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PubMed1986

The complementary role of magnetic resonance imaging, Doppler echocardiography, and computed tomography in the diagnosis of dissecting thoracic aneurysms.

Non-ECG gated MRI was compared with 2DE and/or CT scans in 10 patients with dissecting aneurysms proven by angiography and/or surgery. Patient ages ranged from 48 to 85 years (mean 69.6). Six had DeBakey type I dissections and four had DeBakey type III dissections. MRI was diagnostic for aortic dissection in nine cases and suggestive in the tenth. 2DE was diagnostic in six out of nine patients, suggestive in two patients, and nondiagnostic in one patient. CT was diagnostic in the three cases in which it was employed. MRI demonstrated a dilated ascending aorta with thickened walls in all type I dissections as well as an intimal flap and slow flow in the false channel in four patients. In the other two patients with type I dissection, MRI detected the intimal flap in the descending aorta but not in the ascending aorta, whereas 2DE revealed the ascending aortic intimal flap in both of these patients and CT showed it in one of them. In the type III dissections, MRI demonstrated a thickened wall and thrombus in the lumen in all four cases, and the intimal flap in three out of the four. 2DE excluded ascending aortic involvement in all three type III dissections. Six other patients with fusiform dilated ascending aortas had no evidence of dissection by MRI, 2DE, and aortography. Thus, non-ECG gated MRI alone or in combination with 2DE and/or CT is useful in the diagnosis of dissecting thoracic aneurysm and in assessing the extent of the dissection. In addition, the differentiation of dissecting aneurysms of the aorta from fusiform dilatation of the aorta is made possible by these noninvasive techniques.

Aged↗

PubMed1984

Risk factors for aortic dissection: a necropsy study of 161 cases.

Among 161 necropsy cases of aortic dissection, 87 (54%) were type I, 34 (21%) type II, and 40 (25%) type III, and an intimal tear was identified in each. Systemic hypertension had been present in 63 of 121 cases (52%) with type I or II dissection and in 30 of 40 (75%) with type III dissection. Aortic dissection involved 7 of 16 cases (44%) with the Marfan syndrome. In the 154 cases without the Marfan syndrome, grade 3 or 4 medial degeneration (cystic medial necrosis) was observed in the ascending aorta in only 27 (18%). The risk of aortic dissection in persons with congenitally bicuspid and unicommissural aortic valves, respectively, was 9 and 18 times that in subjects with tricuspid aortic valves. The mean age of those with aortic dissection and tricuspid, bicuspid and unicommissural aortic valves was 63, 55 and 40 years, respectively, and aortic dissection was more common in men than in women. Grade 3 or 4 atherosclerosis involved the intimal tear in only 11 of 121 type I or II dissections (9%) but 32 of 40 type III dissections (80%). Accordingly, the major risk factors for aortic dissection were systemic hypertension, the Marfan syndrome, and, for type I and II dissections, congenitally bicuspid or unicommissural aortic valves. Aortic medial degeneration was a less important risk factor. Rupture of ulcerocalcific aortic atheromas may have initiated the intimal tear in some type III dissections.

Adult↗

PubMed1995

Frequency and explanation of false negative diagnosis of aortic dissection by aortography and transesophageal echocardiography.

OBJECTIVES: This study was designed to define the frequency and explanation of false negative diagnosis of aortic dissection by aortography and transesophageal echocardiography. BACKGROUND: Aortography and transesophageal echocardiography have been widely utilized to diagnose aortic dissection. Previous reports have not fully addressed the reasons why these studies yield false negative results in a large number of patients with aortic dissection. METHODS: Sixty-five consecutive patients with aortic dissection underwent aortography and transesophageal echocardiography. Diagnosis of aortic dissection was confirmed at operation or by computed tomography in all patients. RESULTS: Biplane transesophageal echocardiograms yielded false negative results in two patients (sensitivity 97% [63 of 65]). Both patients had well localized DeBakey type II aortic dissection. The diagnosis was probably missed because of image interference from the air-filled trachea and mainstem bronchi. In both patients, the dissection was readily identified by aortography. Aortograms yielded false negative results in 15 patients (sensitivity 77% [50 of 65]); the aortic dissection was type I in 7 patients, type II in 1 and type III in 7. The dissection in all 15 patients was readily identified by transesophageal echocardiography. The missed diagnosis was probably due to a completely thrombosed false lumen or intramural hematoma with noncommunicating dissection in 13 patients and to a large ascending aortic aneurysm with nearly equal flow on both sides of the intimal flap in 2. In no patient was the diagnosis missed by both aortography and transesophageal echocardiography. CONCLUSION: Transesophageal echocardiography is an excellent screening tool for aortic dissection. However, it may miss small type II aortic dissections localized to the upper portion of the ascending aorta because of image interference from the air-filled trachea. An intramural hematoma cannot be easily visualized by aortography, and this lesion is the principal reason for false negative aortographic findings.

Adult↗

PubMed1993

Presence of sperm in the perivitelline space predicts fertilization rate after partial zona dissection.

OBJECTIVE: To examine the association of the number of spermatozoa present in the perivitelline space and sperm parameters with fertilization after partial zona dissection in male factor patients. DESIGN: Partial zona dissection was applied in 62 couples (84 cycles). A total of 524 oocytes underwent partial zona dissection (1/8 of the zona circumference) (partial zona dissection group) and 171 sibling oocytes were not manipulated (control group). A total of 326 manipulated oocytes were examined for the presence of spermatozoa in the perivitelline space. SETTING: University-based in vitro fertilization (IVF) program. PATIENTS: Fifty-four (87%) couples had at least one complete failure of fertilization, and 8 (13%) couples had low fertilization rate (< 10%) in previous routine IVF attempts. MAIN OUTCOME MEASURES: Fertilization rate, cleavage rate, and the number of spermatozoa present in the perivitelline space after partial zona dissection. RESULTS: Monospermic and polyspermic fertilization rates were 22.3% and 6.7% in the partial zona dissection oocytes and 8.8% and 0.6% in the nonmanipulated oocytes, respectively. The cleavage rate was similar in the partial zona dissection and control group (69.2% and 66.6%, respectively). A total of 81 partial zona dissection embryos and 10 nonmanipulated embryos were transferred to the uterus of 34 women (39 cycles), resulting in four pregnancies. In 46% (18 of 39) of the patients who had both partial zona dissection and control oocytes, only the manipulated oocytes fertilized. In only 48.8% of partial zona dissection oocytes, spermatozoa were detected in the perivitelline space; in this group of oocytes the fertilization rate was 56.6%. Sperm count and morphology were not clearly correlated with the outcome of partial zona dissection. CONCLUSIONS: The partial zona dissection technique enhances fertilization of subfertile sperm. However, the low efficiency of the procedure, apart from being associated with a high polyspermic rate, is related to the failure of sperm to traverse the slit in the zona pellucida in approximately one half of the manipulated oocytes.

Adult↗

PubMed1994

A selective approach to neck dissection for mucosal squamous cell carcinoma.

A personal series of 189 neck dissections performed over 6 years among 154 patients with mucosal squamous cell carcinoma is presented. The most common primary sites were the oral cavity (66), oropharynx (38) and hypopharynx (17). There were 104 therapeutic and 85 elective neck dissections. Over 40% of therapeutic dissections were modified or selective procedures. Radical neck dissection was never used electively. Seventy-eight patients (50%) had postoperative radiotherapy to the neck. Nodes were histologically positive in 110 dissections overall (58%); 92% of therapeutic dissections and 17% of elective dissections. Extracapsular spread was present in 65% of positive dissections. Ipsilateral neck recurrence developed in 10 of 60 patients who had therapeutic radical dissections (17%) and in 2 of 44 patients who had therapeutic, modified or selective dissections (5%). Recurrence after elective dissection occurred in only one patient (1.2%). It is concluded that modified and selective neck dissection are safe and oncologically effective when used among selected patients and combined with adjuvant radiotherapy. Neck recurrence may still occur among patients with advanced and biologically aggressive disease despite radical therapy.

Adult↗

PubMed1997

The dissected aorta: part I. Early anatomic changes in an in vitro model.

PURPOSE: To define early anatomic changes in the aorta in an in vitro hydrostatic model of acute aortic dissection. MATERIALS AND METHODS: Aortic dissections were created in explanted aortas. A small portion of the dissection flap was resected to allow free communication between the true and false lumina. The aortas were suspended in a saline bath and distended by means of a saline fluid column. By using intravascular ultrasonography, the arc lengths of the outer walls of the true and false lumina and of the dissection flap were measured at increasing hydrostatic pressures and at increasing fractions of dissected wall circumference. RESULTS: The dissected aorta immediately became ectatic. At a given fraction of wall circumference involved in dissection, total aortic cross-sectional area increased with increased hydrostatic pressure. At a given hydrostatic pressure, this area increased with increased fraction of wall circumference dissected. Most of the increase was due to dilatation of the false lumen. There were minimal changes in true-lumen size. Dissection flap length, after initial contraction at the time of dissection, changed minimally with increasing pressure. CONCLUSION: Anatomic changes in the dissected aorta depend on hydrostatic pressure and on the percentage of aortic wall involved in the dissection.

Acute Disease↗

PubMed1992

[Acute and subacute dissection of the thoracic aorta: diagnostic importance of magnetic resonance tomography].

The purpose of this study was to retrospectively assess the reliability of ECG-triggered magnetic resonance imaging (MRI) for the diagnosis of acute and subacute thoracic aortic dissection and associated clinical epiphenomena. 67 patients were subjected to MRI; the diagnostic results were compared with morphological standards. 25 patients had type A, 12 patients type B dissection. In 30 cases a dissection was excluded. 17 patients with aortic dissection had acute onset of symptoms, 10 patients had subacute onset of symptoms. 17 patients revealed thrombosis of the false lumen, which was found in the descending aorta in 59% of the cases. Aortic regurgitation and pericardial effusion was most often associated with type A dissection (Table 1). Three patients were studied while on mechanical ventilation. Scan time for MRI ranged from 15 to 71 minutes with an average of 46 +/- 18 minutes. In this series no deleterious events were encountered related to MRI diagnostics. In contrast to previously published data using other noninvasive techniques the sensitivity of MRI was 100% for detecting a dissection in the ascending segment of the thoracic aorta. Moreover, the specificity of MRI for a dissection was 100% and thus higher than previously published data using transesophageal echocardiography. Sensitivity and specificity for detection and correct classification of type B dissection was 100% and 100% respectively (Table 2). In addition, MRI proved to be sensitive in detecting the formation of thrombus material in the false lumen of the ascending aorta (92%), the aortic arch (100%) and the descending segment (88%). Specificity for exclusion of suspected thrombus material even proved to be slightly higher with 100% in the ascending and descending aorta and 96.1% in the aortic arch (Table 3). The site of entry to a dissection was detected in 78%, with a sensitivity of 76% in the ascending and 92% in the descending aorta. The involvement of side branches in the dissecting process was identified in 60%. There were no false positive findings concerning side branch involvement. Aortic regurgitation and pericardial effusion were detected in 100% and 100%, respectively (Tables 1 and 2). MRI performed even in acute cases proved to be a atraumatic, safe and highly sensitive method to identify and classify acute and subacute dissections of the entire thoracic aorta. Limited patient access was not associated with an increased risk and mechanical ventilation did not interfere with MRI. These results may establish MRI as a valid and promising noninvasive technique to establish the diagnosis in patients with thoracic aortic dissection.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗

PubMed1986

[Role of echocardiography in the diagnosis of aortic dissection].

We evaluated sensitivity, specificity and predictive values of echocardiography in detecting aortic dissection. We studied in the same period of time two groups of consecutive patients with good quality echocardiographic examination. Group I, with high prevalence of the disease (76%), was composed of 25 patients; 19 patients with aortic dissection (11 of the type A and 8 of the type B) and 6 patients with clinical and echocardiographic suggestion of aortic dissection which was not confirmed by angiography. Group II, with lower prevalence of the disease (4%), was composed of 382 adult patients who underwent aortic angiography for different reasons. In this second group there were 16 out of the 19 patients of the first group, with aortic dissection, who underwent aortic angiography and the 6 patients with suspicion of aortic dissection which was not confirmed by angiography. Type A dissection: The finding of intimal flap on echocardiography was highly specific (98%) but relatively insensitive (45%); its positive predictive value was low (50% in the first and 34% in the second group). The specificity of increased thickness of aortic wall was lower (89%) and the sensitivity higher (81%); its positive predictive value was satisfactory in the first group (81%) and very low in the second (13%). Aortic root dilatation was fairly specific (76%); the sensitivity of this finding was high (87%) but its positive predictive value was still low (66% in the first and 7% in the second group). To conclude: the positive predictive value of the 3 echocardiographic signs of aortic dissection varied, in relation to the different prevalence of the disease, from 50, 81 and 66% in the first group to 34, 13 and 7% in the second group; the diagnostic utility of the echocardiographic examination appeared limited, in these patients, by the low values of sensitivity and positive predictive values; aortography is still the most valuable technique in the diagnosis of aortic dissection; echocardiography was useful in the early evaluation of some emergency cases (chest pain, shock, collapse...) suggesting sometimes the correct diagnostic hypothesis of aortic dissection; in the presence of a typical clinical picture, the contemporary presence of the 3 echocardiographic signs, though having the lowest sensitivity (36%), was highly predictive of the type A dissection. Type B dissection: In these patients the clinical picture, in contrast with type A dissection, Type A, was not indicating careful and complete echocardiographic aortic scan. Then the echocardiographic examination was even more disappointing: sensitivity 25%.

Adult↗

PubMed1996

[Surgical treatment of aortic dissection with ringed intraluminal graft--late results and fate of the false lumen].

Between April 1981 and March 1992, sixty-nine patients underwent surgery for aortic dissection in our hospital and affiliated hospitals. Of them, 48 patients who survived the operation were followed up 2 months to 11.8 years (mean: 4.6 years). We compared the fate of the false lumen and late results in the 31 patients who underwent ringed intraluminal graft (RIG group) and the 17 patients who underwent conventional graft replacement (GR group). To clarify the status and severity of the dissected aorta, we devised a scoring system (dissection score: DS) to evaluate the long-term changes in the diseased aorta after operation. Of 12 patients (25%) who died of late dissection-related complications, 10 were in the RIG group and 2 in the GR group. The actuarial survival at 5 years was 66 +/- 9% in the RIG group and 88 +/- 8% in the GR group. Late dissection-related events (dissection-related death, redissection, reoperation) were observed in 17 patients, 14 of whom belonged to the RIG group and 3 to the GR group. The dissection-related event-free survival at 5 years was 51 +/- 10% in the RIG group and 88 +/- 8% in the GR group. In 36 (75%) of the 48 patients, including 20 (65%) of the 31 patients in the RIG group and 16 (94%) of the 17 in the GR group (p < 0.05), it was possible to resect the primary intimal tear. The actuarial survival at 5 years was 76 +/- 8% for those 36 cases in which resection of the primary intimal tear was possible and 64 +/- 15% for those in which resection was not possible. The dissection-related event-free survival at 5 years was 72 +/- 8% in the former group and 33 +/- 15% in the latter. The dissection score (DS) decreased from a pre-operative value of 21.5 +/- 8.4 to 12.0 +/- 9.3 postoperatively (p < 0.001). A significant decrease in DS was observed both in the RIG group and the GR group, in the former from 22.1 +/- 7.2 to 13.1 +/- 9.3, and in the latter from 19.9 +/- 11.5 to 9.1 +/- 9.2 (p < 0.01). The DS for those whose primary intimal tear could be resected was significantly decreased postoperatively (pre-operative 20.6 +/- 8.9, post-operative 9.3 +/- 8.4; p < 0.001); but for those whose primary intimal tear could not be resected, there was no difference between the pre- and post-operative DS (pre-operative 23.4 +/- 7.3, post-operative 18.2 +/- 8.7). The percent reduction in DS (%R) was significantly greater in the former group than in the latter one (61% vs. 29%; p < 0.02). DS significantly decreased for those with no late dissection-related events (from 22.4 +/- 9.2 to 10.9 +/- 8.8; p < 0.001) while for those who presented with such events there was no difference between before and after the operation (pre-operative 19.0 +/- 5.7, post-operative 14.9 +/- 10.6). The %R in those with dissection-related events tended to be lower than that in those without such events (33% vs. 58%). Resection of primary intimal tear seemed to be important not only to improve operative results in patients with aortic dissection but also to improve late results. Depending on the site and size of the intimal tear, the ringed intraluminal graft insertion technique often makes intimal tear resection impossible. Indications for this surgical technique are thus quite limited.

Aged↗

PubMedDate not supplied

Prevalence of vertebral artery dissection in Wallenberg syndrome: neuroradiological analysis of 93 patients in the Tohoku District, Japan.

To assess the prevalence of vertebral artery dissection in Wallenberg syndrome (lateral medullary syndrome), records of 93 patients (70 men, 21 women, and 2 patients not identified by gender; mean age at ictus, 58.1 years) with symptoms of Wallenberg syndrome who underwent MRI and/or vertebral angiography were reviewed retrospectively. Study items included the following: (A) headache; (B) arterial intramural hematoma on T1-weighted images as an MR finding; and (C) double lumen, intimal flap, pearl and string sign, and string sign as angiographic findings. These abnormal findings suggesting vertebral artery dissection were scored as 1 or 2 points. According to his or her total score, each patient was classified as "definite dissection." "probable dissection," "suspected dissection," or "no dissection." Twenty-three of 93 patients were classified as "definite dissection," 23 as "probable dissection," 27 as "suspected dissection," and 20 as "no dissection." The frequency of definite or probable dissection in Wallenberg syndrome was estimated at 50% or more. Thus, vertebral artery dissection is a frequent cause of Wallenberg syndrome.

Adult↗

PubMed1992

Therapeutic dissection after successful coronary balloon angioplasty: no influence on restenosis or on clinical outcome in 693 patients. The MERCATOR Study Group (Multicenter European Research Trial with Cilazapril after Angioplasty to prevent Transluminal Coronary Obstruction and Restenosis).

OBJECTIVES: The objective of this study was to examine the relation between an angiographically visible coronary dissection immediately after successful coronary balloon angioplasty and a subsequent restenosis and long-term clinical outcome. BACKGROUND: The study population comprised all 693 patients who participated in the MERCATOR trial (randomized, double-blind, placebo-controlled restenosis prevention trial of cilazapril, 5 mg two times a day). METHODS: Cineangiographic films were processed and analyzed at a central angiographic core laboratory, without knowledge of clinical data, with use of an automated interpolated edge detection technique. Dissection was judged according to the National Heart, Lung, and Blood Institute classification. Angiographic follow-up was obtained in 94% of patients with 778 lesions. Two approaches were used to assess the restenosis phenomenon: 1) categoric, using the traditional cutoff criterion of greater than 50% diameter stenosis at follow-up, and 2) continuous, defined as absolute change in minimal lumen diameter (mm) between the postcoronary angioplasty and follow-up, adjusted for the vessel size (relative loss). Clinical outcome was ranked according to the most serious adverse clinical event per patient during the 6-month follow-up period, ranging from death, nonfatal myocardial infarction, coronary revascularization and recurrent angina requiring medical therapy to none of these. RESULTS: Dissection was present in 247 (32%) of the 778 dilated lesions. The restenosis rate was 29% in lesions with and 30% in lesions without dissection (relative risk 0.97; 95% confidence interval 0.77 to 1.23). The relative loss in both groups was 0.10 (mean difference 0; 95% confidence interval -0.03 to 0.03). Clinical outcome ranged from death in 4 patients (0.9%) without dissection and 1 patient (0.4%) with dissection; nonfatal myocardial infarction in 4 (0.9%) without and 8 (3.2%) with dissection; coronary revascularization in 73 (16.6%) without and 32 (12.7%) with dissection; recurrent angina requiring medical therapy in 88 (20%) without and 47 (18.7%) with dissection to no serious adverse event in 272 (61.7%) without and 114 (65.1%) with dissection. CONCLUSIONS: These data indicate that a successfully dilated coronary lesion with an angiographically visible dissection is no more likely to develop restenosis, and is not associated with a worse clinical outcome, at 6-month follow-up than is a dilated lesion without visible dissection on the post-balloon angioplasty angiogram.

Angioplasty, Balloon, Coronary↗

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↗

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↗

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↗

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↗

PubMed1994

[Surgically treated thoracic aortic dissection. The angiographic follow-up of the perfusion relations].

Control angiography in arterial DSA technique was performed in 27 patients after operative treatment of acute aortic dissection (17 patients with type A dissection) respectively chronic aortic dissection (9 patients with type A dissection/1 patient with type B dissection). The mean interval between surgery and angiography was 59 months. All patients were free from symptoms due to organ complications or redissection. Persistent patency of a false lumen was observed in 40.7% (52.9% after operative treatment of an acute dissection; 20% after operative treatment of a chronic dissection). In all cases with a persistent false lumen the dissection originated at the distal anastomosis. In all patients the beginning of the dissection and the perfusion of the supra-aortal, visceral and iliac vessels whether by the true or false lumen could be shown. In 54.5% the Tr. brachiocephalic trunk was involved in the dissection. In 45.5% the left renal artery was solely perfused by the false lumen. Angiography in arterial DSA technique is evidently a valuable technique to document the beginning and extension of a dissection, sufficiency of the aortic valve, re-entries of the dissection, perfusion of the aortal branches, and the flow in both channels.

Acute Disease↗