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Endoluminal treatment of aortic dissection.

Aortic dissection is most often a catastrophic medical emergency which, if untreated, can be potentially fatal. The intention of therapy in patients with aortic dissection is to prevent aortic rupture or aneurysm formation as well as to relieve branch vessel ischaemia. Patients with aortic dissection are often poor candidates for anaesthesia and surgery and the surgical procedure itself is challenging requiring thoracotomy, aortic cross clamping, blood transfusion as well as prolonged hospital stay in some cases. Operative mortality is especially high in patients with critical mesenteric or renal ischaemia. The past decade has experienced the emergence of a number of interventional radiological or minimally invasive techniques which have significantly improved the management of patients with aortic dissection. These include stent grafting for entry site closure to prevent aneurysmatic widening of the false lumen as well as percutaneous techniques such as balloon fenestration of the intimal flap and aortic true lumen stenting to alleviate branch vessel ischaemia. False lumen thrombosis following entry closure with stent grafts has been observed in 86-100% of patients, whereas percutaneous interventions are able to effectively relieve organ ischaemia in approximately 90% of the cases. In the years to come, it is to be expected that these endoluminal techniques will become the method of choice for treating most type-B dissections and will assist in significantly reducing the number of open surgical procedures required for type-A dissections. The intention of this article is to provide an overview of the current status of these endoluminal techniques based on our own experience as well as on a review of the relevant literature.

Aortic Dissection↗

Pregnancy-associated spontaneous coronary artery dissection: impact of medical treatment. Case report and systematic review.

We report on a 22- year-old woman with postpartum dissection of the left anterior descending artery and the intermediate branch. The patient was treated with acetylsalicylic acid (ASA), clopidogrel, and betablocker only. Coronary angiography performed 20 months later revealed complete resolution of the dissection sites. The patient's cardiovascular risk factors included mild smoking and high total cholesterol and low-density-lipoprotein-cholesterol levels, which showed a marked fall after pregnancy without pharmacological cholesterol-modifying therapy raising the question whether pregnancy-related hypercholesterolemia contributed to the pathogenesis of pregnancy-associated spontaneous coronary artery dissection (P-SCAD). In a systematic review of the literature, 16 women [median age 34 (31-36.5) years] with P-SCAD and angiographic follow-up were identified. The majority (69%) of P-SCAD cases occurred postpartum [median time after delivery: 13 (7-21) days]. In 10/16 (63%) patients medical treatment including betablocker and antiplatelet therapy was given leading to complete resolution of the dissection in 5 of them (31% of all patients) at follow-up, whereas in the other 5 patients the dissections were persisting or even progressive. Of the medically treated patients, 80% were free of symptoms suggestive for ischemia at follow-up. In 5/16 patients percutaneous coronary intervention (PCI) was performed as first-line therapy. Three patients underwent coronary artery bypass grafting, which was performed primarily in one patient, and secondarily in two patients with persisting dissections and ongoing ischemic symptoms after previous medical treatment or PCI without stenting, respectively. In conclusion, medical treatment including ASA, clopidogrel and betablocker therapy results in an excellent clinical and angiographic result in approximately one third of patients with P-SCAD.

Adult↗

Resection of the sternocleidomastoid muscle during radical neck dissection.

BACKGROUND: Surgical therapy of lymph node metastasis is based on accessibility for en bloc resection. First described as "radical neck dissection", this original approach has since undergone various modifications. This has produced controversy about the particular indications for the individual techniques. The aim of this study was to evaluate whether intraoperative macroscopic inspection of the sternocleidomastoid muscle (SCM) in regard to tumor infiltration is sufficient to decide about muscle resection and whether there are prognostic differences between patients undergoing radical-versus modified radical (selective) neck dissection. MATERIALS AND METHODS: In a retrospective study, data on the surgical treatment of cervical lymph nodes and survival rates from 438 patients with head and neck malignancies managed in our department between 1988 and 1994 were analyzed in 1994 and again in 1999. RESULTS: 337 patients (76.9%) underwent unilateral or bilateral selective neck dissection. In 101 patients (23.1%) a radical neck dissection was performed and the SCM was completely resected. Analysis of these cases showed intraoperative macroscopic tumor invasion of the SCM in 12 patients (11.9%), which could be confirmed histologically. In the remaining 89 cases (88.1%), a macroscopically intact muscle was resected; in none of these cases did histopathological examination show tumor infiltration of the SCM. Analysis of radically or selectively neck dissected stage III or IV patients with oral cavity, oropharyngeal, hypopharyngeal or laryngeal carcinomas did not show statistical differences in 2-, 5- and 10-year survival (54.8%, 23.7%, 18.7% versus 62.6%, 25.6%, 21.8%, respectively). CONCLUSIONS: (1) Intraoperative inspection of the SCM constitutes a valid parameter for deciding whether tumor infiltration is present or not. (2) There were no prognostic differences (2-year, 5-year and 10-year-survival) between stage III and IV patients with oral cavity, oropharyngeal, hypopharyngeal and laryngeal carcinomas treated by either radical or selective neck dissection.

Aged↗

A less invasive, selective, functional neck dissection for papillary thyroid carcinoma.

HYPOTHESIS: To describe an alternative lateral neck access in order to perform neck dissection in papillary thyroid carcinoma (PTC) with lymph node involvement. DESIGN: Prospective (January 2000 to December 2003), 36-month study. SETTING: Catholic University of Rome and University of "Tor Vergata", Rome, Italy. PATIENTS AND METHODS: Twenty-four consecutive patients with PTC and cervical lymph node metastases were included. Functional neck dissection (FND), unilateral or bilateral, was performed acceding via a lateral dissection through a traditional Kocher incision, running along the superficial fascia of the neck and posteriorly to the sternocleidomastoideus muscle. RESULTS: Mean age was 39.04+/-13.69 years. Twenty patients were women and four were men. Mean tumour size was 2.5+/-1 cm, while the greatest metastatic lymph node size was 4.5 cm. Minimally invasive, selective FND was performed in all patients associated to total thyroidectomy and central compartment lymph node clearance. Metastatic lymph nodes were found in 142 out of 340 of the lymph nodes dissected. CONCLUSIONS: Minimally invasive neck dissection seems to carry a lower risk in terms of specific morbidity and allows a quicker recovery and a better aesthetic result. This access has to be considered as a less invasive procedure compared to the other surgical accesses for the radical or modified lateral neck dissection.

Adult↗

Real-time thermography during energized vessel sealing and dissection.

BACKGROUND: Energized dissection systems facilitate laparoscopic dissection and hemostasis and reduce instrument traffic. However, they can introduce undesirable thermal collateral/proximity damage to adjacent structures mainly by heat conduction, although other mechanisms may be involved. The latest generation devices have the potential to reduce the incidence of such problems through use of active feedback control over the power output. This effectively regulates the delivery of energy to the target tissue with minimal thermal collateral damage. In addition, innovative heat-sink engineering of the device head ensures that the surface of the instrument tip remains cool (<45 degrees C). In this study, we evaluated the performance of this technology (LigaSure) by using dynamic infrared thermography. The thermal imaging measurements were then correlated with histopathologic studies. The overall value of in situ thermography as an adjunct to energized surgical dissection systems was also assessed. METHODS: Eight anesthetized pigs underwent open surgery to mobilize eight target vessels/organs in a randomized fashion. The LigaSure vessel sealing system with Instant Response Technology was used with three different interchangeable heads. In situ dynamic thermography was undertaken with a thermal imaging camera operating in the mid-infrared (3-5 microm) waveband and with each fully digitized 12-bit thermographic frame acquired at a rate of 60 Hz. Following sacrifice at the end of the dissection, tissue from the dissected regions was harvested for histology by an independent pathologist who was blinded to the thermographic data. RESULTS: Seals made with both the LS1000 5-mm laparoscopic head (predominantly to the small bowel and colon) and the LS1100 10-mm (Atlas) device (on the liver and short gastric tissues) were outwardly satisfactory. The average thermal spread [see text] with the LS1000 was = [see text] 4.4 mm, and the exposed surface of the instrument tip developed a temperature of approximately 100 degrees C. This instrument thus has the potential, albeit small, for heat-related proximity iatrogenic injury. The more technologically advanced LS1100 10-mm laparoscopic instrument exhibited a superior performance, with [see text] = 1.8 mm, and with a maximal temperature on the exposed surface of the jaws well within tolerable limits (approximately 35 degrees C) for use during surgery (laparoscopic or open). This was confirmed by histological studies that demonstrated negligible evidence of thermal damage. CONCLUSIONS: In situ thermal imaging represents a powerful modality for the monitoring of energized dissection/coagulation during surgery. The LigaSure system used with the LS1100 head constitutes a very safe option for energized dissection and hemostasis of vessels with a diameter of up to approximately 7 mm.

Animals↗

Aortic dissections complicating open cardiac surgery: report of three cases.

Between June 1991 and February 1999, three patients suffered ascending aortic dissection as a complication of cardiopulmonary bypass operations with aortic cannulation at our hospital. The dissection occurred during the operation in two of the three patients and several months after the operation in one. Among a total of 2207 cardiac operations performed during this period, the incidence of perioperative ascending aortic dissection was 0.14%. In addition to visual inspection and palpation, either epicardial or transesophageal echocardiography proved extremely useful for establishing an intraoperative diagnosis of ascending aortic dissection as a complication of open cardiac operation. One of the three patients underwent closed plication but subsequently died of vital organ ischemia. In this case, failure of reapproximation of the injured intima by closed plication might have led to extension of the dissection. Despite prolonged cardiopulmonary bypass and myocardial ischemic time, graft replacement of the ascending aorta was successfully carried out in the other two patients. Thus, we believe that graft replacement of the ascending aorta should be performed for patients with extensive aortic dissection complicating an open cardiac operation.

Aged↗

Spontaneous dissection of the celiac artery.

Spontaneous dissection of the celiac artery (CA) is uncommon, considering the number of isolated lesions without associated aortic dissection and exclusive of abdominal trauma. We have treated five cases of isolated spontaneous dissection of the CA or its branches. There were three men and two women with a mean age of 54 years. The presenting manifestation was acute epigastralgia in three cases and chronic abdominal pain in one. In the remaining case, dissecting CA was a coincidental finding. All patients underwent abdominal Doppler ultrasound and CT scan imaging, which demonstrated aneurysm in three cases and dissection in two. Work-up also included arteriography in three cases and magnetic resonance (MR) angiography in one. Management consisted of emergency surgical repair in three cases and close surveillance in two. The repair procedure was resection-anastomosis in one case and prosthetic bypass to the hepatic artery in two cases. Postoperative recovery was uneventful in all three cases and patients were symptom-free at 6, 8, and 18 months. Both patients under surveillance were symptom-free at 1 and 2 years. Because of the risk of ischemic and hemorrhagic complications, surgery should be considered for any patient with CA dissection. However, some patients with uncomplicated asymptomatic lesions may be eligible for medical treatment with regular surveillance.

Adult↗

Endovascular management of traumatic infrarenal abdominal aortic dissection.

Dissection is a recognized finding after blunt trauma to the abdominal aorta. Immediate and long-term prognosis is poor without surgical treatment especially since most patients present severe associated injuries. On the basis of encouraging results using endovascular techniques to treat experimental dissection of the descending thoracic aorta, we treated three patients with traumatic infrarenal abdominal aortic dissection by percutaneous stent placement. There were two men 34 and 41 years of age and one 89-year-old woman. In all patients, dissection began in the infrarenal portion of the aorta and extended into the iliac arteries. All patients had multiple associated injuries. The main symptoms were acute abdominal pain (two patients) and ischemia of the lower extremities (two patients). Diagnosis was missed in one patient despite exploratory laparotomy for an associated injury. Two patients were treated in the acute phase by placement of a self-expanding endovascular prosthesis at the aortoiliac level. The third patient was treated in the chronic phase by placement of a balloon-expandable endovascular stent. All procedures were performed uneventfully by femoral route. Success of treatment was confirmed by arteriography and computed tomography (CT) scan demonstrating obliteration of the dissection. Upon late follow-up examination, all patients were in satisfactory condition, with normal Doppler ultrasound findings. These findings confirm experimental studies using endovascular treatment for dissection of the descending thoracic aorta and are promising for future clinical management.

Adult↗

Treatment of aortic arch dissection using the elephant trunk technique.

The elephant trunk technique was developed to facilitate multiple-stage treatment of extensive aneurysm of the thoracic aorta. However, little information is available concerning its usefulness for aortic dissection. From April 1992 to July 1998, we used the elephant trunk technique for treatment of aortic arch dissection in 22 patients (including 19 men) with a mean age of 58.5 years (range 21 to 85 years). Twelve patients presented with type A dissection (acute in 3 and chronic in 9), 3 with type B acute dissection, and 7 with "non A/non B" dissections with retrograde extension to the aortic arch or entry site located in the aortic arch without involvement of the ascending aorta. All patients had aneurysms of the descending (n = 7) or thoracoabdominal (n = 15) aorta. Procedures were performed under hypothermic circulatory arrest at between 15 degrees and 20 degrees C. Antegrade cerebral perfusion was used in three cases. The procedure was associated with aortic valve replacement and/or coronary bypass in 6 cases and bypass of one or more supraaortic vessels in 13. In two patients the distal end of the elephant trunk was attached with an endovascular prosthesis during the same procedure. The ensuing results in these patients indicate that the elephant trunk technique can be highly effective for treatment of complex aortic arch dissection.

Adult↗

Balloon dilatation of symptomatic subacute intimal dissection presenting as restenosis.

Repeat percutaneous transluminal coronary angioplasty (PTCA) for subacute intimal dissections that produce symptoms after a period of 1 month or more is reluctantly performed for fear of extension and abrupt closure. Patients were identified with demonstrated intimal dissections (intimal contrast staining or frank intimal flap) at the time of initial PTCA who returned a mean of 17.5 weeks (range 9 to 50) later with recurrent chest pain. Repeat angiography revealed luminal compromise due to dissection rather than restenosis in 22 patients. Of these, 17 underwent repeat PTCA. Elective bypass surgery without attempted PTCA was chosen in the other 5 patients because of extensive intimal dissections (greater than 2 balloon lengths) or involvement of critical branches. In the group of 17 patients who had repeat PTCA, 10 (group 1) had a frank intimal flap without persistent contrast staining after the initial PTCA, while 7 (group 2) had both persistent staining and a flap. Successful PTCA was performed in 13 of these 17 patients (76%). There were 2 abrupt closures and 2 unsatisfactory luminal openings. One of these patients required urgent coronary bypass surgery. All 10 group 1 patients had successful repeat procedures versus only 3 of 7 group 2 patients (p = 0.01). The 3 patients with the greatest degree of luminal compromise immediately after the initial PTCA had failed repeat PTCA attempts. These results suggest that repeat PTCA for subacute intimal dissections presenting as restenosis can be successfully performed in selected patients, and that the presence of contrast staining and the degree of luminal compromise by the dissection may be predictive of outcome.

Aged↗

Risk of aortic dissection after aortic valve replacement.

Little information is available regarding the incidence of aortic dissection after previous aortic valve replacement (AVR), and factors associated with its development. Therefore, a meta-analysis of the literature was performed, and a patient population was studied retrospectively. Data from published studies showed that 87% of 31 patients were men (mean age 60 years), and 68% were known to have systemic hypertension. A dilated ascending aorta was observed at the time of AVR in 88% of patients. AVR was performed because of pure aortic regurgitation in 55% of patients, and combined aortic stenosis and regurgitation in 23%. More than 50% of patients did not survive dissection. The present series consisted of 7 patients. Four patients were known to the department before dissection occurred, and the other 3 were referred by other hospitals. Eighteen of 330 patients with previous AVR whose data were stored in an echocardiographic data base had an ascending aortic diameter > 50 mm. Of these 18 patients, aortic dissection occurred in 4. Three of the remaining 14 patients underwent elective ascending aortic replacement. Characteristics including sex, age, severity of dilatation, presence of progression in diameter, left ventricular function and time interval after AVR were not helpful in determining a cumulative risk for developing dissection. Because dissection occurred in 4 of 18 patients (22%) with an ascending aorta diameter > 50 mm, it is suggested to consider replacement of the ascending aorta during AVR when a value of 50 mm is exceeded.

Adult↗

Results in suprahyoid, modified radical, and standard radical neck dissections for metastatic squamous cell carcinoma: recurrence and survival.

Two hundred sixty-one patients who underwent three types of neck dissection for cervical lymphadenopathy in association with squamous cell cancer of the head and neck are analyzed retrospectively. Patients were grouped into those with histologically negative nodes and those with histologically positive nodes. Statistical analyses for neck recurrence and survival rates were made using the sampled permutation method. The results show that suprahyoid neck dissection is associated with an unusually high recurrence rate in the neck in patients with histologically negative nodes. Modified radical neck dissection and standard radical neck dissection are equivalent with regard to recurrences in the neck and five year survival rates when the disease is above the juguloomohyoid lymph node group. The study suggests that simple upper neck dissection is contraindicated in patients with negative or positive nodes and that modified radical neck dissection can be used in selected patients instead of the formal radical neck operation.

Adult↗

Elective versus therapeutic neck dissection in early carcinoma of the oral tongue.

A prospective, randomized trial was carried out to assess the value of elective versus therapeutic neck dissection in early squamous cell carcinoma of the oral tongue. Disease-free survival (median follow-up 20 months) was 52 percent versus 63 percent in patients who underwent hemiglossectomy alone and those who underwent hemiglossectomy and radical neck dissection, respectively (difference not statistically significant). Patients with a tumor depth of less than 4 mm did significantly better than those with a tumor depth of greater than 4 mm; they were also more likely to have uninvolved nodes at elective radical neck dissection compared with those with a tumor depth of greater than 4 mm. However, when the survival rates of patients in the two treatment groups were compared with respect to a tumor depth of 4 mm, there was no significant difference between the hemiglossectomy and the hemiglossectomy and radical neck dissection groups. A policy of interval elective radical neck dissection only in those with a tumor depth of greater than 4 mm may optimize cure rates and avoid neck dissection in those unlikely to develop neck recurrence.

Adult↗

Experimental assessment of newly devised transcatheter stent-graft for aortic dissection.

Despite recent advances, surgical results for Stanford type B dissection are not yet satisfactory because the procedure is so highly invasive. The aim of this study was to devise a new intraaortic (IA) graft that would offer less invasive treatment for type B dissection. To close the entry of type B dissections using transcatheter placement, we devised an IA graft (inner diameter, 15-20 mm; length, 40 to 60 mm) in which a self-expandable stent was covered with a thin, open-cell-structured polyurethane jacket. In acute animal experiments in which type B aortic dissections were prepared in 4 mongrel dogs, IA grafts were implanted to close the entry using a transfemoral catheter sheath, and closure of all the entries was confirmed by aortography. In chronic experiments, five IA grafts for normal descending aortas and one IA graft for an experimentally dissected aorta were implanted to observe histologic biocompatibility for up to 8 months. Histopathologic examination conducted at the projected sacrifice periods revealed that endothelialization of the luminal surface of the IA graft had begun as early as 1 month after implantation and was completed within 4 months. The prototype device that we developed may be promising as an effective, minimally invasive therapeutic intervention for closure of the entry site of type B dissection.

Aortic Dissection↗

Simultaneous graft replacement of the ascending aorta and total aortic arch for type A aortic dissection.

We performed simultaneous graft replacement of the total aortic arch and ascending aorta for type A aortic dissection with a patent false lumen extending through the arch into the descending or abdominal aorta. During the past 7 years, this procedure was performed in 42 patients (28 men and 14 women), aged 20 to 72 years (mean age, 50 years). Nineteen patients underwent the procedure during the acute period, and 23 during the chronic period. The site of the initial intimal tear was the ascending aorta in 17 patients and the transverse aortic arch in 25 patients. Artificial graft replacement was initially accomplished by proximal anastomosis, followed by open distal anastomosis, and finally by anastomosis of each of the three arch vessels. There were 3 hospital deaths (7.1%), 1 resulting from acute dissection (5.3%) and 2 from chronic dissection (8.7%). Among the type A dissections, total arch graft replacement has been indicated in the setting of rupture of the aortic arch, arch dissection, and Marfan's syndrome. However, with increasing experience in arch reconstructions and improvement in outcome, the indications could be expanded to include all type A aortic dissections with a patent false lumen in the descending aorta.

Adult↗

Extensive dissection at the porta hepatis for biliary atresia.

Dissection at the porta hepatis is the crucial step in surgery for biliary atresia. The authors describe their procedure for extensively dissecting the porta hepatis. The technique is based on an anatomic cast corrosion of the human liver, and the portal vein serves as the landmark for dissection. Lateral dissection at the hepatic hilus is critical to the procedure. On the right side, the anterior portal branches are dissected to the bifurcation of the S5 and S7 segmental portal branches, over the bifurcation of the anterior and posterior portal branches. On the left side, the liver parenchyma, which bridges the umbilical point, is sectioned, and the left portal branch is dissected to the umbilical point over the pars transversalis and taped. The fibrous mass that lies within the confines of the portal branches, including the dorsal aspect, is transected completely. This procedure was performed in 16 infants; the jaundice cleared in 93.7%.

Biliary Atresia↗

Dissecting aneurysm: a clinicopathologic and histopathologic study of 111 autopsied cases.

One hundred eleven autopsy cases of dissecting aneurysm were collected from western Japan. The ratio of males to females was 3:2 and the sixth and seventh decades of life were most frequently affected. All 11 cases of Marfan's syndrome were in patients under 40 years of age. DeBakey's type III dissections showed a male predilection and more severe atherosclerosis than in control cases. Many patients with types I and II dissections died of hemorrhage in the acute phase, while many patients with type III dissection died in the subacute or chronic phase, and half of the patients died of diseases other than hemorrhage. Hypertension was recognized in 73.7% of the 95 cases which showed no other obvious risk factors. Histologic examinations suggested that cystic medial necrosis was related to the pathogenesis of the disease in Marfan's syndrome, but was not so apparent in non-Marfan's syndrome. Laminar medial necrosis was found in many cases, but was considered to be a secondary ischemic change following dissection, as supported by other investigators. There were only a few cases in which dissection seemed to be directly caused by atherosclerosis.

Adolescent↗

Sudden death associated with bloodless aortic dissection.

We report a case of rapidly fatal aortic dissection which was unusual because no intimal tear was present and no blood was present in the dissected aortic wall, although the dissection involved the entire aorta. Death was considered to be due to acute myocardial ischaemia from dissection involving the left coronary artery. Prominent cystic medial necrosis was present. There was no history of hypertension and only histological evidence of left ventricular hypertrophy. No other clinical or pathologic states associated with aortic dissection were present. Although cystic medionecrosis was the probable cause in this case, it is present in only a small proportion of patients in the absence of Marfan's syndrome, and more recently investigated defects in the composition of aortic wall connective tissue components may be more relevant factors in the causation of many cases of aortic dissection.

Aortic Dissection↗