midterm survival among patients undergoing VSRR, with similar operative mortality and morbidity. For appropriately selected patients, VSRR provides an attractive and potentially superior alternative to MECH.

Therapeutic treatment with sustained-release platelet-rich plasma restores blood perfusion by augmenting ischemia-induced angiogenesis and arteriogenesis in diabetic mice

OBJECTIVE

The objective of this investigation was to establish the effectiveness of sustained-release platelet-rich plasma (PRP) on perfusion and neovascularization in diabetic murine hind limb ischemia.

METHODS

After surgery in streptozotocin-induced diabetic mice, the mice were randomly assigned to the following 4 experimental groups: control (C), 100 μl of the sustained-release form of platelet-poor plasma (PPP), 100 μl of the solution form of PRP (PRP-sol), and 100 μl of the sustained-release form of PRP (PRP-sr). Endpoint evaluations were: blood perfusion by laser Doppler perfusion imaging (LDPI), vascular density by anti-vWF, and mature vessel density by anti-smooth muscle actin antibody.

RESULTS

This study demonstrated that a sustained release of PRP increases the perfusion of ischemic tissue as measured by LDPI (57 ± 12; 56 ± 9; 72 ± 7, and 98 ± 4 for the C, PPP, PRP-sol, and PRP-sr groups, respectively; p < 0.05), capillary density (151 ± 16; 158 ± 12; 189 ± 39, and 276 ± 39 for groups C, PPP, PRP-sol, and PRP-sr, respectively; p < 0.05), and mature vessel density (28 ± 2; 31 ± 3; 52 ± 10, and 85 ± 13 for the C, PPP, PRP-sol, and PRP-sr groups, respectively; p < 0.05).

CONCLUSION

A sustained release of PRP containing potent angiogenic growth factors restores blood perfusion by stimulating angiogenesis and arteriogenesis.

Angiogenic properties of sustained release platelet-rich plasma: characterization in-vitro and in the ischemic hind limb of the mouse

BACKGROUND

While single growth factor has limitation to induce optimal neovascularization, platelet-rich plasma (PRP) is an autologous reserver of various growth factors. However, little is known about the mechanism of PRP-related neovascularization.The objective of this investigation was to characterize the angiogenic and growth factor content of PRP and to determine, in vitro, its effect on endothelial cell proliferation. Additionally, this experiment sought to determine the effectiveness of different compositions of PRP (solution versus sustained release) on perfusion and neovascularization in a murine model of hind limb ischemia.

METHODS

Different growth factors were measured by enzyme-linked immunosorbent assay (ELISA). In vivo study, we used gelatin hydrogel as a sustained release carrier for growth factors in PRP. We induced hind limb ischemia by excising right femoral artery in wild type C57BL6 mice. After surgery, mice were randomly assigned to four experimental groups; control (C), 100 muL of sustained release form of platelet-poor plasma (PPP), 100 muL of solution form of PRP (PRP-sol), 100 muL of sustained release form of PRP (PRP-sr); each formulation was administered via an intramuscular injection to the ischemic hind limb. Endpoint evaluations were blood perfusion by laser Doppler perfusion image, vascular density by anti Von Willebrand factor (vWF), and mature vessel density by anti smooth muscle actin (SMA) antibody. Green fluorescent protein (GFP+) transgenic mice were generated by transplantation of bone marrow derived mononuclear cells to wild type C57BL6 mice, and finally CD34+ cell in the ischemic site of transgenic mice was detected by staining with anti-CD34 antibody.

RESULTS

In vitro study showed that PRP containing different growth factors induces endothelial cell proliferation and capillary tube formation. In vivo study demonstrated that sustained release of PRP increased perfusion of ischemic tissue as measured by laser Doppler perfusion imaging (LDPI) (57 +/- 12, 56 +/- 9, 72 +/- 7, 98 +/- 4 for groups C, PPP, PRP-sol, and PRP-sr, respectively; P < .05); capillary density (151 +/- 16, 158 +/- 12, 189 +/- 39, 276 +/- 39 for groups C, PPP, PRP-sol, and PRP-sr, respectively, P < .05) and mature vessel density (28 +/- 2, 31 +/- 3, 52 +/- 10, 85 +/- 13 for groups C, PPP, PRP-sol, and PRP-sr, respectively, P < .05) . Sustained release PRP also increases CD34+ cells in the ischemic site of transgenic mice (6 +/- 3 vs 18 +/- 5/mm(2) for groups control and PRP-sr respectively, P < .05).

CONCLUSION

Sustained release of PRP containing potent angiogenic growth factors restores blood perfusion presumably by stimulating angiogenesis, arteriogenesis, as well as vasculogenesis in the mouse hind limb ischemia.

CLINICAL RELEVANCE

PRP is a natural reserver of various growth factors that can be collected autologously and is costeffective. Thus for clinical use, no special considerations concerning antibody formation and infection risk are needed.Some clinical devices to automatically prepare PRP are available at present. PRP are consistently being used clinically inthe department of orthopedics and plastic surgery (oral, maxillary facial) for a long time. On the basis of researchevidence, some publications have reported positive results in either bone or soft tissue healing. However, some researchconcludes that there is no or little benefit from PRP. This is likely due to faster degradation of growth factors in PRP sincesome authors suggest using sustained release form of PRP to deliver optimal effect of PRP. Gelatin hydrogel is also beingused clinically as a slow, sustained release of carrier for growth factors in our center recently.

New therapeutic approach for impaired arteriogenesis in diabetic mouse hindlimb ischemia

BACKGROUND

The combined treatment of sustained-release basic fibroblast growth factor (Sr-bFGF) and a 5-hydroxytryptamine(2A) blocker, sarpogrelate, was evaluated to see whether it reversed the impaired collateral circulation in diabetic (DM) mouse hindlimb ischemia.

METHOD AND RESULTS

Diabetic and normal mice with ischemic hindlimb were randomly assigned to 1 of 5 experimental groups (no treatment, sarpogrelate 50 mg . kg(-1) . day(-1), 20 microg or 50 microg Sr-bFGF and a combined treatment of 20 microg Sr-bFGF and sarpogrelate), and treated for 4 weeks. Tissue blood perfusion (TBP), vascular density (angiogenesis) and the number of mature vessels (arteriogenesis) were checked by the use of standard methods. Although angiogenesis was comparable (161+/-14 vs 154+/-12 vessels/mm(2)), the laser Doppler perfusion image index (LDPII) (0.43+/-0.11 (SD) vs 0.63+/-0.08, p<0.05) and arteriogenesis (8+/-3 vs 12+/-4 vessels/mm(2), p<0.05) were significantly lower in DM mice than those in normal mice. The dose of Sr-bFGF for the sufficient number of mature vessels (>or=45 vessels/mm(2)) and LDPII (>or=0.9) was 20 microg for the normal mice, and 50 microg for the DM mice, which was reduced with the aid of sarpogrelate. Conclusions A combined therapy of Sr-bFGF and sarpogrelate is effective for neovascularization to reverse the impaired arteriogenesis and TBP in DM mice.

Less-invasive and highly effective method for preventing methicillin-resistant Staphylococcus aureus graft infection by local sustained release of vancomycin

OBJECTIVE

Methicillin-resistant Staphylococcus aureus graft infection is one of the most serious complications of vascular surgery. Vancomycin is a potent antibiotic against methicillin-resistant S. aureus; however, systemic administration of vancomycin is not very effective against methicillin-resistant S. aureus graft infection. Therefore, we investigated whether a local sustained release of vancomycin prevents methicillin-resistant S. aureus graft infection.

METHODS

We have developed a poly-L-lactide-co-caprolactone sheet that enabled sustained release of vancomycin for 2 weeks. An expanded polytetrafluoroethylene vascular graft patch (1.5 mm2) was sutured at the anterior wall of the incised murine abdominal aorta. Methicillin-resistant S. aureus (1.0 x 10(3) colony-forming units) was inoculated onto the graft surface. Thereafter, the graft was treated as follows (n = 6 each): no treatment (control group), local injection of an aqueous solution of vancomycin (vancomycin solution group) and local implantation of poly-L-lactide-co-caprolactone containing vancomycin (vancomycin-PLCA group). After 7 days, the graft and blood were sampled and cultured.

RESULTS

The methicillin-resistant S. aureus counts in the grafts of the vancomycin-PLCA group were significantly lower than those of the other groups. Blood cultures of the vancomycin-PLCA group were all negative, whereas those of the other groups were all positive for infection. The survival rate in the vancomycin-PLCA group at 28 days was considerably higher than that in the control group (83.3% vs 16.7%).

CONCLUSIONS

A local sustained-release sheet containing vancomycin reduced methicillin-resistant S. aureus counts in the infected vascular grafts, prevented sepsis, and drastically improved survival rates. This can be used as a highly effective and less-invasive adjunctive treatment method for preventing prosthetic methicillin-resistant S. aureus graft infection.

Gastroepiploic Artery Grafting Does Not Improve the Late Outcome in Patients With Bilateral Internal Thoracic Artery Grafting

BACKGROUND

Bilateral internal thoracic artery grafting in coronary artery bypass surgery has a better long-term outcome than single internal thoracic artery grafting. However, the efficacy of gastroepiploic artery (GEA) grafting in addition to bilateral internal thoracic artery grafting is still not well-established.

METHODS

From 1989 to 1999, 311 patients underwent coronary artery bypass grafting using in situ bilateral internal thoracic arteries anastomosed to the left coronary arteries and either an in situ GEA or a saphenous vein graft (SVG) anastomosed to the right coronary artery. Ninety-nine patients using the in situ GEA (GEA group) were compared with 212 patients using the SVG (SVG group) anastomsed to the right coronary artery. Young patients and patients with hyperlipidemia were more prevalent in the GEA group.

RESULTS

The seven-year survival rate in the GEA group and the SVG group were 94.7% and 87.2%, respectively (p = 0.068). In a multivariate analysis, the age, renal failure, and a low ejection fraction (<0.40) were all significant predictors of survival. The GEA was not a significant predictor. The seven-year freedom rates from cardiac events were similar in both groups (GEA group, 76.5%; SVG group, 78.6%; p = 0.455). The seven-year freedom rates from recurrent angina were also similar between the groups (GEA group, 85.3%; SVG group, 88.8%; p = 0.700).

CONCLUSIONS

In comparison with SVG grafting, GEA grafting to the right coronary artery did not significantly improve the late outcomes in patients with bilateral internal thoracic artery grafting.

[Serotype and susceptibilities to eight antibiotics of fifty strains of Pseudomonas aeruginosa isolated from clinical specimens and changes in susceptibilities of Pseudomonas aeruginosa to various antibiotics during a period between 1983 and 1986]

Efficacies of 8 antibiotics against Pseudomonas aeruginosa in the relation to serotypes and clinical sources were investigated on 50 strains isolated from patients at Nagoya Ekisaikai Hospital between August and September, 1986. Disk sensitivity test was carried out simultaneously for 5 antibiotics including piperacillin (PIPC), cefoperazone (CPZ), cefsulodin (CFS), ceftazidime (CAZ) and amikacin (AMK), using the single-disk method. We also examined changes in susceptibilities of P. aeruginosa to 5 antibiotics including PIPC, CFS, fosfomycin, gentamicin (GM) and AMK during last 4 years (1983-1986). The results are summarized as follows. 1. CAZ and AMK proved to have high antibacterial potencies, and their MIC80's (concentrations to inhibit growth of 80% of objective bacteria) were both 6.25 micrograms/ml. Following these two the order of potencies were; CFS, cefpiramide (CPM), PIPC, CPZ, netilmicin (NTL), and cefmenoxime (CMX). Sixty two percent of the strains of P. aeruginosa showed high resistances (MIC greater than 50 micrograms/ml) to CPM, CPZ, NTL and CFS, 58% to PIPC, and 2% to AMK. 2. With regard to serotypes, strains belonging to type E were less susceptible than those belonging to types G and I. Type E strains showed high resistance to all antibiotics except CAZ and AMK. 3. Strains obtained from pura and secreta were relatively susceptible, while those from urines were resistant, to these antibiotics tested, in general. 4. Good correlation between MIC's obtained with the agar dilution method (MIC less than or equal to 12.5 micrograms/ml) and these with the disk sensitivity test (greater than ¿ was observed. chi 2 statistical analysis showed that the results obtained with the 2 methods were closely related (P less than 0.01). 5. P. aeruginosa showed fairly high susceptibility to AMK through the recent 4 years (1983-1986). On the other hand, highly resistant strains against CFS, PIPC, FOM and GM increased rapidly during this period.

[In vitro combination effects of astromicin and beta-lactam antibiotics against CFS-sensitive and CFS-resistant Pseudomonas aeruginosa. In vitro synergistic activity]

We investigated in vitro synergistic activity of astromicin (ASTM) combined with beta-lactam antibiotics (cefsulodin (CFS), cefoperazone (CPZ), ceftazidime (CAZ), piperacillin (PIPC) and fosfomycin (FOM) against fresh clinical isolated Pseudomonas aeruginosa, which consisted of 13 CFS sensitive (MIC less than or equal to 3.13 micrograms/ml) and 19 CFS resistant (MIC greater than or equal to 400 micrograms/ml) strains according to the FIC index. Against CFS-sensitive P. aeruginosa, ASTM showed good synergistic activities when combined with PIPC (54%), CAZ (38%), CPZ (23%) and CFS (8%). Against CFS-resistant P. aeruginosa, ASTM also showed high synergistic activities when combined with CAZ (63%), CPZ (47%), PIPC (37%) and CFS (11%). Among the CFS-resistant P. aeruginosa, one clinical isolate showed a high sensitivity (MIC0.78 micrograms/ml) against ASTM alone.