Treating a Large Thoracoabdominal Aneurysm With Aberrant Right Subclavian Artery With a Physician-Modified Graft

CLINICAL IMPACT

Large thoracoabdominal aortic aneurysms due to chronic aortic dissection in patients with connective tissue disorders such as Loeys-Dietz syndrome present a challenging scenario, particularly in cases of variant anatomy and when patients are not candidates for conventional open repair. We demonstrate how by combining and modifying off-the-shelf devices during a hybrid procedure, one can create an endovascular solution tailored to the patient's complex anatomy, making use of an aberrant right subclavian artery, and allow for good clinical outcomes.

Caution: Air Embolism Related to Heli-Fx EndoAnchor System in Zone 2 Thoracic Aneurysm Repair

PURPOSE

We report a case of significant air embolization to the ascending aorta immediately following deployment of EndoAnchors in the aortic arch during a procedure to correct a type 1A endoleak.

CASE REPORT

The novel Heli-Fx EndoAnchor system (Medtronic Vascular, Santa Rosa, CA, USA) was used to deploy helical anchors in the distal aortic arch during a procedure to correct a type 1A endoleak following Zone 2 thoracic endovascular aortic repair of a saccular proximal descending thoracic aorta aneurysm (DTAA). The patient developed ST-segment elevations principally in the inferior leads and severe hypotension moments after EndoAnchor deployment at the proximal edge of the endograft. Transesophageal echocardiogram revealed severe right ventricular hypokinesis and a large amount of air in the ascending aorta. Subsequent management and clinical and radiological 30-day follow-up is presented in addition to a review of the literature and ex vivo testing with the Heli-Fx system to examine potential causes and solutions.

CONCLUSION

Precautions, such as pressurized saline infusion to the side port of guiding sheath, should be used whenever manipulating catheters and sheaths such as the EndoAnchor system in the aortic arch to prevent this potentially lethal complication.

Knowledge, attitudes, and practice patterns in surgical management of bicuspid aortopathy: a survey of 100 cardiac surgeons

OBJECTIVE

Clinical practice guidelines have been established for surgical management of the aorta in bicuspid aortic valve disease. We hypothesized that surgeons' knowledge of and attitudes toward bicuspid aortic valve aortopathy influence their surgical approaches.

METHODS

We surveyed cardiac surgeons to probe the knowledge of, attitudes toward, and surgical management of bicuspid aortopathy. A total of 100 Canadian adult cardiac surgeons participated.

RESULTS

Fifty-two percent of surgeons believed that the mechanism underlying aortic dilation in those with bicuspid aortic valve was due to an inherent genetic abnormality of the aorta, whereas only 2% believed that altered valve-related processes were involved in this process. Only a minority (15%) believed that bicuspid valve leaflet fusion type is associated with a unique pattern of aortic dilatation aortic phenotype. Sixty-five percent of surgeons recommended echocardiographic screening of first-degree relatives of patients with bicuspid aortic valve. Most surgeons (61%) elected to replace the aorta when the diameter is 45 mm or greater at the time of valve surgery. Fifty-five percent of surgeons surveyed suggested that in the absence of concomitant valvular disease, they would recommend ascending aortic replacement at a threshold of 50 mm or greater. Approximately one third of surgeons suggested that they would elect to replace a mildly dilated ascending aorta (40 mm) at the time of valve surgery. The most common surgical approach (61%) for combined valve and aortic surgery was aortic valve replacement and supracoronary replacement of the ascending aorta, and only a minority suggested the use of deep hypothermic circulatory arrest and open distal anastomosis. More aggressive approaches were favored with greater surgeon experience, and when circulatory arrest was chosen, the majority (68%) suggested they would use antegrade cerebral perfusion. In the setting of aortic insufficiency and a dilated aorta, 42% of surgeons suggested that they would perform valve-sparing surgery. Of note, 40% of respondents used an index measure of aortic size to body surface area in addition to absolute aortic diameter in assessing the threshold for intervention.

CONCLUSIONS

This large survey uncovered significant gaps in the knowledge and attitudes of surgeons toward the diagnosis and management of bicuspid aortopathy, many of which were at odds with current guideline recommendations. Efforts to promote knowledge translation in this area are strongly encouraged.

Decreased incidence of low output syndrome with a switch from tepid to cold continuous minimally diluted blood cardioplegia in isolated coronary artery bypass grafting

OBJECTIVES

The optimal temperature for blood cardioplegia remains unclear.

METHODS

A retrospective analysis was performed on 138 patients undergoing isolated myocardial revascularization by a single surgeon in our institution over a period of 2 years. Patients operated on early in the study period received tepid (29°C) continuous minimally diluted blood cardioplegia (minicardioplegia), delivered in an antegrade continuous fashion. Later, our surgeon began using cold (7°C) blood minicardioplegia in all patients. Data pertaining to clinical outcomes and postoperative biochemical data were obtained, and the two groups were compared.

RESULTS

Low cardiac output syndrome, defined as the need for intra-aortic balloon pump counter pulsation or inotropic medication for haemodynamic instability, was more frequent in the tepid cardioplegia group than in the cold cardioplegia group (16.0 vs 2.4%, P = 0.006). There was no difference in the maximal serum creatine kinase MB between the two groups (cold 25.4 ± 3.21 μg/ml vs tepid 36.5 ± 7.10 μg/ml, P = 0.62), in the rates of perioperative myocardial infarction (cold 1.2% vs tepid 6.0%, P = 0.15) and the need for postoperative insertion of an intra-aortic balloon pump (cold 4.8% vs tepid 0.0%, P = 0.3). There was no other statistically significant difference between the two groups in the measured parameters.

CONCLUSIONS

A higher rate of low cardiac output syndrome in the tepid cardioplegia group suggests inferior myocardial protection with the tepid cardioplegia. Cold cardioplegia may provide better protection than tepid cardioplegia when minicardioplegia is used.

Pure red cell aplasia and associated thymoma

Pure red cell aplasia is a rare cause of anemia, caused by an absence of red blood cell precursors in the bone marrow. It is usually a paraneoplastic syndrome, associated most commonly with large-cell granular lymphocyte leukemia but also thymoma. For patients who present both pure red cell aplasia and thymoma, thymectomy leads to an initial remission of the aplasia in 30% of cases. However, sustained remission may require the addition of medications such as corticosteroids, cyclosporine, or cyclophosphamide. We present a case of pure red cell aplasia associated with a thymoma in an otherwise healthy 80 year-old woman.

Inhibitory presynaptic 5-hydroxytryptamine(2A) receptors regulate evoked glutamate release from rat cerebellar mossy fibers

We studied the pharmacological characterization of the 5-hydroxytryptamine(2) (5-HT(2)) heteroreceptor located on glutamatergic cerebellar mossy fiber nerve terminals. Depolarization-evoked overflow of endogenous glutamate from rat cerebellar "giant" mossy fiber synaptosomes was inhibited by 5-HT or (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane [(+/-)-DOI], exhibiting pD(2) (= -log EC(50)) values of 7.37 and 7.29, respectively. Trazodone inhibited the depolarization-evoked glutamate overflow, exhibiting lower potency (pD(2) = 6.42) and lower efficacy with respect to 5-HT or (+/-)-DOI (maximal inhibition, 54%, compared with 70% for either 5-HT or (+/-)-DOI). Ketanserin, a 5-HT(2A)/5-HT(2C) receptor antagonist, counteracted the inhibitory effect of (+/-)-DOI or trazodone. Inhibition of glutamate overflow by 5-HT, (+/-)-DOI, or trazodone was prevented by the selective 5-HT(2A) receptor antagonist R-(+)-alpha-(2,3-dimethyoxyphenyl)-1-(2-(4-fluorophenyl)ethyl)-4-piperidine-methanol (MDL 100907), while the potent and selective 5-HT(2C) receptor antagonist 6-chloro-5-methyl-1-[6-(methylpyridin-3-yloxy)pyridin-3yl-carbamoyl] indoline (SB 242084) was ineffective. In cerebellar slices, MDL 100907 increased on its own the K(+)-evoked release of glutamate. It is concluded that the evoked release of glutamate from cerebellar mossy fibers can be controlled by inhibitory presynaptic 5-HT(2A) heteroreceptors, the receptors can be activated by endogenously released 5-HT, and trazodone behaves as a partial agonist at these receptors.

Serotonin inhibition of the NMDA receptor/nitric oxide/cyclic GMP pathway in human neocortex slices: involvement of 5-HT(2C) and 5-HT(1A) receptors

The NMDA receptor/nitric oxide (NO)/cyclic GMP pathway and its modulation by 5-hydroxytryptamine (5-HT) was studied in slices of neocortical samples obtained from patients undergoing neurosurgery. The cyclic GMP elevation produced by 100 microM NMDA was blocked by 100 microM of the NO synthase inhibitor N(G)-nitro-L-arginine (L-NOARG) or by 10 microM of the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3,-alpha] quinoxaline-1-one (ODQ). The NMDA effect was prevented by 5-HT or by the 5-HT(2) agonist (+/-)-1-(2, 5-dimethoxy-4-iodophenyl)-2-aminopropane ((+/-)-DOI; EC(50)=22 nM). The (+/-)-DOI inhibition was insensitive to the 5-HT(2A) receptor antagonist MDL 100907 or the 5-HT(2B) antagonist rauwolscine; it was largely prevented by 1 microM of the non-selective 5-HT(2C) antagonists mesulergine (5-HT(2A,B,C)), ketanserin (5-HT(2A,C)) or SB 200646A (5-HT(2B,C)); it was completely abolished by 0.1 microM of the selective 5-HT(2C) receptor antagonist SB 242084. The NMDA-induced cyclic GMP elevation also was potently inhibited by the selective 5-HT(2C) agonist RO 60-0175 and by the antidepressant trazodone, both added at 1 microM, in an SB 242084-sensitive manner. Finally, the 5-HT(1A) agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT; 1 microM) inhibited the NMDA-evoked cyclic GMP response, an effect blocked by the selective 5-HT(1A) receptor antagonist WAY 100635. In conclusion, the NMDA receptor/NO/cyclic GMP pathway in human neocortex slices can be potently inhibited by activation of 5-HT(2C) or 5-HT(1A) receptors.

Disodium chromium(III) hexamolybdoiodate(VII) 24-hydrate, Na2Cr[IMo6O24]·24H2O

The title compound can be formulated as [Cr(H(2)O)(6)][Na(2)(H(2)O)(10)][IMo(6)O(24)].8H(2)O. The anion has the I atom on an inversion centre and has close to $\overline 3$m symmetry, with I-O bond lengths in the range 1.881-1.890 (2) A and Mo-O bond lengths in the ranges 1.697 (3)-1.714 (3), 1.915 (2)-1.948 (2) and 2.317 (2)-2.357 (2) A.