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PubMed2005

Endovascular stent-graft placement for complications of acute type B aortic dissection.

PURPOSE OF REVIEW: To review the concepts and current clinical results of endovascular stent-graft placement for acute complicated type B aortic dissection. RECENT FINDINGS: The optimal treatment for patients with dissections confined to the descending aorta (Stanford type B-AD) remains a matter of debate. Usually, antihypertensive medical therapy with strict blood pressure lowering below 135/80 mm Hg represents the first choice for patients with uncomplicated type B-AD. Patients with acute complicated type B-AD remain a major therapeutic challenge because surgery of the descending aorta is still associated with high morbidity and mortality. In 1999, endovascular stent-graft placement was introduced as a novel, less invasive treatment option for patients with type B aortic dissection. Current indications include acute (contained) aortic rupture, symptomatic ischemic branch vessel involvement, early aortic expansion, or unrelenting pain. So far, few studies on stent-graft placement in patients with acute complicated aortic dissection have been published reporting an early mortality between 0 and approximately 20%. SUMMARY: To date, there is limited experience with endovascular stent-graft placement for acute complicated type B aortic dissection demonstrating its feasibility and life-saving potential. The endovascular approach can avoid the major trauma of open surgery and should help to get patients out of the acute life-threatening phase of the disease; however, long-term results are needed to assess the durability of this treatment.

Aged↗

PubMed2005

Incidence and significance of clinically unsuspected thyroid tissue in lymph nodes found during neck dissection in head and neck carcinoma patients.

OBJECTIVES/HYPOTHESIS: The objectives were to quantify the incidence of clinically unsuspected thyroid tissue in cervical lymph nodes encountered during neck dissection in patients with head and neck carcinoma, to describe the location and histological aspect of these inclusions, and to assess their clinical significance. STUDY DESIGN: Retrospective study. METHODS: The histological records of 1123 neck dissections in 752 patients with head and neck carcinoma were reviewed. In cases with thyroid inclusions, the pathological diagnosis was reviewed and an immunohistochemical study against thyroglobulin and calcitonin was carried out. RESULTS: Clinically unsuspected thyroid tissue was found in lymph nodes in 11 of the 752 patients with head and neck carcinoma treated with neck dissection. In five cases, the thyroid inclusion was compatible with a metastases of an occult papillary thyroid carcinoma. In the other six cases, a collection of thyroid follicles without malignant characteristics was found beneath the lymph node capsule. These latter cases were considered benign thyroid inclusions. A thyroidectomy was performed in three of the patients with lymph node metastases of the papillary carcinoma. An occult papillary carcinoma was found in only one case. The other two patients had been treated previously with radiotherapy for an early-stage glottic carcinoma. Immunohistochemical study did not find calcitonin-positive cells within the benign thyroid inclusions. After a follow-up period ranging from 1.2 to 8.2 years, no patient had any kind of local, regional, or distant relapse related to the thyroid disease. CONCLUSION: The incidence of unsuspected thyroid tissue in lymph nodes of patients with head and neck carcinoma treated with neck dissection was 1.5%. Both lymph node metastases of a papillary carcinoma and benign thyroid inclusions were found. The study results suggest that the incidental finding of thyroid tissue in the lymph nodes during a neck dissection in patients with head and neck carcinoma does not necessarily indicate the need for aggressive therapy.

Adult↗

PubMed2006

Endolymphatic duct status during middle fossa dissection of the internal auditory canal: a human temporal bone radiographic study.

OBJECTIVE: Successful hearing preservation after acoustic neuroma resection is sometimes complicated by delayed hearing deterioration. The middle fossa approach appears to offer superior long-term hearing results when compared to the retrosigmoid surgical approach. The goal of this study is to investigate the hypothesis that internal auditory canal (IAC) drilling during middle fossa acoustic neuroma removal is associated with a lower incidence of endolymphatic duct (ELD) injury, a potential cause of delayed hearing loss (HL) known to accompany retrosigmoid hearing preservation dissection techniques. STUDY DESIGN: A human temporal bone anatomic and radiographic study complemented with a literature review. METHODS: Twenty human temporal bones were analyzed with high-resolution multislice computed tomography (HRMCT) and subjected to standard extended middle fossa IAC dissection with labyrinthine preservation and follow-up HRMCT for analyses of the ELD. RESULTS: Zero of 20 (0%) temporal bones were found to have violation of the ELD with preservation of the labyrinthine structures and the endolymphatic sac. Reviews of human and animal studies indicate that injury to the ELD may create endolymphatic hydrops, a known cause of hearing deterioration. CONCLUSION: The ELD is not vulnerable to injury during IAC dissection using the middle fossa approach. A previous radiographic study has shown that the ELD is violated in 24% of temporal bones during retrosigmoid dissection of the IAC. These findings support and may help explain other outcome studies that show that long-term hearing results are superior with the use of the middle fossa approach when compared to results following retrosigmoid dissection.

Cranial Fossa, Middle↗

PubMed2003

Endovascular treatment of complicated type-B aortic dissection with stent-grafts:: midterm results.

PURPOSE: To report the midterm results of the endovascular treatment of complicated type-B aortic dissection with use of stent-grafts. MATERIALS AND METHODS: Ten patients with acute (n = 4) or chronic (n = 6) complicated type-B dissection were treated with custom-made stent-grafts. Indications for treatment included uncontrollable hypertension with dissection extension (n = 3), renal ischemia (n = 1), and false lumen aneurysm (n = 6). Stainless-steel Z-stents covered with polyester grafts were placed in the initial six patients. Nitinol stents covered with ultrathin polytetrafluoroethylene were used in the remaining four patients. The patients were followed-up with helical computed tomography for a maximum of 30 months (mean, 20 mo). RESULTS: There was one technical failure related to the access site. Early complications included deep venous thrombosis (n = 1) and embolic stroke (n = 1). Complete thrombosis of the thoracic false lumen was achieved in six patients and partial thrombosis was achieved in three. Aneurysms developed at the ends of the stainless-steel stents in two patients, requiring additional stent-graft placement. Despite successful remodeling of the thoracic aorta, three of four patients with distal reentry into the abdominal aorta experienced progressive abdominal aortic aneurysm (AAA). AAA rupture developed in two patients; one rupture was fatal and the other was treated with emergency surgery. CONCLUSIONS: Endovascular treatment of complicated type-B aortic dissection is technically feasible and effective. Closely monitoring the treated aorta is essential to detect early aneurysm formation at the ends of rigid stents. Despite adequate sealing of the tears in the thoracic aorta, dissection with distal reentry phenomenon into the abdominal aorta may evolve into AAA with late rupture.

Alloys↗

PubMed2004

Carotid dissection associated with a handheld electric massager.

The extracranial internal carotid artery (ICA) is susceptible to injury and dissection from external shear forces applied to the neck. Traumatic ICA dissection usually occurs in the setting of a sudden, high amplitude force causing significant distortion of surrounding soft tissues. Weaker, repetitive forces applied for longer intervals may also pose a risk for ICA dissection. A 38-year-old woman with no significant stroke risk factors had sudden onset of severe dysarthria and left hemiparesis several days after receiving an approximately 20-minute neck massage with a handheld electric massager. The moving elements consisted of two approximately 2-cm-diameter spheres that percuss the skin with low amplitude and high frequency. Magnetic resonance imaging and angiography demonstrated acute infarction in the right middle cerebral artery territory and dissection of the extracranial right ICA. Handheld electric massager units may cause ICA dissection and disabling stroke.

Adult↗

PubMedDate not supplied

Long-term effectiveness of operative procedures for stanford type a aortic dissections.

BACKGROUND: The object was to evaluate the long-term effectiveness of strategies for managing the aortic root and distal aorta in type A dissections. METHODS: From 1990 to 1999, 50 patients (32 men (64.07%); 18 women, (36.0%); mean age 57.4 +/- 11.1 years) underwent operation for ascending aortic dissection. Surgical strategies included aortic root replacement with a composite graft (21/50; 42.0%), valve replacement with supracoronary ascending aortic graft (3/50, 6%), and valve preservation or repair (26/50; 52.0%). RESULTS: Overall hospital mortality rate was 18.0%. Follow-up was completed for 47 patients (94.0%) and ranged from 1 month to 10.5 years (mean 28.8 months). Actuarial survival for patients discharged from the hospital was 84% at 1 year, 75% at 5 years, and 66% at 10 years. There was no significant difference between the various procedures regarding mortality, neurological complications, long-term survival, and proximal reoperations. The ascending aorta alone was replaced in 8 of 50 patients (16%), ascending and hemiarch in 30 of 50 patients (60%), and arch and proximal descending aorta in 12 of 50 patients (24%). Hospital mortality (11.5%, 20.0%, and 16.7%, respectively; p > 0.05) and 5- and 10-year survival (p > 0.05) were not statistically dependent on the extension of the resection distally. Residual distal dissection was not associated with a decrease in late survival. With regard to emergency surgery (36/50) there was no significant difference in hospital mortality (p > 0.05) and 5-year survival (p > 0.05) between those who had undergone coronary angiography (19/36; 52.8%) on the day of surgery with those who had not (17/36; 47.2%). CONCLUSIONS: Preservation or repair of the aortic valve can be recommended in the majority of patients with type A dissection. Distal extension of the resection does not increase surgical risk. Residual distal dissection does not decrease late survival. Preoperative coronary angiography may not affect survival in patients undergoing emergency surgery.

Adult↗

PubMed2007

Anatomical dissection as a teaching method in medical school: a review of the evidence.

CONTEXT: Discussions about dissection as a teaching method in gross anatomy are characterised by a lack of objective evidence. METHODS: A search for such evidence in the literature produced 14 relevant papers. These were reviewed for objective data on the effect of cadaver dissection on cognitive learning outcomes. RESULTS: All reviewed studies compared groups of students exposed to different teaching approaches, including active dissection, learning on prosected material, or a combination with computerised teaching aids. Study and course designs varied substantially and student groups compared were not always homogeneous. In all studies, compared learning experiences differed in more than 1 variable, and assessment of anatomical knowledge was not standardised. DISCUSSION: It is difficult to interpret and generalise from the results of the reviewed studies. Considering the bias that must be assumed for teachers who develop new course designs and compare these with traditional ones, the review shows a slight advantage for traditional dissection over prosection. CONCLUSIONS: More sophisticated research designs may be necessary to solve the general problem of the small measurable impact of educational interventions and to come to scientifically sound conclusions about the best way to teach gross anatomy. Such research will have to include sufficient sample sizes, the use of validated assessment instruments, and a discussion of the educational significance of measured differences. More educational research in anatomy is necessary to counterbalance emotional arguments about dissection with scientific evidence. Anatomical knowledge is too important to future doctors to leave its teaching to the educational fashion of the day.

Anatomy↗

PubMed1981

A morphological study of dissecting aneurysm of aorta in old individuals over 50 years of age.

The authors have investigated the pathogenesis of dissecting aneurysms morphologically in 49 cases over 50 years of age, using 93 cases of other diseases in the same age group as control cases. All cases were autopsied at the Tokyo-to Medical Examiner Office. The dissecting aneurysms were divided into two types: one type occurred chiefly at the ascending aorta where atherosclerosis was missing or slight, and the other type chiefly at the descending aorta with severe atherosclerosis of the intima. In the former type, intimal tears were recognized in all cases and microscopically in the neighboring area of the cleft of aortic wall vacuolous large cyst without accumulation of metachromatic ground substance. Near the cyst, elastic lamellae were destroyed and the vasa vasorum was generally thickened, and multiple dissecting hemorrhages were observed. In the latter type, even when the intimal tears were not obvious, microscope revealed crumbled atheroma and bleeding in the intima or bleeding within the atheroma. The dissecting bleeding continued from it. Moreover, since enlargement of heart was observed in most cases, hypertension was thought to be an important factor among the predisposing factors in the pathogenesis of dissecting bleeding of the aorta.

Age Factors↗

PubMed2004

Catheter-induced dissection of the left main coronary artery with and without extension to the aortic root: a report of two cases and a review of the literature.

Catheter-induced left main coronary artery dissection is quite rare. We describe two cases of iatrogenic left main coronary artery dissection. In the first case, the aortic root was involved in the dissection process, and stenting of the entry point did not halt the progression of dissection. In the second case, the dissection did not involve the aortic root.

Aged↗

PubMed1990

Management of ascending aortic dissections and aneurysms early and late following cardiac operations.

Intraoperative dissection and late ascending aortic dissection and aneurysm formation infrequently complicate cardiac operations but remain a significant source of morbidity and mortality. A review of 11,145 consecutive cardiac operations at Emory University from January, 1982 through December, 1988 yielded 27 patients with an intraoperative ascending aortic dissection (incidence 0.24%) occurring at the time of the original procedure, with a hospital mortality of 14.8%. Nine additional patients with ascending aortic dissection or aneurysm, presenting late after a previous cardiac operation, were treated during this same period with three deaths. The technical aspects and decision making for application of closed aortic plication, open aortic reconstruction, and ascending aortic replacement based directly on the extent of the intraoperative dissection is detailed. An individualized technical approach tailored to the pathology encountered is outlined for the reoperative group of patients. Etiology, risk factors, principles of prevention, and indications for operation are also discussed.

Aged↗

PubMed1994

Aortic dissection after aortic valve replacement: incidence and consequences for strategy.

From 1986 to 1994, 10 patients were observed to have developed an acute aortic dissection at some stage after an aortic valve replacement (AVR). Study of the characteristics of these patients showed that all patients had an aortic diameter of 50 mm or more (range 50 to 80 mm, mean 64 mm), and 70% suffered from systemic hypertension. Subsequently, the echocardiographic database, containing data from 33,105 studies in 21,484 patients, was searched for cases of AVR in which an accurate aortic dimension could be measured. Of 524 patients who had undergone AVR, an accurate aortic diameter was recorded in 419. Thirty-seven patients had an aortic size greater than 50 mm. All acute dissections occurred in this group of patients. The incidence of acute dissections among patients with significant aortic dilatation following AVR was 27%, whereas the overall incidence of acute dissection after AVR is 0.6%. Although there was a preponderance of tilting disc mechanical valves in the dissecting patients, the type of valve implanted does not seem to be of any importance. From these observations, we conclude that implantation of a valved conduit is indicated even in the presence of mild annuloaortic ectasia (aortic size = 50 mm). Patients who have had an AVR and show an enlarging aortic diameter exceeding 50 mm should have an elective reoperation at an early stage, especially when systemic hypertension is present.

Acute Disease↗

PubMed1994

Repair of the aortic arch with fibrin glue in type A aortic dissection.

Location of the intimal tear in the aortic arch in type A aortic dissection is for many authors an indication for replacement of the aortic arch, but this operation has a high in-hospital mortality rate: 20% to 40%. Instead, we suggest repairing the aortic arch by injecting fibrin glue, which contains a human sealer protein concentrate, between the two dissected layers under circulatory arrest while replacing the ascending aorta. To evaluate this technique, we reviewed 45 successive patients operated on for type A acute aortic dissection between January 1989 and July 1993, of which 6 had the intimal tear located on or extending into the aortic arch. Mean age was 71 +/- 4.2 years (range 68 to 74). After proximal supracoronary anastomosis with a collagen-impregnated graft, aortic arch repair was achieved by injecting fibrin glue between the two layers, using circulatory arrest at a mean temperature of 22 degrees C, with a mean duration of 24 minutes. This obliterated the dissection in the arch and also the intimal flap. The distal part of the graft was then anastomosed to the proximal portion of the aortic arch at the origin of the innominate artery under circulatory arrest. There were no early or late deaths. All patients were asymptomatic at a mean follow-up of 2.6 years. Follow-up angioscan showed obliteration of the dissection in the aortic arch in all patients; there were two patients with dilatation of the distal aortic arch of 40 and 45 mm.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMedDate not supplied

Missed acute ascending aortic dissection.

We describe a patient who presented with classic symptoms and signs of acute aortic dissection that escaped detection despite state-of-the-art imaging techniques. We review the pertinent literature concerning the diagnosis of acute dissection of the ascending aorta and describe the types of dissection that might be missed with conventional diagnostic techniques. Repeated efforts should be made to diagnose aortic dissection even though initial studies may be negative in patients with clinical evidence of dissection.

Acute Disease↗

PubMed2001

Anticoagulation and microembolus detection in a case of internal carotid artery dissection.

BACKGROUND: Microembolic signals (MES) have been demonstrated by transcranial Doppler (TCD) in cases of internal carotid artery dissection. The influence of treatment on MES in arterial dissection is uncertain. The authors here present a case of internal carotid artery dissection in which we detected a reduction of MES after the initiation of intravenous heparin. METHODS: A 37-year-old woman developed a right temporal headache 10 days prior to admission. This was followed by episodes of left arm numbness and weakness. Magnetic resonance imaging (MRI) showed a right frontal and deep subcortical ischemic infarct. Catheter angiography confirmed a right internal carotid artery dissection with intracranial extension. She was then monitored with TCD for MES before and after intravenous heparin was started. RESULTS: The first TCD, performed 12 days after symptom onset, showed 39 MES during 60 minutes of insonation of the right middle cerebral artery. Treatment with intravenous heparin resulted in a decline in MES by 50% after 96 hours. This decline continued and no further MES were detected after 11 days of anticoagulation. CONCLUSION: The authors were able to demonstrate a decline of MES with heparin anticoagulation in a case of internal carotid artery dissection.

Adult↗

PubMed2001

Uncomplicated moderate coronary artery dissections after balloon angioplasty: good outcome without stenting.

OBJECTIVE: To study the relation between moderate coronary dissections, coronary flow velocity reserve (CFVR), and long term outcome. METHODS: 523 patients undergoing balloon angioplasty and sequential intracoronary Doppler measurements were examined as part of the DEBATE II trial (Doppler endpoints balloon angioplasty trial Europe). After successful balloon angioplasty, patients were randomised to stenting or no further treatment. Dissections were graded at the core laboratory by two observers and divided into four categories: none, mild (type A-B), moderate (type C), severe (types D to F). Patients with severe dissections (n = 128) or without available reference vessel CFVR (n = 139) were excluded. The remaining 256 patients were divided into two groups according to the presence (group A, n = 45) or absence (group B, n = 211) of moderate dissection. RESULTS: Following balloon angioplasty, there was no difference in CFVR between the two groups. At 12 months follow up, a higher rate of major adverse cardiac events was observed overall in group A than in group B (10 (22%) v 23 (11%), p = 0.041). However, the risk of major adverse events was similar in the subgroups receiving balloon angioplasty (group A, 6 (19%) v group B, 16 (16%), NS). Among group A patients, the adverse events risk was greater in those randomised to stenting (odds ratios 6.603 v 1.197, p = 0.046), whereas there was no difference in risk if the group was analysed according to whether the CFVR was < 2.5 or >/= 2.5 after balloon angioplasty. CONCLUSIONS: Moderate dissections left untreated result in no increased risk of major adverse cardiac events. Additional stenting does not improve the long term outcome.

Aortic Dissection↗

PubMed1986

Computed tomography: the investigation of choice for aortic dissection?

Computed tomography has become established as complementary to aortography in the investigation of patients with suspected aortic dissection. Two cases of dissecting aneurysm are reported in which extensive aortography failed to show evidence of dissection. In both cases dissection was demonstrated by computed tomography. The diagnosis was confirmed in one case at operation and in the other case by follow up. It is suggested that computed tomography is the diagnostic method of first choice in aortic dissection.

Aged↗

PubMed1996

Spontaneous coronary artery dissection: a neglected cause of acute myocardial ischaemia and sudden death.

Spontaneous coronary artery dissection is a rare cause of acute myocardial ischaemia. Eight consecutive fatal cases which occurred in women aged 34-54 years (mean 43) are described. The dissection involved the left anterior descending coronary artery in four, the left main trunk in two, the right coronary artery in one, and both left anterior descending and circumflex arteries in one. The clinical presentation was sudden death in six cases, and acute myocardial infarction in two. Diagnosis was made at necropsy in every case but one, in which coronary dissection was diagnosed during life by selective coronary angiography. The only ascertained risk factor was hypertension in one patient; none of the women was in the puerperium, and Marfan syndrome was excluded in all. Histology showed a haematoma between the coronary tunica media and adventitia, that flattened and occluded the lumen; a coronary intimal tear was detected in only two cases. Unusual histological findings were cystic medial necrosis in one case, eosinophilic inflammatory infiltrates in four, and angiomatosis of the tunica adventitia in one. Patients dying of spontaneous coronary dissection are usually middle aged women, with no coronary atherosclerosis and apparently no risk factors. Spontaneous coronary artery dissection is unpredictable, and sudden death is the usual mode of clinical presentation. Prompt diagnosis and life saving treatment is far from being achieved.

Acute Disease↗

PubMed1991

Dissection of the extracranial vertebral artery: report of four cases and review of the literature.

Four cases of cervical vertebral artery (VA) dissection are reported. In three patients VA dissection was associated with neck trauma. All patients were young or middle-aged (range 27 to 49 years). In two there was a history of migraine. Pain preceded neurological symptoms from hours to six weeks. Three patients had neurological deficits including elements of the lateral medullary syndrome, and one experienced recurrent transient ischaemic attacks in the vertebrobasilar territory. Angiographic findings included irregular stenosis, occlusion and pseudoaneurysm; in two patients VA abnormalities were bilateral. All patients were treated with anticoagulants and improved. In a review of 28 cases with traumatic dissection and 29 cases with spontaneous dissection of the VA reported in the literature, distinct clinical and angiographic features emerge. Aetiology remains obscure in most cases of spontaneous dissection and management is still controversial.

Adult↗