Stuart B. Pett

Catastrophic hemorrhage on sternal reentry: still a dreaded complication?

BACKGROUND To define the incidence of catastrophic hemorrhage (CH) during reoperations, the experience of the University of New Mexico was reviewed and compared with the practice of surgeons contacted by questionnaire. METHODS At the University of New Mexico, 610 reoperations were reviewed and 210 deemed high risk because of multiple reoperation, aneurysm, patent grafts, chambers enlargement, conduit or previous mediastinitis. In the questionnaire, we asked about reentry technique, occurrence and outcome of CH, and precautions for high-risk patients. RESULTS At the University of New Mexico there were 4 CH with 1 death, and in the questionnaire there were 2,046 CH with 392 deaths. Our rate per surgeon was lower than that of the questionnaire. Rate of CH according to the saw was 2.09 for reciprocating, 2.0 for sagittal, and 1.74 for stryker in the questionnaire. Our rate was lower (0.65) with a micro sagittal saw. High-risk category predicted CH during sternotomy (p = 0.01) but only conduit (p = 0.005) was significant by univariate analysis. CONCLUSIONS The risk of CH could be as high as 1%. The sagittal micro oscillating saw is the safest reported to date. Presence of a conduit increases the risk by 2.5 fold.

Selective vulnerability of white matter during spinal cord ischemia

The long-term effects of spinal cord ischemia were studied in 21 rats by lesion scores (LS, n = 21), somatosensory evoked potentials (SEP, n = 16), electromyographic measurements (EMG, n = 12) and histology of the spinal cord (n = 21) 48.5 ± 57.2 days after 10- to 12-min occlusion of the thoracic aorta and subclavian arteries. All the animals were initially paraplegic with a spastic presentation but seven recovered within 2 days (group A), demonstrating low LS (3.4 ± 1.05) normal EMGs (n = 3) and unremarkable histology. The 14 paraplegic animals presented relevant findings of the lumbar cord consisting of white matter lesions only (group B, n = 7) or white and gray matter lesions (group C, n = 7). Group B animals showed severe deficit (LS = 11.8 ± 2.93) without denervation on EMG (n = 5) or muscle atrophy on histology. Group C animals displayed equal impairment (LS = 14.4 ± 0.71), denervation on EMG (n = 4), and muscle atrophy. Resting motor unit activity of groups B and C were significantly different from group A (p < 0.001), while LS of groups B and C did not differ (p = 0.083). These data underscore the nature and the extent of white matter lesions during spinal cord ischemia, a finding which has generally been eclipsed by emphasis on gray matter lesions in previous studies.

Extracorporeal membrane oxygenation support improves survival of patients with severe Hantavirus cardiopulmonary syndrome

OBJECTIVE The purposes of this study are to evaluate the outcome of extracorporeal membrane oxygenation support in a subgroup of patients with Hantavirus cardiopulmonary syndrome who had a predicted mortality of 100% and to assess the complications associated with this treatment modality and with different cannulation techniques. METHODS Thirty-eight patients with severe Hantavirus cardiopulmonary syndrome were supported with extracorporeal membrane oxygenation between April 1994 and June 2006. Cannulation of the femoral vessels was performed on an emergency basis by a percutaneous approach in 15 (39.5%) and by an open technique in 23 (60.5%) patients. Duration of extracorporeal membrane oxygenation averaged 132 hours (range: 5-276 hours). RESULTS Complications from percutaneous cannulation occurred in 4 (26.6%) of 15 patients: retroperitoneal hematoma in 2 (13.3%) and lower extremity ischemia in 2 (13.3%) patients, which resolved after insertion of a distal perfusion cannula. Complications from open femoral cannulation occurred in 8 (34.8%) of 23 patients: severe bleeding in 7 (30.4%) patients and lower extremity ischemia in 1 (4.3%) patient who required a leg amputation. The overall survival was 60.5% (23/38 patients). Six (40%) of the 15 patients cannulated percutaneously and 9 (39.1%) of 23 patients who had open cannulation died. All survivors recovered completely and were discharged from the hospital after a mean hospital stay of 20.8 days (range: 10-39 days). CONCLUSIONS Almost two thirds of the patients with severe Hantavirus cardiopulmonary syndrome who were supported with extracorporeal circulation survived and recovered completely. The complications associated with both types of femoral cannulation may be attributed to the fact that all patients were in shock or in full cardiac arrest, and the procedure had to be done expeditiously. Earlier institution of extracorporeal membrane oxygenation may decrease the complication rates and improve the overall survival.

NMDA receptor blockade and spinal cord ischemia due to aortic crossclamping in the rat model.

Recent brain research proposes that, during ischemia, synaptically released excitatory amino acid neurotransmitters accumulate at toxic concentrations with ensuing neuronal death. Their action is mediated by the receptor subtype N-methyl-D-aspartate (NMDA). The protective effect of NMDA receptor blockade with intrathecal MgSO4 and MK-801 was investigated during spinal cord ischemia induced by aortic occlusion of 12 minutes. Male Sprague-Dawley rats, 250-300g, underwent intrathecal administration of 20 microL of normal saline (SA n = 16), MgSO4 1M (MG n = 16), or MK-801, 25 mM solutions (MK n = 16) in a randomized order. After 2 hours, the animals underwent occlusion of the thoracic aorta and subclavian arteries for 12 min. An additional control group (CO n = 16) underwent occlusion for 12 minutes, without intrathecal injection. The animals were scored according to their functional performance (LS = lesion score) each day for four days by a blinded observer. Mean LS were calculated for each group at a given day. Treatment and control groups were not different at day 1 (P = 0.302). Group MG was improved from groups SA (P = < 0.0039) and CO (P = < 0.0048) at day 4. This study demonstrates that although intrathecal NMDA receptor blockade with MgSO4 or MK-801 does not prevent paraplegia due to spinal cord ischemia in the rat, it could however influence the rate of recovery after ischemic injury.

Videothoracoscopic treatment of hepatic hydrothorax

Hepatic hydrothorax occurs frequently in ascites arising from communications in the diaphragm between peritoneal and pleural cavities. Numerous treatments have been described but are of limited utility due to invasiveness and poor success rate. We describe a case of hepatic hydrothorax in which the pore in the diaphragm was documented photographically and in which successful resolution was achieved with videothoracoscopic suture ligation and talc pleurodesis.

Extracorporeal membrane oxygenation support improves survival of patients with Hantavirus cardiopulmonary syndrome refractory to medical treatment

OBJECTIVE The aim of the study was to evaluate the outcome of extracorporeal membrane oxygenation (ECMO) support in Hantavirus cardiopulmonary syndrome (HCPS) patients with a predicted mortality of 100%, and the complications associated with this treatment modality and different cannulation techniques. METHODS A total of 51 patients with refractory HCPS were supported with ECMO between April 1994 and June 2010. They were divided into group A consisting of the 26 patients treated between 1994 and 2000 and group B consisting of 25 patients treated between 2003 and 2010. No patients were treated between September 2000 and December 2003. Patients in group A were intubated when they became hypoxic and placed on ECMO when they became hemodynamically unstable, whereas patients in group B had elective insertion of vascular sheaths and were almost concurrently intubated and placed on ECMO when they decompensated. Cannulation of the femoral vessels was performed percutaneously in 18 (35.3%) patients and with an open technique in 33 (64.7%) patients. RESULTS Complications from percutaneous cannulation occurred in 4/18 (22.27%) patients: retroperitoneal hematoma in 2/18 (11.1%) and lower-extremity ischemia in 2/18 (11.1%) patients. Complications from open femoral cannulation occurred in 12/33 (36.3%) patients: bleeding in 10/33 (30.3%) patients and ischemia in 2/33 (6.1%) patients. The overall survival was 66.6% (34 of 51 patients); 56% (14/26) for group A and 80% (20/25) for group B (p = 0.048). There was no difference in mortality regarding the method of cannulation. A trend toward increased mortality in patients with cannulation complications was recognized, but it was not statistically significant. Mortality was not associated with ECMO duration (average 121.7h, range: 5-276h). All survivors recovered and were discharged from the hospital after a mean hospital stay of 19.8 days (range: 10-39 days). CONCLUSIONS Two-thirds of 51 HCPS patients with a predicted mortality of 100%, who were supported with ECMO, survived and recovered completely. Survival was significantly higher in the second half of the study. Complications associated with both types of femoral cannulation were associated with a trend toward decreased survival, which was not significant.

Pseudocoarctation of the aorta presenting as a mediastinal mass with dysphagia

Pseudocoarctation is an uncommon anomaly thought to be caused by congenital elongation and kinking of the aorta. We report a case of pseudocoarctation of the aorta presenting as a superior mediastinal mass causing dysphagia. Aortography and echocardiography revealed dilatation of the aorta and an aneurysm below the level of the pseudocoarctation. The patient underwent operative repair of the pseudocoarctation and associated aneurysm with good symptomatic relief. Review of the literature and experience with this case demonstrate that pseudocoarctation of the aorta cannot necessarily be regarded as a benign condition. Surgical treatment is recommended for all symptomatic patients and for those with associated aneurysm formation.

Heterotopic pancreas of the esophagus masquerading as Boerhaave's syndrome

Heterotopic pancreas (HP) of the esophagus is rare. We report a patient with HP of the esophagus and review the presentation, treatment, and results of the nine previously reported cases. Two patients had cancer. This high incidence raises concerns that HP of the esophagus may be premalignant. Because surveillance endoscopy is not possible, all known or suspected esophageal HP should be treated surgically.

Peritoneopericardial diaphragmatic hernia discovered at coronary bypass operation

A 68-year-old man was discovered to have a large peritoneopericardial hernia when operated on for coronary artery bypass. Such hernias are very unusual. The pathogenesis, clinical presentation, and management of this problem are discussed.

Percutaneous cardiopulmonary support for the management of catastrophic mechanical complications of acute myocardial infarction.

Acute papillary muscle rupture and ventricular septal rupture following myocardial infarction are associated with high mortality. We describe the use of cardiopulmonary support to resuscitate two patients, each with one of the above conditions. Early recognition and rapid deployment of CPS were critical to successful outcome.