Jeffrey T. Sugimoto

Positron emission tomography of lung tumors and mediastinal lymph nodes using [18F]fluorodeoxyglucose

Abstract Positron emission tomography detects increased glucose uptake in malignant tissue using the glucose analogue [2- 18 F]fluoro-2-deoxy-d-glucose. We reviewed the scans obtained in 62 patients with lung tumors. All had undergone computed tomography and had tissue-based diagnoses: 22 had adenocarcinomas, 12 had squamous cell carcinomas, 13 had other malignancies, 1 had organizing pneumonia, 1 had a hamartoma, and 13 had granulomas. Positron emission tomography with [2- 18 F]fluoro-2-deoxy-d-glucose identified 44 of 47 malignancies. Two of three false-negative findings were tumors that were 1 cm 2 or less and the other was a bronchioloalveolar carcinoma. All three false-positive findings were granulomas. The sensitivity and specificity of the technique were 93.6% and 80%, respectively, and the positive and negative predictive values were 93.6% and 80%, respectively. The differential uptake ratio was determined in all 62 patients. The mean differential uptake ratio (± the standard error of the mean) for malignant tumors was 6.4 ± 0.56 and that for benign tumors was 1.14 ± 0.26 ( p 18 F]fluoro-2-deoxy-d-glucose identified negative N2 nodes in 19 of 22 patients (86%) with negative nodes and positive N2 nodes in 2 of 3 patients (66%) with positive nodes, including one instance missed by computed tomography. Positron emission tomography with [2- 18 F]fluoro-2-deoxy-d-glucose is a highly accurate and noninvasive method for identifying malignant lung tumors. The clinical application of this imaging technique in the evaluation of N2 lymph nodes awaits the results of ongoing prospective studies.

Seeding with endothelial cells derived from the microvessels of the omentum and from the jugular vein: a comparative study.

Segments of an experimental polytetrafluoroethylene graft (9 cm long, 6 mm I.D.) of high porosity were implanted in 25 dogs as aortic interposition grafts. Nine grafts were seeded with a mean of 7 x 10(5) viable endothelial cells (ECs) derived from the jugular vein (group A) and eight were seeded with a mean of 7 x 10(5) viable ECs derived from the microvessels of the omentum (group B). Eight grafts were not seeded and they served as controls (group C). Animals were put to death 5 weeks after graft implantation. The thrombus-free area was measured at 81% +/- 10% in group A, 65% +/- 22% in group B, and 25% +/- 13% in group C (p less than 0.05, group A vs group B; p less than 0.05, group B vs group C). The thickness of the subendothelial layer was 151 +/- 60 microns in group A, 280 +/- 60 microns in group B, and 100 +/- 75 microns in group C (p less than 0.001, group B vs groups A and C). The production of 6-keto-PGF1 alpha in the presence of sodium arachidonate was higher in seeded grafts (p less than 0.05). Omentally derived microvessel ECs can be seeded in vascular grafts; refinements in the technique of EC procurement are required to minimize contamination and to obtain ECs with more effective biologic activity.

Appropriate timing of elective coronary artery bypass graft surgery following acute myocardial infarction

BACKGROUND The appropriate timing of elective coronary artery bypass surgery (CABG) following acute myocardial infarction (AMI) remains uncertain. It is hypothesized that a waiting period allows the myocardium to recover prior to revascularization, thus decreasing morbidity and mortality. This study was designed to determine if a waiting strategy is justified following AMI in patients requiring elective CABG. METHODS Between 1994 and 1996, 214 patients underwent isolated, nonrepeat, elective CABG. Three groups were evaluated: group I, control, 155 patients with no AMI; group 11, 39 patients with nontransmural AMI; and Group III, 20 patients with transmural AMI. Demographics, intraoperative, and postoperative variables were collected and compared among all groups. RESULTS Groups were well-matched demographically: group I, patients waited an average of 2.3 days in hospital prior to operation; group II, an average of 4.2 days; and group III, an average of 5.2 days. Except for the use of inotropes, group I 34%, group 11 39%, and group III 70% (P = 0.007), and the intra-aortic balloon pump, group I 0%, group 11 8%, and group III 25% (P = 0.001). There were no differences in complications. Importantly, there was no difference in mortality or postoperative length of stay. The mortality in group I was 2.6%, in group 11 2.6%, and in group III 0%. The length of stay in groups I and II was 8.5 days, and in group III, 8.1 days. CONCLUSION A waiting period of 3 to 5 days after a nontransmural AMI and 5 to 7 days after a transmural AMI can produce similar postoperative results to non-AMI patients undergoing CABG. Thus, a waiting strategy to allow the myocardium to recover is justified.

Beware of the Aberrant Innominate Artery

The anatomy of aortic great vessels is relevant in surgeries of the anterior neck, especially with a tracheostomy, thyroidectomy, or mediastinoscopy. Variations in their anatomy could lead to severe complications if not recognized. An aberrant high-riding innominate artery incidentally encountered during mediastinoscopy is presented.

Coronary artery bypass graft: why is the saphenous vein prone to intimal hyperplasia?1

Proliferation and migration of smooth muscle cells and the resultant intimal hyperplasia cause coronary artery bypass graft failure. Both internal mammary artery and saphenous vein are the most commonly used bypass conduits. Although an internal mammary artery graft is immune to restenosis, a saphenous vein graft is prone to develop restenosis. We found significantly higher activity of phosphatase and tensin homolog (PTEN) in the smooth muscle cells of the internal mammary artery than in the saphenous vein. In this article, we critically review the pathophysiology of vein-graft failure with detailed discussion of the involvement of various factors, including PTEN, matrix metalloproteinases, and tissue inhibitor of metalloproteinases, in uncontrolled proliferation and migration of smooth muscle cells towards the lumen, and invasion of the graft conduit. We identified potential target sites that could be useful in preventing and (or) reversing unwanted consequences following coronary artery bypass graft using saphenous vein.

Lung Herniation Secondary to Minimally Invasive Direct Coronary Artery Bypass Grafting

Lung herniation after thoracotomy is rare. We report a 66-year-old man who presented with this complication after undergoing attempted minimally invasive direct coronary artery bypass grafting. The defect was repaired with a composite of Marlex mesh and methyl methacrylate.

Pericardial Cells for Graft Seeding: Isolation, Culture and Identification

The purpose of this study was to determine the feasibility of using the pericardium as a source of endothelial cells. Nineteen pieces of fresh pericardium were obtained from nine mongrel dogs. Cells were prepared by collagenase digestion of the pericardium for 24 minutes followed by centrifugation. The cells were divided into three groups: The supernatant subjected to no further steps, Group I (N = 6); filtration through a 15 micron porous mesh, Group II (N = 6); and Percoll gradient separation with medium 199, Group III (N = 7). The cells obtained were cultured for seven days in tissue culture media. Yield (cells x 10(5)/gram fresh tissue) was determined with Methods I, II, and III, producing 32.4 +/- 25.9 (SD), 0.96 +/- 0.6 and 0.57 +/- 0.5, respectively (I vs II or III, p less than 0.01). Fibroblast contamination determined by phase contrast light microscopy was demonstrated in 6/6 cultures with Method I, 3/6 with II and 1/7 for III (I vs III, p less than 0.01). An assay for endothelial cells (Factor VIII) was positive in 2/6 cultures with Method I, 5/6 with II and 7/7 for III (I vs III, p less than 0.01). The pericardium is a suitable organ for procurement of endothelial cells. Though reducing yield, filtration and Percoll gradient separation allows for isolation of a relatively pure culture of endothelial cells.

Conservative management of traumatic lung hernia.

Traumatic lung hernia is a rare entity. The majority of cases reported in the literature have been treated surgically with early thoracotomy to prevent strangulation of pulmonary tissue. We report the case of a 63-year-old patient who experienced a 20-foot fall, causing multiple rib fractures with a lung hernia that was managed conservatively for 48 hours followed by spontaneous resolution of the herniated pulmonary segment. There is a need to review the indications for surgical versus conservative approach in the management of posttraumatic lung hernia.

Differential effects of calpain inhibitors on hypertrophy of cardiomyocytes

Two inhibitors of the calcium-dependent cysteine protease, calpain, have markedly different effects on the extent of hypertrophy induced by the alpha-adrenergic agonist, phenylephrine, of cultured neonatal rat ventricular myocytes. E64c, an inhibitor of calpain and other cysteine proteases, stimulated the hypertrophy by 59%. PD 150606, a specific calpain inhibitor, reduced the hypertrophy by 38%. Phenylephrine decreased the proteolysis of a calpain substrate by the cells 1–2 h after its addition but not at 24 h. PD 150606 inhibited proteolytic activity at all times, and the combination of phenylephrine and PD 150606 did not give greater inhibition. This suggests that cysteine proteases of the papain sub-family are involved with the hypertrophic response at two points, promoting hypertrophy at the first and limiting it at the second. Calpain appears to be the protease involved at the first point, and there may be another cysteine protease acting at the second site.

A Meta-analysis of Randomized Controlled Trials in Critically Ill Patients to Evaluate the Dose-Response Effect of Erythropoietin

The use of erythropoietin in critically ill patients has been investigated in multiple randomized clinical trials and its role in decreasing the number of units of blood transfused has been demonstrated in some trials. A meta-analysis was conducted to determine the pooled estimate of the decrease in number of units of blood transfused with the use of erythropoietin and investigated its dose-response effect. A systematic search was performed of the MEDLINE, EMBASE, and the Current Controlled Trials Register to identify randomized clinical trials investigating the role of erythropoietin in critically ill patients. Of 664 studies identified in the search, 5 randomized clinical trials met the inclusion criteria. The pooled estimate of the decrease of number of units of blood transfused was —1.64 (95% CI —2.6 to —0.67). Sensitivity analysis to establish the influence of temporal bias, quality of the study and comorbidities such as age and Acute Physiology and Chronic Health Evaluation (APACHE) II score were undertaken and did not reveal a significant difference. The inclusion of studies with higher doses of erythropoietin revealed a greater decrease in the number of units of blood transfused (—2.15; 95% CI —3.06 to —1.24). Despite the limitations of a meta-analysis we believe that the use of erythropoietin significantly decreases the number of units of blood transfused per patient. Our study also reveals the possibility of a dose-response effect of erythropoietin in decreasing the number of units of blood transfused.