Paolo Masetti

Safety and efficacy of hypothermic cardiopulmonary bypass and circulatory arrest for operations on the descending thoracic and thoracoabdominal aorta

BACKGROUND Hypothermic cardiopulmonary bypass with circulatory arrest is an important adjunct for operations on the distal aortic arch and the descending thoracic and thoracoabdominal aorta. Its safety and efficacy compared with other techniques (eg, simple aortic clamping, partial cardiopulmonary bypass, and regional hypothermia) are not clearly established. METHODS One hundred sixty-one patients (ranging from 20 to 83 years old) with descending thoracic or thoracoabdominal aortic disease had resection and graft replacement of the involved aortic segments using hypothermic cardiopulmonary bypass usually with intervals of circulatory arrest (mean interval, 38 minutes). RESULTS The 30-day mortality rate was 6.2% (10 patients). It was 41% (7 of 17) for patients having emergent operations (rupture or acute dissection) and 2.1% (3 of 144) for all other patients (p < 0.001). The 90-day mortality rate was 11.8% (19 patients). Paraplegia occurred in 4 and paraparesis in 1 of the 156 operative survivors whose lower limb function could be assessed postoperatively (3.2%). Among the 91 survivors with thoracoabdominal aortic disease, early paraplegia occurred in 1 of 33 patients with Crawford type I disease, 0 of 34 with type II disease, and 2 of 24 with type III disease. One patient (type II disease) had development of paraplegia on the tenth postoperative day. None of the 50 patients with aortic dissection experienced paralysis. Renal dialysis was required in 4 (2.5%) of the 157 operative survivors, prolonged inotropic support (> 48 hours) in 17 (11%), reoperation for bleeding in 8 (5%), mechanical ventilation (> 48 hours) in 31 (20%), and tracheostomy in 13 (8%). Three patients (1.9%) sustained a stroke. CONCLUSIONS Hypothermic cardiopulmonary bypass provides safe and substantial protection against paralysis and renal, cardiac, and visceral organ system failure that equals or exceeds that of other currently used techniques but without the need of other adjuncts.

Hypothermic cardiopulmonary bypass and circulatory arrest for operations on the descending thoracic and thoracoabdominal aorta

BACKGROUND Hypothermic cardiopulmonary bypass with circulatory arrest is an important adjunct for operations on the distal aortic arch, the descending thoracic, and the thoracoabdominal aorta. The safety and efficacy of this technique when compared with other adjuncts (ie, simple aortic clamping, partial cardiopulmonary bypass, regional hypothermia) is not clearly established. METHODS One hundred and ninety-two patients (age range, 20 to 83 years) with descending thoracic or thoracoabdominal aortic disease had resection and graft replacement of the involved aortic segments using hypothermic cardiopulmonary bypass and intervals of circulatory arrest (mean, 38 minutes). The technique was used when the location and severity of disease precluded placement of clamps on the proximal aorta (31 patients) or (in 161 patients) when extensive thoracic (47) or thoracoabdominal (114) aortic disease was present, and the risk for development of spinal cord ischemic injury was judged to be increased. Lower intercostal and lumbar arteries were attached separately to the aortic graft in 101 of the 161 patients (63%) who had extensive aortic replacement. No other adjuncts for spinal cord protection were used. RESULTS The 30-day mortality was 6.8% (13 patients). It was 40% (8 of 20) for patients having emergent operations (acute aortic dissection or rupture) and 2.9% (5 of 172) for all others (p < 0.001). The 90-day mortality was 12.5% (24 patients). Paraplegia occurred in 4 and paraparesis in 1 (full recovery) of the 186 operative survivors whose lower limb function could be assessed postoperatively (2.7%). Among the 109 survivors with thoracoabdominal aortic disease, early paraplegia occurred in 1 of 36 with Crawford extent I, 0 of 42 with extent II, and 2 of 31 with extent III disease. One patient (extent II) developed paraplegia on the 9th postoperative day after a hypotensive episode. None of the 47 patients with aortic dissection developed paralysis. Among the 186 operative survivors, renal dialysis was required in 4 patients (2.2%), prolonged inotropic support in 18 (10%), reoperation for bleeding in 9 (5%), mechanical ventilation (> or = 48 hours) in 64 (34%), and tracheostomy in 17 (9%). Four patients (2%) sustained a stroke. CONCLUSIONS Hypothermic cardiopulmonary bypass with circulatory arrest provides safe and substantial protection against paralysis and renal, cardiac, and visceral organ system failure that equals or exceeds that of other currently used techniques but without the need of other adjuncts.

S100B protein is increased in asphyxiated term infants developing intraventricular hemorrhage.

ObjectiveTo establish whether S100B protein may be useful in the early detection of intraventricular hemorrhage in asphyxiated term infants. DesignCase-control study. PatientsTwenty full-term newborns with intraventricular hemorrhage, 20 asphyxiated infants without intraventricular hemorrhage, and 80 normal newborns. InterventionsRoutine laboratory variables and neurologic patterns were assessed at birth after 12 and 72 hrs. Ultrasound imaging and middle cerebral artery Doppler velocimetry pulsatility index were recorded at 12 and 72 hrs after birth. S100B protein blood concentrations were determined at 12 hrs. Measurements and Main ResultsS100B protein levels were significantly higher in samples collected from newborns who developed intraventricular hemorrhage (1.87 ± 0.60 &mgr;g/L) than from those who did not develop intraventricular hemorrhage (0.72 ± 0.39 &mgr;g/L) or from normal infants (0.66 ± 0.31 &mgr;g/L). Multiple logistic regression analysis showed a significant correlation between circulating S100B protein concentrations and the occurrence of intraventricular hemorrhage. ConclusionsThis study suggests that elevated S100B protein represents a useful tool for the early detection of intraventricular hemorrhage in the postasphyxia period when clinical examination and cerebral ultrasound might still be silent.

One-Stage Repair of Extensive Chronic Aortic Dissection Using the Arch-First Technique and Bilateral Anterior Thoracotomy

BACKGROUND We evaluated a one-stage technique for extensive replacement of the thoracic aorta in patients with chronic aortic dissection. METHODS Fifty-one patients with chronic expanding thoracic aortic dissections (48 type A, 3 type B with proximal extension) were treated with a single procedure using a bilateral anterior thoracotomy, hypothermic circulatory arrest, and reperfusion of the arch vessels first to minimize brain ischemia. Forty-six patients had previous operations: for acute type A aortic dissection (n = 36), aortic valve disease (n = 6), or coronary artery disease (n = 4). The ascending aorta and entire arch were replaced in all patients combined with varying lengths of the descending aorta. RESULTS Hospital mortality was 3.9% (2 patients). Five patients (10%) required reoperation for bleeding. Two patients were discharged on ventilatory support and 2 on dialysis. No patient sustained a stroke, and paraplegia developed in one. The 5- and 7-year survival rates were 79% and 68%. Freedom from reoperation on the thoracic or abdominal aorta was 92% at 5 and 7 years postoperatively. Serial tomograms have documented substantial enlargement of the residual dissected aorta in only 2 patients (reoperated). CONCLUSIONS The technique is a safe and suitable alternative to the two-stage (elephant trunk technique) and hybrid procedures for treatment of chronic dissection with aneurysm of the thoracic aorta. It eliminates the risk of rupture in the interval between staged procedures and the risks associated with a second thoracic aortic procedure, and is associated with a low rate of reoperation on the remaining aorta.

Hypothermic cardiopulmonary bypass and circulatory arrest in the management of extensive thoracic and thoracoabdominal aortic aneurysms

Hypothermic cardiopulmonary bypass, usually in combination with an interval of circulatory arrest, was used for the treatment of 211 patients with extensive thoracic or thoracoabdominal aortic disease during a 17-year interval. Profound hypothermia, distal perfusion, and intravenous methylprednisolone and thiopental were used for neuroprotection. No other technique or other adjunctive agents were used. The 30-day mortality rate was 7.1% (15 patients). It was 40% (8 of 20) for patients undergoing emergent operations for aortic rupture or acute dissection and 3.7% (7 of 191) for all other patients (P<0.001). Paraplegia occurred in 5 and paraparesis in 1 of the 205 operative survivors whose lower limb function could be assessed postoperatively (2.9%). Of the 121 survivors with thoracoabdominal aortic disease, paraplegia occurred in 1 of 38 patients with Crawford type I disease (2.6%), 2 of 49 with type II (4.1%), and 2 of 34 with type III (5.9%). Paralysis developed in 1 (1.7%) of the 58 patients who underwent aortic dissection. Renal dialysis was required in 6 (2.9%) of the 205 operative survivors, prolonged inotropic support (>48 hours) in 23 (11%), reoperation for bleeding in 10 (5%), mechanical ventilation (>48 hours) in 50 (24%), and tracheostomy in 21 (10%). Four (1.9%) patients sustained a stroke. Hypothermic cardiopulmonary bypass provides safe and substantial protection against paralysis, and renal, cardiac, and visceral organ system failure that equals or exceeds that of other currently used techniques but without the need for other adjuncts.

Elevated S100B protein as an early indicator of intracranial haemorrhage in infants subjected to extracorporeal membrane oxygenation.

The aim of this investigation was to verify whether plasma S100B could be a useful tool in identifying which infants subjected to extracorporeal membrane oxygenation (ECMO) might develop intracranial haemorrhage (ICH). A case‐control study of eight infants who developed ICH during ECMO was conducted. Plasma samples collected daily after ECMO insertion were assessed for S100B and compared with those obtained from eight infants supported by ECMO who did not develop ICH. Cerebral ultrasound and Doppler velocimetry waveform patterns in the middle cerebral artery (MCA PI) were also recorded at the same time as blood sampling. S100B blood concentrations were significantly higher in the group of infants with ICH 72 h before any signs of haemorrhage could be detected by ultrasound (ICH: 2.91 ± 0.91 μg/L vs. control: 0.53 ± 0.15 μg/L), reaching their peak at day 6, when cerebral ultrasound scan patterns were suggestive of intracranial haemorrhage (ICH: 3.50 ± 1.03 μg/L vs. control: 0.66 ± 0.27 μg/L) (p < 0.05, for both). The highest S100B levels were observed in the three ICH infants who expired during the ECMO procedure (3.43 μg/L, 4.0 μg/L, 4.12 μg/L, respectively). MCA PI values in the ICH group were also significantly higher, but only 24 h before any ultrasound pattern of bleeding was detected (ICH: 2.31 ± 0.22 vs control: 1.81 ± 0.24) (p < 0.05).

Vasopressin Therapy for Vasoplegic Syndrome Following Cardiopulmonary Bypass

Abstract Background: Hypotension refractory to maximal doses of alpha‐adrenergic drugs after cardiac operations employing cardiopulmonary bypass (CPB) has been referred as “vasoplegic syndrome.” Vasopressin has been used for its therapy with encouraging results. Material and methods: 16 patients (mean age 71, range 47 to 84 years) were treated with intravenous vasopressin (0.1–1 IU/min) for hypotension refractory to maximal doses (>30 μg/kg/min) of norepinephrine after undergoing complex cardiac operations employing CPB. Preoperative ejection fraction was 40.5% (mean, range 20% to 60%), preoperative NYHA class was 3.5 (mean). Hemodynamic measurements were obtained one hour before and one hour after beginning vasopressin infusion; urine output was measured for the 4 hours before and the 4 hours after beginning the infusion. Duration of vasopressin treatment was 58.8 ± 37.3 hours (mean ± SD) . Results: Systolic blood pressure increased from 89.6 ± 7.9 to 119.6 ± 10.5 mmHg (mean ± SD) (p < 0.001) ; systemic vascular resistance increased from 688.0 ± 261.7 to 1043.3 ± 337.1 dyne/s/cm2 (mean ± SD) (p < 0.001) ; cardiac index decreased from 2.69 ± 0.8 to 2.2 ± 0.5 L/min/m2 (mean ± SD) (p < 0.008) ; urine output increased from 36.8 ± 30.4 to 72.8 ± 38.2 mL/h (mean ± SD) (p < 0.001) . Seven patients (44%) survived the hospital stay. Conclusions: High‐dose vasopressin is effective in the treatment of the vasoplegic syndrome after cardiac operations employing cardiopulmonary bypass.(J Card Surg 2002;17:485‐489)

Valve-sparing procedure for dilatation of the autologous pulmonary artery and ascending aorta after the Ross operation

The need for reoperation remains a principal limitation of the Ross procedure and most commonly includes replacement of the neo-aortic valve. We describe the use of a valve-sparing procedure in a patient with progressive dilatation of the pulmonary autograft and the remaining native ascending aorta and mild regurgitation of the neo-aortic valve.

Phentolamine administration increases blood S100B protein levels in pediatric open-heart surgery patients

Aim: Phentolamine administration during open‐heart surgery shortens the cooling and rewarming phases of cardiopulmonary bypass (CPB) and hastens weaning from mechanical ventilation and extubation. Data on the effects of phentolamine on cerebral circulation and function in this setting are lacking. This study reports the cerebral effects of phentolamine using blood S100B protein levels and the middle cerebral artery pulsatility index (MCA PI). Methods: Sixty pediatric patients undergoing congenital heart disease repair were randomly assigned to receive either phentolamine 0.2 mg kg‐1 i.v. (n= 30) or placebo (n= 30) before the cooling and rewarming phases of CPB. Samples for S100B measurement were collected at seven predetermined time‐points before, during and after surgery. MCA PI values were recorded at the same times as sampling. Results: S100B blood levels were higher in the phentolamine‐treated group than in controls after rewarming (3.53 ± 1.88 vs 1.58 ± 0.53 μg l‐1; p < 0.001), remained persistently higher at the end of surgery (2.95 ± 0.91 vs 0.79 ± 0.21 μg l‐1; p < 0.001) and returned to normal ranges 12 h later than in the placebo group (p > 0.05). MCA PI values were also significantly higher at the end of surgery in the phentolamine‐treated group (1.83 ± 0.50 vs 1.22 ± 0.34; p < 0.01). Cooling and rewarming times were shorter in the phentolamine‐treated group (p < 0.01, for all).

Reversal of protein-losing enteropathy after ligation of systemic-pulmonary shunt

A 21-year-old white woman, born with a univentricular heart, had undergone staged procedures before Fontan correction. She then began to develop edema, protein-losing enteropathy, and ascites refractory to diuretic therapy. Cardiac angiography showed a patent right Blalock-Taussig shunt, with turbulent cavopulmonary circulation. After undergoing an unsuccessful attempt at coil embolization she then underwent shunt ligation, with resolution of symptoms and normalization of protein levels. This report draws attention to the importance of cavopulmonary laminar flow to prevent the development of protein-losing enteropathy.