PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Dissection”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22Linked to original sources

Antegrade approach to radical retropubic prostatectomy in patients with difficult apical dissection.

Among 335 radical retropubic prostatectomies an antegrade dissection was used in 30 because of difficulty in developing the usual planes of dissection during apical dissection. The adequacy of tumor resection, preservation of sexual potency and urinary continence were compared in patients who underwent the antegrade dissection and those who underwent the standard retrograde nerve-sparing radical retropubic prostatectomy. Histopathological evaluation revealed no significant difference in the over-all completeness of tumor excision between the group having an antegrade dissection (16 of 30, 53% completely excised) and those having a retrograde dissection (177 of 305, 58% completely excised) (p = 0.62). Patients with clinically localized but pathological stage C disease undergoing an antegrade dissection and a nerve-sparing procedure had a significantly higher incidence of positive lateral margins (9 of 12, 75%) than the comparable group undergoing a retrograde dissection (40 of 99, 40%) (p = 0.02). The incidence of positive apical margins was similar in both groups, with 5 of 14 (36%) of the antegrade stage C cases (36%) having positive apical margins compared to 37 of 117 of the retrograde stage C cases (32%) (p = 0.65). Sexual potency was preserved in 5 of 6 patients (83%) treated with an antegrade dissection who had both neurovascular bundles preserved and were followed for at least 6 months, compared to 86 of 142 (61%) who underwent retrograde dissection (difference not significant, p = 0.26). Potency was preserved in 6 of 13 evaluable patients (46%) undergoing unilateral antegrade nerve-sparing procedure compared to 21 of 48 evaluable patients (44%) undergoing unilateral retrograde nerve-sparing procedure (p = 0.88). Of 22 patients followed for 1 year 21 (95%) have regained urinary continence. We conclude that the antegrade approach to radical retropubic prostatectomy provides results that are comparable to those achieved with the standard retrograde approach but that when an antegrade approach is chosen because of periprostatic fibrosis, bilateral preservation of the neurovascular bundles may result in a higher incidence of positive surgical margins.

Adenocarcinoma↗

Pathology of spontaneous dissection of intracranial arteries.

Spontaneous dissection of a major subarachnoid artery is an uncommon cause of stroke in young and apparently healthy individuals. Such dissection does not correlate well with systemic conditions such as emboli, thrombotic or hemorrhagic tendencies or hypertension, nor with disease of blood vessels such as atherosclerosis, fibromuscular dysplasia, cystic medial necrosis or Moya-Moya disease. Unusual exertion has been implicated as a factor in some cases. Gap defects were found in the internal elastic lamina near the site of dissection in three of four cases of spontaneous dissection reported here. It is suggested that such defects, because of their unusual size or number, may be responsible for initiating dissection in susceptible individuals. A detailed study of the major cerebral arteries in cases of dissection and control cases to document the size and frequency of such defects could shed light on the pathogenesis of spontaneous dissection. The subsequent course of events tends to differ in the internal carotid and vertebro-basilar systems. In most cases, the dissection in the internal carotid system is sub-intimal leading to thrombosis and cerebral infarction, while in the vertebrobasilar system dissection lies between the media and adventitia leading to subarachnoid hemorrhage. It is not known what structural differences of the two arterial systems may underlie this difference in the pattern of arterial dissection.

Adult↗

Stage I melanoma of the limbs. Immediate versus delayed node dissection.

553 patients with stage I malignant melanoma of the limbs entered a prospective randomized clinical trial carried out by the W.H.O. Collaborating Centres for Evaluation of Methods of Diagnosis and Treatment of Melanoma from September 1967 to January 1974. 286 patients were submitted to wide excision of primary and node dissection at the time as appearance of regional lymph node metastases and 267 to wide excision and immediate node dissection. Survival was identical in the 2 groups. Different subsets of patients were evaluated to assess whether some groups of patients may benefit from immediate node dissection. As regards sex, females and a significantly higher survival rate than males (p < 0.05), but results were not improved by immediate node dissection. Maximum diameter and elevation of primary melanoma were significantly related to survival but also in these cases immediate node dissection did not achieve better results. 63 patients had an excisional biopsy of their melanoma within 4 weeks before final treatment. This procedure did not worsen survival and also in this case immediate node dissection did not improve survival. 273 cases were classified according to histologic type: survival of superficial spreading and nodular melanoma was not different at a statistically significant level after the 2 treatment modalities. 325 cases were considered classifiable according to Clark's levels, out of these 165 were submitted to immediate node dissection. Neither level III nor level IV cases showed higher survival rate after immediate node dissection. Maximum tumor thickness according to Breslow was evaluated in 338 cases: 188 were submitted to wide excision and immediate node dissection. In no clusters of thickness did the enlarged surgical procedure achieve better results. The authors conclude that there is good evidence that in stage I melanoma of the extremities delayed dissection.

Adolescent↗

Extended lymph node dissection for gastric cancer: who may benefit? Final results of the randomized Dutch gastric cancer group trial.

PURPOSE: The extent of lymph node dissection appropriate for gastric cancer is still under debate. We have conducted a randomized trial to compare the results of a limited (D1) and extended (D2) lymph node dissection in terms of morbidity, mortality, long-term survival and cumulative risk of relapse. We have reviewed the results of our trial after follow-up of more than 10 years. PATIENTS AND METHODS: Between August 1989 and June 1993, 1,078 patients with gastric adenocarcinoma were randomly assigned to undergo a D1 or D2 lymph node dissection. Data were collected prospectively, and patients were followed for more than 10 years. RESULTS: A total of 711 patients (380 in the D1 group and 331 in the D2 group) were treated with curative intent. Morbidity (25% v 43%; P <.001) and mortality (4% v 10%; P =.004) were significantly higher in the D2 dissection group. After 11 years there is no overall difference in survival (30% v 35%; P =.53). Of all subgroups analyzed, only patients with N2 disease may benefit of a D2 dissection. The relative risk ratio for morbidity and mortality is significantly higher than one for D2 dissections, splenectomy, pancreatectomy, and age older than 70 years. CONCLUSION: Overall, extended lymph node dissection as defined in this study generated no long-term survival benefit. The associated higher postoperative mortality offsets its long-term effect in survival. For patients with N2 disease an extended lymph node dissection may offer cure, but it remains difficult to identify patients who have N2 disease. Morbidity and mortality are greatly influenced by the extent of lymph node dissection, pancreatectomy, splenectomy and age. Extended lymph node dissections may be of benefit if morbidity and mortality can be avoided.

Adenocarcinoma↗

Significance of para-aortic lymph node dissection in advanced gastric cancer.

BACKGROUND/AIMS: Since surgical results in advanced gastric cancer remain poor and para-aortic lymph node dissection may contribute to survival, it is useful to determine the significance of para-aortic lymph node dissection. METHODOLOGY: Para-aortic lymph node dissection was provisionally indicated for patients with invasion depth deeper than the subserosal layer. Clinicopathologic variables were retrospectively analyzed using univariate analysis and multivariate analysis to predict para-aortic lymph node metastasis. Similarly, they were analyzed using univariate analysis and the Cox's proportional hazards regression model to estimate the prognostic factor in 120 patients who underwent para-aortic lymph node dissection. Surgical results and post-operative complications were compared between para-aortic lymph node dissection and D2 dissection. RESULTS: Univariate analysis revealed that the mean diameter, the degree of lymph node metastasis, and the invasion depth were significant predictors of para-aortic lymph node metastasis. Multivariate analysis showed that n2 was the only independent predictive factor as to para-aortic lymph node metastasis. Univariate analysis revealed tumor site, tumor diameter, lymph node metastasis, number of positive lymph nodes, INF, and stage were significantly associated with 5-year survival. The Cox's proportional hazards regression model showed that the number of positive lymph nodes and the number of positive para-aortic lymph nodes were independent prognostic factors. Patients with < or = 10 positive lymph nodes in any stage or < or = 3 positive para-aortic lymph nodes in stage IVb had significantly better surgical results. Surgical results for patients who underwent para-aortic lymph node dissection with n2 or invasion depth deeper than the exposed serosa were significantly higher than those in D2. As to post-operative complications, pancreatic fistula and respiratory complications were significantly frequent after para-aortic lymph node dissection. CONCLUSIONS: n2 is helpful in predicting para-aortic lymph node metastasis. Whereas, post-operative morbidity such as pancreatic fistula and respiratory complications after para-aortic lymph node dissection were significantly higher, they were controllable. Para-aortic lymph node dissection should be indicated in advanced gastric cancer patients in which lymph node metastasis is over n2 or invasion depth is deeper than the exposed serosa. But the number of positive para-aortic lymph nodes must be less than three.

Aorta↗

[The anatomy lesson of Dr Nicolaes Tulp by Rembrandt (1632) and the findings during dissection of the forearm of a cadaver: anatomical discrepancies].

OBJECTIVE: To compare The anatomy lesson of Dr Nicolaes Tulp by Rembrandt (1632) with the findings during dissection of the forearm of a cadaver. DESIGN: Descriptive. METHOD: The left forearm of a 41-year-old white male cadaver was dissected, photographs being taken at every stage of dissection. The anatomical structures in the original painting and during dissection were described and compared. At dissection, several structures were displaced in an attempt to reproduce the anatomical structures as shown in the painting. RESULTS: Dissection revealed four anatomical differences in comparison with Rembrandt's painting: (a) the muscle belly seen at the proximal ulnar side of the forearm in the painting was not seen on dissection; section of the insertion of the M. flexor carpi radialis and transposition of this muscle to the location of the muscle belly created the possibility of lifting up the M. flexor digitorum superficialis and reproducing the muscle belly; (b) in the painting, Tulp lifted only the M. flexor digitorum superficialis, but the amount of muscle tissue found in the forceps was increased in the painting compared with the dissection; (c) the positions of the bellies of the M. flexor digitorum superficialis to the index finger and 5th digit and to the 3rd and 4th digits were found to be reversed; (d) the longitudinal white structure situated in the ulnar part of the 5th digit in the painting was not found on dissection. This may have been an anatomical variant of the ulnar nerve. CONCLUSION: The anatomical characteristics of the painting could not be reproduced by dissection of the forearm of a cadaver.

English Abstract↗

Aortic dissection: current expectations and treatment. Experience with 258 patients over 20 years.

Aortic dissection, the most common acute disease of the thoracic aorta, is associated with high mortality and morbidity. The authors reviewed their experience over the last 20 years with 258 patients who had aortic dissection (259 dissections). The diagnosis was made at autopsy in 69 (27%) patients (59 type A, 10 type B). Of the remainder, 97 patients had type A dissection (78 acute, 19 chronic) and 93 had type B dissection (56 acute, 37 chronic). The sudden onset of severe, unremitting chest pain associated with hyper- or hypotension or a history of hypertension are suggestive of acute aortic dissection. The diagnosis should be followed by prompt investigation and treatment. The 30-day survival rate for patients with type A dissection who underwent surgical treatment was 62%; survival rates for patients with type B dissection, acute and chronic, were 70% and 86% respectively with pharmacotherapy and 66% and 91% with surgery. The authors stress the importance of early, accurate diagnosis and immediate surgical treatment for all patients who have type A dissection and complicated or unresponsive (carefully monitored pharmacologic control of blood pressure) type B dissection.

Adult↗

[Rational evaluation of different lymph node dissection].

To evaluate the effect and indication of different lymph node dissection (D1+, D2, D3), we performed radical operations for 371 cases of gastric cancer. The results showed that D1+ or D1 lymph node dissection was enough for gastric cancer of Ia stage, D2 was suitable for Ib stage. For localized or massive type gastric cancer of II + III stage, D3, D2 dissection was better than D1+ dissection. For the gastric cancer of the same type in IV stage, the 5-year survival rate after D3 + D2 dissection was 42.9%, but for the gastric cancer of infiltrative type or diffused growth pattern in II + III stage, the effect was not significantly increased even after the D3, D2 dissection. For the gastric cancer of this type in IV stage, the effect was not improved after the extended lymph node dissection. Extended dissection needn't be performed if there was no lymph node metastasis. D3, D2 dissection was better if there was little lymph node metastasis or the metastasis was limited to 1st group. For those metastasized to 2nd group or the quantity was more, D3 was better than D2, D1+. The effect of D3, D2 dissection was not significantly improved in the extensive metastasis case (more than 10 or to the 3rd group).

Adult↗

Gastric carcinoma: does lymph node dissection alter survival?

BACKGROUND: Extragastric lymphadenectomy (D2 node dissection) is strongly supported by Japanese data to have survival benefit. Randomized trial data are either inconclusive or nonsupportive of this view. We have reviewed a prospectively gathered database of 18,346 cases of gastric carcinoma from a gastric cancer patient care evaluation study conducted by the American College of Surgeons to assess whether the performance of extragastric node dissection was associated with improved survival in patients who had resection with curative intent (all margins microscopically clear). STUDY DESIGN: We reviewed a subgroup of patients with curatively resected gastric carcinoma and compared the outcome in patients having extragastric lymph node dissection with the outcome in patients who did not have dissection of N2 nodes. RESULTS: Among the 3,804 patients having curative resection in the long-term study with more than a five-year follow-up, 695 had dissection of the nodes along the celiac axis, hepatic artery, or splenic artery (N2 nodes); 1,529 patients had removal of the adjacent nodes (N1 nodes) along the gastric tube or the gastric or perigastric nodes (N1 nodes); and 903 patients who had no nodes identified in the resection specimen (essentially N0 nodes removed). For patients having a dissection of N2 nodes, the median survival time was 19.7 months with a five-year survival rate of 26.3 percent; for patients having a dissection of N1 nodes, the median survival time was 24.8 months with a five-year survival rate of 30 percent; among patients having no nodes removed, the median survival time was 29.5 months with a five-year survival rate of 35.6 percent. CONCLUSIONS: Lymph node dissection (D2) of N2 nodes did not augment survival compared with gastrectomy without node dissection or that included perigastric nodes in the resection. Subgroup analysis of patients with gastric carcinoma having a curative resection did not show benefit of the extragastric node dissection (D2). Continued study is warranted and the data from ongoing clinical trials may yield more conclusive information.

Aged↗

[Demonstration of the sentinel lymph node in axillary dissection for breast cancer].

OBJECTIVES: The sentinel node is defined as the first-line axillary lymphatic drainage node in breast cancer. If the sentinel node can be identified, during axillary dissection for breast cancer, resection could be limited reducing subsequent morbidity. However, before modifying the standard dissection procedure, it is important to prove that the sentinel node is representative of the metastatic status of other axillary nodes. PATIENTS AND METHODS: Between March and December 1996, 86 patients (mean age 58 years, range 32-82) underwent amputation (n = 20), tumorectomy with dissection (n = 56) or tumorectomy followed by secondary dissection (n = 10) for breast cancer. Ten ml of diluted patent blue was injected either into the peripheral portion of the tumor or the tumorectomy cavity. Node dissection was performed 10 to 20 minutes after injection. The blue sentinel node was identified prior to standard dissection. RESULTS: A mean 12 nodes were removed (range 4-21). Seventy-nine sentinel nodes were identified (91%) and in 7 cases (8%) a sentinel node could not be identified. In 7 other cases the sentinel node was a false negative, i.e. non malignant despite metastases in other dissected nodes. In all the other cases, the status of the sentinel node predicted the status of the other nodes, i.e. a non-metastatic sentinel node associated with other metastatic nodes. Finally, in 7 cases, the sentinel node was the only invaded node among the nodes dissected. During the last 3 months of the study, the sentinel node was identified in 100% of the cases and was representative of the overall dissection. CONCLUSION: Identifying the sentinel node is an alternative to standard axillary node dissection procedures. The method requires a training period and identification can be improved with radioimmunologic guidance. Patient selection within the framework of a rigorous multidisciplinary protocol is indispensable. A nationwide study is currently being conducted to validate these preliminary results.

Adult↗

Incidence and outcome of cervical artery dissection: a population-based study.

BACKGROUND: Incidence rates for internal carotid artery dissection (ICAD) have been reported to be 2.6 to 2.9 per 100,000, but reliable epidemiologic data for vertebral artery dissection (VAD) are not available. OBJECTIVE: To determine the incidence rate of cervical artery dissection (CAD) in a defined population. METHODS: With IRB approval, we used the medical record linkage system of the Rochester Epidemiology Project to identify all patients diagnosed with spontaneous ICAD and VAD for the period of 1987-2003 in Olmsted County, MN. RESULTS: Of 48 patients with CAD, there were 32 patients with ICAD and 18 patients with VAD. In Olmsted County, the average annual incidence rate for ICAD was 1.72 per 100,000 population (95% CI, 1.13 to 2.32) and for VAD 0.97 per 100,000 population (95% CI, 0.52 to 1.4). The average annual incidence rate for CAD was 2.6 per 100,000 population (95% CI, 1.86 to 3.33). The most frequently encountered symptoms in CAD were head or neck pain (80%), cerebral ischemia (TIA or infarct) (56%), and Horner syndrome (25%). Good outcome (defined as modified Rankin score of 0 to 2) was seen in 92% of patients. No recurrence of dissection was observed during a mean 7.8 years of follow-up. CONCLUSIONS: Internal carotid artery dissection was detected approximately twice as frequently as vertebral artery dissection in the overall study, but in the latter half of the study period, vertebral artery and internal carotid artery dissection incidence rates were equivalent. The majority of cervical artery dissection patients in the community have excellent outcome, and contrary to many tertiary referral series, re-dissection is rare.

Adult↗

Discontinuous vs in-continuity neck dissection in carcinoma of the oral cavity.

We compared the results of transoral excision of the primary tumor with discontinuous neck dissection with the results of in-continuity dissection of primary tumor and neck nodes in anteriorly localized squamous cell carcinoma of the oral cavity. We analyzed 27 patients who underwent 28 discontinuous dissections and 34 patients who underwent 40 in-continuity dissections for T2 anterior tongue or floor-of-mouth carcinoma. The overall ipsilateral neck recurrence rate was 11%. The discontinuous dissection group did significantly worse than the in-continuity dissection group, with a neck recurrence rate of 19%. Consequently, the actuarial 5-year survival of patients who underwent a discontinuous dissection was substantially decreased (63%) compared with patients who were treated by an in-continuity dissection (80%). Discontinuous neck dissection, thus, is not to be recommended in oral cancer.

Adult↗

The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease.

CONTEXT: Acute aortic dissection is a life-threatening medical emergency associated with high rates of morbidity and mortality. Data are limited regarding the effect of recent imaging and therapeutic advances on patient care and outcomes in this setting. OBJECTIVE: To assess the presentation, management, and outcomes of acute aortic dissection. DESIGN: Case series with patients enrolled between January 1996 and December 1998. Data were collected at presentation and by physician review of hospital records. SETTING: The International Registry of Acute Aortic Dissection, consisting of 12 international referral centers. PARTICIPANTS: A total of 464 patients (mean age, 63 years; 65.3% male), 62.3% of whom had type A dissection. MAIN OUTCOME MEASURES: Presenting history, physical findings, management, and mortality, as assessed by history and physician review of hospital records. RESULTS: While sudden onset of severe sharp pain was the single most common presenting complaint, the clinical presentation was diverse. Classic physical findings such as aortic regurgitation and pulse deficit were noted in only 31.6% and 15.1% of patients, respectively, and initial chest radiograph and electrocardiogram were frequently not helpful (no abnormalities were noted in 12.4% and 31.3% of patients, respectively). Computed tomography was the initial imaging modality used in 61.1%. Overall in-hospital mortality was 27.4%. Mortality of patients with type A dissection managed surgically was 26%; among those not receiving surgery (typically because of advanced age and comorbidity), mortality was 58%. Mortality of patients with type B dissection treated medically was 10.7%. Surgery was performed in 20% of patients with type B dissection; mortality in this group was 31.4%. CONCLUSIONS: Acute aortic dissection presents with a wide range of manifestations, and classic findings are often absent. A high clinical index of suspicion is necessary. Despite recent advances, in-hospital mortality rates remain high. Our data support the need for continued improvement in prevention, diagnosis, and management of acute aortic dissection.

Adult↗

Does this patient have an acute thoracic aortic dissection?

CONTEXT: The diagnosis of acute thoracic aortic dissection is difficult to make and often missed. OBJECTIVE: To review the accuracy of clinical history taking, physical examination, and plain chest radiograph in the diagnosis of acute thoracic aortic dissection. DATA SOURCES: A comprehensive review of the English-language literature was conducted using MEDLINE for the years 1966 through 2000. Additional sources were identified from the references of retrieved articles. STUDY SELECTION: The search revealed 274 potential sources, which were reviewed for pertinence and quality. Articles included were original investigations describing the clinical findings for 18 or more consecutive patients with confirmed thoracic aortic dissection. Twenty-one studies were identified that met selection criteria. DATA EXTRACTION: Critical appraisal and data extraction were performed by the author. DATA SYNTHESIS: Most patients with thoracic aortic dissection have severe pain (pooled sensitivity, 90%) of sudden onset (sensitivity, 84%). The absence of sudden pain onset lowers the likelihood of dissection (negative likelihood ratio [LR], 0.3; 95% confidence interval [CI], 0.2-0.5). On examination, 49% of patients have an elevated blood pressure, 28% have a diastolic murmur, 31% have pulse deficits or blood pressure differentials, and 17% have focal neurological deficits. Presence of a diastolic murmur does little to change the pretest probability of dissection (positive LR, 1.4; 95% CI, 1.0-2.0), whereas pulse or blood pressure differentials and neurological deficits increase the likelihood of disease (positive LRs, 5.7 and 6.6-33.0, respectively). The plain chest radiograph results are usually abnormal (sensitivity, 90%); hence, the presence of a normal aorta and mediastinum decreases the probability of dissection (negative LR, 0.3; 95% CI, 0.2-0.4). Combinations of findings increase the likelihood of disease. CONCLUSIONS: The presence of pulse deficits or focal neurological deficits increases the likelihood of an acute thoracic aortic dissection in the appropriate clinical setting. Conversely, a completely normal chest radiograph result or the absence of pain of sudden onset lowers the likelihood. Overall, however, the clinical examination is insufficiently sensitive to rule out aortic dissection given the high morbidity of missed diagnosis.

Acute Disease↗

Accuracy of M-mode and two-dimensional echocardiography in the diagnosis of aortic dissection: an experience with 128 cases.

The accuracy of combined M-mode and two-dimensional echocardiography in the diagnosis of aortic dissection was evaluated in 673 patients with a clinical suspicion of aortic dissection, over a six-year period. In 128 cases, the diagnosis of aortic dissection was confirmed by angiographic, tomographic (CT scan), or autopsy findings, or during surgery. Two echocardiographic features were found to support a diagnosis of aortic dissection: a dilation of at least one segment of the aorta (sensitivity 95%, specificity 51%) and a typical abnormal linear intraluminal echo corresponding to the intimal flap (sensitivity 67%, specificity 100%). This pathognomonic intimal flap was observed in 86 cases, of which three types could be distinguished: (1) a long oscillating flap (n = 15), (2) a long but minimally mobile linear echo which was duplicated and parallel to one or two aortic walls (n = 64), (3) a short, double linear image with a rapid systolic motion and high frequency oscillations. These features were found to have a high sensitivity in type I aortic dissection (88%), although in types II and III the sensitivity was much lower. In some cases, a fourth type of abnormal image could be detected: a small intraluminal echo moving in parallel to the aortic wall. This feature should be interpreted with caution since its predictive value for a positive examination was low (48%). Out of 23 cases in which the diagnosis of aortic dissection was suspected on the basis of this doubtful abnormal echo, it was confirmed in only 11 patients. The results in these 128 cases of aortic dissection indicate that two-dimensional echocardiography, which is easily performed at the patient's bedside, could take priority in investigations of this condition. It is extremely sensitive in the diagnosis of ascending aortic dissection, but much less so in the diagnosis of descending aortic dissection.

Aortic Dissection↗

Spontaneous dissection of the abdominal aorta: experience with five patients.

Spontaneous dissection of the infradiaphragmatic abdominal aorta is a rare form of aortic dissection. Its natural history and management are not well defined. We have recently treated five patients with spontaneous aortic dissection. Two patients had acute dissections and three had chronic dissections. Three patients developed saccular aneurysms and underwent resection. Two patients had stable dissections and were treated medically. All patients are alive and well at 6 months to 5 years. We think that spontaneous aortic dissection can be treated as a variant of type III dissection with initial medical management, reserving surgery for those patients in whom a saccular aneurysm or a complication of the dissection develops.

Aged↗

[Aortic dissection--when operative treatment, when endoluminal therapy?].

GOAL: To demonstrate the Heidelberg results of the previous 2 years in patients referred for acute aortic dissection. MATERIAL AND METHODS: 93 patients referred for acute aortic dissection were treated by cardiac surgery, vascular surgery and interventional radiology according to a novel therapeutic algorithm including stent-grafts and combined open and interventional procedures and conservative medical therapy when no malperfusion syndrome was present or patients were considered prohibitive for even minor surgical procedures. Stent-graft placements were done assisted by short term cardiac arrest to facilitate correct device deployment. RESULTS: 36 patients presented with type A and the other 57 with type B dissection. 32 of the A patients were operated and 20 of the B patients, respectively. 12 patients with B dissection were treated with stent-grafts. 3 required additional interventional therapy for organ malperfusion. The mortality was 0% in these 12 patients The overall mortality rate in the A group was close to 40% mainly as a result of postoperative organ malperfusion while it was 15% in the B group. In both groups mortality was highest in the respective untreated patient subgroup (3/4 and 8/37, respectively). The main mortality factor was visceral (mesenteric or liver) ischemia. Paraplegic complications occured in neither group. In 4 patients a combined approach applying cardiac surgery of the ascending aorta and endluminal stent-graft placement for the residual B dissection was successfully performed. In one patient this was done simultaneously. DISCUSSION: Acute aortic dissection of type A with or without valve involvement, coronary artery ischemia can be treated with high technical success rates. However, remaining distal aortic dissection associated with true lumen collapse and organ malperfusion is the main causative factor for clinical failures. Successful combination of open proximal aortic surgery with endoluminal treatment of residual B dissection encourages further use of this novel approach. Acute B type dissection appears to be effectively and safely treated by endoluminal approach in selected cases. Unsolved questions of this less invasive therapeutic approach focus mainly on the design of the proximal anchoring part of the devices.

Acute Disease↗

Towards waterjet dissection in neurosurgery: experimental in-vivo results with two different nozzle types.

Waterjet dissection is under close investigation as a new neurosurgical tool. Experimentally, a precise tissue dissection with vessel preservation has been demonstrated in the porcine cadaver brain. The safety of the device has been shown in first clinical applications. However, a detailed in-vivo analysis of the waterjet device is still awaited. In the present study, two often applied nozzle types (100 microm diameter emitting a coherent straight jet; 120 microm diameter emitting a helically rotating jet) were experimentally studied in vivo. Forty-one rabbits received a frontal waterjet corticotomy on either side with one nozzle type after microsurgical removal of the arachnoid membranes. Animals were sacrificed at 1, 3, 7 days and 6 weeks after surgery. Dissection morphology and vessel preservation were evaluated. Tissue trauma was analyzed by the extent of intra-operative haemorrhage, postsurgical oedema formation and astrocytic as well as microglial reactions. In all animals, reliable brain dissection was observed. Macroscopically, only minor bleeding occurred. Microscopically, also very precise brain dissection with both nozzle types was found. Vessels were preserved with both pressures applied (5 and 10 bar). Dissections with the 100 microm straight nozzle were more precise with respect to dissection margins. However, no significant difference in vessel preservation and extent of haemorrhage, oedema formation, astrocytic and microglial reactivity was shown. Malfunction defined as clotting of the instrument occurred only with the 100 microm nozzle. In four 100 microm straight nozzle hemispheres, even no brain dissection was seen. The results indicate that the waterjet enables very precise and reliable brain parenchyma dissection with minimal trauma and vessel preservation in vivo. If this can be proven to be of clinical relevance, the instrument will become a valuable neurosurgical tool. Based on these results, the authors selected the 120 microm Helix nozzle for further research with this device in the CNS.

Animals↗