Coronary artery mechanics induces human saphenous vein remodelling via recruitment of adventitial myofibroblast-like cells mediated by Thrombospondin-1.

Rationale: Despite the preferred application of arterial conduits, the greater saphenous vein (SV) remains indispensable for coronary bypass grafting (CABG), especially in multi-vessel coronary artery disease (CAD). The objective of the present work was to address the role of mechanical forces in the activation of maladaptive vein bypass remodeling, a process determining progressive occlusion and recurrence of ischemic heart disease. Methods: We employed a custom bioreactor to mimic the coronary shear and wall mechanics in human SV vascular conduits and reproduce experimentally the biomechanical conditions of coronary grafting and analyzed vein remodeling process by histology, histochemistry and immunofluorescence. We also subjected vein-derived cells to cyclic uniaxial mechanical stimulation in culture, followed by phenotypic and molecular characterization using RNA and proteomic methods. We finally validated our results in vitro and using a model of SV carotid interposition in pigs. Results: Exposure to pulsatile flow determined a remodeling process of the vascular wall involving reduction in media thickness. Smooth muscle cells (SMCs) underwent conversion from contractile to synthetic phenotype. A time-dependent increase in proliferating cells expressing mesenchymal (CD44) and early SMC (SM22α) markers, apparently recruited from the SV adventitia, was observed especially in CABG-stimulated vessels. Mechanically stimulated SMCs underwent transition from contractile to synthetic phenotype. MALDI-TOF-based secretome analysis revealed a consistent release of Thrombospondin-1 (TSP-1), a matricellular protein involved in TGF-ß-dependent signaling. TSP-1 had a direct chemotactic effect on SV adventitia resident progenitors (SVPs); this effects was inhibited by blocking TSP-1 receptor CD47. The involvement of TSP-1 in adventitial progenitor cells differentiation and graft intima hyperplasia was finally contextualized in the TGF-ß-dependent pathway, and validated in a saphenous vein into carotid interposition pig model. Conclusions: Our results provide the evidence of a matricellular mechanism involved in the human vein arterialization process controlled by alterations in tissue mechanics, and open the way to novel potential strategies to block VGD progression based on targeting cell mechanosensing-related effectors.

Comparison of SFA lesion treatment with Zilver PTX in diabetics vs. non-diabetics: 2-year clinical and functional results.

BACKGROUND: Prospective single-arm study, aimed at evaluating safety and effectiveness at 12 and 24 months of the paclitaxel-eluting nitinol stent (Zilver PTX), and focused in particular on the treatment of complex lesions and/or diabetic patients. METHODS: Between May 2010 and March 2012, 67 patients (78% males) were treated by Zilver PTX, because of stenosis or occlusions of the superficial femoral artery in one of two centers. The mean age of patients was 70.1±8 years. Thirty-two of 67 (48%) were diabetics, 14 (21%) active smokers and 11 (14.6%) had chronic renal failure (end stage renal disease). The average length of lesions was 104±60 mm. Occlusion was complete in 46.3% of cases, whereas severely calcified lesions were present in 30% of patients (18.8% in diabetics and 31.4% in non-diabetics). Twenty-six patients (39%) had type C or D lesions according to TASC 2. RESULTS: One hundred-two stents were used (1.7±0.9 per patients); median 1 (range 1-4). All patients had successful stent placement. Primary patency, evaluated by Kaplan-Meier method was 88±0.06% at 12 months, and 68±0.1% at 24 months. In particular, the difference between diabetics (D) and non-diabetics (non-D) was not significant (P=0.07, Log-Rank). Patients turned from 4.2±1.3 to 1.6±1.3 Rutherford class. There were 5 deaths due to systemic comorbidities. There also were 3 major amputations, all of them also in the D group. Among the other patients, differences between D and non-D patients were not significant in terms of wound healing, bipedal stay and spontaneous ambulation. The mean follow-up length was 28±5 months (range 24-36 months). There was only one patient who had fracture and stent migration (1.5%). In 13 diabetic patients, tibial PTA was also associated. Additional treatment was required in 6 D and 1 non-D. CONCLUSIONS: The use of Zilver PTX is safe and effective in the treatment of SFA lesions. In particular, both stent patency and functional results on the basis of both clinical and instrumental tools were similar in D and non-D, suggesting a particularly favorable activity of PTX in a subpopulation of diabetics. Further studies are required to confirm these results, which seem to be particularly promising in diabetic patients.

Characterization of the Pall Celeris system as a point-of-care device for therapeutic angiogenesis.

BACKGROUND AIMS: The Pall Celeris system is a filtration-based point-of-care device designed to obtain a high concentrate of peripheral blood total nucleated cells (PB-TNCs). We have characterized the Pall Celeris-derived TNCs for their in vitro and in vivo angiogenic potency. METHODS: PB-TNCs isolated from healthy donors were characterized through the use of flow cytometry and functional assays, aiming to assess migratory capacity, ability to form capillary-like structures, endothelial trans-differentiation and paracrine factor secretion. In a hind limb ischemia mouse model, we evaluated perfusion immediately and 7 days after surgery, along with capillary, arteriole and regenerative fiber density and local bio-distribution. RESULTS: Human PB-TNCs isolated by use of the Pall Celeris filtration system were shown to secrete a panel of angiogenic factors and migrate in response to vascular endothelial growth factor and stromal-derived factor-1 stimuli. Moreover, after injection in a mouse model of hind limb ischemia, PB-TNCs induced neovascularization by increasing capillary, arteriole and regenerative fiber numbers, with human cells detected in murine tissue up to 7 days after ischemia. CONCLUSIONS: The Pall Celeris system may represent a novel, effective and reliable point-of-care device to obtain a PB-derived cell product with adequate potency for therapeutic angiogenesis.

Expanding extrapleural hematoma from rib fractures after cardiac surgery.

A 79-year-old man underwent coronary artery bypass grafting and ascending aorta prosthetic replacement for aneurysm at our Institution. His postoperative course was characterized by rapid onset of hypotension and anemia. Re-exploration found no surgical source of bleeding. A chest computed tomography showed a huge extrapleural hematoma caused by rib fractures. Percutaneous chest drainage was effective, and the patient recovered quickly. Follow-up computed tomography confirmed a good result.

Cumulative radiation exposure during thoracic endovascular aneurysm repair and subsequent follow-up.

OBJECTIVES: Thoracic endovascular aneurysm repair (TEVAR) is an appealing alternative to the standard surgical approach, but requires rigorous radiological follow-up. The cumulative radiation exposure (RE) of patients undergoing TEVAR-including pre-operative workup, the procedure and subsequent follow-up computed tomography (CT) imaging-has not previously been investigated. METHODS: From August 2003 to February 2011, 48 patients underwent TEVAR at our institution. Mean age was 66 ± 11 years, with 10 patients (21%) aged <60 years. Forty-one (85%) patients were male; 7 (15%) had urgent/emergent operation; 21 (44%) had undergone previous aortic surgery. Mean aortic diameter was 7.3 ± 2.1 cm. Intra-operative screening time and RE were reviewed, and typical institutional thoracic CT scan RE was calculated (17.8 mSv). Life expectancy of an age- and sex-matched population was estimated to assess the cumulative RE from recurrent CT follow-up. RESULTS: The average screening time was 15.7 ± 11.4 min, with an RE of 11.3 ± 9 mSv. Obese patients had significantly higher RE during TEVAR (Pearson's coefficient = 0.388, P = 0.019). The RE dropped from 14.9 ± 9.4 mSv to 8.6 ± 7.9 mSv (P = 0.033) after a hybrid suite was established. Our institutional TEVAR protocol involves one pre-operative thoracoabdominal CT scan and three follow-up thoracic CT scans for the first year, with a yearly evaluation thereafter. The life expectancy of an age- and sex-matched population was 17 years. A patient adhering to our surveillance protocol would be subjected to an overall exposure of 89 mSv at 1 year and 161 mSv at 5 years, with a projected lifetime RE >350 mSv. CONCLUSIONS: A 2-year RE exceeding the threshold of 100 mSv with a life expectancy >15 years can be estimated to lead to a lifetime risk increase in radiation-induced leukaemia and solid-tumour cancer >2.7%. The risks of cumulative RE especially in younger and/or obese patients must be balanced with the expected morbidity and mortality reduction in TEVAR versus traditional open repair, and the anticipated benefits of recurrent radiographic imaging.

Vascular homograft use in a femoropopliteal rare bacterial infection bypass.

We report on a patient with a femoropopliteal bypass infected by Kytococcus sedentarius. Treatment consisted of resection of the infected prosthesis with homograft substitution and antibiotic therapy started postoperatively. At 6 months followup, the patient showed no signs of infection and results of laboratory findings were normal.

Endovascular treatment of abdominal aortic aneurysm after previous left pneumonectomy: a sound choice.

Surgical treatment of abdominal aortic aneurysm after previous pneumonectomy is a challenge because of the impaired respiratory function and increased surgical risks. Endovascular aneurysm repair in anatomically suited high-surgical-risk patients offers excellent short-term results and provides good protection from aneurysm-related death. In this article, we report a successful endovascular aneurysm repair of an infrarenal aortic aneurysm in a patient with past left pneumonectomy.

Measuring the collateral network pressure to minimize paraplegia risk in thoracoabdominal aneurysm resection.

OBJECTIVE: To minimize paraplegia during thoracoabdominal aortic aneurysm repair, the concept of the collateral network was developed. That is, spinal cord perfusion is provided by an interconnecting complex of vessels in the intraspinal, paraspinous, and epidural space and in the paravertebral muscles, including intercostal and lumbar segmental as well as subclavian and hypogastric arteries. METHODS: Collateral network pressure was measured with a catheter in the distal end of a ligated segmental artery in pigs and human beings. RESULTS: In the pig, collateral network pressure was 75% of the simultaneous mean aortic pressure. With complete segmental arterial ligation, it fell to 27% of baseline, recovering to 40% at 24 hours and 90% at 120 hours. Spinal cord injury occurred in approximately 50% of animals. When all segmental arteries were taken in 2 stages a week apart, collateral network pressure fell only to 50% to 70% of baseline, and spinal cord injury was rare. In human beings, baseline collateral network pressure also was 75% of mean aortic pressure, fell in proportion to the number of segmental arteries ligated, and began recovery within 24 hours. Collateral network pressure was lower with nonpulsatile distal bypass than with pulsatile perfusion. CONCLUSIONS: After subtraction of a measure of spinal cord outflow pressure (cerebrospinal fluid pressure or central venous pressure), collateral network pressure provides a clinically useful estimate of spinal cord perfusion pressure.

When to operate on the bicuspid valve patient with a modestly dilated ascending aorta.

BACKGROUND: Bicuspid aortic valves (BAV) are frequently associated with root/ascending aorta dilatation, but there is controversy regarding when to operate to prevent dissection of a dilated aorta associated with a well-functioning BAV. METHODS: From 1988 through 2008, 158 patients (mean age: 56 ± 13.5 years) with a dilated ascending aorta (AA) and a well-functioning BAV were referred to our institution. All patients underwent computed tomographic (CT) scanning and digitization to calculate mean AA diameter. Forty-two patients underwent operation a median of 52 days after initial CT scan with a mean AA diameter of 5.6 ± 0.5 cm. One hundred sixteen patients (mean diameter 4.6 ± 0.5 cm) were enrolled in annual or semiannual surveillance. Seventy-one patients, 45 with 2 or more CT scans, are still under surveillance. RESULTS: Average follow-up was 6.5 ± 4.1 years. Overall survival after the first encounter was 93% at 5 years and 85% at 10 years. A total of 87 of 158 patients had a Bentall or Yacoub procedure, with two hospital deaths (2.3%). Mean duration of surveillance in the 116 patients without immediate operation was 4.2 ± 2.9 years (481 patient-years). Average growth rate of the AA in patients with 2 scans or greater was 0.77 mm/year (p < 0.0001 versus normal population) with no significant impact of hypertension, sex, smoking or age. Forty-five of the 116 surveillance patients underwent operation after a mean of 3.4 ± 2.9 years (mean age 55 ± 14.7 years; mean AA diameter 4.9 ± 0.6 cm). Six patients died without surgery, median age 82 (range, 44 to 87) years, but none within one year of the last CT scan. CONCLUSIONS: A consistent approach to patients with a well-functioning BAV and AA dilatation, recommending operation to those with an AA diameter greater than 5 cm and deferring operation in patients under surveillance in the absence of significant enlargement (>0.5 cm/year), resulted in overall survival equivalent to a normal age-matched and sex-matched population. Operation was necessary in approximately 10% of patients under surveillance each year.

Predicting the risk of paraplegia after thoracic and thoracoabdominal aneurysm repair.

BACKGROUND: Endovascular repair of descending thoracic and thoracoabdominal aortic aneurysms is an appealing alternative to the standard surgical approach, but precludes revascularization of segmental arteries (SAs). For safer surgical and endovascular repairs, an accurate prediction of the risk of paraplegia in relation to the extent of SA sacrifice is needed. METHODS: From January 1994 to October 2008, 609 patients (mean age, 63 ± 14 years) underwent surgical descending thoracic or thoracoabdominal aortic aneurysm repair without SA reimplantation. Three hundred seventy-six patients (62%) were male; 159 (26%) had urgent or emergent operation; 199 (33%) had previous aortic surgery. Somatosensory- or motor-evoked potential monitoring and cerebrospinal fluid drainage were routinely performed. RESULTS: Hospital mortality was 10.7% (65 patients). Spinal cord injury (SCI) occurred in 3.4% (21 patients). The extent of resection-expressed as the number of SAs sacrificed (p = 0.007)-and the need for visceral artery reimplantation (p = 0.03) were independent risk factors for paraplegia. Further analysis identified four risk groups (p < 0.0001): fewer than 8 SAs sacrificed (group A, SCI = 1.2%); sacrifice of 8 to 12 SAs with proximal origin in the upper thorax (group B, SCI = 3.7%); 8 to 12 SAs sacrificed beginning in the lower thorax (group C, SCI = 15.4%); and 13 or more SAs sacrificed (group D, SCI = 12.5%). This four-group model more accurately predicts SCI risk than the Crawford classification (goodness of fit c statistic: 0.748 versus 0.640). CONCLUSIONS: The extent of SA sacrifice is the most powerful predictor of paraplegia risk. For aneurysms of moderate extent, a more distal location involving the abdominal aorta increases the risk of spinal cord injury. Sacrifice of fewer than 8 SAs is associated with a very low paraplegia risk regardless of location.

Experimental two-stage simulated repair of extensive thoracoabdominal aneurysms reduces paraplegia risk.

BACKGROUND: In a pig model, we compared spinal cord injury after extensive segmental artery (SA) sacrifice in a single stage with recovery after a two-stage procedure: lumbar artery followed by thoracic SA sacrifice. METHODS: Twenty juvenile Yorkshire pigs were randomly assigned to undergo extensive SA sacrifice at 32 degrees C in a single operation (group 1, n = 10), or thoracic SA ligation 7 days after lumbar artery sacrifice (group 2, n = 10). Spinal cord perfusion pressure (SCPP) was monitored using a catheter placed in the distal stump of L1. Hind limb function was evaluated intraoperatively using motor-evoked potentials and for 5 days postoperatively using a modified Tarlov score. RESULTS: Motor-evoked potentials were intact in all pigs until 1 hour after surgery. All pigs in group 2 fully recovered hind limb function, whereas 40% in group 1 experienced paraplegia (median Tarlov scores 9 versus 7; p = 0.004). Group 1 SCPP fell to 28 +/- 6 mm Hg after SA sacrifice, compared with 44 +/- 8 mm Hg in group 2 (p < 0.0001). After sacrifice of all residual SAs, SCPP in group 2 remained consistently greater than 85% of baseline, significantly higher than group 1 SCPP from end clamping until 72 hours (p = 0.0002). Histopathologic analysis showed more severe ischemic damage to the lower thoracic (p < 0.001) and lumbar spinal cord (p = 0.01) in group 1. CONCLUSIONS: In contrast with the single-stage approach, a two-stage procedure, starting with ligation of six or fewer lumbar SAs, leads to only a mild drop in SCPP and stimulates vascular remodeling, minimizing the impact of subsequent SA sacrifice on spinal cord function. The greater safety of extensive SA sacrifice when undertaken in two stages has important implications for endovascular and hybrid aneurysm repair.

Staged repair significantly reduces paraplegia rate after extensive thoracoabdominal aortic aneurysm repair.

OBJECTIVE: Paraplegia remains a devastating, and still too frequent, complication after repair of extensive thoracoabdominal aortic aneurysms. Strategies to prevent ischemic spinal cord damage after extensive segmental artery sacrifice-or occlusion, essential for endovascular repair-are still evolving. METHODS: Ninety patients who underwent extensive segmental artery sacrifice (median, 13; range, 9-15) during open surgical repair from June 1994 to December 2007 were reviewed retrospectively. Fifty-five patients (mean age, 65 +/- 12 years; 49% were male), most with extensive Crawford type II thoracoabdominal aortic aneurysms, had a single procedure (single-stage group). Thirty-five patients (mean age, 62 +/- 14 years; 57% were male) had 2 procedures (2-stage group), usually Crawford type III or IV repair after operation for Crawford type I descending thoracic aneurysm. The median interval between the 2-stage procedures was 5 years (3 months to 17 years). There were no significant differences between the groups with regard to age, gender, cause of the aneurysm, hypertension, chronic obstructive pulmonary disease, urgency, previous cerebrovascular accidents, year of procedure, or cerebrospinal fluid drainage. In single-stage procedures, hypothermic circulatory arrest was used in 29% of patients, left-sided heart bypass was used in 40% of patients, and partial cardiopulmonary bypass was used in 27% of patients. Somatosensory-evoked potentials were monitored in all patients, and motor-evoked potentials were monitored in 39% of patients. Cerebrospinal fluid was drained in 84% of patients. RESULTS: Overall hospital mortality was 11.1%. There were no significant differences in mortality, stroke, postoperative bleeding, infection, renal failure, or pulmonary insufficiency between the groups. However, 15% of patients in the single-stage group had permanent spinal cord injury versus none in the 2-stage group (P = .02). The significantly lower rate of paraplegia and paraparesis in the 2-stage group occurred despite a significantly higher number of segmental arteries sacrificed in this group: a median of 14 (11-15) versus 12 (9-15) (P < .0001). CONCLUSION: A staged approach to extensive thoracoabdominal aortic aneurysm repair may reduce the incidence of spinal cord injury. This is of particular importance in designing strategies involving hybrid or entirely endovascular procedures.

Long-term survival after open repair of chronic distal aortic dissection.

BACKGROUND: The optimal treatment of chronic distal aortic dissection remains controversial, with endovascular stent-graft techniques challenging traditional surgery. METHODS: From January 1994 to April 2007, 104 patients (82 male, median age 60.5 years) with chronic distal aortic dissection underwent surgical repair, 0 to 21 years after initial diagnosis of acute type A or B dissection (median 2.1 years). Twenty-three (22%) patients underwent urgent-emergent surgery. Mean aortic diameter was 6.9 +/- 1.4 cm. Indications for surgery, other than aortic expansion, were pain in 6 (6%) patients, malperfusion in 6 (6%), and rupture in 11 (11%). Forty-nine (47%) had previous cardioaortic surgery (29% dissection-related), 21 (20%) had coronary artery disease, 12 (12%) had Marfan syndrome, and 4 (4%) were on chronic dialysis. Twenty-six (25%) had a thrombosed false lumen. Thirty (29%) patients required reimplantation of visceral arteries; 8.3 +/- 2.7 segmental artery pairs were sacrificed. RESULTS: Hospital mortality was 9.6% (10 patients). Paraplegia occurred in 5 (4.8%). Twenty-seven patients (26%) experienced adverse outcome (death within one year, paraplegia, stroke, or dialysis). Adverse outcome was associated with atheroma (p = 0.04, odds ratio = 4.3). Survival was 78% at 1, 68% at 5, and 59% at 10 years (average follow-up, 7.7 +/- 4.1 years). Freedom from distal aortic reoperation was 99% at 1, 93% at 5, and 83% at 10 years. After one year, patients enjoyed longevity equivalent to a normal age-sex matched population (standardized mortality ratio = 1.38, p = 0.23). By multivariate analysis, atheroma (p = 0.0005, relative risk = 9.32) and age (p = 0.0003, relative risk = 1.15/year) were risk factors for long-term survival. CONCLUSIONS: The efficacy of open repair for distal chronic dissection is highlighted by normal survival after the first year, and a low reoperation-reintervention rate.

Aortic dissection complicating intraaortic balloon pumping: percutaneous management of delayed spinal cord ischemia.

Iatrogenic acute type B dissection is a rare complication of intraaortic balloon pumping. Delayed visceral and spinal cord malperfusion can occur for distal progression of the dissection or relative hypotension. Cerebrospinal fluid drainage and percutaneous balloon fenestration provide a safe and effective method for managing ischemic complications.

Redo lateral thoracotomy for reoperative descending and thoracoabdominal aortic repair: a consecutive series of 60 patients.

BACKGROUND: Reoperative descending thoracic aorta (DTA) or thoracoabdominal aortic aneurysm (TAAA) surgery is a challenge because of increased risk of lung injury and diffuse bleeding. METHODS: Sixty patients (34 male, mean age 54.4 years) underwent redo thoracotomy for DTA (22 patients) or extended thoracoabdominal incision for reoperative TAAA (38 patients) from March 1988 to June 2007, after 1.7 +/- 0.9 previous cardioaortic procedures. Forty-one patients were hypertensive (68%), 18 were smokers (30%), 9 had Marfan syndrome (15%), 9 had coronary artery disease (15%), 5 had chronic obstructive pulmonary disease (8%), and 3 had diabetes mellitus (5%). In all, 45% (27 patients) had previous dissection, 30% (18) had atherosclerotic aneurysms, 15% had coarctation surgery (9), and 6 patients had other etiologies. Mean follow-up, 100% complete, was 6.5 years. RESULTS: Hospital mortality for reoperative DTA/TAAA was 13.3% (8 patients). Although 6.3 +/- 2.9 (0 to 14) segmental artery pairs were sacrificed at reoperation-and 6.2 +/- 2.3 (1 to 12) initially-for a total of 10.6 +/- 3.9 (2 to 15) segmental artery pairs sacrificed, only 1 patient had paraplegia (1.6%). Four patients had a 2-day procedure, with 12 to 24 hours of intensive care unit recovery after lysis of extensive adhesions: all survived. Respiratory complications occurred in 13 patients (21.6%), and permanent dialysis was required in 2 (3.3%), but there were no strokes. Adverse outcome-1-year mortality, stroke, permanent dialysis, or paraplegia-occurred in 13 patients (21.6%). Adverse outcome was marginally associated (p < 0.2) with increased age, atherosclerotic aneurysms (33% versus 17% other), TAA incision (30% versus 9%), and greater aneurysm extent, and was significantly associated with perfusion technique (p = 0.02). Adverse outcome occurred in 3 of 4 patients who had clamp-and-sew technique, 6 of 21 using partial cardiopulmonary bypass (28.6%), and 3 of 17 with partial left heart bypass (17.7%), but only 1 of 18 with hypothermic circulatory arrest (5.6%). CONCLUSIONS: Reoperative DTA/TAAA repair was significantly safer with hypothermic circulatory arrest rather than partial cardiopulmonary bypass, partial left heart bypass, or clamp-and-sew strategy. A 2-day procedure may be advisable for patients with extensive adhesions.

Selective cerebral perfusion at 28 degrees C--is the spinal cord safe?

OBJECTIVE: To shorten cooling/rewarming associated with hypothermic neuroprotection strategies during complex aortic arch surgery, selective cerebral perfusion (SCP) at 28 degrees C has recently been advocated, although its safe limits - especially with regard to the ischaemic tolerance of the spinal cord - have not been systematically examined. METHODS: Twenty juvenile Yorkshire pigs (30.3+/-2.8kg) were randomly allocated to undergo circulatory arrest and SCP at 28 degrees C for 90 min (group A; N=12) or 120 min (group B; N=8) at 50 mmHg using alpha-stat pH management. Spinal cord blood flow (SCBF) was assessed using fluorescent microspheres at baseline (prior to SCP); at 5 and 80 min during SCP, and at 1, 5 and 48 h after cardiopulmonary bypass (CPB). A modified Tarlov score was used to evaluate neurobehavioural recovery in all survivors blindly from videotapes for 5 days postoperatively. Histological ischaemic spinal cord injury was scored after sacrifice. RESULTS: All pigs could be weaned from CPB and ventilation, but seven pigs (58%) in group A and five (63%) in group B developed multi-organ failure and died within 24h. SCBF diminished immediately after initiation of SCP and was absent throughout SCP in all segments below T8/9, recovering to baseline 1h after SCP at all cord levels. All survivors suffered moderate-to-severe histological lumbar spinal cord damage, more severe in group B (p< or =0.049). Three of five group A pigs recovered normal function, but two suffered paraparesis. Group B survivors had a worse neurologic outcome (p<0.0001): all suffered paraplegia (one immediate, and two on day 2, after initial recovery). CONCLUSION: SCP provides insufficient SCBF below T8/9 to sustain cord viability. At 28 degrees C, the ischaemic tolerance of the cord may be exceeded enough by 90 min to impair function; by 120 min, SCP at 28 degrees C invariably results in paraplegia.

Direct spinal cord perfusion pressure monitoring in extensive distal aortic aneurysm repair.

BACKGROUND: Although maintenance of adequate spinal cord perfusion pressure (SCPP) by the paraspinal collateral network is critical to the success of surgical and endovascular repair of descending thoracic and thoracoabdominal aortic aneurysms, direct monitoring of SCPP has not previously been described. METHODS: A catheter was inserted into the distal end of a ligated thoracic segmental artery (SA) (T6 to L1) in 13 patients, 7 of whom underwent descending thoracic and thoracoabdominal aortic aneurysm repair using deep hypothermic circulatory arrest. Spinal cord perfusion pressure was recorded from this catheter before, during, and after serial SA sacrifice, in pairs, from T3 through L4, at 32 degrees C. Somatosensory and motor evoked potentials were also monitored during SA sacrifice and until 1 hour after cardiopulmonary bypass. Target mean arterial pressure was 90 mm Hg during SA sacrifice and after nonpulsatile cardiopulmonary bypass, and 60 mm Hg during cardiopulmonary bypass. RESULTS: A mean of 9.8 +/- 2.6 SAs were sacrificed without somatosensory and motor evoked potential loss. Spinal cord perfusion pressure fell from 62 +/- 12 mm Hg (76% +/- 11% of mean arterial pressure) before SA sacrifice to 53 +/- 13 mm Hg (58% +/- 15% of mean arterial pressure) after SA clamping. The most significant drop occurred with initiation of nonpulsatile cardiopulmonary bypass, reaching 29 +/- 11 mm Hg (46% +/- 18% of mean arterial pressure) before deep hypothermic circulatory arrest. Spinal cord perfusion pressure recovered during rewarming to 40 +/- 14 mm Hg (51% +/- 20% of mean arterial pressure), and further within the first hour of reestablished pulsatile flow. Somatosensory and motor evoked potentials returned in all patients intraoperatively. Recovery of SCPP began intraoperatively, and in 5 patients with prolonged monitoring, continued during the first 24 hours postoperatively. All but 1 patient, who had remarkably low postoperative SCPPs and experienced paraparesis, regained normal spinal cord function. CONCLUSIONS: This study supports experimental data showing that SCPP drops markedly but then recovers gradually during the first several hours after extensive SA sacrifice. Direct monitoring may help prevent a fall of SCPP below levels critical for spinal cord recovery after surgery and endovascular repair of descending thoracic and thoracoabdominal aortic aneurysms.

Endovascular treatment of a post-traumatic tibial pseudoaneurysm and arteriovenous fistula: case report and review of the literature.

Here we report a rare case of a 74-year-old man with a pseudoaneurysm of the anterior tibial artery and a concomitant arteriovenous fistula (AVF). The patient was admitted because of increasing pain following the formation of a large mass located in the anterior mid-portion of the calf after a moderate non-penetrating blunt trauma. A polytetrafluoroethylene-covered stent was placed over the origin of the pseudoaneurysm, with complete exclusion of the pseudoaneurysm and disappearance of the AVF. One year after the procedure the mass had completely disappeared and the vascular anatomy of the calf is well preserved.