Biomedical subjects
Michael E Jessen
Publications and source records attributed to Michael E Jessen.
Effects of early steroid withdrawal after heart transplantation.
BACKGROUND: Managing immunosuppression is a significant aspect of posttransplantation patient care. Previously, our institution reported that prednisone could be withdrawn in cardiac allograft recipients without jeopardizing midterm survival. We returned to this group of patients to investigate the long-term effects of our steroid taper protocol. METHODS: We reviewed the records of 162 consecutive cardiac transplant recipients from our institution. Patients who underwent transplantation between 1988 and 1990 were treated with traditional triple-therapy immunosuppression (cyclosporine, azathioprine, and prednisone). Beginning June 1990, we instituted a protocol of early steroid taper with discontinuation by 6 months after transplant. The two groups were comparable with respect to age, sex, ethnicity, cause of heart failure, ischemic time, body mass index, and creatinine at the time of transplantation. RESULTS: Fifty-seven percent of the patients in the early steroid taper group were successfully withdrawn from steroids at 6 months after transplantation. This group had a decreased freedom from and increased frequency of acute rejection (p < 0.01 for each) when compared with the traditional therapy group. There was, however, no difference in freedom from posttransplant coronary artery disease (p = 0.53). The early steroid taper group enjoyed an increased freedom from malignancy (p = 0.01) and trended toward a decreased frequency of infection (p = 0.10) and improved survival (p = 0.06). CONCLUSIONS: Steroid withdrawal is possible in 57% of patients at 6 months after transplantation. The institution of an early steroid taper protocol improves the overall freedom from malignancies and may decrease the frequency of infection and prolong overall survival without increasing the risk of posttransplant coronary artery disease.
Management of hepatic and intracardiac echinococcal cysts: case report and review of the literature.
BACKGROUND: Infection with Echinococcus granulosus affects the liver commonly, but disseminated involvement is rare. We describe a 63 year-old man with echinococcal infection producing both hepatic and cardiac involvement that was managed surgically after failed percutaneous hepatic treatment. METHODS: This report is a case study of a unique surgical problem. Various treatment modalities are reviewed. RESULTS: The patient was a 63 year-old man from Iraq who immigrated to the United States after becoming infected with Echinococcus granulosus. He had undergone percutaneous management and albendazole therapy prior to presentation for treatment of hepatic hydatid cysts. He continued to have abdominal pain and fever and was referred to our institution. Imaging revealed persistence of the hepatic hydatid cysts, as well as a new finding of an intracardiac hydatid cyst. The patient underwent successful treatment of his complicated hepatic hydatid cysts with pericystectomy and repair of a biliary fistula. The cardiac cyst was removed as well. The patient made an uneventful recovery, and his symptoms resolved. CONCLUSION: Although rare, echinococcal infection may be encountered in the United States as travel increases to and from regions of the world where the disease is endemic. It is important for surgeons to be familiar with the multiple options for treatment of hydatid disease.
Pro: Heparin-coated circuits should be used for cardiopulmonary bypass.
Explore the source record for details and available documents.
Lung preservation solution substrate composition affects rat lung oxidative metabolism during hypothermic storage.
Lungs harvested for transplantation utilize oxygen after procurement. We investigated the effects of storage solution substrate composition on pulmonary oxidative metabolism and energetics during the preservation interval. Rat lungs were harvested and stored at 10 degrees C in low-potassium dextran (LPD) solution. Groups of lungs were preserved with preservation solution containing 5mM carbon-13 ((13)C) labeled glucose or increasing concentrations of (13)C labeled pyruvate. Additional groups of rat lungs were studied with dichloroacetate (DCA) added to the pyruvate-modified preservation solutions. Oxidative metabolism (measured by (13)C-enrichment of glutamate) and adenine nucleotide levels were quantified. Increasing preservation solution pyruvate concentration augmented glutamate (13)C-enrichment up to a concentration of 32mM pyruvate. DCA further stimulated oxidative metabolism only at lower concentrations of pyruvate (4 and 8mM). ATP and ADP were not different among groups, but AMP levels were higher in the glucose group. These data suggest that altering the substrate composition of the preservation solution influences lung metabolism during allograft preservation for transplantation.
Characterizing lung metabolism with carbon-13 magnetic resonance spectroscopy in a small-animal model: evidence of gluconeogenesis during hypothermic storage.
Experimental evidence suggests storing lungs inflated with oxygen and with oxidizable substrate improves results of lung transplantation. Glucose is included in the low-potassium-dextran (LPD) solution Perfadex to achieve this goal. The authors hypothesized that other substrates might be more effective. Rat lungs were stored for 6 or 24 hr in LPD solution with the following carbon-13--labeled substrates: 5 mM glucose (Perfadex group), 32 mM pyruvate (pyruvate group), or both (combination group). Metabolism was assessed by magnetic resonance spectroscopy. Small amounts of exogenous glucose were oxidized in the Perfadex group. In contrast, exogenous pyruvate was the major substrate oxidized in the pyruvate and combination groups (P<0.01 vs. Perfadex). Carbon-13--labeled glucose and glycogen were detected in the pyruvate group, suggesting that gluconeogenesis and glycogen synthesis occur in glucose-deprived lungs. Lungs for transplantation metabolize substrates through both anabolic and catabolic pathways. These reactions may be important in designing improved solutions for lung preservation.
Traumatic rupture of a descending thoracic aortic homograft.
My colleagues and I report an unusual case of traumatic aortic injury in an 18-year-old woman who had undergone multiple prior surgical procedures for repair of a type B interrupted aortic arch. Her most recent procedure included replacement of the proximal descending thoracic aorta with a 19-mm homograft at age 11 years. Seven years later, she was involved in a motor vehicle collision after a syncopal episode. Imaging studies revealed rupture of the body of the aortic homograft with formation of a pseudoaneurysm. The injury was successfully repaired with a Dacron graft by using hypothermic circulatory arrest.
Infective endocarditis associated with a scorpion sting.
We report the successful surgical intervention in two cases of aortic valve bacterial endocarditis after scorpion stings. Infective endocarditis developed in both patients several weeks after they suffered repeated scorpion stings. Both patients had similar, but uncommon features: (1) the isolated organisms were unusual causes of infective endocarditis (streptococcus group G and Streptococcus milleri), (2) annular abscesses developed that required either aortic root replacement with a homograft or annular patch repair with pericardium, and (3) complete heart block developed postoperatively, requiring permanent pacemaker implantation. Both patients completed a 6-week postoperative course of antibiotic therapy and are without recurrent infection.
Impact of recipient age and procedure type on survival after lung transplantation for pulmonary fibrosis.
BACKGROUND: The decision to perform single-lung (SLT) or bilateral sequential lung (BSLT) transplantation in patients with pulmonary fibrosis is controversial. Some centers use recipient age (<50 years) as a criterion to select BSLT over SLT, but the rationale for this approach is not well established. METHODS: Eight hundred twenty-one patients (636 SLT, 185 BSLT), aged 30 to 69 years, who were recipients of transplants for pulmonary fibrosis in the United States between 1994 and 2000 were reported to the United Network for Organ Sharing. Survival was compared by procedure type within three age groups (30 to 49 years, 50 to 59 years, and 60 to 69 years) using the Kaplan-Meier method. Multivariate logistic regression analysis was used to calculate risk-adjusted mortality within 1-month after transplantation, and proportional hazards regression was used to calculate risk-adjusted mortality after 1 month. RESULTS: Early (1-month) and late (3-year) survival in recipients aged 30 to 49 years was significantly better with SLT than BSLT (early, 90.9% versus 77.1%; late, 63.8% versus 46.2%, respectively; p = 0.02). Survival was also significantly better with SLT than BSLT at these time points in those patients aged 50 to 59 years (early, 89.5% versus 81.7%; late, 53.6% versus 46.7%, respectively; p = 0.03). When posttransplant survival was reanalyzed contingent on survival to 1 month, no significant difference in survival by procedure type (SLT versus BSLT) was detected for any age group. Multivariate analysis of survival, adjusted for other known risk factors, as well as propensity analysis, yielded similar results. CONCLUSIONS: Patients younger than 60 years of age who were recipients of transplants for pulmonary fibrosis appear to have better survival with SLT than with BSLT. Although the basis for this observation is unclear, events occurring in the early period (first month) after transplantation may play a role. Further studies will be needed, but these data do not appear to support the preferential use of BSLT for younger patients with pulmonary fibrosis.
Pyruvate-modified perfadex improves lung function after long-term hypothermic storage.
BACKGROUND: Lungs harvested for transplantation are stored while inflated with oxygen, which can serve to support oxidative metabolism. However, strategies aimed at increasing graft metabolism during storage have received little attention. In this study, we added pyruvate to the preservation solution Perfadex and measured the effects on oxidative metabolism and reperfusion lung function. METHODS: Rat lungs were stored for 6 and 24 hours in low-potassium dextran solution at 10 degrees C containing either 5 mmol/liter uniformly carbon-13 (U-(13)C) labeled glucose (Perfadex), 32 mmol/liter 3-(13)C pyruvate (pyruvate), or both (combined). Oxidation of exogenous substrates was measured as the incorporation of (13)C into tricarboxylic acid cycle intermediates by magnetic resonance spectroscopy. Additional groups of lungs with each substrate modification were preserved for 6 or 24 hours and then reperfused. RESULTS: Enrichment of tricarboxylic acid cycle intermediates was low in the Perfadex group (9% at 6 hours and 32% at 24 hours of storage, respectively). In contrast, enrichment was significantly increased in both the pyruvate group (50% and 59%, respectively) and combined group (39% and 54%, respectively) compared with the Perfadex group (p<0.01). Graft function was excellent after 6-hour storage in all groups. All lungs stored for 24 hours exhibited inferior lung function, but oxygenation, pulmonary artery pressures, and airway pressures in the combined group were significantly improved compared with the Perfadex group (p<0.05). CONCLUSIONS: Preservation solution substrate composition influences graft metabolism during storage. The addition of pyruvate to Perfadex increases metabolism during storage and improves reperfusion lung function.
Routine computed tomography screening of the chest in high-risk cardiac transplant recipients may improve survival.
BACKGROUND: Multiple studies have demonstrated an increased incidence of lung cancer in the heart transplant population. We reviewed our cardiac transplantation experience with respect to the development of bronchogenic carcinoma and explored the role of routine chest computed tomography (CT) in its surveillance. METHODS: We performed a review of our cardiac transplantation experience, highlighting the incidence of lung cancer, and we analyzed our recent experience with screening chest CT in lung cancer surveillance in this patient group. RESULTS: Eighteen patients developed 20 cases of bronchogenic carcinoma for an incidence of 6.83%. In 10 cases, the patients underwent surgical resection; however, in the remaining cases, the patients were either treated with chemotherapy and/or radiation or they died before initiation of therapy. The actuarial 1-, 2- and 5-year overall survival rates were 49%, 29% and 13%, respectively. The median survival of patients who underwent surgical resection was 28 months (3 to 85 months), whereas the median survival of patients who were either ineligible for surgery or died before initiation of treatment was only 1 month (1 to 13 months). All patients diagnosed with lung cancer by chest CT underwent surgical resection; however, only 37.5% of patients diagnosed with lung cancer by chest X-ray were found at an appropriate stage for resection (p = 0.025). CONCLUSIONS: Cardiac transplant recipients have a significant risk of developing bronchogenic carcinoma. Routine chest CT screening in high-risk patients may enable clinicians to identify disease earlier, which is essential for the option of surgical resection and, therefore, prolonged survival.
Contemporary assessment of laryngotracheal trauma.
OBJECTIVES: Laryngotracheal trauma is a rare and potentially deadly spectrum of injuries. We sought to characterize the contemporary mechanisms, diagnostic modalities, and outcomes common in laryngotracheal trauma today. METHODS: We performed a retrospective analysis of all laryngotracheal trauma cases at 2 major metropolitan hospitals between 1996 and 2004, detailing mechanisms, associated injuries, diagnostic modalities, and outcomes of laryngotracheal trauma. RESULTS: We identified 71 patients with a mean age of 32.8 +/- 13.3 years (range, 15-71 years). In our series penetrating trauma was the cause in 73.2% of patients; however, blunt trauma had a significantly higher mortality (63.2% vs 13.5%, respectively; P < .0001). Blunt mechanisms involved older patients (38.5 +/- 15.2 years vs 30.1 +/- 11.9 years, P = .017), and these patients were more likely to require emergency airways than those with penetrating trauma (78.9% vs 46.2%, P = .017). The requirement of an emergency airway was an independent predictor of mortality (P = .0066). CONCLUSION: Laryngotracheal trauma is a deadly spectrum of injuries with a mortality of 26.8%. Blunt mechanisms are decreasing in frequency. This might reflect improvements in automobile safety. Additionally, violent crime is on the increase, producing penetrating injuries with increasing frequency. The most fundamental intervention for patients with laryngotracheal injury is airway control. Either routine intubation or a tracheostomy can secure the airway. Blunt trauma and the requirement of an emergency airway are independent predictors of mortality. Laryngotracheal trauma requires prompt recognition, airway protection, and skillful management to lessen the mortality of this deadly spectrum of injuries.
Improved pain management outcomes with continuous infusion of a local anesthetic after thoracotomy.
OBJECTIVE: We sought to determine the effectiveness of an incisional infusion of local anesthetics through a continuous-infusion elastomeric pump for the management of postoperative pain after thoracotomy. METHODS: We performed a retrospective comparative analysis of 110 patients undergoing thoracotomies between November 1999 and March 2003. Postoperative pain management with a continuous-infusion elastomeric pump providing local anesthetic into the incisional area was compared with a single-shot epidural in combination with continuous local anesthetic infusion and continuous thoracic epidural infusion. Data sources were reviewed for mean narcotic use, pain score, and complications. RESULTS: After thoracotomy procedures, 38 patients received the ON-Q Pain Relief System (I-Flow Corp, Lake Forest, Calif), 32 received the ON-Q device and single-shot epidural infusion, and 40 received continuous epidural infusion. Demographic attributes, including age, body mass index, and sex were similar between the groups. Preoperative American Society of Anesthesiologists status was significantly higher in the ON-Q group compared with that in the other groups (P = .02). Narcotic use and pain scores were significantly reduced in the ON-Q group compared with that in the epidural group at all time points (P < .001). There were no wound-healing complications or infections associated with the use of the pump. CONCLUSION: A continuous infusion of 0.25% bupivacaine at 4 mL/h through the ON-Q elastomeric infusion pump is a safe and effective adjunct in postoperative pain management after thoracotomy. The use of the ON-Q Pain Relief System results in decreased narcotic use and lower pain scores compared with continuous epidural infusion.
Perfusion preservation maintains myocardial ATP levels and reduces apoptosis in an ex vivo rat heart transplantation model.
BACKGROUND: Machine perfusion preservation improves reperfusion function of many solid organs, compared with conventional storage, but has received limited clinical attention in preserving hearts for transplantation. We evaluated representative extracellular (Celsior) and intracellular (University of Wisconsion) storage solutions using static and perfusion protective strategies over a clinically relevant preservation period. METHODS: Rat hearts were preserved for 200 minutes by either static storage or perfusion preservation in Celsior or University of Wisconsin solutions. Three conditions were studied: conventional static storage; static storage using either solution with 5.5 mmol/L glucose added; and perfusion preservation using either solution with 5.5 mmol/L glucose added. Glucose was provided as U-13C-labeled glucose, and glycolysis and oxidative metabolism during preservation were quantified from incorporation of (13)C into glycolytic and tricarboxylic acid cycle intermediates. Adenosine triphosphate levels after preservation, and apoptosis and cardiac function after reperfusion were measured. RESULTS: Both perfusion preservation groups had higher myocardial oxygen consumption during storage and better early graft function, compared with static preservation groups (P < .05). Adenosine triphosphate levels were higher after storage in the perfusion groups (P < .01). Apoptosis was reduced in the perfusion groups (P < .01). Comparing perfusion groups, hearts preserved with Celsior had higher myocardial oxygen consumption and glucose utilization during perfusion storage and exhibited decreased reperfusion coronary vascular resistance and myocardial water content, compared with the UW perfusion group (P < .05). CONCLUSIONS: Perfusion preservation results in greater metabolism during storage and superior cardiac function with improved myocyte survival, compared with static storage. Extracellular preservation solutions appear more effective for perfusion preservation, possibly by augmenting cellular metabolism.
The emergency use of recombinant hirudin in cardiopulmonary bypass. 1999.
Explore the source record for details and available documents.
Myocardial oxygen demand and redox state affect fatty acid oxidation in the potassium-arrested heart.
BACKGROUND: Fatty acid (FA) metabolism is suppressed under conditions of cardioplegic arrest, but the mechanism behind this effect is unknown. We hypothesized that alterations in redox state and oxygen demand control myocardial FA utilization during potassium arrest. METHODS: Rat hearts were perfused with Krebs-Heinseleit buffer containing physiologic concentrations of FAs, ketones, and carbohydrates with unique (13)Carbon labeling patterns. Cytosolic and mitochondrial redox states were altered by manipulating the lactate/pyruvate and ketone redox couples, respectively. Myocardial oxygen consumption was increased by adding the mitochondrial uncoupler 2,4-dinitrophenol to the perfusate. Experiments were conducted under conditions of normokalemic perfusion and potassium cardioplegia (PC). Substrate oxidation rates were derived from (13)Carbon isotopomer data and myocardial oxygen consumption. RESULTS: Continuous perfusion under conditions of potassium arrest dramatically reduced fatty acid oxidation. Both the addition of 2,4-dinitrophenol and alteration of mitochondrial redox state significantly increased FA oxidation during PC. In contrast to normokalemic perfusion, altering cytosolic redox state during PC did not change FA oxidation. CONCLUSIONS: These data suggest that mitochondrial redox state and oxygen demand are important determinants of myocardial FA oxidation during potassium arrest. FA oxidation appears to be regulated by different factors during PC than normokalemic perfusion.
Effects of epsilon-aminocaproic acid and aprotinin on leukocyte-platelet adhesion in patients undergoing cardiac surgery.
BACKGROUND: The administration of aprotinin during cardiopulmonary bypass (CPB) is hypothesized to decrease activation of leukocytes and platelets and possibly reduce their adhesion. Although epsilon-aminocaproic acid (EACA) shares the ability of aprotinin to inhibit excessive plasmin activity after CPB, its effect on leukocyte and platelet activation and leukocyte-platelet (heterotypic) adhesion is largely unknown. This study was performed to determine the relative effectiveness of the antifibrinolytics, aprotinin and EACA, at reducing leukocyte and platelet activation and leukocyte-platelet conjugate formation in patients undergoing CPB. METHODS: Thirty-six patients scheduled to undergo cardiac surgery with CPB were randomized in a double-blind fashion to receive EACA, aprotinin, or saline (placebo). Markers of plasmin activity (D-dimer concentrations), platelet activation (CD62P), leukocyte activation (CD11b), and leukocyte-platelet adhesion (monocyte- and neutrophil-platelet conjugates) were measured before, during, and after CPB. RESULTS: Platelet CD62P (P-selectin), monocyte CD11b, and monocyte-platelet conjugates were all significantly increased (compared with baseline) in the saline group during and after CPB. Despite equivalent reductions in D-dimer formation in patients receiving EACA (P < 0.0001) and aprotinin (P < 0.0001), decreases in platelet CD62P and monocyte CD11b expression were incomplete (not significantly different from saline control). In contrast, peak monocyte-platelet conjugate formation was significantly reduced by both EACA (P = 0.026) and aprotinin (P = 0.039) immediately after CPB. CONCLUSIONS: EACA seems to be as effective as aprotinin at reducing peak monocyte-platelet adhesion after CPB. Furthermore, inhibition of excessive plasmin activity seems to influence monocyte-platelet adhesion. The findings suggest that monocyte-platelet conjugate formation may be a useful marker of monocyte and platelet activation in this clinical setting.
Antifibrinolytic therapy during cardiopulmonary bypass reduces proinflammatory cytokine levels: a randomized, double-blind, placebo-controlled study of epsilon-aminocaproic acid and aprotinin.
OBJECTIVES: Aprotinin is a broad-spectrum serine protease inhibitor that has been shown to attenuate the systemic inflammatory response in patients undergoing cardiac surgery with cardiopulmonary bypass. Although epsilon-aminocaproic acid is similar to aprotinin in its ability to inhibit excessive fibrinolysis (ie, plasmin activity and D-dimer formation), its ability to influence proinflammatory cytokine production remains unclear. This study was designed to compare the effects of epsilon-aminocaproic acid and aprotinin on plasma levels of interleukin-6 and interleukin-8 during and after cardiopulmonary bypass. METHODS: Sixty patients were randomized in a double-blind fashion to receive epsilon-aminocaproic acid, aprotinin, or saline (placebo) in similar dosing regimens (loading dose, pump prime, and infusion). Arterial blood samples were collected before, during, and after cardiopulmonary bypass, and plasma levels of D-dimer, interleukin-6, and interleukin-8 were measured. Data were analyzed using repeated measures analysis of variance. RESULTS: Both epsilon-aminocaproic acid and aprotinin administration resulted in significant (P <.05) reductions in D-dimer and interleukin-8 levels compared with saline. These reductions in D-dimer and interleukin-8 levels did not differ between the 2 drug-treated groups. The effect of these two antifibrinolytic agents on interleukin-6 was qualitatively similar to that noted with interleukin-8 but did not reach statistical significance. CONCLUSIONS: When dosed in a similar manner, epsilon-aminocaproic acid seems to be as effective as aprotinin at reducing interleukin-6 and interleukin-8 levels in patients undergoing primary coronary artery bypass graft surgery. These data indicate that suppression of excessive plasmin activity or D-dimer formation or both may play an important role in the generation of proinflammatory cytokines during and after cardiopulmonary bypass.