Giovanni P. Deriu

In vivo regeneration of small-diameter (2 mm) arteries using a polymer scaffold

The difficulty of obtaining significant long‐term patency and good wall mechanical strength in vivo has been a significant obstacle in achieving small‐diameter vascular prostheses. The aim of the present study was to develop a prosthetic graft that could perform as a small‐diameter vascular conduit. Tubular structures of hyaluronan (HYAFF‐11 tubules, 2 mm diameter, 1 cm length) were grafted in the abdominal aorta of 30 rats as temporary absorbable guides to promote regeneration of vascular structures. Performance was assessed by histology, immunohistochemistry, and ultra‐structural analysis. These experiments resulted in three novel findings: 1) complete endothelialization of the tubes luminal surface occurred; 2) sequential regeneration of vascular components led to complete vascular wall regeneration 15 days after surgery; and 3) the biomaterial used created the ideal environment for the delicate regeneration process during the critical initial phases, yet its biodegradability allowed for complete degradation of the construct four months after implantation, at which time, a new artery remained to connect the artery stumps. This study assesses the feasibility to create a completely biodegradable vascular regeneration guide in vivo, able to sequentially orchestrate vascular regeneration events needed for very small artery reconstruction.

Outcome from Carotid Endarterectomy. Neuropsychological Performances, Depressive Symptoms and Quality of Life: 8-Month Follow-up

A preliminary study was carried out on a population of twenty-five consecutive and unselected patients undergoing carotid endarterectomy. A matched control group of subjects suffering from same pathology, but unoperated, was compared to experimental sample. A battery of neuropsychological tests, the Zung Self-Rating Depression Scale and the Jachucks Quality of Life Impairment Scale were administered one week before surgery, two weeks after (surgical sample only) and then eight months later. The research shows that carotid endarterectomy does not impair neuropsychological performances, but produces some improvement, reaching significant level in the case of Word Fluency 1 and Similarities tests; depressive scores remained substantially unchanged, while quality of life improved slightly.

Prospective, randomized study of external jugular vein patch versus polytetrafluoroethylene patch during carotid endarterectomy: perioperative and long-term results

OBJECTIVES The purpose of this study was to evaluate the relative risks and advantages of using external jugular vein (EJV) patch, compared with polytetrafluoroethylene (PTFE) patch, during carotid endarterectomy. The primary end point was the relevant neurologic complication rate (RNCR; fatal or disabling stroke) at any time during follow-up. Secondary end points included stroke-free survival, 30-day and long-term mortality, recurrent stenosis rate (> or =50%), occlusion, patch infection, aneurysm formation, and other local complications. METHODS The study, a prospective randomized clinical trial carried out at a single center, was divided into two 3-year phases: December 1996 to March 1999, when patients were enrolled, and March 1999 to March 2002, which was the follow-up period. Inclusion criteria included an external jugular vein suitable for patching, defined as vein diameter 3 mm or larger and absence of collateral vessels noted on preoperative color duplex ultrasound scans. Patients were prospectively randomized 1:1 to receive either the EJV (n = 80; group A) or synthetic (n = 80; group B) patch. RESULTS Carotid endarterectomy and patching was performed by one surgeon. At 30 months the RNCR-free rate, analyzed with the Kaplan-Meier method, was 98.7% for group A (1 ipsilateral lethal stroke) and 94.6% for group B (4 ipsilateral disabling strokes), and remained stable to 60 months. No statistical difference was observed with the log-rank test. Stroke-free survival rate was 100% for group A and 98.7% for group B at 1 year, 98.7% for group A and 93.6% for group B (1 ipsilateral minor stroke) at 30 months, and was unchanged at 60 months. Life table analysis demonstrated freedom from significant recurrent stenosis (> or =50%) of 97.5% for both groups at 6 months, 93.6% for group A and 92.2% for group B at 30 months, and 90.2% for group A and 86.7% for group B at 60 months. No statistical difference was observed with the log-rank test. In no patients was recurrent stenosis greater than 70%. No aneurysm formation was noted during follow-up. CONCLUSIONS We can conclude, with the power limitation of the study, that carotid endarterectomy can be safely performed with either the EJV or PTFE patch. Advantages of the EJV for carotid angioplasty include no cost for material, low risk for graft infection, and preservation of the saphenous vein.

Specific Cellular Features of Atheroma Associated With Development of Neointima After Carotid Endarterectomy The Carotid Atherosclerosis and Restenosis Study

BACKGROUND The purpose of this study was to investigate whether some cellular and molecular features of tissue retrieved at carotid endarterectomy are associated with the extent of neointima formation at ultrasound follow-up. METHODS AND RESULTS One hundred fifty patients were studied. Endarterectomy specimens were tested by immunocytochemistry with the use of (1) monoclonal antibodies that identify smooth muscle cells (SMCs) and fetal-type SMCs on the basis of smooth muscle and nonmuscle myosin content, (2) the anti-macrophage HAM 56, and (3) the anti-lymphocyte CD45RO. The maximum intima-media thickness (M-IMT) of the revascularized vessel was assessed by the use of B-mode ultrasonography 6 months after surgery. The M-IMT values were related positively to the number of SMCs (r=0.534, P<0.0005) and negatively to that of macrophages and lymphocytes (r=-0.428, P<0.0005, and -0.538, P=0.001, respectively). Patients were classified as class 1 (M-IMT </=1.0 mm), class 2 (1. 01.3 mm). An abundance of SMCs, mostly of fetal type, was found in the plaque of class 3 patients, whereas lesions from class 1 patients were rich in macrophages and lymphocytes. In the multivariate analysis, factors related to M-IMT were the number of SMCs and the percentage of fetal-type SMCs present in the plaque. CONCLUSIONS Although the classic risk factors did not play a role, an abundance of SMCs and a scarcity of macrophages characterized the primary lesion of patients in whom neointima developed after surgery. In patients in whom neointima did not develop, lesions were rich in macrophages and lymphocytes. This approach can be useful in defining patients at risk of restenosis.

Hybrid endovascular treatment of aneurysm degeneration in a rare right-aortic arch anomaly with Kommerell diverticulum

We present a hybrid endovascular approach to a 6.5-cm aneurysm of the right-sided aortic arch with an aberrant left subclavian artery arising from a Kommerell diverticulum, connected to the left pulmonary artery through the ligamentum arteriosum. The two-step procedure consisted of a bilateral carotid-subclavian bypass, followed by an ascending aorta-bicarotid bypass and completed by an endovascular exclusion of the aneurysms by covering the whole aortic arch and its branches. The patient had no complications and is asymptomatic 21 months after surgery. Hybrid procedures may be helpful in complex aortic arch pathologies, reducing complications of challenging open surgery.

Carotid artery endarterectomy in patients with contralateral carotid artery occlusion: Perioperative hazards and late results

The aim of this study was to analyze and compare the perioperative hazards and late results of internal carotid endarterectomy (CEA) in patients with and without contralateral internal carotid artery occlusion. From March 1980 to April 1990, 375 consecutive patients underwent 439 CEAs at the First Department of Vascular Surgery of Padova Medical School. Patients were divided into two groups; group 1 (61 patients) had contralateral internal carotid artery occlusion and group 2 (314 patients) did not (378 CEAs, 64 bilateral). Indications for CEA were similar in both groups. The only significant difference in patient characteristics was a higher rate of previous stroke in group 1 (11% vs. 3%,p< 0.001). General anesthesia, continuous EEG monitoring, selective intraluminal shunt, and arteriotomy closure with a polytetrafluoroethylene patch (PTFE) were used routinely in both groups. An intraluminal shunt was inserted more frequently in group 1 than in group 2 (69% vs. 17%,p<0.001). Major perioperativestroke occurred in one patient in each group (1.7% vs. 0.31%, respectively; NS). Early fatal stroke rates were 0% and 0.95% in groups 1 and 2, respectively (NS). All patients had neurologic examinations and duplex scans every 6 months (range 6 to 118 months; mean 42 months). Kaplan-Meier survival curves were virtually identical in the two groups; the majority of deaths were caused by myocardial infarction and cancer. There were no stroke-related deaths in group 1 as compared with 8.2% in group 2 (NS). New neurologic symptoms appeared in 4.7% of patients in group 1 and 6% in group 2 (NS) whereas the late stroke rates were 0% and 3.1%, respectively (NS). Restenosis was observed in two and three patients in groups 1 and 2, respectively (NS). In conclusion, CEA for ulcerated or stenotic lesions of the internal carotid artery in patients with contralateral carotid occlusion is associated with very low early and long-term neurologic morbidity and mortality, similar to findings in patients who undergo CEA with a patent contralateral carotid artery.

Natural history of ascending thrombosis of the abdominal aorta

During 1980, 30 patients underwent successful operations for ascending thrombosis of the abdominal aorta in its three forms: low (below the inferior mesenteric artery, 11 patients); middle (above the inferior mesenteric artery, 6 patients); and high (at the level of the renal arteries, 13 patients). An angiogram that reveals high ascending thrombosis of the abdominal aorta is paradoxically more favorable than one that reveals middle or low ascending thrombosis of the abdominal aorta. In fact, the patient with a juxtarenal thrombosis has already overcome two of the three phases that constitute the critical moments of potential failure of the collateral circulation. Progressive ascending thrombosis with a poor prognosis and a rapidly downward course can cause acute ischemia with paraplegia of the legs and intestinal infarction. Most patients die suddenly in the emergency or intensive care unit from paraplegia, acute abdomen, or anuria; the latter is due to further progressive thrombosis with obstruction of the orifice of the renal arteries. On the basis of the angiogram only (apart from subjective symptoms), ascending thrombosis of the abdominal aorta constitutes an absolute indication for surgical treatment.

Suprarenal Fixation of Endograft in Abdominal Aortic Aneurysm Treatment: Focus on Renal Function

Objective:The objective of this work was to evaluate any variation of renal function detected by renal scintigraphy after the suprarenal fixation of endografts for abdominal aortic aneurysm (AAA) repair. Summary Background Data:In the few articles that have considered this problem, renal function was evaluated only by biochemical tests, which are inadequate in demonstrating small changes in renal function and in appreciating the worsening of a single kidneys function. Methods:Between April 1999 and May 2002, 47 patients with an inappropriate infrarenal proximal neck had a suprarenal fixation for AAA. To assess renal function, a technetium-99m diethylene triamine penta-acetic acid (99mTC-DTPA) perfusion scintigraphy was performed preoperatively on the third postoperative day and at 6, 12 months, and then yearly thereafter. Worsening of renal function was defined as a decrease of glomerular filtration rate (GFR) ≥20% (detected with Gates method). Serum creatinine level was tested preoperatively and at the first and third postoperative day. Results:Endograft deployment was technically successful in 44 patients (93.6%); clinical perioperative success was obtained in 46 patients (97.8%). In 12 patients (25.5%), a permanent reduction of the GFR was observed using postoperative 99mTC-DTPA perfusion scintigraphy. By 99m TC-DTPA perfusion scintigraphy, a permanent reduction of GFR was observed postoperatively in 12 patients. A slight GFR reduction (<20%) was present in 7 (14.9%) patients, due to the planned occlusion of accessory renal arteries. A more significant GFR reduction (>20%) was present unexpectedly in 5 (10.6%) patients, in 3 of these a single kidney was involved, in 5 both with an increase of the serum creatinine level >20%. Conclusions:Suprarenal fixation of endografts in AAA treatment is a safe procedure with good early and midterm procedural results and a risk of GFR impairment (>20%) of 10.6%.

Great saphenous vein protection in arterial reconstructive surgery

An original method of great saphenous vein bypass protection during reconstructive arterial surgery is described. The use of a reinforced prosthetic support (Ringed PTFE), surrounding the vein, avoids possible compression by anatomical structures and strangulation by scar tissue after reoperation. This technique can also prevent eventual dilatation of the vein graft. Since 1981, this technique has been successfully applied to 30 selected patients. On the basis of clinical experience, the authors conclude that this method is safe and effective, and may increase the long-term patency rate of saphenous vein grafts.

Stroke risk reduction in asymptomatic and symptomatic patients treated surgically: The effectiveness of carotid endarterectomy with patch graft angioplasty

From March 1980 to March 1987, 217 consecutive patients underwent 252 carotid revascularisations with routine use of continuous EEG monitoring and selective use of an intraluminal shunt for symptomatic (70%) or asymptomatic (30%) internal carotid artery (ICA) atherosclerotic stenosis. All carotid endarterectomies were routinely performed with a patch graft angioplasty. None of the patients suffered permanent or transient neurological deficits in the immediate postoperative period and none of them died. There was an 0.8% stroke rate and 0.4% mortality rate in the early postoperative course. Neurological assessment, Doppler and Echo doppler sonography of both the operated and the contralateral ICA was performed every 6 months. One-hundred and twenty-one patients (142 carotid revascularisations) operated on up to December 31st 1985 were reassessed in July 1986. The mean follow-up time was 35 months (range: 6 months to 6 years). New neurological symptoms were present in 7.4% of the patients; 2.5% of patients developed a stroke and 8.9% showed progression of stenosis in the contralateral ICA. One patient had a common carotid artery stenosis 2 years after surgery. Re-stenosis of the ICA was found in two patients who underwent re-operation without difficulty. The late mortality was 21.4% (11.9% of the overall series). In only two patients (7.6%) was stroke the cause of death.