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Chronic aortic dissection not a risk factor for neurologic deficit in thoracoabdominal aortic aneurysm repair.

OBJECTIVE: chronic aortic dissection has long been considered a risk factor for neurologic deficit following thoracoabdominal aortic aneurysm (TAA) surgery. We reviewed our experience with regard to aneurysm extent and the use of adjunct, (distal aortic perfusion/cerebrospinal fluid drainage), and examined the impact of these factors on neurologic deficit among chronic dissection and non-dissection cases. METHODS: between February 1991 and March 2001, we repaired 800 aneurysms of the descending thoracic and thoracoabdominal aorta. Seven hundred and twenty-nine cases were elective; 196 chronic dissection, 533 non-dissection. 182/729 (24.9%) were TAA extent II. Among these, 61/182 (33%) involved chronic dissection. Adjunct was used in 507/729 (69.6%). We conducted detailed multivariate analyses to isolate the impact of chronic aortic dissection on neurologic morbidity, with other important risk factors taken into account. RESULTS: overall, 32/729 (4.4%) patients had neurologic deficit upon awakening; 7/196 (3.6%) in chronic dissections, and 25/533 (4.7%) in non-dissections. Adjunct had a major effect, reducing neurologic deficit in TAA extent II from 10/36 (27.8%) to 10/146 (6.9%) (p=0.001). However, in univariate and multivariate analysis, chronic dissection did not increase the risk of neurologic deficit, regardless of extent or mode of treatment. CONCLUSION: in contrast to previous reports, we determined that chronic aortic dissection is not a risk factor in TAA patients.

Aortic Aneurysm, Abdominal↗

[Historical outline on the nomenclature of neck lymph nodes as a basis of neck dissection classification].

BACKGROUND: The neck dissection classification is based considerably on the organization of the lymph nodes of the neck. Terminology and anatomical allocation of nearly 300 cervicofacial lymph nodes repeatedly changed since the beginning of the 20th century. METHODS: Analysis of the literature on neck lymph node organization with reference to the development of the neck dissection classification. RESULTS: The first fundamental nomenclature of the neck lymph nodes is founded on the work of Rouviére (1932). Suárez (1963) described the functional neck dissection on the basis of the fascial compartmentalization of the neck. Lindberg (1972) left the predominantly anatomically correlated grouping of the cervical lymph nodes as described by Rouviére and divided the lymphatic system of the neck on basis of pathophysiological mechanisms. The attention regarding the location of occult metastases led to the description of the selective neck dissection. Since the fundamental work of Shah et al. (1981) there was a multiplicity of more or less slight changes of the neck node regions. These changes were again basis for new neck dissection terminologies. A new classification was introduced in the year 2000 as the revised version of the American Head and Neck Society. CONCLUSIONS: The revised version of the neck dissection classification can reduce former controversies, particularly regarding an optimized intraoperative allocation of the lymph nodes and a simplified terminology of the selective neck dissection. With the goal of a standardization of the neck dissection forms it remains to be seen if the proponents of the functional neck dissection after Suárez consider the extent of the neck dissection in patients with N0 neck in favor of the selective neck dissection.

Anatomy↗

[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↗

Isolated dissection of the abdominal aorta: clinical presentation and therapeutic options.

INTRODUCTION: Arterial dissection commonly affects the thoracic aorta and is associated with high morbidity and mortality rates. Although dissection of the abdominal aorta is considered rare, liberal use of diagnostic computed tomographic scan imaging for evaluation of abdominal pain has identified this process with increasing frequency. Because the clinical features and therapeutic options of isolated abdominal aortic dissection are not well characterized, we reviewed our recent experience and provide an algorithm for treatment. PATIENTS AND RESULTS: Since 1996, we have treated 10 patients with abdominal aortic dissection. The mean age was 62 +/- 17 years, and 40% were female. Presentation included abdominal pain in seven patients and lower extremity ischemia in one patient. Dissection was asymptomatic in two of the patients. Hypertension, smoking history, remote trauma, and claudication were noted in four, three, two, and two of the patients, respectively. Three patients had abdominal tenderness, three had a pulsatile mass, and five had a benign abdominal examination. The diagnosis of dissection was made on abdominal computed tomographic scan in eight cases, on arteriogram in one case, and at operation in one case. No patient had an associated thoracic aortic dissection. The dissection flap originated below or at the renal arteries in nine of the cases and at the superior mesenteric artery in one case. Length of the dissection ranged between 21 and 110 mm, and in three patients, the dissection flap extended beyond the aortic bifurcation into the common iliac arteries. In three patients who had an aortogram, evidence of flow limitation was found on the basis of the presence of aortic stenosis or occlusion. Treatment consisted of aortic stent graft deployment in one patient, direct aortic reconstruction in three patients, and observation in the remaining six patients. CONCLUSION: Although the natural history of isolated abdominal aortic dissection has not been well defined, our experience adds to the understanding of this rare process. Because aneurysmal degeneration can occur, close surveillance is indicated if definitive treatment is not used initially. Patients with ischemic symptoms and those with intractable pain need intervention, the nature of which should be based on risk profile and aortoiliac anatomy.

Adult↗

How safe is high-power ultrasonic dissection?

OBJECTIVE: To evaluate the safety of ultrasonic dissection. SUMMARY BACKGROUND DATA: High-power ultrasonic dissection is in widespread use for both open and laparoscopic operations and is generally perceived to carry a low risk of collateral damage, but there is no published evidence for this. METHODS: Under controlled experimental conditions, ultrasonic dissections were performed in pigs using Ultracision (Ethicon) or Autosonix (Tyco/USSC) at the three power settings (3, 4, and 5) in random fashion to mobilize the cardia and fundus, bile duct, hepatic artery, portal vein, aorta from the inferior vena cava, renal vessels, colon, and ureters. The dissections (open and laparoscopic) were carried out on pigs at each power setting with each device. Thermal mapping of the tissues during dissection was performed with an infrared thermal camera and associated software. The animals were killed at the end of each experiment and specimens were harvested for quantitative histology. RESULTS: Extreme and equivalent temperature gradients were generated by ultrasonic dissection with both systems. Heat production was directly proportional to the power setting and the activation time. The core body temperature of the animals after completion of the laparoscopic dissections rose by an average of 2.3 degrees C. The zone around the jaws that exceeded 60 degrees C with continuous ultrasonic dissection for 10 to 15 seconds at level 5 measured 25.3 and 25.7 mm for Ultracision and Autosonix, respectively. At this power setting and an activation time of 15 seconds, the temperature 1.0 cm away from the tips of the instrument exceeded 140 degrees C. Although there was no discernible macroscopic damage, these thermal changes were accompanied by significant histologic injury that extended to the media of large vessels and caused partial- to full-thickness mural damage of the cardia, ureter, and bile duct. Collateral damage was absent or insignificant after dissections at power level 3 with both systems and an activation time not exceeding 5 seconds. CONCLUSIONS: High-power ultrasonic dissections at level 5 and to a lesser extent level 4 result in considerable heat production that causes proximity collateral damage to adjacent tissues when the continuous activation time exceeds 10 seconds. Ultrasonic dissections near important structures should be conducted at level 3. At power levels of 4 and 5, the ultrasonic energy bursts to the tissue should not exceed 5 seconds at any one time.

Animals↗

Observations on the treatment of dissection of the aorta.

The results are presented of treatment in twenty-three patients with dissection of the thoracic aorta, in four of whom it was acute (less than 14 days' duration), and in nineteen chronic (more than 14 days' duration). Sixteen patients had Type I and II dissection (involving the ascending aorta) and five Type III (descending aorta at or distal to the origin of the left subclavian artery); in two, dissection complicated coarctation of the aorta in the usual site. Thirteen patients had aortic regurgitation. Three of the patients with acute dissection were treated medically; two, both with Type I dissection, died, and the third, with Type III, survived. The remaining acute patient was treated surgically and also died. Of the patients with chronic dissection, eight were treated medically and eleven surgically. None of the medical group died in hospital; three died between 3 months and 1 year, and five have survived from periods of 12-72 months. Eleven patients with chronic dissection were treated surgically; four died in hospital at or shortly after operation; and the remaining seven lived for periods of 12-84 months. The presentation, indications for surgical treatment and results are discussed. It is concluded that surgical treatment of chronic dissection may carry a higher initial mortality than medical, but that there may be slightly better overall long term results in the former. As this series was not selected randomly, because patients with complications were selected for surgery, and there are only a few patients in each group, the results do not permit firm conclusion regarding the relative merits of medical and surgical treatment. It is suggested that all patients should initially be treated medically but that surgical treatment should be considered if the dissection continues, if aortic regurgitation is severe, if an aneurysm develops or enlarges, if cardiac tamponade develops or there is evidence of progressive involvement of the branches of the aorta. Attention is drawn to the important syndrome of chronic dissecting aneurysm of the ascending aorta with severe aortic regurgitation which requires definitive surgical treatment and aortic valve replacement. The importance of adequate visualization of the origin and extent of the dissection as a preliminary to surgical treatment is stressed.

Acute Disease↗

Recurrent spontaneous arterial dissections: risk in familial versus nonfamilial disease.

BACKGROUND AND PURPOSE: Among patients with spontaneous cervical artery dissections, the risk of recurrent arterial dissection is relatively low at 1% per year, but this risk may be higher for patients with a family history of arterial dissections. We compared the risk of a recurrent arterial dissection in patients with familial versus non familial disease. METHODS: Long-term follow-up was established in 200 patients (104 women and 96 men with a mean age of 44.9 years) with spontaneous cervical artery dissections evaluated at a single institution between 1970 and 1990. RESULTS: Among the 200 patients, 10 (5%) were identified who had a family history of spontaneous arterial dissections. In a multivariate analysis, family history was the only significant variable associated with the risk of recurrent dissection (X2=15.51; P=.0001). A recurrent arterial dissection was identified in 5 (50%) of the 10 patients with familial disease compared with 11 (5.8%) of the 190 patients with nonfamilial disease, with an estimated relative risk of 6.3 (95% confidence interval, 2.2 to 18.3; P=.0007). CONCLUSIONS: Among patients with spontaneous cervical artery dissections, a family history of arterial dissection is an important risk factor for the development of a recurrent arterial dissection.

Adolescent↗

Changes in false lumen after transluminal stent-graft placement in aortic dissections: six years' experience.

BACKGROUND: Transluminal stent-graft placements (TSGPs) are a new, less invasive procedure now recognized as the choice for aortic disease repair. Treatment of aortic dissections with TSGPs has resulted in good early results, but the long-term results and changes in the false lumen have not been elucidated in detail. METHODS AND RESULTS: TSGPs were performed in 49 patients with primary tears in their descending aortas, and the follow-up period ranged from 4 months to 6 years. The patients were divided into 32 acute-onset and 17 chronic dissections; of the acute-onset cases, there were 15 Stanford type A retrograde dissections. Periodic enhanced spiral CT was conducted after TSGP. The false lumen in the ascending aorta in 14 (93%) of the Stanford type A cases was obliterated completely within 3 months. The CT study was continued for >2 years for 17 acute-onset dissection and 11 chronic dissection patients. The average false lumen diameters of the proximal, middle, and distal descending aorta before treatment were 15.9, 16.2, and 15.6 mm in the acute-onset dissection group and 28.1, 25.2, and 21.0 mm in the chronic dissection group, respectively. The false lumen diameters 2 years after treatment were 3.0, 3.7, and 3.1 mm in the acute-onset dissection group and 10.6, 10.5, and 11.9 mm in the chronic dissection group, respectively. Two years after TSGPs, the false lumen of the thoracic aorta totally disappeared in 76% of the acute-onset dissection group and 36% of the chronic dissection group. No cases showed rupture after TSGP. CONCLUSIONS: Complete obliteration of the false lumen is more likely in acute-onset cases than in chronic cases.

Aged↗

Functional neck dissection: an evaluation and review of 843 cases.

After briefly reviewing the principles, indications, and merits of functional neck dissection, the results of 1200 neck dissections performed on 843 patients in the period 1961-1979 are presented. They compare very favorably with those reported for classic (radical) neck dissection by other leading authors; however, a retrospective analysis of data derived from material of different origin is hardly possible and has a disputable value. Therefore, we decided to compare our data on functional neck dissections (FND) with those of classic neck dissections (CND) performed by the same surgical team at the same clinic in the period 1948-1960. The clinical material was largely the same in both cases, and the data were collected and analyzed using the same criteria. In both series, neck dissections were divided into elective and curative. It could be demonstrated that the number of neck recurrences observed in the dissected necks is the same for FND and CND in curative dissections, while it is considerably lower for FND in elective neck dissections. This of course does not prove improved radicality in FND, but only proves that a systematic bilateral elective neck dissection in N0 cases affords improved cancerological safety. This radical bilateral approach to regional lymph nodes is made possible routinely by FND which avoids the problems of unnecessary mutilation. The figures produced speak in favor of a wider adoption of FND especially for expanding the indications to elective treatment of regional lymph nodes in cancer of the head and neck. Elective neck dissection is made practically harmless by this newer technique and averts the dreadful appearance of late metastases in N0 cases.

Head and Neck Neoplasms↗

Type A dissection following endovascular thoracic aortic stent-graft repair.

PURPOSE: To describe our experience with endovascular stent-graft repairs in the thoracic aorta focusing on the secondary complication of type A dissection. METHODS: Between January 1996 and April 2004, 73 patients were treated for traumatic thoracic aortic rupture (n=15), type B dissection (n=22), or atherosclerotic descending thoracic aortic aneurysms (TAA, n=36). A retrospective review of the records found 5 (6.8%) patients (3 men; median age 64 years, range 43-87) who experienced a type A dissection at a median 20 days (range 2-124) after thoracic stent-graft repair for 3 type B dissections, 1 TAA, and a late type I endoleak that appeared 28 months after initial stent-graft repair of a traumatic dissection. RESULTS: In 3 patients (2 dissections, 1 endoleak), a tear in the aortic wall at the proximal stent-graft was responsible for a retrograde type A dissection. Underlying disease was the cause of the type A dissection in the 2 other patients (1 dissection, 1 TAA) and was unrelated to the stent-grafts. Three patients underwent open surgery at 3, 26, and 124 days after stent-graft placement; 2 procedures were successful, but the third patient died 3 months later due to multiorgan failure. Two type A dissections were untreated: one patient died from cardiac tamponade 14 days after successful stent-graft exclusion of the type I endoleak; the other patient refused further treatment and survived. The procedure-related mortality following acute retrograde type A dissection was 40%. CONCLUSIONS: Endovascular stent-graft repair of the thoracic aorta is associated with lower morbidity and mortality rates than surgical repair, although potentially lethal complications, acute or delayed, may occur.

Adult↗

Dissecting aneurysms at the A1 segment of the anterior cerebral artery--two case reports.

Two rare cases of dissections which involve the anterior cerebral artery (ACA) are reported. A 58-year-old woman presented with a ruptured dissecting aneurysm manifesting as sudden onset of severe headache and consciousness disturbance followed by aphasia, right hemiparesis, paresis of the left lower extremity, and choreoathetotic movements of the upper arms and face. Computed tomography and angiography revealed subarachnoid hemorrhage due to a dissecting aneurysm at the left A1 segment. The dissecting aneurysm was trapped surgically on the day of onset. Her neurological deficits disappeared within a month. A 39-year-old woman experienced continuous dull headache from the day before onset, and then suffered right hemiparesis. Magnetic resonance (MR) imaging revealed cerebral infarction at the left globus pallidus. Angiography and MR imaging revealed a dissecting aneurysm at the left A1 segment and occlusion of the left Heubner's artery. She received conservative treatment and her neurological findings were improved. Dissections or dissecting aneurysms involving the ACA can be classified into three types: Extension of a dissection to the ACA from the internal carotid artery, dissection at the A1 segment, and dissection at the A2-A4 segments. These types of dissection have distinct uniform clinical features.

Aortic Dissection↗

Endovascular treatment of vertebral artery dissections and pseudoaneurysms.

Sixteen patients with dissecting aneurysms or pseudoaneurysms of the vertebral artery, 12 involving the intradural vertebral artery and four occurring in the extradural segment, were treated by endovascular occlusion of the dissection site. Patients with vertebral fistulas were excluded from this study. The dissection was caused by trauma in three patients (two iatrogenic) and in the remaining 13 no obvious etiology was disclosed. Nine patients presented with subarachnoid hemorrhage (SAH), two of whom had severe cardiac disturbances secondary to the bleed. The nontraumatic dissections occurred in seven women and six men, with a mean age on discovery of 48 years. Fifteen patients were treated with endovascular occlusion of the parent artery at or just proximal to the dissection site. One patient had occlusion of a traumatic pseudoaneurysm with preservation of the parent artery. Four patients required transluminal angioplasty because of severe vasospasm produced by the presenting hemorrhage, and all benefited from this procedure with improved arterial flow documented by transcranial Doppler ultrasonography and arteriography. In 15 patients angiography disclosed complete cure of the dissection. One patient with a long dissection of extracranial origin extending intracranially had proximal occlusion of the dissection site. Follow-up angiography demonstrated healing of the vertebral artery dissection but persistent filling of the artery above the balloons, which underscores the need for embolic occlusion near the dissection site. No hemorrhages recurred. One patient had a second SAH at the time of therapy which was immediately controlled with balloons and coils. This patient and one other had minor neurological worsening resulting from the procedure (mild Wallenberg syndrome in one and minor ataxia in the second). Symptomatic vertebral artery dissections involving the intradural and extradural segments can be effectively managed by endovascular techniques. Balloon test occlusion and transluminal angioplasty can be useful adjuncts in the management of this disease.

Adult↗

Waterjet dissection in neurosurgical procedures: clinical results in 35 patients.

OBJECT: Waterjet dissection represents a new minimally traumatic surgical method for dissection that can be used in various parenchymal organs, in which it allows highly precise parenchymal dissection while preserving blood vessels, resulting in reduced intraoperative blood loss. This study was performed to investigate the clinical application of this new technique in neurosurgical procedures, such as brain tumor resection and epilepsy surgery. METHODS: Thirty-four patients with gliomas (Grades II-IV), cerebral metastases, temporal lobe epilepsy, or cerebellar hemangioblastomas, and one patient with internal carotid artery (ICA) stenosis were treated surgically with the aid of the waterjet. Resection was performed using waterjet dissection in combination with conventional neurosurgical procedures. Intraoperatively, the waterjet was easy to handle, and no complications due to the device were observed. Dissection of tissue was possible for all pathological conditions, and pressures between 3 and 45 bars were used. In gliomas, metastases, epilepsy surgery, and hemangioblastoma, the tissue was dissected at pressures between 3 and 17 bars, which preserved blood vessels. Dissection of meningiomas and the ICA stenosis required higher pressures (between 20 and 45 bars); with these pressures, blood vessels were also dissected. CONCLUSIONS: These results indicate that the waterjet dissection procedure can be used intraoperatively without complications. This device appears to be particularly suitable for the dissection of highly vascularized gliomas or normal brain tissue, in which tissue dissection with sparing of blood vessels can be achieved. To prove that this is a useful addition to the neurosurgical armamentarium, reduction of blood loss or postoperative brain edema compared with conventional methods should be demonstrated in future studies.

Adolescent↗

New classification of aortic dissection with reference to a case report.

The authors present a case report of a patient who was diagnosed with aortic dissection during a hemodynamic exam following acute myocardial infarction. With reference to this case, the European Society of Cardiology's latest classification of aortic dissection, published in 2001, is also presented. The patient had the usual risk factors described for aortic dissection, which are simultaneously those for coronary disease. The patient reported an isolated episode in the past of retrosternal pain, radiating to the back, which may have been caused by the aortic dissection. Since then he had been asymptomatic. Four years later, the patient was admitted to hospital following an anteroseptal acute myocardial infarction; fibrinolysis was contraindicated due to recent episodes of rectal bleeding and the patient underwent hemodynamic study (coronary angiography). Due to difficulties in manipulating the guide wire during this exam, aortography was performed, which showed aneurysm and Stanford type B aortic dissection of the thoracic aorta. During hospitalization, a thoracic-abdominal CT scan was performed, which confirmed chronic type B aortic dissection (with intraluminal thrombi). The authors present their reasons for considering this case to be Class 4 according to the new sub-types/classes of aortic dissection of the European Society of Cardiology (ESC): Class 1--Classical aortic dissection Class 2--Intramural hematoma/hemorrhage Class 3--Subtle/discrete aortic dissection Class 4--Plaque rupture/ulceration Class 5--Iatrogenic/traumatic aortic dissection. The authors consider this case to be of interest because of its rarity, the risk that fibrinolysis could have represented, and its categorization according to the latest classification of aortic dissection by the ESC.

Aortic Dissection↗

Anatomic dissection tractography: a new method for precise MR localization of white matter tracts.

BACKGROUND AND PURPOSE: Several white matter tracts in the brain cannot be identified on MR studies because they are indistinguishable from the surrounding white matter. We sought to develop a method to precisely localize white matter tracts by correlating anatomic dissections with corresponding MR images. METHODS: MR imaging was used to guide anatomic dissection of the uncinate fasciculus. Formalin-preserved brains were imaged before and after several stages of dissection. Progressive dissection was guided by using volume-rendered and cross-sectional images of the dissected specimens. To precisely define the location of a tract, its surface was traced on the corresponding three-dimensional MR image of the dissected specimen. MR images of the dissected and intact specimens were coregistered to allow the tracings to be projected onto multiplanar reformatted images of the intact specimen. RESULTS: The uncinate fasciculus in the anterior temporal lobe and external and extreme capsules was dissected without destroying adjacent structures. Coregistration of the MR images from intact and dissected specimens permitted precise MR identification of the surface of this tract. These methods were successful for two additional tracts. (The dissected anatomy, MR anatomy, and clinical examples of the three tracts are described in a companion article.) CONCLUSION: MR-assisted anatomic dissection permits limited removal of brain tissue so that important anatomic and surgical relationships can be demonstrated on correlated MR studies. This method can be applied to other white matter tracts that are indistinguishable on MR studies and to situations in which anatomic validation of normal and abnormal diffusion tractographic studies is needed.

Adult↗

[Value of elective neck dissection in patients with clinically stage I squamous cell carcinoma of the tongue].

OBJECTIVE: To determine the value of elective neck dissection in patients with clinically stage I (cT1N0M0) squamous cell carcinoma of the tongue. METHODS: This was a retrospective study of patients with surgical treatment between November 1984 and November 1999. A total of 130 patients were included in the study, all of whom received operation of the primary site, meanwhile, 99 of whom underwent elective neck dissection simultaneously including level I -III or level I -IV neck dissection in 20 patients and level I - V neck dissection in 79 patients. Results Among all these patients, the rate of occult metastasis to the neck were 12. 0%. Local failure rate in patients with only local treatment, level I II, II, III/IV neck dissection and level I - V neck dissection were 25. 8%, 15. 0% and 7. 6% respectively. There were significant difference in regional failure between patients with only local treatment and patients with elective neck dissection (P < 0.05). Also, no significant differences were noted in the survival rate between patients with only local treatment, elective neck dissection (level I -III or level I -IV) and level I -V neck dissection (P > 0.05). CONCLUSIONS: Elective neck dissection significantly reduced regional control failure but was not able to reduce distant metastasis or increase the overall survival. A prospective randomized study is worthwhile to further evaluate the benefit of elective neck dissection in the treatment of clinically stage I squamous cell carcinoma of the tongue.

Adult↗

[MMP-9 gene -1562C/T polymorphism in aortic dissection in Chinese hypertensive patients].

OBJECTIVE: To investigate the association of matrix metalloproteinase 9 (MMP-9) gene -1562C/T polymorphism with the pathogenesis and site involved range of aortic dissection in Chinese population. METHODS: 142 hypertensive patients with aortic dissection and 130 hypertensive patients without aortic dissection were enrolled. Genomic DNAs were extracted from peripheral blood leucocytes. MMP-9 gene -1562C/T polymorphism was determined with PCR-RFLP. MMP-9 gene -1562C/T genotype and allele frequency were compared between hypertensive patients with aortic dissection and without. In addition, associations of MMP-9 gene -1562C/T polymorphism with clinical aspects were analyzed in hypertensive patients with aortic dissection. RESULTS: There was a significant difference in the T allele frequency of the C-1562T MMP-9 polymorphism between the two groups, with more T allele (17.6%) observed in hypertensive patients with aortic dissection as compared with these without (11.2%) (P = 0.033). The genotype distribution for the MMP-9 -1562C/T polymorphism in hypertensive patients with aortic dissection (-1562CC: 69.0%; -1562 CT: 26.8%; -1562TT: 4.2%) and those without (-1562CC: 79.2%; -1562CT: 19.2%; -1562TT: 1.6%; P = 0.118) showed no remarkable difference, but hypertensive patients with aortic dissection possessing T allele showed a higher odds ratio for involving ascending aorta (OR = 2.063, 95% CI = 0.998 - 4.264, P = 0.049) as compared with those without T allele. CONCLUSIONS: The T variant of MMP-9 gene -1562C/T polymorphism was significantly associated with aortic dissection in hypertensive patients and may represent an important genetic component contributing to aortic dissection susceptibility. Furthermore, hypertensive patients with aortic dissection possessing MMP-9 gene -1562T allele are more prone to involvement of ascending aorta.

Adult↗

Aortic dissection resulting from tear of transverse arch: is concomitant arch repair warranted?

Forty-seven patients with aortic dissection resulting from a primary tear located in the transverse aortic arch underwent surgical treatment. Twenty-six patients had acute type A, 7 had acute type B, 7 had chronic type A, and 7 had chronic type B aortic dissections. Of the 33 patients with acute dissections, 11 (7 acute type A and 4 acute type B) underwent concomitant arch repair with an operative (less than or equal to 30 days) mortality rate of 55% (35% to 73%, +/- 1 asymmetric 70% confidence limit) (2 of 7 acute type A and 4 of 4 acute type B). Concomitant arch repair was omitted in 22 patients with acute dissections (19 acute type A and 3 acute type B); the operative mortality rate was 41% (29% to 54%) (7 of 19 acute type A and 2 of 3 acute type B) (p = not significant versus arch repair). The overall survival rate for those with arch repair was 45% +/- 15% (+/- 1 standard error of the estimate) at 4 years, compared with 43% +/- 11% for patients without arch repair (p = not significant). Considering the type of dissection, the 4-year survival estimate for patients with acute type A dissections who underwent arch repair (5 hemiarch and 2 total arch) was 71% +/- 17% (versus 44% +/- 12% for acute type A patients without arch repair). There were no survivors among the 4 patients with acute type B dissections who had an arch repair (1 hemiarch and 3 total arch), whereas patients with acute type B dissections who did not undergo concomitant arch repair had a 4-year survival estimate of 33% +/- 27% (p = not significant versus arch repair). Four other patients with acute type B dissections resulting from an arch tear were managed medically and tended to have a slightly better prognosis (2-year survival estimate of 75% +/- 22% versus 14% +/- 13% for all surgically treated acute type B patients), but again this difference was not statistically significant. Multivariate analysis of the 47 surgical patients revealed that advanced age (p = 0.0008), preoperative dissection complications (p = 0.02), and other coexistent medical problems (p = 0.03) were the only significant, independent determinants of overall mortality. Initial arch repair was not a significant predictor. Nine percent (2/22) of patients with acute type A dissections who initially underwent isolated ascending aortic replacement required subsequent arch replacement; 1 died after reoperation.(ABSTRACT TRUNCATED AT 400 WORDS)

Actuarial Analysis↗