Enhancement of extended lung preservation with a vasoactive intestinal peptide-enriched University of Wisconsin solution.

Vasoactive intestinal peptide (VIP) is a known pulmonary and bronchial vasodilator as well as an oxygen free radical scavenger. Since its effect as an additive to University of Wisconsin (UW) solution for lung preservation has been shown previously, the aim of this study was to determine the ability of VIP to improve lung preservation followed by reperfusion. Four groups of excised Sprague-Dawley rat lungs (n = 24) were studied using an isolated blood perfused working lung model. The first 3 groups of lungs were flushed and stored in UW solution at 4 degrees C for: (1) 4 hr, (2) 18 hr, and (3) 24 hr. Group 4 lungs were flushed with UW solution + VIP (1 microgram/ml) and stored in UW solution + VIP (0.5 microgram/ml) for 24 hr. After preservation, the lungs were reperfused to evaluate their functions for 2 hr or until lung failure occurred (arterial oxygen saturation less than 90% and/or appearance of bronchial fluid in the bronchial cannula). In the lungs stored in UW solution for 24 hr, failure occurred after 10 min of reperfusion and all functions were significantly altered. The addition of VIP to UW solution maintained the functional capacity of the lungs, recorded by lung resistance, lung compliance, elastic work, flow resistive work, shunt fraction, and blood oxygen tension. No statistical difference in these parameters other than shunt fraction was found when the VIP group was compared with the group preserved for 4 hr in UW solution. We conclude that lung preservation can be extended to 24 hr with the maintenance of lung functional capacity if VIP is added to UW solution.

Successful extended lung preservation with UW solution.

Maximum preservation times of 4-6 hr continue to plague lung transplantation. The high-potassium colloid University of Wisconsin solution (UWS) has proved superior to the crystalloid modified Eurocollins' solution (ECS) for preservation of the liver, kidney, and pancreas. The purpose of this study was to compare UWS and ECS for extended lung preservation using a technique of combined pulmonary and bronchial artery perfusion. Simultaneous pulmonary artery and bronchial artery (via a closed aortic segment) perfusion was employed to harvest the lungs of ten mongrel dogs (wt 25-35 kg) using either UWS (n = 5) or ECS (n = 5) preservation solutions. Following 17 hr of cold (4 degrees C) pulmoplegic storage, the lungs were placed in an isolated perfused working lung (IPWL) apparatus. Seven freshly harvested lungs served as a control group (CON). Lung aerodynamics and gas exchange were evaluated at standard intervals until failure of the lung on the IPWL apparatus. Time until failure (mean +/- SEM) for each group was: CON = 209 +/- 14 min; UWS = 227 +/- 26 min; and ECS = 123 +/- 29 min. Only one of the ECS lungs lasted longer than 90 min. UWS-preserved lungs displayed a gas exchange efficiency equal to the CON group and better than that in the ECS-preserved lungs (lower A-aDO2, lower intrapulmonary shunt), suggesting better protection of the alveolar capillary membrane. Although the UWS lungs were initially less compliant than the ECS lungs, at no time was there a significant difference in the total work of respiration between the two groups. We conclude that UWS provides superior protection of the alveolar capillary membrane. The aerodynamic disadvantages of UWS preservation did not effect lung survival or total work of respiration.

Endocardial activation mapping and endocardial pace-mapping using a balloon apparatus.

The relation between endocardial activation mapping and endocardial pace-mapping was evaluated in 8 dogs while they were on cardiopulmonary bypass. Pacing or recording was accomplished by using a balloon apparatus (with 32 bipolar electrodes) inserted through a left apical ventriculotomy. Ventricular tachycardia (VT) was produced by occlusion followed by reperfusion of the left anterior descending coronary artery. During each VT, activation mapping was performed and early sites determined. Pace-map correlates (sites at which endocardial pacing produced a similar QRS morphology to that of the VT) were also determined. Isochronous maps were constructed for activation mapping and pace-mapping. There was a total of 29 morphologically distinct VTs. Groups were delineated according to correlations between activation mapping and pace-mapping. In 14 episodes of VT (group 1), pace-mapping confirmed the findings of activation mapping with all early sites being pace-map correlates (total number of early sites (tES) = 19; total number of pace-map correlates (tPMC) = 88; tES same as tPMC = 19). In 9 episodes of VT (group 2), there was a partial correlation between pace-mapping and activation mapping, such that pace-mapping when used with activation mapping appeared to further delineate the region of arrhythmogenesis (tES = 31; tPMC = 59; tES same as tPMC = 14). In 6 episodes of VT (group 3), there was no correlation between pace-mapping and activation mapping (tES = 15; tPMC = 0). With the balloon apparatus, endocardial activation mapping can be performed without the need for sustained monomorphic VT, and endocardial pace-maps may be generated easily.(ABSTRACT TRUNCATED AT 250 WORDS)

Interhospital transport of patients with ongoing intraaortic balloon pumping.

During a 5-year period (1979 to 1983), 50 consecutive patients undergoing continuous intraaortic balloon (IAB) pumping were transferred from Evanston Hospital to Northwestern Memorial Hospital (16 miles), where they underwent cardiac operation. All patients had cardiac catheterization before transfer. Indications for IAB were cardiogenic shock (9 patients), postinfarction angina (18 patients), unstable angina (9 patients), evolving myocardial infarction (3 patients), accelerating angina or hemodynamic instability during cardiac catheterization (9 patients) and prophylactic insertion for high-grade left main stenosis (2 patients). Transportation after stabilization was uneventful in all patients. All patients underwent operative coronary revascularization. There was concomitant mitral valve replacement in 3 patients, acute ventricular septal defect repair in 1 patient, aortic valve replacement in 1, and ventricular aneurysmectomy in 1. Three patients (5%) died postoperatively. Nine patients (20%) had complications directly related to IAB insertion. One patient required femoral-femoral arterial bypass preoperatively, 4 patients had postoperative lower limb ischemia treated by IAB removal or thrombectomy and 1 patient had thrombocytopenia (less than 60,000/mm3), 1 false aneurysm, 1 anterior compartment syndrome and 1 prolonged bleeding at the insertion site. Interhospital transfer with IAB pumping in progress should not be restricted to patients with cardiogenic shock, but can be effectively used for all patients who require preoperative IAB insertion.(ABSTRACT TRUNCATED AT 250 WORDS)

Does every patient with enigmatic lung disease deserve a lung biopsy? The continuing dilemma.

STUDY OBJECTIVE: Define the negative predictive factors for survival in patients who undergo open-lung biopsy. DESIGN: Retrospective analysis from July 1988 through January 1992 (prior to widespread use of video-assisted techniques). Factors included in analysis were: oxygen therapy, requirement for intubation, and HIV status. Also analyzed were the accuracy of the preoperative presumptive diagnosis and the outcome of therapy. SETTING: University hospital in an urban area with active medical and surgical critical care services. PATIENTS: All patients who underwent open-lung biopsy during the study design period. Patients excluded were those with lung transplants and one patient who had a thoracoscopic biopsy. Forty-eight lung biopsies were performed and 31 patients without AIDS and 15 with AIDS. Twenty-four (16 without AIDS, 8 with AIDS) were receiving oxygen therapy, met intubation criteria, or were intubated and ventilated at the time of biopsy. The indications were undiagnosed nodular or interstitial lung disease. INTERVENTIONS: Presurgical evaluation included a preoperative diagnostic algorithm of transthoracic needle biopsy and nodular disease (9 patients) and at least one bronchoscopy with bronchoalveolar lavage and transbronchial biopsy in interstitial disease (22 patients). Seven patients with nodular disease and nine with infiltrate had no preoperative procedures. MEASUREMENTS AND RESULTS: Lung biopsy obtained at definitive diagnosis in 98 percent of patients. Biopsy significantly altered therapy in 79 percent (81 percent without AIDS, 73 percent with AIDS). Postoperatively, in-hospital mortality was 8 (17 percent): 5 (16 percent) without AIDS and 3 (20 percent) with AIDS p > 0.1. Mortality rates showed patients without respiratory compromise, 4.2 percent (7 percent without AIDS, 0 percent with AIDS); patients receiving oxygen therapy, 6 percent (10 percent without AIDS; 0 percent with AIDS); patients who met intubation criteria, 60 percent (33 percent without AIDS, 100 percent with AIDS); patients who were ventilated, 75 percent (66 percent without AIDS [p < 0.05], 100 percent with AIDS [p < 0.05]. CONCLUSION: We recommend that the decision for lung biopsy be individualized based on respiratory status.

Photodynamic therapy in the palliation of late stage obstructing non-small cell lung cancer.

Photodynamic therapy selectively destroys malignant tumors by laser activation of injected hematoporphyrin derivative. Between July 1985 and January 1989, ten patients underwent 13 courses of PDT for relief of endobronchial tumor obstruction due to endstage primary non-small lung cancer. Initial biopsy specimens demonstrated squamous carcinoma in eight patients and adenocarcinoma in two. At the time of treatment, all patients were considered surgically unresectable: T4N2M1(one), T4N2M0(one), T3N3M1(two), T3N2M0(five), and T2N1M0(one). This latter patient had exclusionary medical conditions. The average Karnofsky status was 75 (worst was 60, best was 90). Obstruction was mainstem for six, bronchus intermedius in one, and left upper lobe in three. The average obstruction was 86 +/- 2 percent. Following treatment, the average obstruction was 57 +/- 3 percent. Responses were greater than 50 percent reduction in four and less than 50 percent in six. Half of the patients still had more than 70 percent obstruction following PDT. However, all patients had a decrease in symptoms, especially coughing. Six of ten patients subsequently received external beam radiation. Three of these patients developed significant problems during and following radiation. Side effects of HPD were minimal and included burns in two and mild anasarca in one patient. PDT appears to offer palliation of obstructive symptoms in patients with late stage lung cancer. Since life span is so short in these individuals, physicians must weigh carefully the potential side effects of combination therapy.

Dissemination of malignant tumors after video-assisted thoracic surgery: a report of twenty-one cases. The Video-Assisted Thoracic Surgery Study Group.

Video-assisted thoracic surgical techniques are widely used for biopsy and resection of thoracic tumors, but studies of long-term outcomes have not been reported. Dissemination of tumor by these techniques is a potential hazard. Therefore we surveyed the surgical members of the Video-Assisted Thoracic Surgery Study Group to determine whether tumor implants thought to be directly related to video-assisted techniques had occurred. Surgeons reported 21 cases. The sites of recurrence were the incision (n = 14), pulmonary staple line (n = 2), pleura (n = 2), both staple line and incision (n = 1), both pleura and incision (n = 1), and both pleura and staple line (n = 1). Review of these cases illustrates the pitfalls of present video-assisted techniques for malignant tumors of the thorax.

Chronic rejection in single-lung transplantation manifested by obliterative bronchiolitis.

Chronic rejection of the lung in patients with heart-lung transplants has most often been associated with the development of obliterative bronchiolitis. Previously only one patient receiving a single-lung transplant suffered from the development of this problem. We describe a patient whose obliterative bronchiolitis developed 9 months after single-lung transplantation. Progressive deterioration occurred until his death from obliterative bronchiolitis at 21 months after transplantation. The functional and histologic changes are described and the possible mechanisms discussed.

Complex pleural effusion associated with a subphrenic gallstone phlegmon following laparoscopic cholecystectomy.

A 90-year-old man presented with a large right-sided complex pleural effusion 4 months after a laparoscopic cholecystectomy. An initial thoracic CT scan confirmed the presence of the effusion, and the results of thoracentesis on three separate occasions were consistent with an exudative process. Another CT scan of the chest with thin-section cuts through the diaphragm along with an abdominal ultrasound revealed a retrohepatic subdiaphragmatic gallstone collection that eroded into the right hemidiaphragm. Thoracoscopic evacuation of the phlegmon, removal of the spilled gallstones, and repair of the diaphragm resulted in resolution of the effusion.

Pleural ascites without abdominal fluid: surgical considerations.

The presence of ascitic fluid in the pleural cavity in the absence of peritoneal fluid is rare. We have recently encountered two patients who presented with red-sided pleural effusions and no abdominal ascites. Both patients had diaphragmatic defects: One was an old traumatic diaphragmatic tear and the other a pinpoint spontaneous perforation. These cases are unique because the diagnosis of total ascitic fluid movement across the diaphragm was made during life, and the condition was surgically corrected. The literature concerning transdiaphragmatic movement of fluid is reviewed, and an operative approach is outlined.

Impact of initial flush potassium concentration on the adequacy of lung preservation.

The effects of initial lung flushing with intracellular and extracellular fluid type solutions were studied in lungs stored with the University of Wisconsin solution. Excised Sprague-Dawley rat lungs (n = 39) were flushed first with one of the following solutions: (1) the University of Wisconsin solution (K+ = 140 mmol/L), (2) modified (low potassium) University of Wisconsin solution (K+ = 20 mmol/L), (3) phosphate buffered saline solution (K+ = 3.9 mmol/L), (4) modified low-potassium phosphate-buffered saline solution (K+ = 20 mmol/L), (5) modified high-potassium phosphate-buffered saline solution (K+ = 40 mmol/L), and (6) Euro-Collins solution (K+ = 115 mmol/L) followed by secondary flush with storage solution and cold (4 degrees C) storage in University of Wisconsin solution for 24 hours. The lungs were then reperfused in the isolated, pulsatile, blood-perfused working lung system for 2 hours or until lung failure. Blood gas analysis and shunt fraction, aerodynamic parameters (airway resistance, lung compliance, elastic work, and flow resistive work), and total pulmonary vascular resistance were measured throughout the perfusion period. The mean oxygen tensions (in millimeters of mercury) at 30 minutes after the onset of reperfusion for University of Wisconsin solution, modified University of Wisconsin solution, phosphate-buffered saline solution, modified phosphate-buffered saline solutions (20 and 40 mmol/L), and Euro-Collins solution were 56.1 +/- 4.2, 72.7 +/- 9.1, 87.7 +/- 6.9 (p < 0.01 versus University of Wisconsin solution; p < 0.01 versus Euro-Collins solution), 86.0 +/- 9.6 (p < 0.01 versus University of Wisconsin solution; p < 0.01 versus Euro-Collins solution), 87.9 +/- 7.7 (p < 0.01 versus University of Wisconsin solution; p < 0.01 versus Euro-Collins solution), and 53.5 +/- 6.0, respectively. All aerodynamic parameters in the lungs flushed with extracellular fluid type solutions were superior to those flushed with intracellular fluid type solutions. We conclude that the efficacy of initial flushing was essential for successful lung preservation and that extracellular fluid type solutions were superior to intracellular fluid type solutions, at least for flushing the lung before storage with University of Wisconsin solution. Potassium concentration in flushing solution should be 20 mmol/L or less to obtain appropriate flushing and subsequent adequate distribution of the storage solution.

Short-term and long-term results of experimental wrapping techniques for bronchial anastomosis.

Major complications of bronchial anastomoses for either transplantation or sleeve resection include early leak, fistula formation, granulation tissue, and stenosis. To evaluate the impact of technique on these complications, we designed a nonimmunocompromised canine model with a totally ischemic bronchial segment. We wished to discover the prevalence of early and late complications of a telescoping anastomosis and if wrapping techniques modify them. We autotransplanted 25 mm of left main-stem bronchus by telescoping 1 mm of proximal into distal bronchus sutured with interrupted 4-0 polyglactin sutures. The animals were divided into four groups: no wrap; omental pedicle wrap; detached-free omental wrap; and Gelfoam sponge soaked in porcine omental extract. Weekly bronchoscopic studies assessed airway patency. After the animals were put to death at 70 days, the luminal areas of the proximal anastomoses were compared with the origin of the left main bronchus. No air leak, bronchial disruption, or infection occurred in any group at any time. Luminal narrowing occurred in all four groups but was most pronounced in the three groups in which wrapping techniques were used. We conclude that wrapping of a telescoped anastomosis is not necessary to prevent early complications. However, no method completely eliminates stenosis. Further experiments should determine the effects of immunomodulation in this model.

Transcatheter bronchial artery embolization in the multimodality management of massive hemoptysis.

To illustrate the potential role of transcatheter bronchial artery embolization (TBAE) in the multimodality management of massive hemoptysis, we describe a case in which TBAE was successfully employed as the definitive therapy. In recent years, the technique of TBAE has joined the armamentarium of managing methods for massive hemoptysis. While massive hemoptysis has traditionally been defined in terms of the volume of blood produced within a period of time, with a rate of 600 ml in 24 hours the most commonly used definition, a more functional definition has been proposed: bleeding into the tracheobronchial tree at a rate that poses a threat to life. It is the life-threatening nature of this symptom that often results in the early involvement of thoracic surgeons in the care of these patients.

Laser-assisted parenchyma-sparing pulmonary resection.

The neodymium:yttrium-aluminum-garnet laser is an excellent tool for removing lesions while sparing surrounding normal tissue. Local excision of 32 pulmonary lesions in 26 patients was performed with the Nd:YAG laser. Fourteen patients had moderate to severe impairment of pulmonary function: average forced vital capacity = 2.2 +/- 0.3 L and forced expiratory volume in 1 second = 1.3 +/- 0.3 L. Limited thoracotomy was used in the last 23 patients. The resected lesions included 16 primary malignant tumors: nine adenocarcinomas, five squamous carcinomas, and two large cell carcinomas. Eight of these lesions were classified as T1 N0, seven were T2 N0; and one was T1 N2. There were 10 metastatic lesions: three lymphomas, two adenocarcinomas, two leiomyosarcomas, and one case each of melanoma, squamous cell carcinoma, and renal cell carcinoma. There were six benign lesions: three granulomas, two hamartomas, and one carcinoid. Twelve lesions were deep seated, could not have been removed by wedge resection or segmentectomy, and would have necessitated lobectomy without this technique. With the laser, the lesion could be precisely excised with minimal loss of lung parenchyma. Mean operating time was 80 +/- 20 minutes; laser resection time was 15 +/- 8 minutes. Resection necessitated 10,000 to 20,000 J. Total blood loss was minimal (less than 100 ml). Chest tubes were always used and remained in place 5 +/- 2 days. The mean hospitalization time was 10 +/- 2 days. Pulmonary function testing, perform 6 weeks to 6 months after discharge, showed no significant difference from preoperative levels. To date, there have been no local recurrences (longest follow-up 2 years). The Nd:YAG laser is an excellent adjunct for pulmonary resection in patients who have marginal pulmonary function or who have deep parenchymal lesions not amenable to wedge resection. The operative technique for laser resection is presented.

Successful bronchoscopic placement of tracheobronchial stents without fluoroscopy.

BACKGROUND: Tracheobronchial stenting is performed increasingly often. Fluoroscopic control, which leads to significant radiation exposure for patients and staff, is recommended for the placement of metal stents. METHODS: All consecutive patients referred to two airway centers in need of airway stenting who received stents (Ultraflex; Boston Scientific, Natick, MA) underwent placement using endoscopic guidance only. All data were collected in an ongoing continuous database. RESULTS: One hundred stents were placed in 96 patients for central airway obstruction, and the data were reviewed. Stents were placed in all locations within the central airways for a variety of indications but mainly for malignant obstruction. No complications occurred, and all stents were placed satisfactorily. CONCLUSION: At centers with dedicated airway teams, Ultraflex stents can be quickly and safely inserted without the need for fluoroscopy. This saves radiation exposure to patients and to staff and may lead to a more cost-effective procedure.

Computed tomography in patients with esophageal perforation.

Contrast esophagram is the diagnostic procedure of choice in patients with clinically suspected perforation of the esophagus. In patients in whom the usual clinical signs or symptoms are unrecognized and in whom the diagnosis is obscure, the diagnosis of a perforated esophagus may be suggested by the finding of mediastinal fluid and air on CT. Three patients are reviewed. The perforations included one spontaneous, one from erosion of an esophageal carcinoma, and one iatrogenic. In two of the three patients, the diagnosis of perforated esophagus had not been made initially and in one patient the initial esophagram was interpreted as normal. Computed tomography of the chest in each patient led to the suspected diagnosis of perforated esophagus. Prompt appropriate surgical intervention followed. The findings of mediastinal fluid and more importantly mediastinal air on CT of the chest are strongly suggestive of esophageal perforation.

Oblique transseptal left atriotomy for optimal mitral exposure.

Twenty patients underwent mitral valve replacement or other surgical procedures within the left atrium with Dubost's transseptal left atriotomy. The left atrium was grossly enlarged in six patients. Exposure was considered to be excellent in 13 patients and poor in only two. One patient (with a second aortic and mitral valve replacement) required a permanent pacemaker after operation, none had a residual shunt at the atrial level, and none required reoperation for bleeding. The Dubost transseptal left atriotomy affords excellent exposure of left atrial structures, is easy to close, and does not increase the prevalence of postoperative rhythm disturbances.

Selective preoperative evaluation for possible N2 disease in carcinoma of the lung.

The efficacy of computed tomography and surgical mediastinal exploration in determining tumor resectability were retrospectively evaluated in 92 consecutive patients with non-small cell lung carcinoma. Status of mediastinal nodes was ultimately determined by surgical mediastinal exploration or thoracotomy. Patients were divided into three groups on the basis of chest roentgenography: Group I comprised 30 patients with peripheral T1 or T2 lesions with normal hilar and mediastinal shadows. Only one patient was found to have an involved node. Chest roentgenography had an accuracy rate of 96% and computed tomography, 93%. Thoracotomy is recommended without either computed tomography or surgical mediastinal exploration in this group. Group II comprised 47 patients with T1 or T2 lesions with an abnormal hilus, an abnormal mediastinal shadow, or either the hilus or mediastinum obscured by overlying parenchymal disease. Computed tomography revealed mediastinal nodes 1 cm or greater in size (abnormal node group) in 21 patients (45%) and smaller than 1 cm (normal node group) in 26 patients (55%). Surgical mediastinal exploration was performed in the abnormal node group and involved nodes were found in 17 of 21 patients (81%). In the normal node group, thoracotomy only was performed and no involved nodes were found. Computed tomography is recommended in all patients in Group II. Patients in the normal node group may be subjected to thoracotomy only and those in the abnormal node group should undergo surgical mediastinal exploration as the next diagnostic step before thoracotomy. Group III comprised 15 patients with grossly abnormal mediastinal shadows. Findings from computed tomography were abnormal in all 10 patients in whom it was done. Surgical mediastinal exploration was done in all 15 and yielded abnormal results in 14. It is recommended in this group that computed tomography is unnecessary and surgical mediastinal exploration should be the only diagnostic procedure. Thus, in potentially resectable non-small cell lung carcinoma, the use of computed tomography and surgical mediastinal exploration should be selective and should be determined by appropriate initial interpretation of the chest roentgenogram.

Experimental air leaks in lung sealed by low-energy carbon dioxide laser irradiation.

When a focused carbon dioxide laser beam strikes a surface of tissue, the light energy is converted instantly into thermal energy, causing cells directly in the laser's path to vaporize. Because the carbon dioxide laser's energy is well absorbed by water, this thermal effect is attenuated at a distance of 100 mu. If the laser beam is "defocused," the same thermal energy is dissipated over a larger area, causing only desiccation and melting of tissue without vaporization; however, the depth of injury remains shallow. This modified technique has been used to seal artificially created air leaks in the canine lung. Twelve mongrel dogs were anesthetized, intubated, and ventilated. The lingula was exposed sterilely through a left thoracotomy. A 1 X 3-mm hole was made in the lung at 1 cm from the edge. The created air and blood leaks were sealed with a defocused carbon dioxide laser beam set at 8 W (32 W/sq cm). Each tissue "weld" withstood 40 cm H2O of peak ventilation pressure without leak. At the time of reoperation three weeks later, there was apparent complete healing of the pulmonary surface. No air leaks were present. Histologic examination showed a small zone of amorphous coagulated pleura and lung overlying a zone of minimal atelectasis. Normal lung was present within 150 mu of the laser seal. This new technique was performed safely and easily with currently available carbon dioxide lasers in the laboratory. It is presently undergoing intraoperative trials in a controlled clinical setting.

Safety of bedside percutaneous dilatational tracheostomy in obese patients in the ICU.

STUDY OBJECTIVE: To examine the safety of bedside percutaneous dilatational tracheostomy in obese patients. DESIGN: Case series of consecutive obese patients (body mass index > or = 27 kg/m(2)) with acute respiratory failure in a medical, cardiac, or surgical ICU unit who required tracheostomy for failure to wean and continued mechanical ventilatory support. RESULTS: Thirteen obese patients were identified and consented to the procedure. Bedside percutaneous dilatational tracheostomy was successfully performed in the ICU for all 13 patients. Procedural complications were limited to paratracheal tracheostomy tube placement in one patient, with immediate identification and appropriate correction. Postprocedural complications were limited to a cuff leak in one patient. CONCLUSION: Bedside percutaneous tracheostomy can be safely performed in obese patients.