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PubMed2000

Judging the therapeutic value of lymph node dissections for melanoma.

BACKGROUND: The management of the regional lymph nodes remains controversial for early-stage melanoma and for those patients with lymph node metastases; American Joint Committee on Cancer stage III. This study examines the importance of quality of the surgical resection measured by the extent of lymph node dissection (quartile of the total number of lymph nodes removed) to determine if this factor is an important prognostic factor for survival. STUDY DESIGN: We reviewed our computer-assisted database of more than 8,700 melanoma patients prospectively collected from 1971 through the present to identify patients who underwent lymph node dissection for stage III melanoma. We included only patients who had their nodal dissections performed at our institute. Patients who underwent sentinel lymph node dissection were excluded. These patients were then analyzed as a group and by individual lymphatic basins: cervical, axillary, and inguinal basins. Univariate and multivariate analyses were used to examine the model that included tumor burden, thickness of the primary melanoma, gender, age, clinical status of the lymph nodes (palpable versus not palpable), and the primary site. The survival and recurrence rates were analyzed using the Cox proportional hazards model. RESULTS: Five hundred forty-eight patients underwent regional lymph node dissections. Of these patients, 214 underwent axillary dissections, 181 inguinal dissections, and 153 cervical dissections. The extent of the nodal dissections was based on the quartile of nodes excised, ranging from 1 to 98 (mean +/- SD = 25.8 +/- 15.8). Patients were stratified by tumor burden and quartile of number of lymph nodes removed. The overall 5-year survival of patients with four or more lymph nodes having tumor and the highest quartile of lymph nodes removed was 44% and was 23% for the lowest quartile of total lymph nodes excised (p = 0.05). By univariate analysis, tumor burden (p = 0.0001), quartile of total lymph nodes removed (p = 0.043), and primary site (p = 0.047) were statistically significant for predicting overall survival. Gender, clinical status of the nodes, primary tumor thickness, age, and dissected basin were not significant (p > 0.05). By multivariate analysis only the tumor burden (p = 0.0001) and quartile of lymph nodes resected (p = 0.044) were statistically significant. CONCLUSIONS: The extent of lymph node dissection for melanoma when analyzed by quartiles is an independent factor in overall survival. This factor appears to be more important with increasing tumor burden in the lymphatic basin. The extent of lymph node dissection should be considered as a prognostic factor in the design of clinical trials that involve stage III melanoma.

Female↗

PubMed2000

Accessory nerve function after modified radical and lateral neck dissections.

OBJECTIVES: Evaluate preoperative and postoperative electrophysiological changes related to the accessory nerve with reference to dissection technique, modified radical neck dissection, and lateral neck dissection. STUDY DESIGN: Prospective electrophysiological analysis of accessory nerve function in a total of 20 laryngeal carcinoma patients after neck dissection, 12 being lateral neck dissection (4 bilateral) and 8 being modified radical neck dissection. METHODS: Distal latencies, compound muscle action potentials, and electromyography findings were investigated before surgery and, in early and late postoperative periods in 20 laryngeal carcinoma patients. Results were evaluated by Student t test and chi2 test for intragroup and intergroup differences. RESULTS: In the lateral neck dissection group, postoperative distal latencies were longer, without statistical significance, whereas in the modified radical neck dissection group postoperative latencies were statistically longer. Postoperative compound muscle action potentials were significantly lower in both groups. Electromyographic work-up showed deterioration in early postoperative periods and improvement in late postoperative periods. When intergroup differences were compared, both postoperative compound muscle action potential and electromyographic findings were worse in the lateral neck dissection group. CONCLUSIONS: The accessory nerve function after modified radical neck dissection is better than function after lateral neck dissection because of increased stress applied to the nerve during retraction of the sternocleidomastoid muscle for achievement of a better exposed surgical field in lateral neck dissection.

Accessory Nerve↗

PubMed2001

Angiographic classification of coronary dissections after plain old balloon angioplasty for prediction of regression at follow-up.

Coronary dissection after plain old balloon angioplasty often shows regression during follow-up. This study sought to determine whether we can predict such phenomenon angiographically. We analyzed 64 patients with 71 type B-D coronary dissections determined by the National, Heart, Lung, and Blood Institute (NHLBI) criteria. Regression was considered present when minimal lumen diameter increased by more than 0.3 mm during follow-up. Dissections were divided into subgroups using the NHLBI criteria and our classification in which type a and b dissections were characterized by the width of a dissection lumen exceeding one quarter of the reference diameter with the outer edge of the dissection lumen within the boundary of reference in type a and beyond it in type b. In type c and type d dissections, the width of the dissection lumen was within one quarter of the reference with its outer edge within the boundary of reference in type c and beyond it in type d. Type e dissection had a protruding flap or spiral appearance. Regression was recognized in 23.9%. The distribution of dissection types was similar in the groups with and without regression by the NHLBI criteria, but type c dissection had regression more frequently than the other types of coronary dissections (p<0.001) using our classification.

Aged↗

PubMed1994

[Mediastinal lymph node dissection improves survival rate in N2(-) non-small cell lung cancer patients].

The effect of mediastinal lymph node dissection on survival rate in clinical N2(-) non-small cell lung cancer patients was assessed. N2(-) was evaluated by both pre-operative computed tomography studies and physical examination during surgery. Systematic mediastinal lymph node dissection, including nodes #1, 2, 3, 3a, 3p, 4, 7, 8 and 9 was performed in 27 patients (T1 or 2, N0 or 1, M0) since 1987 (dissected group). Survival rate and complications were compared with those in 21 patients treated before 1986, in whom mediastinal lymph nodes were not dissected (non-dissected group). 1, 3 and 5 year survival rates in the dissected group were 92.6%, 74.9%, and 74.9%, respectively, which were significantly higher than those in the non-dissected group (71.4%, 61.9% and 41.3%, respectively). Mediastinal lymph node metastases were detected histologically found in three patients, 11% of the dissected group. Respiratory complications showed a significantly higher incidence in the dissected group (p = 0.001). However these complications did not increase the mortality rate in that group. Among elderly patients over 70 years old (8 patients in the dissected group, 7 in the non-dissected group), survival rates were similar in the two groups. In conclusion, systematic mediastinal lymph node dissection significantly improved the survival rate in clinical N2(-) non-small cell lung cancer patients.

Aged↗

PubMed1997

Neck dissection for surgical treatment of lymphnode metastasis in papillary thyroid carcinoma.

In papillary thyroid carcinoma lymphnode metastases at presentation do not seem to adversely affect survival, but do increase the risk of loco-regional tumor recurrence. The value of systematic versus selective lymphadenectomy is far less standardized, whereas the role of postoperative radioiodine in preventing either nodal recurrence or cancer death remains controversial. Clinical data of 36 N+ patients with papillary thyroid carcinoma who had undergone from 1990 to 1996 ipsilateral or bilateral neck dissection were retrospectively reviewed, to analyse the value of systematic lymphadenectomy. In our series of 50 extensive lymph node dissections (levels 2-6), the number of metastases in each specimen (mean value: 5) and the incidence of multiple level metastases (36%) were high. In 37.5% of the metastases at level 6 and in 11.1% at level 4, coexisting nodal involvement at level 2 was observed, without metastasization at intermediate levels. Multiple levels metastases and skip metastases were present in at least one third of the patients and could be excised only performing a complete dissection of the levels 2-6. Extra-capsular spread was found in 56% of the specimens. In 64.3% of these cases a functional neck dissection was performed. A modified radical or radical neck dissection was carried out in the other 35.7% of the cases. These patients received modified radical neck dissection (functional dissection with sacrifice of internal jugular vein) in 60% of the cases and radical neck dissection in the other 40%. In papillary thyroid carcinoma extensive lymphnode dissection at presentation has been stated to offer no advantage versus selective lymphadenectomy, causing increased morbidity. However, experienced surgeons report a low incidence (less than 5%) of accessory spinal nerve and cervical plexus permanent sequelae after functional neck dissection. In our opinion, patients with cervical lymph node metastases require a complete loco-regional neck dissection. Systematic lymphadenectomy, performed by lateral neck plus upper anterior mediastinal dissection, can yield a high disease-free survival. Moreover, this can limit the overall radio-iodine therapeutic dose and the risk of de-differentiation of recurrent tumor to the anaplastic type in patients with a long-term and near normal life-span.

Adult↗

PubMed2000

Arterial dissections complicating cerebral angiography and cerebrovascular interventions.

BACKGROUND AND PURPOSE: Iatrogenic dissections are an uncommon complication of cerebral angiography. We retrospectively reviewed 12 cases of arterial dissections complicating cerebral angiography and cerebrovascular interventions to evaluate the clinical course of these dissections. METHODS: Cases from a large tertiary center performing a large number of neurovascular procedures were collected retrospectively. The patients' medical records and imaging studies were reviewed, with particular attention given to the cause of the dissection, the development of ischemic events resulting from the dissection, and the treatment used. RESULTS: Each of nine dissections affected a vertebral artery, each of two affected an internal carotid artery, and one affected a common carotid artery. The prevalence of iatrogenic dissections was 0.4%. Seven of the dissections were noted at the time of contrast material injection for the filming of cerebral angiograms. The other five dissections occurred during catheter or wire manipulations for interventional neuroradiologic procedures. Five of the patients in our series were treated with IV administered heparin for 24 to 48 hours. The other seven patients had recently suffered acute intracranial hemorrhage or undergone neurosurgery and could not undergo anticoagulant therapy. None of the patients developed symptoms of ischemia, but one was later found to have an asymptomatic infarct in the territory supplied by the dissected artery. CONCLUSION: Arterial dissections are an uncommon complication of cerebral angiography and cerebrovascular interventions and usually have a benign clinical course.

Adult↗

PubMed2005

Effectiveness of superselective and selective neck dissection for advanced nodal metastases after chemoradiation.

OBJECTIVE: To determine the efficacy of selective and superselective neck dissection for patients with bulky or residual nodal metastasis treated with concomitant intra-arterial cisplatin and radiotherapy. DESIGN: Prospective study. SETTING: University of Tennessee, Memphis. PATIENTS: A total of 240 patients with stage III or IV head and neck squamous cell carcinoma. INTERVENTIONS: Treatment with cisplatin, 150 mg/m2 intra-arterially, and sodium thiosulfate, 9 g/m2 intravenously, weekly for 4 weeks; and radiotherapy, 2 Gy per fraction per day, 5 times weekly, for a total of 68 to 74 Gy over 6 to 7 weeks. MAIN OUTCOME MEASURES: Regional control, distant metastases, and overall survival for patients undergoing radical or modified radical neck dissection (n = 12), selective neck dissection (n = 65), and superselective neck dissection (levels II-III only) (n = 7). RESULTS: Among the total group of 240 patients, 106 neck dissections were performed on 84 patients who had bulky nodal disease. With a median follow-up of 58 months (range, 12-96 months), regional failure occurred in 11 (4.6%) of 240 patients: 2 (17%) of the 12 who had modified radical neck dissection, 3 (5%) of the 65 who had selective neck dissection, none of the 7 patients who had superselective neck dissection, and 6 (4%) of the 156 who had no neck dissection. The rates of overall survival and distant metastases were not significantly different among the 3 neck dissection subsets. CONCLUSION: Selective and superselective neck dissection, which spare function and minimize morbidity, are viable therapeutic alternatives for patients with residual disease confined to 1 level after intra-arterial chemoradiation treatment, and possibly for other chemoradiation protocols.

Adult↗

PubMed1997

Expanded application of selective neck dissection with regard to nodal status.

BACKGROUND: The efficacy of extending the application of selective neck dissection to include more-extensive neck disease in patients with squamous carcinoma of the upper aerodigestive tract remains controversial. METHODS: A review of all patients undergoing selective neck dissection at a single institution during a 5-year period was undertaken. The analysis was conducted on 82 patients who received 94 selective neck dissections as part of initial therapy for management of squamous carcinoma of the upper aerodigestive tract, including: oral cavity, oropharynx, larynx, and hypopharynx. RESULTS: Forty-six of the 94 dissected necks were supraomohyoid dissections, and 48 were lateral neck dissections. Sixty-five percent of patients were followed a minimum of 2 years and formed the cohort for final analysis. There were eight regional recurrences, three of which occurred in the contralateral, undissected neck. The regional recurrence rate for all patients undergoing selective neck dissection, with or without radiotherapy, according to pathologic N status was as follows: NO (1/33), 3%; N1 (1/8), 12.5%; and multiple positive nodes (3/26), 11.5%. A comparison of recurrence rates with respect to extent of neck disease (N0-N1 versus multiple positive nodes) for both types of neck dissection did not demonstrate significant differences; supraomohyoid neck dissection, p < .5; lateral neck dissection, p < .25. CONCLUSIONS: There exists an expanded role for selective neck dissection in selected patients with primary squamous cell carcinoma of the upper aerodigestive tract and multiple N+ cervical disease. The selection of patients who are candidates for selective lymphadenectomy should be based on pathoanatomic considerations with reference to the primary site of tumor and demonstrated level(s) of metastatic involvement.

Aged↗

PubMed2006

Should we continue teaching anatomy by dissection when ...?

The central role that human dissection has long held in clinical education is being reevaluated in many institutions. Despite the impression that many institutions are abandoning dissection, very few have and most of those have reinstated dissection within a few years. What are the inherent qualities that lead institutions back to dissection? In our efforts to redesign a shortened dissection course, our consultations with a broad range of clinicians lead us to understand how the rhythms of clinical practice are modeled and developed in the small-group setting of the dissection laboratory. Following further consultation with colleagues who have experimented with different models of anatomy instruction, we discuss three themes in support of dissection. First, problem-solving in the dissection laboratory develops the habits-of-mind of clinical practice. Second, relating dissection to imaging modalities develops the spatial reasoning skills needed to understand computer simulations, interpret imaging data, and interact with surgeons, radiologists, and patients. Third, the human face of dissection fosters self-reflection and integration of the cognitive and affective skills required for medical practice. Through group process, the collaborative effort of dissection teams develops essential of attributes of clinical professionalism.

Anatomy↗

PubMed2006

Overcoming the tension between scientific and religious views in teaching anatomical dissection: the Israeli experience.

More than three thousand years of Jewish historical and scholarly writings have addressed the problematic relationship between anatomical dissection for the purpose of medical education and Judaism, which values the wholeness and sanctity of the human body. The Department of Anatomy at Tel Aviv University's Sackler Faculty of Medicine has sought to bridge the gap between science and Jewish religious-cultural values. The Department requires students to conduct laboratory dissections on cadavers in an ethical and respectful manner. Student emotions are also addressed by the Department as students are encouraged to share their apprehensions and concerns about participating in dissections in discussion groups. At the same time, the high academic standards of the medical school are strictly upheld, ensuring that each student has a thorough knowledge of human anatomy. Teaching anatomy in Israeli medical school involves reconciling two conflicting approaches to dissection: (1) The scientific-medical approach, which views the human body as inert material and anatomical dissection as a means of studying anatomy and gaining medical knowledge. (2) A Jewish religious point of view, which perceives anatomical dissection as a threat to the sanctity of a human body and leads to the defilement of those participating in the dissection. In this article, the views of major Jewish scholars regarding dissection are presented and discussed in relation to their implementation in the dissection theater. These views are examined in an anthropological light based on observations in the dissection room and interviews with students and faculty members. The findings reflect the emotions and concerns of Israeli medical students at the Sackler Faculty of Medicine in particular as well as those of the Israeli-Jewish population as a whole. In the dissection theater, medical students must gain a comprehensive understanding of human anatomy while dealing with their own personal ethical, cultural, and religious views on death and dying. Confronting these issues enhances both personal growth as individuals and professional behavior as future physicians.

Anatomy↗

PubMed1995

Coronary artery disease in patients with type A aortic dissection.

The usefulness of preoperative coronary arteriography in patients with type A dissection of the aorta is controversial. To determine the prevalence of arteriosclerotic coronary artery disease in patients with type A dissection of the aorta, we reviewed our experience in 62 patients (42 with acute dissection and 20 with chronic dissection) who underwent operation between January 1, 1986, and December 31, 1993. Among 23 patients with acute dissection who underwent coronary arteriography, 8 (34.8%) had one or more coronary artery lesions causing a greater than 50% narrowing. Among 14 patients with chronic dissection who underwent coronary arteriography, 6 (42.9%) had one or more coronary artery lesions causing a greater than 50% narrowing. There were no fatal complications associated with coronary arteriography. Four patients with acute dissection and 6 patients with chronic dissection underwent coronary artery bypass grafting at the time of operative repair of the aortic dissection, with no operative deaths. On the basis of these findings and the success of combined coronary artery bypass grafting and aortic repair, we recommend that patients with an acute type A dissection who are in stable condition and all patients with a chronic type A dissection of the aorta should undergo preoperative coronary arteriography.

Acute Disease↗

PubMed2006

Chronic dissection of the ascending aorta: surgical results during a 20-year period (previous surgery excluded).

OBJECTIVE: We study here the surgical results of chronic dissection involving the ascending aorta over the last 20 years. Patients with previous cardiac surgery, or proximal aortic repair, were excluded. The patients survived an acute dissection, undiagnosed as pauci- or asymptomatic. The aorta was normal or pathological (atheromatous aneurysm in 15 cases, Marfan's disease in 12 cases, and annuloectasic disease in 18 cases). Two patients had a bicuspid aortic valve. METHODS: Between January 1981 and December 2001, 77 patients (mean age 48+/-15) underwent surgery for chronic dissection of the ascending aorta; 60 patients had severe aortic regurgitation, 12 had Marfan syndrome, and 18 had annuloaortic ectasia. Only the ascending aorta was dissected in 37 patients, the ascending aorta and arch in 26, and the whole aorta in 14. Coronary artery disease occurred in five patients. Statistical analysis was performed using SAS software. Different surgical procedures were used. The aortic arch was repaired in 40 cases; selective antegrade cerebral perfusion and partial circulatory arrest were used. Total aortic replacement was performed on four patients. RESULTS: In-hospital mortality was 10%. The only risk factor was the extent of the dissection. The rate of neurologic stroke was 2.5%. Late survival rate was 42+/-7.5% at 12 years for all the patients; it was 71+/-10% when only the ascending aorta was dissected, 44+/-11% when the ascending aorta and arch were dissected, and 33+/-15% when the whole aorta was dissected (p = 0.0329). The extent of the dissection was the only risk factor for late mortality. Reoperation was required for one proximal and five distal problems. CONCLUSION: In chronic aortic dissection, in-hospital and late mortality were related to the extent of the dissection; in-hospital mortality remained unchanged during the operative period.

Adult↗

PubMed1997

Angiographic evolution of intracoronary thrombus and dissection following percutaneous transluminal coronary angioplasty (the Thrombolysis and Angioplasty in Unstable Angina [TAUSA] trial).

The evolution and progression of thrombus and dissection after percutaneous transluminal coronary angioplasty (PTCA) are unknown. As part of the protocol of the Thrombolysis and Angioplasty in Unstable Angina (TAUSA) trial, 1 and 15 minutes post-PTCA angiograms were routinely performed and evaluated by the core laboratory for the presence of thrombus and either minor or major dissection. Thrombus was present at 1 minute in 4.4% of culprit lesions. This increased to 16% at 15 minutes (p < 0.005) and was equally seen in patients receiving both urokinase and placebo. Any dissection was noted in 25.2% at 1 minute versus 30.5% at 15 minutes (p < 0.08), and this trend was mainly related to an increase in major dissection with urokinase at 15 minutes versus 1 minute (10.1% vs 5.9%, respectively, p = 0.10). The in-hospital clinical outcome of patients with lesions that did or did not have thrombus or major dissection at 1 and 15 minutes was retrospectively assessed in the placebo group. The presence of either thrombus or major dissection at 1 minute was associated with a subsequent incidence of acute closure of 14% and an incidence of emergency bypass surgery of 11% (p < 0.01 compared with no thrombus or major dissection at 1 minute). The absence of thrombus and major dissection at 15 minutes (n = 173) was associated with no subsequent acute closure or emergency bypass surgery, (p < 0.05 for acute closure vs thrombus or major dissection at 15 minutes). Thrombus evolves progressively over 15 minutes after PTCA in unstable angina, whereas dissection is usually present immediately after PTCA. The absence of thrombus and major dissection at 15 minutes is associated with very low-acute in-hospital complications. Delayed angiograms following standard balloon angioplasty for unstable angina may be predictive of low complications and our study suggests a possible role for their use.

Acute Disease↗

PubMed1994

Classification of neck dissection: variations on a new theme.

BACKGROUND: Commencing in 1984, we initiated a head and neck service surgical database that included a classification system for neck dissection. The aim was to reduce the confusion in terminology resulting from growing interest in modifications of conventional radical neck dissection. METHODS: We considered a neck dissection as radical when four or five lymph node levels were excised; this included patients who had an otherwise classical neck dissection for supraglottic larynx or hypopharyngeal cancer sparing level 1. Lymph-node levels removed, nonlymphatic structures preserved, and excised nonlymphatic structures not ordinarily included in a classical radical neck dissection were all specified by the operating surgeon. We defined as a selective neck dissection any lymphadenectomy that encompassed no more than three nodal levels, usually supraomohyoid (levels 1, 2, 3), or jugular (levels 2, 3, 4). We defined as a limited neck dissection any lymphadenectomy that involved removal of no more than two nodal levels. RESULTS: At the 10-year mark, this database of 10,650 patients now includes 2,635 lymphadenectomies in 2,426 patients, the precise extent of which is accurately described in each patient. CONCLUSIONS: The current classification of neck dissection does not cover all possibilities. If we define as radical those lymphadenectomies that resect four or five nodal levels and specify structures preserved or additional nonlymphatic structures sacrificed, we allow for the possibility that some procedures may be both modified and extended. Selective would describe the standard, three-level dissections (eg, supraomohyoid or jugular node dissections), and the term limited would be introduced to indicate a neck dissection that involves removal of no more than two nodal levels. Such a three-tiered classification would more accurately reflect the time and effort involved and provide a more equitable basis for reimbursement.

Carcinoma, Squamous Cell↗

PubMed2002

Spontaneous dissecting aneurysms of anterior and middle cerebral artery associated with brain infarction: a case report and review of the literature.

BACKGROUND: Intracranial dissecting aneurysms have been reported with increasing frequency and are recognized as a common cause of stroke. In some reviews and case reports, attempts have been made to compare the outcomes of surgical and medical treatments. However, the appropriate management of dissecting aneurysms in the anterior circulation remains controversial, especially in patients who also manifest cerebral infarction. CASE DESCRIPTION: A 45-year-old male was diagnosed as having a dissecting aneurysm of the right middle cerebral artery (MCA) with cerebral infarction. In the course of conservative treatment, he developed a new cerebral infarction in the territory of the right anterior cerebral artery (ACA). Repeat cerebral angiograms revealed an increase in the aneurysmal dilatation of the right M2 and the appearance of a segmental dilatation of the right A2. He continued to be treated conservatively and his course was satisfactory. On subsequent angiograms, we observed resolution of the right A2 dissection and no further progression of the dilatation of the right M2. CONCLUSION: This is the first reported case of simultaneous idiopathic dissecting aneurysms of different major arterial branches in the anterior circulation. Our review of the literature disclosed 36 and 23 cases, respectively, of dissecting aneurysms of the ACA and MCA. Many previously reported patients with these dissecting aneurysms involving subarachnoid hemorrhage (SAH) underwent surgery, which resulted in better outcome. More than half of the patients with ACA and MCA dissecting aneurysms had cerebral infarction. All ACA dissecting aneurysms involving ischemia occurred in the A2 region. The outcomes of both surgical and conservative management were equally satisfactory. On the other hand, in patients with MCA dissecting aneurysms, the area of ischemia frequently involved the M1 region; in these patients, conservative treatment resulted in poor outcomes. Therefore, revascularization distal to the compromised artery should be considered in patients with MCA-dissecting aneurysms who have ischemia. Careful interpretation of serial angiograms and/or magnetic resonance (MR) images is necessary because of the possibility of disease progression. If the aneurysmal size increases or there is progression of ischemic symptoms in the course of conservative treatment, surgery must be urgently evaluated.

Aortic Dissection↗

PubMed1996

Detecting acute thoracic aortic dissection in the emergency department: time constraints and choice of the optimal diagnostic test.

STUDY OBJECTIVES: To compare diagnostic strategies for the emergency assessment of patients with suspected acute thoracic aortic dissection and to measure the effect of delays related to the availability of these tests on the selection of the most appropriate one. METHODS: We carried out a decision analysis representing the risks of performing one or two sequential tests, the tests' accuracy, the risks and benefits of treatment, and the time-dependent mortality rate in untreated patients with dissection (1%/hour). Data were drawn from a Medline search. Our subjects were patients who presented to the emergency department with chest pain in whom acute thoracic aortic dissection was suspected. For different clinical probabilities of aortic dissection, we compared the risks and benefits of testing using the following procedures (alone and in combinations): aortography, computed tomography (CT), magnetic resonance imaging (MRI), and both transesophageal (TEE) and transthoracic echocardiography (TTE). We then measured the effect of delays in these tests on the selection of the appropriate procedure. The outcome studied was 30-day survival. RESULTS: We determined that the "threshold" clinical probability of aortic dissection above which the benefits of testing outweigh its risks is low. It ranges from 2% with the most reliable procedure (MRI) to 9% with the least (TTE). At low probability of dissection (< 15%), the accuracy of all tests except TTE is sufficient to rule out dissection. Delays have negligible effect on these results. When the likelihood of dissection is higher, the preferred option is to order a second diagnostic test if the results of the first are negative. The threshold probabilities above which to order a second test range from 15% (CT, then aortography) to 35% (MRI, then aortography). Excessive delays may affect the selection of tests when the likelihood of dissection is high (eg, 50%). Thus, although it is less accurate, a CT scan obtained within 2 hours or a TEE obtained within 6 hours of presentation to the ED yields a higher survival rate than an MRI obtained within 9 hours. Similarly, the benefits of ordering a second test, if the result of the first are negative, outweigh the risks only if the delay in obtaining the test does not exceed 10 hours. CONCLUSION: All patients in whom aortic dissection is suspected, even if the index of suspicion is very low, should undergo one of the available diagnostic procedures (except TTE). A patient with a moderate to high probability of disease should undergo a second investigation if the findings of the first are negative. When the probability of dissection is high, the physician must consider delays in obtaining specific diagnostic tests and order those that will be the most quickly available.

Aortic Dissection↗

PubMedDate not supplied

Use of a balloon-expandable intravascular graft in the management of type B aortic dissection in an animal model.

PURPOSE: To evaluate obliteration of an experimental aortic dissection with a balloon-expandable intravascular stent. MATERIALS AND METHODS: Fourteen adult dogs were divided into two groups. In group 1 (n = 6), a thoracoabdominal aortic dissection was surgically created to observe the natural course of this lesion. In group 2 (n = 8), a balloon-expandable intraluminal vascular graft was introduced via the femoral artery in a dissected aorta to try to obliterate the dissection. Angiography was performed postoperatively and again 6 weeks later before the aortae were explanted for pathologic evaluation. RESULTS: In group 1, postoperative aortography depicted evidence of aortic dissection in all animals. Autopsy revealed persisting dissection with reentry tear near the celiac axis in five animals. In group 2, placement of a stent at only entry and reentry sites resulted in partial obliteration of the dissection (n = 3). When the entire length of dissected aorta was treated, the dissection was completely obliterated (n = 4). CONCLUSION: An aortic dissection can be obliterated with a balloon-expandable stent if the entire dissected aorta is treated.

Aortic Dissection↗

PubMed2000

Vertebral artery dissection: warning symptoms, clinical features and prognosis in 26 patients.

BACKGROUND AND OBJECTIVES: Internal carotid artery dissection has been extensively studied and well-described. Although there has been a recent increase in the number of reported cases of vertebral artery (VA) dissection, the clinical variety of presentation and the early warning symptoms have not been well-described before. Our objectives in this study include: (1) To determine the early symptoms and warning signs which may help the clinician in the early identification and treatment of patients with VA dissection. (2) To explore the variety of clinical presentation of VA dissection and its relation to prognosis. DESIGN AND SETTING: Retrospective analysis of hospital records in a tertiary academic centre for the period 1989-1999. RESULTS: Twenty-six patients were identified (13 men and 13 women). The mean age was 48. Possible precipitating factors were identified in 14 patients (53%). Sporting activity and chiropractic manipulations were the most common (15% and 11% respectively). Headache and/or neck pain was the prominent feature in 88% of patients and was a warning sign in 53%, preceding onset of stroke by up to 14 days. The most common clinical features included vertigo (57%), unilateral facial paresthesia (46%), cerebellar signs (33%), lateral medullary signs (26%) and visual field defects (15%). Bilateral VA dissection presented in six patients (24%). The most common region of dissection was the C1-C2 level (16 arteries, 51%). Intracranial VA dissection was found in eight arteries (25%). The majority of patients (83%) had favorable outcome. Poor prognosis was associated with (1) bilateral dissection; (2) intracranial VA dissection accompanied by subarachnoid hemorrhage. Only two patients reported stroke recurrence. CONCLUSIONS: Our findings show that VA dissection affects mainly middle age persons and involves both sexes equally. Headache and/or neck pain followed by vertigo or unilateral facial paresthesia is an important warning sign that may precede onset of stroke by several days. Although the majority of patients will have excellent prognosis, this was less likely in patients presenting with subarachnoid hemorrhage or bilateral VA dissection. Recurrence rate was low.

Adult↗