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Biomedical subjects

G B Haasler

Publications and source records attributed to G B Haasler.

At least 19 recordsLinked to original sources
PubMed2001

Cigarette smoking is strongly associated with mutation of the K-ras gene in patients with primary adenocarcinoma of the lung.

BACKGROUND: The majority of lung carcinoma cases occur in current or former smokers. K-ras gene mutations are common in lung adenocarcinoma and have been associated with cigarette smoking, asbestos exposure, and female gender. METHODS: In the current study, the authors examined the contribution of cigarette smoking to K-ras gene mutations in patients with primary lung adenocarcinoma. Smoking histories were obtained from 106 prospectively enrolled patients with primary adenocarcinoma of the lung. RESULTS: K-ras mutations were detected in the primary tumor using an allele-specific ligation assay. Ninety-two of the 106 patients (87%) with lung adenocarcinoma were smokers. Nonsmokers with this tumor were more likely to be women (11 of 14; 79%), whereas the majority of smokers (57%) were men. K-ras mutations were detected in 40 of 106 tumors (38%) and were significantly more common in smokers compared with nonsmokers (43% vs. 0%; P = 0.001). CONCLUSIONS: The results of the current study confirm and extend previous observations that smokers with adenocarcinoma of the lung are more likely to have K-ras mutant tumors compared with nonsmokers. The strong link between cigarette smoking and K-ras mutations in adenocarcinoma of the lung supports the role of specific tobacco carcinogens in the etiology of this malignancy.

Adenocarcinoma↗
PubMed1998

Utility of CT scan evaluation for predicting pulmonary hypertension in patients with parenchymal lung disease. Medical College of Wisconsin Lung Transplant Group.

OBJECTIVE: To determine the utility of CT-determined main pulmonary artery diameter (MPAD) for predicting pulmonary hypertension (PH) in patients with parenchymal lung disease. DESIGN: Retrospective review of right-heart hemodynamic data and chest CT scans in 45 patients. SETTING: Tertiary-referral teaching hospital and VA hospital. PATIENTS: Between October 1990 and December 1995, 36 patients referred for evaluation of parenchymal lung disease or possible pulmonary vascular disease were found to have PH, as defined by mean pulmonary artery pressure (mPAP) > or =20 mm Hg. Nine control patients (mPAP <20 mm Hg) were also identified (4 from hospital records search, 5 after evaluation for possible PH). RESULTS: CT-determined MPAD was 35+/-6 mm in patients with PH and 27+/-2 mm in control subjects. In our group of patients, MPAD > or =29 mm had a sensitivity of 87%, specificity of 89%, positive predictive value (PPV) of 0.97, and positive likelihood ratio (LR) of 7.91 for predicting PH; in the subgroup of patients with parenchymal lung disease (n=28, PH and control subjects), MPAD > or =29 mm had a sensitivity of 84%, specificity of 75%, PPV of 0.95, and positive LR of 3.36 for predicting PH. The most specific findings for the presence of PH were both MPAD > or =29 mm and segmental artery-to-bronchus ratio > 1:1 in three or four lobes (specificity, 100%). There was no linear correlation between the degree of PH and MPAD (r=0.124). CONCLUSIONS: CT-determined MPAD has excellent diagnostic value for detection of PH in patients with advanced lung disease. Therefore, standard chest CT scans can be used to screen for PH as a cause of exertional limitation in patients with parenchymal lung disease. Because CT is commonly used to evaluate parenchymal lung disease, this information is readily available.

Adult↗
PubMed1997

Tracheal wire stent complications in malacia: implications of position and design.

BACKGROUND: Although expandable endoluminal wire stents that can be incorporated into body tissues are very attractive for use in the airway, disease-related factors that can lead to stent failure have received little attention in the literature. METHODS: The cases of all 4 patients who underwent insertion of one or more Gianturco stents into the trachea, main bronchi, or both for tracheobronchial malacia in our institution were reviewed. RESULTS: All three tracheal stents required removal for stent-related complications within the first 6 months. Complications included metallic strut fracture and unraveling or breakage of the encircling nylon suture leading to progressively bizarre and widening radiographic configurations suggesting imminent airway perforation. One of the six bronchial stents disrupted 10 months after insertion. CONCLUSIONS: Our findings suggest relatively less dynamic, repetitive bending wire stress in the bronchus (and likewise strictured trachea) compared with the malacic trachea. Although Gianturco stents are easily placed and give excellent functional results, we recommend against their use in the trachea for tracheal malacia. The bronchial position may be reasonably safe.

Aged↗
PubMed1997

Functional and oximetric assessment of patients after lung reduction surgery.

OBJECTIVE: The goal of this study was to clarify the issue of functional oxygen requirement by regimented exercise oximetry in patients undergoing lung reduction surgery. METHODS: Thirty-seven patients underwent lung reduction surgery and were followed up for at least 3 months. Patients routinely completed a 6-week program of cardiopulmonary rehabilitation. Preoperative and postoperative spirometry, dyspnea scores, 6-minute walk distances, respiratory mechanics, and exercise oximetry were recorded. RESULTS: After the operation, patients had a 37% increase in forced vital capacity and a 59% increase in forced expiratory volume in 1 second. Six-minute walk distance increased from 913 +/- 310 feet before the lung reduction operation to 1202 +/- 274 feet 6 months after the operation (p < 0.001). Maximal inspiratory and expiratory pressures were significantly increased in 16 patients after lung reduction surgery. Perceived dyspnea was significantly improved. Exercise pulse oximetry demonstrated that 83% of patients met American Thoracic Society criteria for supplemental oxygen use before lung reduction surgery. After the operation, 70% of patients continued to meet American Thoracic Society criteria for supplemental oxygen use. Notably, 10 patients with exertional desaturation while breathing room air discontinued supplemental oxygen use because of a reduction in dyspnea. CONCLUSIONS: These findings demonstrate significant subjective and functional improvements related to lung reduction surgery. Exercise-induced hypoxia was not reversed by lung reduction surgery. Discontinuance of supplemental oxygen use owing to reduction in dyspnea and improved physical performance may not be warranted in lieu of continued exertional desaturation.

Adult↗
PubMed1997

Pulmonary artery thrombolysis and stenting after a bilateral sequential lung transplantation.

Bilateral sequential lung transplantation was complicated by pulmonary artery anastomotic stenosis and bilateral pulmonary thromboemboli. Pulmonary artery thrombus was eliminated by intrathrombotic but not by systemic administration of urokinase. The pulmonary emboli resulted in localized pulmonary infarctions, supporting the need for thrombolytic intervention to restore pulmonary perfusion in the absence of collateral bronchial blood flow after lung transplantation. Pulmonary artery stenosis was relieved by endovascular stenting, avoiding an early reoperative procedure. This case suggests that direct administration of thrombolytic agent may be superior to intravenous administration in the treatment of pulmonary thromboemboli. Pulmonary arterial anastomotic stenoses after lung transplantation can be relieved by endovascular procedures.

Adult↗
PubMed1996

Mortality and neurologic morbidity after repair of traumatic aortic disruption.

BACKGROUND: Traumatic disruption of the thoracic aorta frequently results in death before operative repair. The determinants of mortality after repair, however, are uncertain. In addition, intraoperative strategies for reducing the incidence of spinal cord injury remain controversial. METHODS: The records of 45 consecutive patients undergoing repair of traumatic disruption of the thoracic aorta at a single institution during a 9-year period were reviewed in a retrospective fashion. Patient age ranged from 15 to 81 years (mean age, 33.9 years). Twenty-two patients (49%) had multiple associated injuries, and 8 (18%) had isolated aortic injuries. Nine patients (20%) experienced preoperative hypotension (systolic blood pressure of less than 90 mm Hg). Repair was performed with partial bypass in 22 patients, a heparinized shunt in 2, and no distal perfusion (clamp and sew technique) in 21. RESULTS: Nine patient (20%) died after operation. Multivariate logistic regression analysis of preoperative and intraoperative variables identified advancing age and preoperative hypotension as independent predictors of operative death. The presence of associated injuries was not an independent predictor of operative death. All 4 patients with injuries proximal to the aortic isthmus died. Ten patients were excluded from analysis of spinal cord injury either because of preoperative neurologic deficit or because of death before postoperative evaluation. Six (17%) of the remaining 35 patients had development of paraplegia: 5 of the 15 patients having the clamp and sew technique, 1 of the 2 with a shunt, and 0 of the 18 patients with bypass (p < 0.05, clamp and sew versus bypass). In the clamp and sew group, patients in whom paraplegia developed had significantly longer aortic clamp times than those without neurologic injury (40.6 +/- 4.4 minutes versus 28.7 +/- 2.9 minutes, respectively; p < 0.05). CONCLUSIONS: Advancing age, preoperative hypotension, and perhaps injury location are important determinants of death after repair of traumatic disruption of the thoracic aorta. Adjunctive perfusion with partial bypass should be used during repair to reduce the incidence of spinal cord injury.

Adolescent↗
PubMed1996

Early and late morbidity in patients undergoing pulmonary resection with low diffusion capacity.

BACKGROUND: We sought to determine whether low diffusion capacity of the lung to carbon monoxide (DLCO) is a predictor of high postoperative mortality and morbidity after major pulmonary resection and whether major pulmonary resection in patients with low DLCO results in substantial long-term morbidity. METHODS: Sixty-two major pulmonary resections were performed in 61 patients with low DLCO (DLCO < or = 60% predicted for pneumonectomy or bilobectomy; < or = 50% predicted for lobectomy). Contemporaneously, 262 other patients underwent 263 major pulmonary resections (group II). Long-term morbidity was assessed in subsets of patients with low (n = 24) and high (n = 22; DLCO > 60% predicted) DLCO. RESULTS: The hospital mortality rates were equivalent (4.8% low DLCO versus 4.9% group II), whereas respiratory complications were more frequent in patients with low DLCO (18% versus 9.5%; p = 0.05). In the subgroup analyses, patients with low DLCO had more hospitalizations for respiratory compromise and worse median dyspnea scores. Analysis of patients with substantial dyspnea revealed an association with extended pulmonary resection and postoperative radiation therapy in patients with low DLCO. CONCLUSIONS: Patients with low DLCO underwent major pulmonary resection with a low mortality rate and an acceptable, but increased, respiratory complication rate. Long-term respiratory morbidity was increased in patients with low DLCO; however, the extent of pulmonary resection and the use of postoperative radiation therapy may have contributed to the development of dyspnea in these patients.

Aged↗
PubMed1996

A comparative study of thoracoscopic vs open removal of benign neurogenic mediastinal tumors.

STUDY OBJECTIVE: To assess the relative benefit of thoracoscopy vs open thoracotomy in the removal of benign neurogenic, mediastinal tumors (BNMTs). DESIGN: Retrospective comparative study of thoracoscopy and open thoracotomy. SETTING: Patients underwent surgery at the thoracic surgical services of two institutions from 1988 to 1994. Patients who underwent thoracoscopy were operated on more recently, 1992 to 1994. Patients who had thoracotomies underwent resection from 1988 to 1992. PATIENTS: All adult patients undergoing isolated removal of BNMTs at both institutions were included. Eleven patients underwent removal by posterolateral thoracotomy while six patients underwent thoracoscopic removal. INTERVENTIONS: BNMTs were removed by standard posterolateral thoracotomy or by three-hole thoracoscopic techniques with extension of incisions and conversion to an open procedure as necessary. MEASUREMENTS AND RESULTS: Larger tumors were more difficult to remove thoracoscopically. Two cases of transient postoperative ptosis were noted among the patients who underwent thoracoscopy. Operative time was longer in the thoracoscopy group (171 vs 112 min; p<0.05). Postoperative stay was significantly shorter (2.6 vs 4.5 days; p<0.02) and return to work tended to be more rapid (4.3 vs 7.7 weeks; p=0.13) among patients who underwent thoracoscopy. CONCLUSIONS: Thoracoscopic resection of BNMTs can be achieved safely and effectively with more rapid postoperative recovery when compared with an open thoracotomy approach to these mediastinal tumors.

Adult↗
PubMed1994

Thoracostomy tubes after acute chest injury: relationship between location in a pleural fissure and function.

OBJECTIVE: The purpose of this study was to determine how often chest tubes placed for acute trauma lie within a pleural fissure and to determine whether an intrapleural location influences outcome. SUBJECTS AND METHODS: Fifty-eight consecutive thoracostomy patients who had 66 chest tubes were studied prospectively. Tube location was determined from frontal and lateral chest radiographs. Outcome measures recorded included the following: duration of thoracostomy drainage, quantity of pleural fluid drained, need for further tubes, length of hospital stay, appearance on last chest radiograph before discharge, and need for surgical intervention. RESULTS: Thirty-eight (58%) of the tubes were placed within a pulmonary fissure, 15 (23%) were posterior, nine (13%) were anterior, and four (6%) were in other locations. We found no significant difference in any of the outcome measures between tubes located in the fissure and other tubes. CONCLUSION: A large percentage of tubes placed for acute chest trauma lie within a pleural fissure. These tubes, however, appear to function as effectively as those located elsewhere in the pleural space.

Acute Disease↗
PubMed1993

CT after reconstructive repair of the sternum and chest wall.

Acute mediastinitis and sternal infection after sternotomy are potentially devastating complications, but considerable advances in treatment have been made during the past decade. Sternectomy followed by reconstruction with use of either an omental transposition or a muscle flap has markedly decreased mortality and morbidity. After extensive rib resection, various reconstructive repairs, including the use of polytetrafluoroethylene mesh, have proved successful. The authors retrospectively reviewed 27 postoperative computed tomographic (CT) scans obtained in 19 patients. Twelve of these patients had sternal wounds repaired with either omental or muscle flap procedures. Seven patients had chest wall reconstructions with polytetrafluoroethylene patches, muscle transpositions, or both. The authors found no cases of unexpected or unexplained fluid collections on CT scans obtained beyond the 1st month. Any persistent or recurrent collection is suggestive of infection. If clinical and imaging findings are at odds, imaging-directed needle aspiration can help determine whether a fluid collection is infected and in need of further treatment.

Adult↗
PubMed1993

The lack of effect of hemodilution, myocardial water content, and increased coronary artery blood flow on integrated myocardial ultrasonic backscatter in the beating canine heart.

The effects of coronary blood flow, tissue water content and hematocrit variation on the Integrated Myocardial Backscatter Rayleigh 5 (IBR5) and Fourier coefficient of amplitude modulation (FAM, an index of cardiac cycle-dependent variation in IBR5) were measured in five open chest dogs. Data were obtained at baseline, during adenosine infusion and after two hours of crystalloid hemodilution (Hct 15%). IBR5 of -46.4 +/- .94 dB at baseline did not change significantly during adenosine infusion (-45 +/- .85 dB) and after hemodilution (-46.4 +/- 2.0 dB). FAM at baseline was (4.0 +/- 1.0 dB) (3.8 +/- -1.0 dB) during adenosine infusion and after hemodilution (5.0 +/- 1.8 dB). Myocardial water content increased significantly (p < .05) from 78 +/- .20% at baseline to 80.7 +/- .17% after hemodilution. Coronary blood flow demonstrated a three-fold increase with adenosine and two-fold increase with hemodilution. Electronmicroscopy demonstrated an increase in intracellular and extracellular water content. In conclusion, IBR5 and FAM did not change significantly despite significant increases in coronary blood flow and myocardial water content. Myocardial cellular derangements seen with nonischemic cell swelling, increased blood flow and a fall in hematocrit are insufficient to affect integrated backscatter.

Animals↗
PubMed1992

Transhiatal and transthoracic esophagectomy for adenocarcinoma of the esophagus.

Adenocarcinoma of the esophagus is no longer rare and is treated by resection. To determine whether the approach used for resection influences outcome, we studied 88 patients who underwent resection; 14 had stage I or II disease, 74 had stage III, and 40 had stage IV. One third of those with Barrett's esophagus were noted on screening endoscopy to have potentially curable disease; the others were diagnosed with stage III or IV disease. Transhiatal esophagectomy was performed in 63 patients; 24 patients underwent transthoracic esophagectomy. We found no difference in survival or morbidity between transhiatal and transthoracic esophagectomy. Overall 5-year survival for stage I and II disease was 86%. For stage III and IV disease, 5-year survival was 14.5%. Aggressive surveillance of Barrett's esophagus facilitates the discovery of early disease. Esophagectomy for adenocarcinoma can result in cure of early cancers and improved palliation of more advanced disease.

Adenocarcinoma↗
PubMed1990

Open fixation of flail chest after blunt trauma.

Progressive left chest volume loss developed in a patient with severe flail chest despite reasonable oxygenation without intubation. Because of this chest volume loss, pain, and shortness of breath, she underwent open chest wall repair using multiple metallic struts. Rapid recovery ensued, despite a perforated duodenal ulcer on postoperative day 1. Benefits of open fixation of severe flail chest are clearly demonstrated and should be considered instead of prolonged ventilation or supportive care alone for select patients.

Aged↗
PubMed1988

Blood flow velocity of internal mammary artery and saphenous vein grafts to the coronary arteries.

Doppler-derived blood flow velocity measurements were used to characterize the hemodynamics of 66 internal mammary artery grafts and 60 saphenous vein grafts to the coronary arteries at operation. Pulsed Doppler spectral analysis of centerstream graft flow demonstrated predominantly diastolic flow with a variable, multiphasic flow pattern in systole. The magnitude and configuration of the graft flow velocity waveform varied with graft type and whether the runoff was to single or multiple arteries. At operation, peak diastolic flow velocity was greater (P less than 0.0001) in internal mammary artery grafts to a single outflow artery (71 +/- 2 cm/sec) compared with single vein grafts (31 +/- 4 cm/sec). Sequential grafts demonstrated increased flow velocity and forward flow throughout the pulse cycle, indicative of low outflow resistance. Analysis of the phasic flow patterns permitted an assessment of functional graft patency. Technical errors (anastomotic stricture, internal mammary pedicle torsion) were identified in three grafts with low or absent diastolic flow. Vasospasm of the internal mammary artery was associated with high flow velocity throughout the pulse cycle. Observed differences in patency and the development of intimal hyperplasia between internal mammary artery and saphenous vein grafts may be related to graft hemodynamics.

Aged↗