Detection of Sulphate-Reducing Bacteria and Others Cultivable Facultative Bacteria in Dental Tissues

Aim

To detect for the presence of sulphate-reducing bacteria (SRB) and evaluate the possible association between SRB and cultivable facultative bacterial of oral sites with different periodontal conditions.

Methods

The study was carried out on 9 samples from different oral sites in 8 patients (two samples were collected from the same patient). Material was collected using modified Postgate E culture medium, indicated for the growth and isolation of SRB. In addition, a reducing solution for anaerobic bacteria was used as a transport solution for facultative bacteria and identified by polymerase chain reaction amplification (PCR) and sequencing of the 16S rRNA gene.

Results

SRB was found in 3 patient samples: the first in a root fragment, the second in a root fragment and a healthy tooth with vertical bone loss and a mobility degree of 3; and the third in a healthy tooth extracted for orthodontic treatment. In the final patient, the cultivable facultative species Lactobacillus casei was identified. Other facultative bacterial species were identified in patient 5 (Kurthia Gibsonii) and patient 7 (Pseudomonas aeruginosa).

Conclusions

The detection of SRB in different dental tissues with distinct periodontal features demonstrated that new studies need to be developed in order to determine the true role of SRB in the oral microbiota. In addition, it was possible to verify the presence of Lactobacillus casei together with SRB in one sample.     

Percutaneous Closure of Atrial Septal Defects in Patients with an Aberrant Retroaortic Coronary Artery: Is It Safe?

Coexistence of an ostium secundum type atrial septal defect and a coronary artery anomaly with an aberrant retroaortic course is a rare congenital anomaly that may potentially complicate percutaneous atrial septal defects (ASD) closure. If the anterosuperior rim of the defect is deficient, the abnormally located coronary artery may be compressed or distorted by the implanted device causing myocardial ischemia, arrhythmias, and eventually sudden cardiac death. Due to the potential occurrence of these fatal cardiac events, diagnosis of an aberrant coronary artery with a retroaortic course must be established before percutaneous ASD closure. In this report, two patients with this rare association are described in whom percutaneous closure of the defect was feasible and uneventful. The importance of a careful periprocedural, noninvasive echocardiographic coronary artery imaging is emphasized, and the rational for percutaneous atrial septal defect closure in this unusual anatomic arrangement is proposed.     

Intermediate follow-up following intravascular stenting for treatment of coarctation of the aorta.

BACKGROUND: We report a multiinstitutional study on intermediate-term outcome of intravascular stenting for treatment of coarctation of the aorta using integrated arch imaging (IAI) techniques. METHODS AND RESULTS: Medical records of 578 patients from 17 institutions were reviewed. A total of 588 procedures were performed between May 1989 and Aug 2005. About 27% (160/588) procedures were followed up by further IAI of their aorta (MRI/CT/repeat cardiac catheterization) after initial stent procedures. Abnormal imaging studies included: the presence of dissection or aneurysm formation, stent fracture, or the presence of reobstruction within the stent (instent restenosis or significant intimal build-up within the stent). Forty-one abnormal imaging studies were reported in the intermediate follow-up at median 12 months (0.5-92 months). Smaller postintervention of the aorta (CoA) diameter and an increased persistent systolic pressure gradient were associated with encountering abnormal follow-up imaging studies. Aortic wall abnormalities included dissections (n = 5) and aneurysm (n = 13). The risk of encountering aortic wall abnormalities increased with larger percent increase in CoA diameter poststent implant, increasing balloon/coarc ratio, and performing prestent angioplasty. Stent restenosis was observed in 5/6 parts encountering stent fracture and neointimal buildup (n = 16). Small CoA diameter poststent implant and increased poststent residual pressure gradient increased the likelihood of encountering instent restenosis at intermediate follow-up. CONCLUSIONS: Abnormalities were observed at intermediate follow-up following IS placement for treatment of native and recurrent coarctation of the aorta. Not exceeding a balloon:coarctation ratio of 3.5 and avoidance of prestent angioplasty decreased the likelihood of encountering an abnormal follow-up imaging study in patients undergoing intravascular stent placement for the treatment of coarctation of the aorta. We recommend IAI for all patients undergoing IS placement for treatment of CoA.     

Stenting vs. balloon angioplasty for discrete unoperated coarctation of the aorta in adolescents and adults.

More information is needed to clarify whether stenting is superior to balloon angioplasty (BA) for unoperated coarctation of the aorta (CoA). From September 1997, 21 consecutive adolescents and adults (24 +/- 11 years) with discrete CoA underwent stenting (G1). The results were compared to those achieved by BA performed in historical group of 15 patients (18 +/- 10 years; P = 0.103; G2). After the procedure, systolic gradient reduction was higher (99% +/- 2% vs. 87% +/- 17%; P = 0.015), residual gradients lower (0.4 +/- 1.4 vs. 5.9 +/- 7.9 mm Hg; P = 0.019), gain at the CoA site higher (333% +/- 172% vs. 190% +/- 104%; P = 0.007), and CoA diameter larger (16.9 +/- 2.9 vs. 12.9 +/- 3.2 mm; P < 0.001) in G1. Aortic wall abnormalities were found in eight patients in G2 (53%) and in one in G1 (7%; P < 0.001). There was no major complication. Repeat catheterization (n = 33) and/or MRI (n = 2) was performed at a median follow-up of 1.0 year for G1 and 1.5 for G2 (P = 0.005). Gradient reduction persisted in both groups, although higher late gradients were seen in G2 (median of 0 mm Hg for G1 vs. 3 for G2; P = 0.014). CoA diameter showed no late loss in G1 and a late gain in G2 with a trend to being larger in G1 (16.7 +/- 2.9 vs. 14.6 +/- 3.9 mm; P = 0.075). Two patients required late stenting due to aneurysm formation or stent fracture in G1. Aortic wall abnormalities did not progress and one patient required redilation in G2. Blood pressure was similar in both groups at follow-up (126 +/- 12/81 +/- 11 for G1 vs. 120 +/- 15/80 +/- 10 mm Hg for G2; P = 0.149 and 0.975, respectively). Although satisfactory and similar clinical outcomes were observed with both techniques, stenting was a better means to relieve the stenosis and minimize the risk of developing immediate aortic wall abnormalities.     

A new Amplatzer device to maintain patency of Fontan fenestrations and atrial septal defects.

This study evaluated use of Amplatzer fenestrated device to maintain patency of the Fontan fenestration and atrial septal defect. Fenestrations are routinely created in patients with lateral tunnel or extracardiac Fontan. Spontaneous closure of the fenestration can lead to Fontan circulation failure. Other patients without single-ventricle physiology may benefit from a small communication between the left and right atria for decompression if closure of the atrial septal defect leads to failure of a dysfunctional ventricle. Amplatzer septal occluder device was modified to create a fenestration through the disks. Three patients with modified Fontan and one patient with a large atrial septal defect underwent placement of the device by transcatheter technique. The device deployment was guided by transesophageal echocardiography. The procedure was successful in all patients. Contrast injection after placement revealed patent fenestration with free flow. Follow-up ranged from 3 months to 1 year. All devices were patent by transthoracic echocardiography. These preliminary results suggest that the Amplatzer fenestrated device can serve as a valuable tool in failing Fontan circulation and may help to avoid surgical intervention. More studies are needed to assess long-term efficacy of the device.     

Endovascular stenting for aortic coarctation

Surgery had been the traditional treatment for native coarctation of the aorta, one of the most common cardiovascular congenital malformations. As a less invasive mode of treatment, balloon angioplasty has emerged as an alternative to surgery but has not gained universal acceptance due to its rates of restenosis secondary to vessel recoil and concerns over aortic wall injury resulting in aneurysm formation. To overcome these problems, endovascular stents were introduced in the management of this condition. The early- and intermediate-term results are encouraging, with low rates of restenosis and complications. In this article, the authors review the current evidence on coarctation stenting and discuss future trends in this area.