The use of cardiopulmonary bypass during extended resection of non-small cell lung cancer

We undertook a retrospective study in order to assess the risks and benefits of the use of cardiopulmonary bypass (CPB) during operative resection of non-small cell lung cancer (NSCLC). Eleven patients (nine male and two female with a median age of 62 years, range 28-76 years) underwent extended resection of locally advanced NSCLC using CPB. The indication for the use of CPB was resection of the left atrium (n=4), the aorta (n=3), the pulmonary artery (n=3), or for respiratory support (n=1). No deaths occurred during the first 30 days postoperatively. With exception of one hospital death due to MRSA mediastinitis and local recurrence, all the patients were discharged and returned to their social activities. Two patients are alive with recurrent disease at follow-up 37 and 41 months post-surgery, respectively. Eight patients died due to recurrence and the median postoperative survival time was 269 days (range: 112-1132 days). One patient who had no evidence of recurrence died of aspiration pneumonia 10 months after surgery. CPB is a safe and effective tool for use during extended resection of locally advanced NSCLC. However, careful consideration for the risk/benefit ratio should be required when assessing the indication for surgical intervention.     

Changes in respiratory mechanics during cardiac surgery

We investigated the role of cardiopulmonary bypass (CPB) in compromised lung function associated with cardiac surgery. Low-frequency respiratory impedance (Zrs) was measured in patients undergoing cardiac surgery with (n = 30; CPB group) or without (n = 29; off-pump coronary artery bypass [OPCAB] group) CPB. Another group of CPB patients received dopamine (DA) (n = 12; CPB-DA group). Extravascular lung water was determined in five CPB subjects. Zrs was measured before skin incision and after chest closure. Airway resistance and inertance and tissue damping and elastance were determined from Zrs data. Airway resistance increased in the CPB group (74.9% +/- 20.8%; P < 0.05), whereas it did not change in the OPCAB group (11.8% +/- 7.9%; not significant) and even decreased in the CPB-DA patients (-40.6% +/- 9.2%; P < 0.05). Tissue damping increased in the CPB and OPCAB groups, whereas it remained constant in the CPB-DA patients. Significant increases in elastance were observed in all groups. There was no difference in extravascular lung water before and after CPB, suggesting that edema did not develop. These results indicate a significant and heterogeneous airway narrowing during CPB, which was counteracted by the administration of DA. The mild deterioration in tissue mechanics, reflecting partial closure of the airways, may be a consequence of the anesthesia itself. IMPLICATIONS: We observed that cardiopulmonary bypass deteriorates lung function by inducing a heterogeneous airway constriction, whereas no such effects were observed in patients undergoing cardiac surgery without bypass. The impairment in parenchymal mechanics, which was obtained in both groups, may result from peripheral airway closure and/or be a consequence of mediator release.     

Soluble tumor necrosis factor receptor prevents post-pump syndrome.

Post-pump syndrome is an acute lung injury following cardiopulmonary bypass (CPB) which is indistinguishable from the adult respiratory distress syndrome (ARDS). Tumor necrosis factor (TNF) is central to the inflammatory process and is capable of triggering the entire pathophysiologic response leading to ARDS. We hypothesized that treatment with a soluble TNF receptor-binding protein (TNFbp) would reduce the increase in serum TNF and prevent acute lung injury in our sequential insult model of ARDS following CPB. Anesthetized pigs were randomized to one of three groups: Control (n = 3), surgical preparation only; CPB + LPS (n = 6), femoral-femoral hypothermic bypass for 1 h followed by infusion of low dose Escherichia coli lipopolysaccharide (LPS; 1 microg/kg); and TNFbp + CPB + LPS (n = 4), pretreatment with intravenous TNFbp (2 mg/kg) followed immediately by both insults. CPB + LPS caused severe lung injury demonstrated by a significant fall in PaO2 and an increase in both intrapulmonary shunt and peak airway pressure as compared to all groups (P < 0.05). These changes were associated with a significant increase in plasma TNF level and pulmonary neutrophil sequestration. TNFbp significantly reduced plasma levels of TNF and prevented the lung injury typically observed with this ARDS model, but did not reduce pulmonary neutrophil sequestration. Thus, elevated serum TNF is not responsible for neutrophil sequestration but does play a role in neutrophil activation which causes lung injury. Prophylactic use of TNFbp in CPB patients may prevent neutrophil activation and reduce the incidence of post-pump ARDS.     

A prospective, randomized study of endothelin and postoperative recovery in off-pump versus conventional coronary artery bypass surgery

OBJECTIVE: The objectives are 2-fold: (1). to serially determine endothelin (ET) levels in arterial vascular compartments in patients undergoing coronary artery bypass surgery using either cardiopulmonary bypass or off-pump techniques, and (2). to define potential relationships between endothelial levels and specific perioperative parameters of patient recovery. METHODS: In a prospective, randomized study, endothelin plasma content was measured from patients undergoing coronary artery bypass grafting using either off-pump techniques (OPCAB group, n = 25) or conventional cardiopulmonary bypass (CPB group, n = 25) before surgery, before and after coronary artery anastomosis, and 6 and 24 hours postoperatively. Specific indices of patient recovery including pulmonary artery pressures, ventilation requirement, and hospital stay were documented for patients in both study groups. RESULTS: Postoperative systemic arterial ET levels were significantly increased by 200% in the CPB group and 50% in the OPCAB group. ET levels remained significantly higher in the CPB group relative to the OPCAB group throughout the postoperative period of observation (p < 0.05). Pulmonary artery pressures, ventilation requirement, and hospital stay were significantly increased in patients in the CPB group. CONCLUSIONS: Postoperative ET levels were higher in patients who underwent CPB for coronary artery bypass surgery. Increased ET in the postoperative period may contribute to a more complex recovery from coronary artery bypass surgery in patients undergoing cardiopulmonary bypass.     

Simultaneous cardiac surgery with pulmonary resection: presentation of series and review of literature

Background: The issue of performing simultaneous pulmonary resection and cardiac surgery in patients with coexisting lung carcinoma and ischaemic heart disease remains controversial. We report our experience and review the literature. Methods: Thirteen patients (male ten, female three; mean age 65 years) underwent simultaneous cardiac surgery and pulmonary resection. Lung pathology consisted of primary lung carcinoma (n=10), benign disease (n=2) and carcinoid (n=1). Lung resections included pneumonectomy (n=3), lobectomy (n=4), segmentectomy (n=1) and local excision (n=5). Cardiac procedures consisted of coronary artery bypass grafting (CABG) in 11, aortic valve replacement in one and mitral valve repair with CABG in one patient. In all but one case the lung resection was performed prior to heparinization and cardiopulmonary bypass (CPB). In two patients, with suitable coronary anatomy, myocardial revascularization without CPB was performed to reduce morbidity. Results: There was no hospital mortality. Postoperative blood loss and ventilation requirements were reduced in the patients who were operated on without CPB. Prolonged ventilatory support was required in two cases. All patients with benign pathology are alive. In the lung cancer group there have been five late deaths: disseminated metastatic disease (n=3), anticoagulant related haemorrhage (n=1) and broncho-pleural fistula (n=1). Of the remaining five patients four are alive and disease free 7–23 months post-operatively; one patient has recurrent disease 40 months post-operatively. Conclusions: Simultaneous pulmonary resection and cardiac surgery is associated with acceptable operative morbidity and mortality. In patients with lung carcinoma long-term survival was determined by tumour stage. The avoidance of CPB may be advantageous by decreasing blood loss and ventilation requirements.     

Does sodium nitroprusside reduce lung injury under cardiopulmonary bypass?

Objective: We hypothesized that direct pulmonary arterial infusion of sodium nitroprusside (SNP) would ameliorate lung injury under cardiopulmonary bypass. Methods: Experiments were performed on 12 adult mongrel dogs of both sexes weighing 20–28 kg. The animals were randomly divided into two groups of six animals each. All animals were subjected to total cardiopulmonary bypass (CPB) and moderate hypothermia (28°C core temperature). During total CPB, the aorta was clamped together with the pulmonary artery to prevent any antegrade flow to the lungs. After cardioplegic arrest for 120 min, the animals were rewarmed, weaned from CPB, and their condition stabilized for another 90 min. After the release of the aortic cross-clamp, the dogs received either a 5% glucose solution as a placebo (group I) or SNP (0.5 μg/kg per min) (group II), both infused into the pulmonary arterial line. The infusion was stopped after 60 min. To measure lung tissue malondialdehyde (MDA), water content and polymorphonuclear leukocytes count, lung tissue samples were taken before CPB and after weaning from CPB. In addition, alveolar-arterial oxygen difference (AaDO₂) for tissue oxygenation was calculated by obtaining arterial blood gas samples. Results: Values of MDA before CPB of 42.0±5.3 nmol/g of tissue rose to 67.6±5.7 nmol/g of tissue after weaning from CPB in group I (P=0.028). In group II MDA values also increased from 43.1±4.3 to 52.4±5.7 nmol MDA/g of tissue after weaning from CPB (P=0.046). The MDA increase in group II after CPB was found to be significantly lower than that for group I (P=0.004). The wet-to-dry lung weight ratio in the sodium nitroprusside group was 5.1±0.2, significantly lower than in the control group (6.8±0.4), (P=0.01). AaDO₂ increased significantly in group I (P=0.028). There was no statistically significant difference (P=0.065) between groups I and II. During histopathological examination it was observed that neutrophil counts in the lung parenchyma rose significantly after CPB in both groups. The increase in group I was significantly larger than that in group II (P<0.001). Conclusions: The results represented in our study indicate that pulmonary arterial infusion of sodium nitroprusside during reperfusion can reduce lung injury under cardiopulmonary bypass.     

Does the technique of cardiopulmonary bypass affect lung water content?

Several efforts have been made to improve the technique of cardiopulmonary bypass (CPB), including the use of pulsatile flow and the modification of cannulation technique. The present study focused upon extravascular lung water (EVLW) in 60 aortocoronary bypass patients subjected to four different perfusion techniques during CPB: group 1 (n = 15): non-pulsatile flow and standard cannulation; group 2 (n = 15); pulsatile flow and standard cannulation; group 3 (n = 15): nonpulsatile flow and monoatrial cannulation (i.e., always "partial" bypass during CPB); group 4 (n = 15): pulsatile flow and monoatrial cannulation. EVLW content was measured using the double-indicator dilution technique with indocyanine green; in addition, various hemodynamic and laboratory variables were measured. Lung water content rose above normal values (mean: 5.79 +/- 0.33 ml/kg) only in the groups submitted to the standard cannulation technique, irrespective of whether the perfusion flow was pulsatile or not (group 1: + 27.4%; group 2: + 25.5%). Pulmonary gas exchange, too, was compromised only in these patients (PaO2 in group 1 -19% and in group 2 -17%; Qs/Qt in group 1 + 36 rel. % and in group 2 + 29 rel. %), whereas all patients with monoatrial cannulation and partial bypass throughout the CPB period showed no rise in EVLW content or Qs/Qt and no drop in PaO2. From the results of this study we conclude that pulsatile perfusion during open heart surgical procedure has no advantages in regard to lung water content. Monoatrial cannulation with partial bypass at all times during CPB, however, seems to be beneficial, probably owing to the maintenance of pulmonary circulation during the bypass period.     

Resection of advanced thoracic malignancies requiring cardiopulmonary bypass.

OBJECTIVES: Patients with malignancies involving cardiac structures have limited therapeutic options and significant risk of mortality. The decision to offer radical palliative or curative resection must be made only after consideration of the substantial surgical risks. The purpose of this retrospective study was to determine the feasibility and benefits of resection with cardiopulmonary bypass (CPB) of metastatic or non-cardiac primary malignancies extending directly into or metastasizing to the heart in select patients. Our results were examined to assess the risks and benefits of such radical therapy. METHODS: We retrospectively reviewed patient charts and identified all patients with malignancies involving the cardiac chamber or great vessels (excluding renal carcinomas with caval extension) or with substantial cardiac compression who had undergone resection with CPB at The University of Texas M.D. Anderson Cancer Center between January 1995 and July 2000. We evaluated demographic data, symptomatology, tumor characteristics, and outcomes. RESULTS: Nineteen patients (six males and 13 females; median age of patients, 47 years; age range, 17-67 years) were included in the study. Eleven patients underwent surgery with curative intent, and eight underwent surgery with palliative intent. Seventeen patients had tumors that required CPB because their tumors directly involved the heart and/or great vessels (nine sarcomas, seven epithelial carcinomas, and one unclassified), and two patients (both with sarcomas) required CPB to relieve tumor tamponade. The technique included CPB (n=5), CPB with diastolic arrest (n=12), and CPB with hypothermic circulatory arrest (n=2). Five patients underwent concomitant pneumonectomy, and three underwent lobectomy. Two patients (11%) died in the hospital after resection with palliative intent. Of the 11 patients who underwent resection with curative intent, ten (91%) had complete resections. The median time in the intensive care unit was 5.3 days (range, 0-37 days) and the median length of hospital stay was 17.2 days (range, 0-107 days). Major complications occurred in 11 patients (58%); the most common major complications were pneumonia (n=7 patients), mediastinal hematoma (n=4 patients), and acute respiratory distress syndrome (n=2 patients). The median follow-up duration was 27 months. The overall 1- and 2-year survival rates were 65 and 45%, respectively. CONCLUSIONS: Extensive thoracic tumors involving cardiac structures can be resected with acceptable risk. When resection was performed with curative intent, excellent 1- and 2-year cumulative survival rates were achieved. Although resection with palliative intent was associated with greater mortality rates, some patients survived for 1 and 2 years. The use of CPB in selected patients with thoracic malignancies should be considered, especially when complete resection can be achieved.     

Lung protection during total cardiopulmonary bypass by isolated lung perfusion: preliminary results of a novel perfusion strategy

BACKGROUND: The present pilot study was conducted to evaluate the effect of isolated short-term lung perfusion during cardiopulmonary bypass (CPB) on inflammatory response and oxygenation. METHODS: A total of 24 patients undergoing elective cardiac surgery with routine CPB were prospectively assigned to three groups. Group I (n = 7), control subjects receiving neither lung perfusion nor ultrafiltration; group II (n = 9), patients undergoing lung perfusion; and group III (n = 8), patients undergoing lung perfusion plus ultrafiltration. Lung perfusion consisted of single-shot hypothermic pulmonary artery perfusion with oxygenated blood. Proteins indicative of leukocyte activation and lung injury were measured in plasma and bronchoalveolar lavage fluid (BALF). The alveolar-arterial oxygen gradient (A-aDO2) and the oxygenation index (PO2/FiO2) were also determined. RESULTS: Oxygenation values were best preserved in group III, followed by group II. After CPB, elastase-alpha1-proteinase inhibitor complex had increased in plasma in all groups; in BALF it increased in groups I and II, but not in group III. Alpha2-macroglobulin increased significantly in BALF in group I but not in groups II and III. CONCLUSIONS: These preliminary results provide some evidence that single-shot hypothermic lung perfusion with oxygenated blood at the beginning of CPB may have a protective effect on the lungs, especially when combined with ultrafiltration.     

Perioperative mortality and major cardio-pulmonary complications after lung surgery for non-small cell carcinoma.

OBJECTIVES: A database of patients operated of lung cancer was analyzed to evaluate the predictive risk factors of operative deaths and life-threatening cardiopulmonary complications. METHODS: From 1990 to 1997, data were collected concerning 634 consecutive patients undergoing lung resection for non-small cell carcinoma in an academic medical centre and a regional hospital. Operations were managed by a team of experienced surgeons, anaesthesiologists and chest physicians. Operative mortality was defined as death within 30 days of operation and/or intra-hospital death. Respiratory failure, myocardial infarct, heart failure, pulmonary embolism and stroke were considered as major non-fatal complications. Preoperative risk factors, extent of surgery, pTNM staging, perioperative mortality and major cardiopulmonary complications were recorded and evaluated using chi-square statistics and multivariate logistic regression. RESULTS: Complete data were obtained in 621 cases. The overall operative mortality was 3.2% (n = 19). Cardiovascular complications (n = 10), haemorrhage (n = 4) and sepsis or acute lung injury (n = 5) were incriminated as the main causative factors. In addition, there were 13 life-threatening complications (2.1%) consisting in strokes (n = 4), myocardial infarcts (n = 5), pulmonary embolisms (n = 1), acute lung injury (n = 1) and respiratory failure (n = 2). Four independent predictors of operative death were identified: pneumonectomy, evidence of coronary artery disease (CAD), ASA class 3 or 4 and period 1990-93. In addition, the risk of major complications was increased in hypertensive patients and in those belonging to ASA class 3 or 4. A trend towards improved outcome was observed during the second period, from 1994 to 97. CONCLUSION: Our data demonstrate that perioperative mortality is mainly dependent on the extent of surgery, the presence of CAD and provision of adequate medical and nursing care. Preoperative testing and interventions to reduce the cardiovascular risk factors may help to further improve perioperative outcome.     

Hepatic resections for non-colorectal, non-neuroendocrine metastases. Results of 32 hepatectomies in 27 patients

STUDY AIM: Liver resections for metastases are commonly performed in colorectal primary tumors and poorly documented in non colorectal tumors. The aim of this study was to report a series of 32 liver resections in 27 patients for different types of non colorectal, non neuroendocrine liver metastases. PATIENTS AND METHOD: From 1986 to 1997, 27 patients (20 women and 7 men, mean age: 56.8 years) were operated on in the same center for liver metastases. Initial cancer was female genital tract (ovarian and fallopian tube) adenocarcinomas (n = 5), gastrointestinal tract adenocarcinomas (n = 8), sarcomas (n = 8), and miscellaneous cancers (n = 6). Liver resections included atypical resections (n = 9), right hepatectomies (n = 11), extended right hepatectomies (n = 2), left hepatectomies (n = 4) and resections of 2 or 3 segments (n = 6). RESULTS: There was no perioperative death. Postoperative morbidity included 8 complications in seven patients, requiring reintervention in three patients. Follow-up was complete for all patients. Survival rate at one, two and five years was 59, 44 and 29% respectively. The longest median survival time was observed in genital tract adenocarcinomas (27 months), whereas the other types of malignancies had a 13- to 17-month mean survival rate. CONCLUSION: These results are almost similar to those observed in liver resections for colorectal metastases. Some carefully selected patients may benefit from liver resection for non colorectal, non neuro-endocrine metastases.     

Time course of changes in jugular venous oxygen saturation during hypothermic or normothermic cardiopulmonary bypass in patients with diabetes mellitus

BACKGROUND: Preexisting diabetic mellitus is a risk factor determining postoperative neurological disorders. The present study assesses the effects of normothermic and hypothermic cardiopulmonary bypass (CPB) on jugular venous oxygen saturation (SjvO2)in patients with preexisting diabetic mellitus. METHODS: Sixteen diabetic patients who underwent elective coronary artery bypass grafting surgery were randomly divided into two groups: Group DN (n=8, diabetic patients) underwent normothermic CPB (>35 degrees C), and group DH (n=8, diabetic patients) underwent hypothermic CPB (32 degrees C). Controls were 16 age-matched non-diabetic patients (normothemic group, CN: n=8; hypothemic group, CH: n=8). A 4.0 F fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to continuously monitor SjvO2 values. Hemodynamic parameters and arterial and jugular venous blood gases were measured seven times. RESULTS: Cerebral desaturation, which was defined as SjvO2 values below 50%, was observed during normothermic CPB in diabetic patients (at the onset of CPB: 46+/-3%, at 20 min after onset of CPB: 49+/-3%, means+/-SD, respectively). No cerebral desaturation occurred in diabetic and control patients during hypothermic CPB. CONCLUSIONS: Patients with preexisting diabetes mellitus experienced cerebral desaturation during normothermic CPB.     

Concomitant cardiac and pulmonary operation: the role of cardiopulmonary bypass.

To assess the safety and efficacy of concomitant pulmonary resection and cardiac operation requiring cardiopulmonary bypass, the records of 19 patients were reviewed. Eighteen patients (94.7%) presented with cardiac symptoms and were found to have pulmonary pathology of indeterminate etiology. Pulmonary resections were performed through a median sternotomy in all but 1 patient, who underwent posterolateral thoracotomy and right middle lobectomy after repositioning because dense adhesions prevented adequate dissection through the initial incision. A total of 24 resections were performed. Sixteen (66.7%) were performed on cardiopulmonary bypass. Six wedge resections (25.0%) were performed before bypass. Two lobectomies (8.3%) were performed after infusion of protamine sulfate. Nine patients (47.4%) had benign pathology, 7 (36.8%) had primary carcinoma, and 3 (15.8%) had metastatic disease. Bleeding complications occurred in 15.8% of patients (3/19). There was 1 perioperative death (5.3%), which was due to adult respiratory distress syndrome after intraoperative hemorrhage followed lobectomy for bullous disease. Another patient required lateral extension of the sternotomy during an episode of exsanguinating intraparenchymal pulmonary hemorrhage, which resulted in lobectomy, as well as costochondral and sternal osteomyelitis. A third patient required exploration for bleeding at the staple line. Postoperative complications occurred in 7 patients (36.8%) and were predominantly respiratory (5/7, 71.4%) (p = 0.006). The median postoperative hospitalization was 15 days. Although comparison of patients who underwent pulmonary resection during bypass with those who had resection either before heparinization or after protamine infusion showed no significant difference with respect to age, incidence of malignancy, operation performed, complications, postoperative hospitalization, or survival, this was probably due to the small number of patients in the study.(ABSTRACT TRUNCATED AT 250 WORDS)     

Matrix metalloproteinase inhibitor: differential effects on pulmonary neutrophil and monocyte sequestration following cardiopulmonary bypass

Acute respiratory distress syndrome (ARDS) following cardiopulmonary bypass (CPB), also known as "post-pump" or "post-perfusion syndrome" (PPS), results from sequential priming and activation of neutrophils. We hypothesized that chemically modified tetracycline (CMT-3) an inhibitor of neutrophil matrix metalloproteinase (MMP) and elastase, would prevent PPS. We performed histometric analysis of lung tissue from our porcine PPS model to correlate cellular sequestration and histologic injury with CMT-3 treatment. METHODS: Yorkshire pigs were randomized into five groups: Control (n = 3); CPB (n = 5); femoral-femoral bypass 1 hour; LPS (n = 7), Escherichia coli lipopolysaccharide (1 microgram/kg); CPB + LPS (n = 6); and CPB + LPS + CMT (n = 5), sequential insults and CMT-3. Protocol histometric analysis defined cellular and tissue components of lung injury. RESULTS: CMT-3 decreased neutrophil sequestration in the CPB + LPS + CMT-3 group (p < 0.0001 vs. CPB + LPS). There were no differences in monocytes between CPB + LPS and CPB + LPS + CMT treatment groups. CONCLUSIONS: CMT-3 attenuates neutrophil sequestration but has no effect on mononuclear sequestration in our PPS model. This finding supports current research on leukocyte chemokines and has important implications regarding mechanisms of CMT-3. Despite lack of monocyte response to CMT-3, PPS was prevented by inhibiting neutrophils alone; confirming the primary role of neutrophils in PPS.     

Surgical treatment of primary pulmonary sarcomas.

OBJECTIVE: We sought to identify the long-term prognosis after surgical treatment for primary pulmonary sarcoma. METHODS: Twenty-three patients were retrospectively identified as having been treated surgically for primary pulmonary sarcoma between 1981 and 1996. The records of all patients were reviewed, and the histopathology reexamined by a pathologist. RESULTS: Fifteen patients were male and eight female; their ages ranged from 20 to 78 (mean 51) years. Tumors measured between 0.9 and 12.0 (mean 5.2) cm across the greatest diameter. The histologic diagnoses were malignant fibrous histiocytoma (8, three grade 1 or 2, two grade 3), synovial sarcoma (4), malignant schwannoma (3), leiomyosarcoma (3), and one case each of angiosarcoma, intimal sarcoma, epitheloid hemangioendothelioma, fibrosarcoma and primitive neuroectodermal tumor. Three patients were found to be unresectable. All three underwent radiation and chemotherapy. Lobectomies or bilobectomies were performed in 13 patients including two sleeve resections, one carinal resection, and one chest wall resection. Four patients underwent radical pneumonectomies. Three patients with invasion of the pulmonary artery, pulmonary veins or atrial wall underwent extended resections with the use of cardiopulmonary bypass. In two, a homograft was used to reconstruct the right ventricular outflow tract. Of the resected patients, six had a positive resection margin, and four had at least one positive lymph node in the specimen. Three patients underwent repeat pulmonary resections for recurrences. Eleven patients received postoperative chemotherapy and eight had radiation therapy. Follow-up was available on 22 patients, and ranged from 2 to 183 (mean 48) months; 14 patients are disease free, six died of disease, one died of surgical complications (operative mortality 5%), and two are alive with disease. Actuarial 3- and 5-year survival of the resected patients was 69%. Size and grade were not found to be correlated with significantly increased survival, but completeness of resection was (P<0.05). CONCLUSIONS: Resection of primary pulmonary sarcomas can produce an acceptable survival rate if the resection is complete. Cardiopulmonary bypass can be a useful adjunct when tumors involve a resectable area of the heart or great vessels.     

Cardiotomy Suction: A Major Source of Brain Lipid Emboli During Cardiopulmonary Bypass

Background. Brain injury remains a significant problem in patients undergoing cardiac surgery assisted by cardiopulmonary bypass (CPB). Autopsy brain specimens of patients after cardiac operations with CPB reveal numerous acellular lipid deposits (10 to 70 μm) in the microvasculature. We hypothesize that these small capillary and arterial dilatations result from a diffuse inflammatory response to CPB or from emboli delivered by the bypass circuit. This study was undertaken to determine which aspect of CPB is most clearly associated with these dilatations.

Methods. Thirteen dogs were studied in four groups: group I (n = 3), right-heart CPB; group II (n = 2), lower-extremity CPB; group III (n = 3), hypothermic CPB; and group IV (n = 5), hypothermic CPB with cardiotomy suction. All dogs in all groups were maintained on CPB for 60 minutes and then euthanized. Brain specimens were harvested, fixed in ethanol, embedded in celloidin, and stained with the alkaline phosphate histochemical technique so that dilatations could be counted.

Results. All dogs completed the protocol. The mean density of dilatations per square centimeter for each group was as follows: group I, 1.77 ± 0.77; group II, 4.17 ± 1.65; group III, 4.54 ± 1.69; and group IV, 46.5 ± 14.5. In group IV (cardiotomy suction), dilatation density was significantly higher than in group III (hypothermic cardiopulmonary bypass) (p = 0.04) and all other groups (p = 0.04).

Conclusions. Blood aspirated from the surgical field and subsequently reinfused into dogs undergoing CPB produces a greater density of small capillary and arterial dilatations than CPB without cardiotomy suction, presumably because of lipid microembolization.     

含抑肽酶低温灌注液减轻体外循环肺损伤

目的;研究体外循环期间低温保护液肺动脉灌注对肺脏的保护作用。方法;１２只杂种犬随机均分为２组。主动脉阻断后,对照组右肺动脉灌注４℃乳酸林格液,实验组灌注４℃肺保护液。开放主动脉后和停ＣＰＢ后５,３０,６０,９０分钟;分别取各组肺静脉血标本行生化分析,测定肺功能,并行组织学检查。     

Retrograde autologous priming: is it useful in elective on-pump coronary artery bypass surgery?

BACKGROUND: The effect of reduced cardiopulmonary bypass (CPB) prime volume by retrograde autologous priming (RAP) was studied. METHODS: Twenty patients undergoing elective coronary artery bypass grafting were randomized to either standard prime (SP) volume (1,602 +/- 202 mL crystalloid prime, n = 10) or RAP (395 +/- 150 mL). RAP was performed by draining crystalloid prime from the arterial and venous lines into a recirculation bag before CPB. Cardiac index, pulmonary vascular resistance index, systemic vascular resistance index, alveolar-arterial oxygen tension difference, pulmonary shunt fraction, extravascular lung water (EVLW), plasma colloid osmotic pressure (COP), crystalloid fluid balance, body weight, and clinical parameters were evaluated perioperatively. RESULTS: Demographic data and operative parameters were equal for patients in both groups. During CPB, COP was reduced by 55% in the SP group (9.8 +/- 2.0 vs 21.4 +/- 2.1 mm Hg) and by 41% in the RAP group (12.4 +/- 1.1 vs 20.9 +/- 1.8 mm Hg) (p = 0.008, SP vs RAP group). Compared with preoperatively, EVLW was unchanged in the RAP group 2 hours post-CPB, but it was elevated by 21% in the SP group (p = 0.002, SP vs RAP group). End-CPB crystalloid fluid balance was significantly reduced in the RAP group (1,857 +/- 521 vs 2,831 +/- 637 mL). Postoperative (day 2) weight gain in the SP group (1.5 +/- 1.2 kg, p = 0.021) was absent in the RAP group (0.1 +/- 0.9, NS). Postoperative time to full mobilization was shorter in the RAP group. Postpump cardio-respiratory function did not differ among groups. CONCLUSIONS: This small-scale pilot study indicates that by reducing crystalloid fluid administration and fall of COP during CPB, RAP reduces postpump EVLW accumulation and weight gain in uncomplicated coronary artery bypass graft patients with no associated effects on cardio-respiratory function.     

Acute hemodynamic collapse after induction of general anesthesia for emergent pulmonary embolectomy

Patients undergoing pulmonary embolectomy often experience hemodynamic deterioration during induction of general anesthesia (GA). Therefore, we studied the incidence and possible risk factors for hemodynamic deterioration during GA induction. Fifty-two consecutive patients undergoing emergent pulmonary embolectomy at our institution were included. Hemodynamic collapse after GA induction was defined as hypotension refractory to vasopressor, inotrope, or fluid administration, requiring cardiopulmonary resuscitation followed by urgent institution of cardiopulmonary bypass (CPB). Demographic variables, comorbidities, specific location of thromboemboli, preoperative inotropic support, and anesthetic drugs used for GA induction were evaluated as possible risk factors. After GA induction, hemodynamic collapse occurred in 19% of patients (n = 10). However, the occurrence of hemodynamic instability was not predicted by any of the evaluated risk factors. In addition, the incidence of in-hospital mortality did not differ between hemodynamically stable or unstable patients (10%; 4 of 42 versus 10%; 1 of 10 patients, respectively). In conclusion, hemodynamic deterioration after GA induction develops frequently during emergent pulmonary embolectomy. On the basis of our experience from this study and the unpredictable nature of hemodynamic deterioration, we suggest that patients undergoing pulmonary embolectomy should be prepared and draped before GA induction, and a cardiac surgical team should immediately be available for emergent institution of cardiopulmonary bypass.     

Off-pump versus on-pump coronary bypass in high-risk subgroups

BACKGROUND: Cardiopulmonary bypass (CPB) has pathophysiologic sequelae that may be more severe in high-risk subsets. We wanted to determine whether off-pump coronary bypass (OPCAB) could optimize outcomes. METHODS: Our database of 242 OPCAB patients undergoing complete revascularization was compared to a base of 483 CABG patients undergoing CPB. Results were compared for the overall series and in the following high-risk subsets: 80 years of age or older, ventricular dysfunction (ejection fraction (EF) < or = 0.25), prior neurologic event or renal failure, chronic obstructive pulmonary disease (COPD), and reoperation. RESULTS: In the overall series, OPCAB significantly reduced the incidence of intraoperative transfusion requirements and showed a trend toward reduced morbidity in terms of postoperative neurologic and renal complications, prolonged ventilator requirement greater than 3 days, and bleeding requiring reexploration. Mortality was less in the OPCAB group (0.4% versus 2.7%, p = not significant). Similar results were achieved in the following high-risk subgroups (n = off-pump/on-pump): 80 years of age or older (n = 28/58), EF less than or equal to 25% (n = 13/26), preoperative neurologic event (n = 25/36), preoperative renal failure (n = 27/46), COPD (n = 33/43), and reoperation (n = 28/76). OPCAB decreased the incidence of prolonged ventilation in COPD patients (0/33 [0%] versus 4/43 [9.3%] p = not significant) and decreased the incidence of renal complications in the elderly (1/28 [3.6%] versus 9/58 [15.5%] p = not significant). Off-pump coronary bypass reduced but did not eliminate neurologic events in the elderly (2/28 [7.1%] versus 8/58 [13.8%] p = not significant). CONCLUSION: Off-pump coronary bypass significantly reduced the incidence of transfusion requirement compared to the CPB counterparts and had a consistent trend in reducing morbidity and mortality overall and in all high-risk subsets. Neurologic events are not eliminated in OPCAB.