Anesthetic management for transcatheter aortic valve replacement: A national anesthesia clinical outcomes registry analysis

Background

General anesthesia has traditionally been used in transcatheter aortic valve replacement; however, there has been increasing interest and momentum in alternative anesthetic techniques.

Aims

To perform a descriptive study of anesthetic management options in transcatheter aortic valve replacements in the United States, comparing trends in use of monitored anesthesia care versus general anesthesia.

Settings and Design

Data evaluated from the American Society of Anesthesiologists' (ASA) Anesthesia Quality Institute's National Anesthesia Clinical Outcomes Registry.

Materials and Methods

Multivariable logistic regression was used to identify predictors associated with use of monitored anesthesia care compared to general anesthesia.

Results

The use of monitored anesthesia care has increased from 1.8% of cases in 2013 to 25.2% in 2017 (p = 0.0001). Patients were more likely ages 80+ (66% vs. 61%; p = 0.0001), male (54% vs. 52%; p = 0.0001), ASA physical status > III (86% vs. 80%; p = 0.0001), cared for in the Northeast (38% vs. 22%; p = 0.0001), and residents in zip codes with higher median income ($63,382 vs. $55,311; p = 0.0001). Multivariable analysis revealed each one-year increase in age, every 50 procedures performed annually at a practice, and being male were associated with 3% (p = 0.0001), 33% (p = 0.012), and 16% (p = 0.026) increased odds of monitored anesthesia care, respectively. Centers in the Northeast were more likely to use monitored anesthesia care (all p < 0.005). Patients who underwent approaches other than percutaneous femoral arterial were less likely to receive monitored anesthesia care (adjusted odds ratios all < 0.51; all p = 0.0001).

Conclusion

Anesthetic type for transcatheter aortic valve replacements in the United States varies with age, sex, geography, volume of cases performed at a center, and procedural approach.

Antagonism between tamoxifen and doxorubicin in the MCF-7 human breast tumor cell line

Tamoxifen, an antiestrogen, and doxorubicin, an anthracycline antibiotic, are each utilized alone and in combination in the treatment of breast carcinoma. In view of conflicting reports relating to the interaction between these drugs, studies were undertaken to characterize the influence of tamoxifen on growth inhibition by doxorubicin in the MCF-7 breast tumor cell line in vitro. Studies combining 5 microM tamoxifen, a clinically relevant concentration, with various concentrations of doxorubicin, indicated that this drug combination produces antiproliferative effects that appear to be less than additive. Concentration-dependent growth inhibition was analyzed further using various concentrations of tamoxifen and doxorubicin by the combination index-isobologram method; this quantitative approach provided clear evidence of antagonism between these agents, a finding with potential relevance to the treatment of breast cancer.

Variable effects of tamoxifen on human hematopoietic progenitor cell growth and sensitivity to doxorubicin

To determine the influence of tamoxifen on the drug sensitivity of normal human hematopoietic progenitor cells, T-cell- and adherent-cell depleted human bone marrow mononuclear cells (T-, Ad-) were exposed in vitro to 5 microM tamoxifen for 24 h. The effects of tamoxifen were highly variable, as exposure to tamoxifen produced an increase (97% +/- 12.3%) in the growth of day-12 committed myeloid progenitors (CFU-GM) in only four of ten experiments utilizing bone marrow from different donors. When T-, Ad- myeloid progenitor cells treated with tamoxifen were subsequently exposed to doxorubicin, 7 of 14 experimental samples studied demonstrated a net increase in the number of surviving clonogenic cells as compared with cells exposed to doxorubicin alone. Tamoxifen also stimulated the growth of a more purified (CD34(+)-selected) progenitor cell population in four of four experiments (by 62.5% +/- 4.9%) but did not increase the survival of these cells upon exposure to doxorubicin; in fact, in five of ten experimental samples, tamoxifen enhanced cell sensitivity to doxorubicin. Taken together, these observations indicate that tamoxifen produces variable stimulation of committed myeloid progenitor cell growth in vitro. Furthermore, while under some circumstances, tamoxifen appears to have the capacity to enhance CFU-GM survival in the presence of doxorubicin, this drug combination may also result in enhanced toxicity to normal bone marrow progenitors.

Components of intrinsic drug resistance in the rat hepatoma

A carcinogen-transformed rat hepatoma cell line (Reuber H-35) was utilized as a model system for investigation of the biochemical factors which may limit the effectiveness of chemotherapy in intrinsically resistant tumors such as hepatocellular carcinoma. Northern blotting demonstrated expression of mRNA coding for the P-170 membrane-glycoprotein associated with the multi-drug resistance phenotype, while Western blotting identified the P-170 glycoprotein in the hepatoma cell membrane. Consistent with these observations, tumor cell sensitivity to the vinca alkaloids, vincristine and vinblastine, to the anthracycline antibiotics, Adriamycin and daunorubicin, and to the demethylepipodophyllotoxin derivative, VM-26, was enhanced by continuous incubation in the presence of the calcium channel antagonist, verapamil. Verapamil produced a minimal change in cell sensitivity to the demethylepipodophyllotoxin derivative, VP-16, and to the aminoacridine, m-AMSA. Relatively high detoxification potential via the glutathione metabolic pathway was also observed in the hepatoma cell. The capacity of topoisomerase II in nuclear extracts from the hepatoma cell to mediate cleavable complex formation stimulated by VM-26, VP-16 and m-AMSA appeared to be at least comparable to, if not greater than that from drug-sensitive HL-60 cells, suggesting that drug resistance may not occur at the level of this enzyme. Consistent with findings in a number of tumor cell lines resistant to antineoplastic drugs, the antiproliferative activity of the topoisomerase II inhibitors VM-26, VP-16 and m-AMSA appeared to be dissociable from the induction of DNA strand breaks, suggesting that such lesions in DNA may fail to fully account for the antiproliferative activity of these agents in the hepatoma cell.

Enhanced sensitivity of the rat hepatoma cell to the daunorubicin analogue 4-demethoxydaunorubicin associated with induction of DNA damage

The H-35 rat hepatoma, a cell line which is relatively resistant to the classical anthracycline antibiotics such as Adriamycin [the concentration of drug which inhibits cell proliferation by 5090 (IC50) = 2.5 microM] and daunorubicin (IC50 of 0.5 microM), is markedly more sensitive to the 4-demethoxydaunorubicin derivative, idarubicin (IC50 of 0.025 microM). In contrast to daunorubicin, which has previously been shown to inhibit hepatoma cell proliferation in the absence of perceptible DNA cleavage, idarubicin induces concentration-dependent DNA damage which may account for its enhanced capacity to inhibit proliferation of the rat hepatoma. Free radical scavengers fail to interfere with inhibition of cell proliferation induced by idarubicin. Damage to the cell membrane or alterations in mitochondrial integrity do not appear to represent components of idarubicin toxicity in this tumor cell line. Inhibition of DNA synthesis by idarubicin parallels inhibition of cell growth; however, sensitivity of DNA synthesis to idarubicin is significantly less than that for cell proliferation (IC50 values of 0.5 microM and 0.025 microM, respectively). It is postulated that the antiproliferative effects of idarubicin in the H-35 rat hepatoma model may be a consequence of alterations in DNA integrity which ultimately result in the inhibition of cellular biosynthetic processes.

Invasive basal cell carcinoma of the temporal bone

Basal cell carcinomas involving the ear represent a spectrum of diseases, from a small superficial auricular lesion to an advanced destructive malignancy invading the temporal bone. The biologic activity of the morphea-form basal cell carcinoma variant of tumor and a postauricular location predispose to an aggressive biologic pattern. Management requires a thorough evaluation with determination of the degree of cranial and possible intracranial invasion. These lesions usually can be managed with partial temporal bone resections, although prognosis for patients with advanced lesions may be poor.