Ian Nixon |
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St. Vincent's Hospital Melbourne
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Department of Cardiothoracic Surgery
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Publications (18) View all
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Article: Stent-Assisted Balloon-Induced Intimal Disruption and Relamination in Aortic Dissection Repair: The STABILISE concept.
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ABSTRACT: OBJECTIVES: The study objective was to describe the Stent-Assisted Balloon-Induced Intimal Disruption and Relamination in Aortic Dissection Repair technique for aortic dissection repair using proximal descending aortic endografting with distal aortic relamination through bare-metal stent and balloon-induced intimal disruption with immediate intimal reapposition. METHODS: Between April 2007 and September 2011, 11 selected patients (10 male; median age, 50 years) underwent proximal descending aortic endografting plus stent-assisted balloon-induced intimal disruption of the thoracoabdominal aorta to treat complicated aortic dissection (7 type A, 4 acute type B). Patients with type A dissection underwent open surgical intervention plus adjunctive retrograde endovascular repair. Serial computed tomography angiography was used to assess aortic remodeling. RESULTS: There were no intraprocedural complications. Thirty-day incidence of death, stroke, and paralysis/visceral ischemia was 9% (n = 1), 0%, and 0%, respectively. Median follow-up was 18 months (range, 4-54 months). Two patients (18%) required secondary endovascular reintervention. No late adverse events or aortic-related deaths occurred. Complete false lumen obliteration occurred in 90% (n = 10) of patients, with stable maximal diameters in the thoracic (P = .6) and abdominal aortas (celiac trunk: P = .34; renal; P = .6; infrarenal: P = .7) at latest follow-up. CONCLUSIONS: The Stent-Assisted Balloon-Induced Intimal Disruption and Relamination in Aortic Dissection Repair approach is a feasible endovascular technique that shows promise to achieve complete repair of the dissected aorta by inducing complete false lumen obliteration. The restoration of uniluminal flow in the thoracoabdominal aorta has the potential to improve long-term outcomes. Prospective, multicenter investigations are required to implement this strategy more broadly.The Journal of thoracic and cardiovascular surgery 04/2013; · 3.41 Impact Factor -
SourceAvailable from: Andrew E Newcomb
Article: Hybrid proximal surgery plus adjunctive retrograde endovascular repair in acute DeBakey type I dissection: Superior outcomes to conventional surgical repair.
Sophie C Hofferberth, Andrew E Newcomb, Michael Y Yii, Kelvin K Yap, Raymond C Boston, Ian K Nixon, Peter J Mossop[show abstract] [hide abstract]
ABSTRACT: OBJECTIVE: The present study compared the outcomes between conventional surgery and the hybrid approach of proximal surgery with adjunctive retrograde descending aortic endografting plus distal bare metal stenting in acute DeBakey type I dissection. METHODS: From 2003 to 2011, 61 patients underwent surgical management for acute type A aortic dissection at our institution. Of these, 37 were DeBakey type I dissections: 18 patients (group 1) received conventional surgical repair alone, and 19 (group 2) underwent conventional hybrid surgery with adjunctive retrograde descending aortic stent grafting plus distal bare metal stenting. RESULTS: The patients' baseline characteristics were comparable, including the incidence of preoperative malperfusion syndromes (P = .23). The intraoperative and postoperative characteristics were similar, except 4 (22%) patients in group 1 (vs 0 in group 2) had ongoing malperfusion postoperatively (P = .04). Overall, hospital mortality was 11% (n = 2) for group 1 versus 5% (n = 1) for group 2. At a mean follow-up of 50 months, 4 (25%) subjects in group 1 required secondary thoracoabdominal aortic reintervention versus none in group 2 (P = .03). CONCLUSIONS: The use of adjunctive retrograde descending aortic endografting plus distal bare metal stenting during acute DeBakey type 1 dissection repair is a feasible method to enhance thoracoabdominal remodeling. This hybrid strategy improves perioperative outcomes and decreases late distal aortic complications compared with conventional surgical repair for acute DeBakey type I dissection. A prospective, multicenter study is warranted to definitively assess this promising new treatment paradigm.The Journal of thoracic and cardiovascular surgery 11/2012; · 3.41 Impact Factor -
SourceAvailable from: Andrew E Newcomb
Article: Combined proximal stent grafting plus distal bare metal stenting for management of aortic dissection: Superior to standard endovascular repair?
Sophie C Hofferberth, Andrew E Newcomb, Michael Y Yii, Kelvin K Yap, Raymond C Boston, Ian K Nixon, Peter J Mossop[show abstract] [hide abstract]
ABSTRACT: The present study compared the outcomes between combined proximal descending aortic endografting plus distal bare metal stenting and conventional proximal descending aortic stent-graft repair in patients with type A and type B aortic dissection. From January 2003 to December 2010, 63 patients underwent endovascular treatment for acute (type A, 24; type B, 21) and chronic (type B, 18) aortic dissection. Of these, 40 patients underwent proximal descending aortic endografting plus distal bare metal stenting (group 1), and 23 underwent proximal descending stent-graft repair alone (group 2). All patients with type A dissection underwent open surgical intervention plus adjunctive retrograde endovascular repair. The patients were comparable for baseline characteristics and treatment indicators, but more group 1 patients were active smokers (P = .03). The intraoperative characteristics were also similar, although 4 patients, all in group 2, developed malperfusion syndrome postoperatively (P = .02). The overall hospital mortality was 6%. At a mean follow-up of 49 months, 9 group 2 patients (43%) required unplanned secondary intervention compared with 4 in group 1 (11%; P = .007). Reintervention for thoracoabdominal aortic aneurysm or visceral ischemia was performed in 4 patients (19%) from group 2 (P = .03). Late aortic-related deaths occurred in 1 (5 %) and 2 (5%) patients in groups 1 and 2, respectively. Combined proximal descending aortic endografting plus distal bare metal stenting for aortic dissection provides favorable short-term outcomes and decreases late distal aortic complications compared with conventional endovascular repair. These results support a more widespread application of this approach. A prospective, randomized trial is needed before definite conclusions can be made.The Journal of thoracic and cardiovascular surgery 08/2012; 144(4):956-62. · 3.41 Impact Factor -
Article: Aortic false lumen thrombosis induction by embolotherapy (AFTER) following endovascular repair of aortic dissection.
Sophie C Hofferberth, Ian K Nixon, Peter J Mossop[show abstract] [hide abstract]
ABSTRACT: To report the use of a technique (AFTER: aortic false lumen thrombosis induction by embolotherapy) to achieve false lumen (FL) thrombosis and aortic remodeling in patients with residual FL patency after initial endovascular repair of aortic dissection. Between January 2003 and January 2010, 31 patients underwent staged total aortic and branch vessel endovascular reconstruction (STABLE) of type A (n = 13) and type B (n = 18) dissection. Of these, 10 patients (5 men; mean age 61 years) who had undergone repair of 4 acute type A, 3 acute type B, and 3 chronic type B dissections demonstrated re-entry tear(s) and FL patency associated with aortic expansion ≥5 mm or flow into a persistently dilated aortic segment. Catheter-directed embolization using coils, glue, or occlusion balloons was performed via a transfemoral approach to the true lumen at a mean of 7 months (range <1 to 26) after initial repair. Technical success was achieved in all patients, with no intraoperative complications. Thirty-day morbidity and mortality was nil. Mean follow-up was 63 months (range 13-96). Reversal or stabilization (<5-mm increase) of thoracoabdominal aortic growth occurred in 9 patients. Complete thrombosis of the thoracic and abdominal FL occurred in 2 patients. In 4, FL occlusion and subsequent thrombosis of the upstream thoracic segment was achieved. Four demonstrated partial FL thrombosis in the thoracic and abdominal aorta. One patient with chronic aneurysmal type B dissection died 4 months post-embolization from aortic rupture. The AFTER strategy appears to be a safe and promising adjunctive endovascular approach to treat residual FL patency or aortic enlargement post endovascular repair of aortic dissection. Elimination of FL flow and stabilization of aortic expansion may reduce the risk of late distal aortic complications.Journal of Endovascular Therapy 08/2012; 19(4):538-45. · 2.86 Impact Factor -
SourceAvailable from: Andrew E Newcomb
Article: High incidence of insulin resistance and dysglycemia amongst nondiabetic cardiac surgical patients.
Sophie C Hofferberth, Andrew E Newcomb, Marno C Ryan, Michael Y Yii, Ian K Nixon, Alexander Rosalion, Raymond C Boston, Glenn M Ward, Andrew M Wilson[show abstract] [hide abstract]
ABSTRACT: Undiagnosed glycometabolic dysfunction is prominent amongst nondiabetic cardiac surgical patients, whereas perioperative dysglycemia is associated with adverse outcomes. This study assessed whether the preoperative level of insulin resistance predicts the degree of perioperative dysglycemia in nondiabetic, normoglycemic cardiac surgical patients. Twenty-two nondiabetic patients awaiting cardiac operations were assessed for metabolic parameters and whole-body insulin resistance (mean glucose infusion [GINF] rate) using the hyperinsulinemic-euglycemic clamp. Intraoperative and postoperative glucose levels and treatment requirements were analyzed. Linear regression analysis was used to find predictors of baseline, peak intraoperative, and mean postoperative fasting blood glucose (FBG). The mean GINF recorded in nondiabetic, normoglycemic patients was 3.5 ± 1.4 mg/kg/min. The mean peak intraoperative and mean postoperative FBG concentrations were 154.9 ± 34.2 mg/dL (range, 108.1 to 227.0 mg/dL) and 120.7 ± 16.2 mg/dL (range, 100.9 to 154.9 mg/dL), respectively. The GINF correlated inversely with mean peak intraoperative (r = -0.7, p = 0.02) and mean postoperative FBG (r = -0.8, p = 0.01). The GINF did not correlate with preoperative FBG levels (r = 0.3, p = 0.4). Preoperative FBG did not correlate with peak intraoperative (r = 0.4, p = 0.5) or mean postoperative FBG (r = 0.5, p = 0.3). Nondiabetic, normoglycemic cardiac surgical patients are highly insulin resistant using the hyperinsulinemic-euglycemic clamp. Preoperative insulin resistance, not FBG, is significantly associated with the development of perioperative dysglycemia. Insulin resistance screening may be useful to identify insulin resistance preoperatively and predict the degree of perioperative dysglycemia in cardiac surgical patients but should be performed with a more appropriate and reproducible test.The Annals of thoracic surgery 04/2012; 94(1):117-22. · 3.74 Impact Factor