Angelo Pierangeli

Nonsurgical reconstruction of thoracic aortic dissection by stent-graft placement.

BACKGROUND The treatment of thoracic aortic dissection is guided by prognostic and anatomical information. Proximal dissection requires surgery, but the appropriate treatment of distal thoracic aortic dissection has not been determined, because surgery has failed to improve the prognosis. METHODS We prospectively evaluated the safety and efficacy of elective transluminal endovascular stent-graft insertion in 12 consecutive patients with descending (type B) aortic dissection and compared the results with surgery in 12 matched controls. In all 24 patients, aortic dissection was diagnosed by magnetic resonance angiography. In each group, the dissection involved the aortic arch in 3 patients and the descending thoracic aorta in all 12 patients. With the patient under general anesthesia, either surgical resection was undertaken or a custom-designed endovascular stent-graft was placed by unilateral arteriotomy. RESULTS Stent-graft placement resulted in no morbidity or mortality, whereas surgery for type B dissection was associated with four deaths (33 percent, P=0.09) and five serious adverse events (42 percent, P=0.04) within 12 months. Transluminal placement of the stent-graft prosthesis was successful in all patients, with no leakage; full expansion of the stents was ensured by balloon inflation at 2 to 3 atm. Sealing of the entry tear was monitored during the procedure by transesophageal ultrasonography and angiography, and thrombosis of the false lumen was confirmed in all 12 patients after a mean of three months by magnetic resonance imaging. There were no deaths or instances of paraplegia, stroke, embolization, side-branch occlusion, or infection in the stent-graft group; nine patients had postimplantation syndrome, with transient elevation of C-reactive protein levels and body temperature plus mild leukocytosis. All the patients who received stent-grafts recovered, as did seven patients who underwent surgery for type B dissection (58 percent) (P=0.04). CONCLUSIONS These preliminary observations suggest that elective, nonsurgical insertion of an endovascular stent-graft is safe and efficacious in selected patients who have thoracic aortic dissection and for whom surgery is indicated. Endoluminal repair may be useful for interventional reconstruction of thoracic aortic dissection.

Brain protection using antegrade selective cerebral perfusion: a multicenter study

BACKGROUND To evaluate the results of antegrade selective cerebral perfusion as a method of brain protection during surgery of the thoracic aorta and to determine predictors of hospital mortality and adverse neurologic outcome. METHODS Between October 1995 and March 2002, 588 patients underwent aortic surgery with the aid of antegrade selective cerebral perfusion. There were 334 men (56.8%); the mean age was 63.7 +/- 11.8 years. One hundred sixty-two patients (27.6%) underwent urgent operation. The separated graft technique was employed to reimplant the arch vessels in 230 patients (65.3%) of the 352 requiring aortic arch replacement. Associated procedures were performed in 254 patients (43.2%). One hundred twelve patients underwent elephant trunk procedure. The mean cerebral perfusion time was 67 +/- 37 minutes. RESULTS The overall hospital mortality rate was 8.7%. A logistic regression analysis revealed urgent operation, recent central neurologic event, tamponade, unplanned coronary artery revascularization and pump time to be independent predictors of hospital mortality (p < 0.05). The permanent neurologic dysfunction rate was 3.8%. A logistic regression analysis showed tamponade to be independent predictor of permanent neurologic dysfunction (p < 0.05). The transient neurologic dysfunction rate was 5.6%. Recent central neurologic event, tamponade, coronary disease, and aortic valve replacement were indicated as independent predictors of transient neurologic dysfunction by logistic regression (p < 0.05). CONCLUSIONS In our experience the utilization of antegrade selective cerebral perfusion resulted in encouraging results in terms of hospital mortality and brain complications. Neither the extent of the replacement nor the duration of the cerebral perfusion had an impact on hospital mortality and neurologic outcome.

Surgical Indications and Timing of Repair of Traumatic Ruptures of the Thoracic Aorta

BACKGROUND The outcome of patients with acute traumatic rupture of the thoracic aorta after motor vehicle accidents is strongly conditioned by injuries to other districts. The timing of repair is controversial when the patients arrive alive to the hospital. METHODS A series of 42 patients with acute traumatic rupture of the thoracic aorta observed between January 1980 and June 1996 was divided into two groups: group I underwent immediate repair (21 patients) and in group II operation was performed after intensive medical treatment and management of the associated lesions and monitoring of the aortic tear. RESULTS The mortality in group I patients was 19% and the morbidity was more significant than in group II where no deaths were reported and complications were minor. CONCLUSIONS Patients with acute traumatic rupture of the thoracic aorta may have a better fighting chance if aortic operation is postponed to the most favorable moment after undergoing life-sustaining measures and management of the major associated lesions. Needless to say, evolution should be closely monitored by computed tomographic scans and magnetic resonance imaging.

Evolution of aortic dissection after surgical repair

Patients after aortic dissection repair still have long-term unfavorable prognosis and need careful monitoring. The purpose of this study was to analyze the evolution of aortic dissection after surgical repair in correlation to anatomic changes emerging from systematic magnetic resonance imaging (MRI) follow-up. Between January 1992 and June 1998, 70 patients underwent surgery for type A aortic dissection. Fifty-eight patients were discharged from the hospital (17% operative mortality) and were followed by serial MRI for 12 to 90 months after surgery. In all, 436 postoperative MRI examinations were analyzed. In 13 patients (22.5%) no residual intimal flap was identified, whereas 45 patients (77.5%) presented with distal dissection, with a partial thrombosis of the false lumen in 24. The yearly aortic growth rate was maximum in the descending aortic segment (0.37 +/- 0.43 cm) and was significantly higher in the absence of thrombus in the false lumen (0.56 +/- 0.57 cm) (p <0.05). There were 4 sudden deaths, with documented aortic rupture in 2. Sixteen patients underwent reoperation for expanding aortic diameter. In all but 1 patient, a residual dissection was present (in 13 without any thrombosis of the false lumen). Close MRI follow-up in patients after dissection surgical repair can identify the progression of aortic pathology, providing effective prevention of aortic rupture and timely reoperation. Thrombosis of the false lumen appears to be a protective factor against aortic dilation.

Delayed treatment of isthmic aortic rupture

Traumatic rupture of the thoracic aorta is a life-threatening injury with a high mortality, and is difficult to manage in polytraumatized patients. Between 1980 and 1998, 50 patients were admitted to our Department with acute traumatic aortic rupture (TAR). The site of lesion was usually isthmic (86% of patients). From 1980 to 1992, 21 patients (Group I) underwent emergency surgical repair; from 1992 to January 1998, 29 patients (Group II) underwent intensive medical treatment, except one who was haemodynamically unstable and died 8h after the trauma from a massive haemothorax before an emergency thoracotomy could be attempted. The aortic rupture was followed up by MRI or CT scan. Twenty-one patients in Group II underwent aortic repair an average of 8.6 months after the injury. In two patients the operation was expedited because of an enlarging aortic aneurysm. In Group I the postoperative mortality was 19%, three patients developed postoperative paraplegia and one acute renal failure. In Group II there were no postoperative deaths and no major complications.

Delayed Surgery of Traumatic Aortic Rupture: Role of Magnetic Resonance Imaging

BACKGROUND Traumatic aortic rupture (TAR) is a pathological entity with a high mortality, both spontaneous and perioperative. Delayed surgical repair has been proposed when associated lesions are stabilized. The aim of this study was to validate MRI for detecting both the presence and type of TAR and to monitor posttraumatic aneurysm and associated lesions. METHODS AND RESULTS Twenty-four consecutive patients with acute chest trauma and suspected aortic rupture, as suggested by emergency CT or chest radiographs, were subjected to MRI and/or angiography in random order. Such parameters as the presence and type of lesion; presence of periaortic, pericardial, mediastinal, or pleural effusion; and presence of associated lesions were considered in every patient. Follow-up imaging was performed exclusively by MRI every 1 to 2 months. TAR was present in 20 patients. No patient underwent surgery in the acute phase; 14 patients underwent surgery at 6.8 +/- 2.7 months; 5 are waiting for surgery; and 1 healed spontaneously. There was no overall mortality. For detection of TAR, the accuracy of MRI was 100%; angiography, 84%; and CT, 69%. In detecting the type of lesion, the diagnostic accuracy of MRI was 92%. During follow-up, a significant increase in the posttraumatic aneurysm was observed in 2 patients, and surgical repair was initiated. CONCLUSIONS In chest trauma patients, MRI provides complete anatomic data to assess the severity of aortic and thoracic lesions. Moreover, along with the concept of delayed surgical repair of TAR, MRI is the ideal modality to monitor and follow TAR before surgical repair.

Antegrade selective cerebral perfusion during operations on the thoracic aorta: our experience

BACKGROUND Various methods of cerebral protection have been used during aortic arch operations. Deep hypothermia with circulatory arrest is the most common technique but has a limited safe period for circulatory arrest. Selective cerebral perfusion has been introduced to prolong this safe period. We reviewed our experience with antegrade selective cerebral perfusion during surgical repair of the thoracic aorta. METHODS Between November 1996 and December 1998, 57 consecutive patients were operated on for aortic arch aneurysms using selective cerebral perfusion. Forty-one were men (71.9%), and 16 were women. The mean age was 63.2 years. Thirty-seven patients had chronic aneurysms, and 20 had type A acute dissection. Preoperative, intraoperative, and postoperative factors were analyzed by univariate and multivariate analysis to identify predictors of early mortality and transient neurologic dysfunction. RESULTS There were no permanent neurologic deficits. The early mortality rate was 8.8% (5 patients). Multivariate analysis revealed preoperative renal failure (p = 0.0338) and repeat thoracotomy for bleeding (p = 0.0201) to be independent risk factors for early mortality. The factor postoperative cardiac complications (p = 0.0368) was the only independent predictor of transient neurologic dysfunction, and it occurred in 3 patients (5.3%). CONCLUSIONS The present study confirmed that preoperative renal failure and repeat thoracotomy for bleeding are significant predictors of mortality in aortic arch operations using selective cerebral perfusion and that cerebral perfusion time has no influence on the postoperative outcome. We believe that selective cerebral perfusion is an optimal technique of cerebral protection during operations on the aortic arch.

Protective effect of low frequency low energy pulsing electromagnetic fields on acute experimental myocardial infarcts in rats.

This series of experiments assesses the effect of exposure to low-frequency pulsing electromagnetic fields (PEMFs) in 340 rats with acute experimental myocardial infarcts. The left anterior descending artery was ligated with suture thread, and the rats underwent total body exposure to PEMFs until they were killed. Twenty-four hours after surgery, the necrotic area was evaluated by staining with triphenyltetrazolium chloride. A significant reduction of the necrotic area was observed in the animals exposed to PEMFs compared with the nonexposed controls. Exposure for up to 6 days does not appear to affect the area of necrosis, although in exposed animals an increase of vascular invasion of the necrotic area is observed: 24.3 % as against 11.3 % in controls. No effect on the necrotic area size from exposure was found when the left anterior descending artery was occluded for 60 min, followed by reperfusion. The results reported show that exposure to PEMFs is able to limit the area of necrosis after an acute ischemic injury caused by permanent ligation of the left anterior descending artery. These data are in agreement with the protective effect of PEMFs observed on acute ischemia in skin free flaps in rats and in cerebral infarcts in rabbits.

Surgery for acute type A dissection using antegrade selective cerebral perfusion: experience with 122 patients

BACKGROUND Antegrade selective cerebral perfusion (ASCP) has proved to be a reliable method of brain protection during surgery of the thoracic aorta, but its use during aortic dissection surgery still remains controversial. In this study, we present our results after the operative repair of acute type A aortic dissections using ASCP and moderate hypothermic circulatory arrest. METHODS Between October 1995 and August 2001, 122 patients (76 men, 46 women) underwent repair of acute type A aortic dissection with the aid of ASCP and open distal anastomosis. The average age of the patients was 61 +/- 12 (mean +/- standard deviation). Preoperative complications included cardiac tamponade (n = 34; 27.0%), aortic regurgitation (n = 27; 22.1%), and new neurological deficits (n = 11; 9%). RESULTS Stepwise logistic regression revealed preoperative cardiac tamponade (p = 0.018) and new neurological deficits (p = 0.017) to be independent determinants for hospital mortality (19.7%). Permanent neurological complications occurred in 7% of the patients. Independent risk factors for temporary neurological dysfunction (11.2%) included cardiac tamponade (p = 0.019) and preoperative neurological deficits (p = 0.000). CONCLUSIONS In our experience, the surgical treatment of acute type A aortic dissection with the aid of ASCP was associated with acceptable hospital mortality and neurologic morbidity rates.

Activity–rest stimulation of latissimus dorsi for cardiomyoplasty: 1-year results in sheep

BACKGROUND In dynamic cardiomyoplasty electro-stimulation achieves full transformation of the latissimus dorsi (LD); therefore, its slowness limits the systolic support. Daily activity-rest could maintain partial transformation of the LD. METHODS Sheep LD were burst-stimulated either 10 or 24 hours/day. Before and 2, 4, 6, and 12 months after stimulation, LD power output, fatigue resistance, and tetanic fusion frequency were assessed. Latissimus dorsi were biopsied at 6 months, and sheep sacrificed at 12 months. RESULTS After 1 year of 10 hours/day stimulation LD was substantially conserved and contained large amounts of fast type myosin. From 2 months to 1 year of stimulation the power per muscle of the daily rested LD was greater than that of the left ventricle, being three to four times higher than in the 24-hour/day stimulation. CONCLUSIONS If extended to humans, these results could be the rationale for the need of a cardiomyostimulator, whose discontinuous activity could offer to patients the long-standing advantage of a faster and powerful muscle contraction.