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Biomedical subjects

J LoCicero

Publications and source records attributed to J LoCicero.

At least 55 records · Page 3Linked to original sources
PubMed1992

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.

Anastomosis, Surgical↗
PubMed1992

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.

Adolescent↗
PubMed1991

Endoscopic thoracic sympathectomy: evaluation of pulsatile laser, non-pulsatile laser, and radiofrequency-generated thermocoagulation.

We describe a modified technique for percutaneous denervation of the thoracic sympathetic chain by laser to treat selected cases of sympathetic causalgia of the upper extremities. The technique involves transpleural ablation with laser under thoracoscopic guidance through the second or third intercostal space-anterior axillary line. We also compare four different modalities of endoscopic denervation: A xenon chloride excimer laser (308 nm, 35 mJ/pulse, 20 pulses/sec, 2.2 mm catheter tip), CO2 laser (14 W, CW, 2 mm spot size), Nd:YAG laser (88 W, CW, 3 mm spot size), and radiofrequency-generated thermocoagulation (3 W, CW, 2.1 mm catheter tip) by performing bilateral thoracic sympathectomy on 12 mongrel dogs (three dogs each). Criteria analyzed included duration of exposure, power density, total energy output, laser penetration and spread, gross morphology, and scanning electron microscopy (SEM) of the destroyed neural tissue. Total ablation of the inferior segment of the stellate ganglion and the T1-T2 nerve roots by excimer laser required 83 +/1 1 Joules over an exposure period of 118 seconds. Ablation by CO2 and Nd:YAG laser required 153 +/- 13 Joules and 554 +/- 47 Joules delivered over 11 and 6 seconds respectively. In contrast, ablation of the same volume of nerve tissue by RF required 810 +/- 50 Joules over 270 seconds. SEM evaluation revealed that excimer and CO2 laser lesions were narrower in configuration compared to RF and Nd:YAG lesions which showed more lateral spread. The actual depth of penetration per 1 second exposure was similar for Excimer and CO2 (1.5 mm) and RF (1.3 mm), but deeper for Nd:YAG (3 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Living-related lobar lung transplantation in beagle puppies.

Unilateral lung transplantation has provided effective short-term therapy in adults with end-stage lung disease. Rejection continues to be the most common cause of transplant failure. Living-related lung transplantation may decrease the recipient immune response. The purpose of this study is to test the technical and physiological feasibility of living-related lobar lung transplantation from adult beagles into beagle puppies in a chronic model. Twenty purebred adult beagle donors underwent left thoracotomy with harvest of the left lower lobe using cold perfusion of the pulmonary artery and cold immersion. Twenty recipient purebred beagle puppies from the same colony underwent left thoracotomy, left pneumonectomy, and implantation of the donor adult lobe. Anastomoses were performed in sequence: pulmonary vein to left atrium, bronchus, pulmonary artery. Postoperative immunosuppression was with Cyclosporine. Respiratory function of the implanted lobe was evaluated by pulmonary angiography and during balloon occlusion of the right pulmonary artery with arterial blood gases 1 month after transplantation. Ten recipient puppies died of rejection (4), infection (3), or bronchial dehiscence (3) prior to angiography. Seventeen pulmonary angiograms in 10 surviving animals showed normal left pulmonary arterial blood flow (2), diminished left pulmonary arterial flow (5), and occluded left pulmonary artery (3). In two recipients balloon occlusion of the right pulmonary artery was performed and respiratory function was maintained solely by the transplanted lobe for 2 days in one recipient and for 30 minutes at 1 month and 2 months postimplant in a second recipient. Living-related lung transplantation of adult beagle lobes into pneumonectomized beagle puppies is technically feasible. High mortality rates in a chronic model are related to infection and rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Contribution of the bronchial circulation to lung preservation.

Short preservation time still severely limits lung transplantation. To determine the effect of bronchial arterial flush preservation, we studied 54 dogs using the isolated perfused working lung model. After baseline measurements, lungs were flushed with lactated Ringer's solution (60 ml/kg at 8 degrees C) by one of three methods: pulmonary artery perfusion, bronchial artery perfusion through a 15 cm closed aortic segment, or simultaneous pulmonary-bronchial artery perfusion. These groups were further subdivided and tested after 0, 4, and 17 hours of storage at 4 degrees C (n = 6 each). Lungs were ventilated (flow rate 140 ml/kg/min; inspired oxygen fraction 0.21) and continuously reperfused with normothermic deoxygenated autologous blood in a closed loop. Measured variables were hemodynamics, aerodynamics, and leukocytes in bronchoalveolar lavage. Survival time was determined from initial reperfusion to failure of the lung to oxygenate. After 0 and 4 hours of storage, there was no significant difference in survival times. After 17 hours, lungs subjected to pulmonary-bronchial artery perfusion survived longer than those perfused via either the pulmonary or bronchial arteries alone (120 +/- 24 versus 38 +/- 14 or 52 +/- 16 minutes; p less than 0.01). Pulmonary artery pressure and resistance in all groups except at failure were never different from baseline values in the intact animal. Shunts in the pulmonary-bronchial artery perfusion groups were closest to baseline at onset (8% +/- 4%) and remained lower throughout reperfusion than in the groups subjected to pulmonary or bronchial artery perfusion alone. After 17 hours, static compliance of pulmonary artery-perfused lungs was worse than baseline (1.1 +/- 0.2 x 10(-2) versus 3.2 +/- 0.7 x 10(-2) L/cm H2O/sec; p less than 0.05), whereas compliance in the pulmonary-bronchial artery perfusion groups remained constant (3.6 +/- 1.5 x 10(-2) L/cm H2O/sec). Elastic work performed by lungs subjected to pulmonary-bronchial artery flushing at onset was significantly lower when these lungs were reperfused immediately (201 +/- 14 versus 295 +/- 35 gm-m/min for pulmonary artery-flushed lungs) or after 4 hours of storage (229 +/- 30 versus 290 +/- 24 gm-m/min for pulmonary artery-flushed lungs). Bronchoalveolar lavage after 17 hours in the group subjected to pulmonary bronchial artery flushing demonstrated leukocyte counts similar to those of intact lungs (45 +/- 5 versus 29 +/- 8/mm3) and significantly less than in lungs subjected to pulmonary or bronchial artery flushing (137 +/- 18 or 82 +/- 10/mm3, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

New uses of the laser in thoracic and cardiovascular surgery.

Lasers have been accepted in general thoracic surgery as resectional tools which allow precise hemostasis and maximal salvage of normal lung tissue. Used endoscopically, with or without associated photodynamic therapy, we have provided acceptable palliation in some patients with obstructing tumors of the tracheobronchial tree and esophagus. Cardiovascular uses of the laser have been under extensive investigation at our medical center for many years. We have demonstrated that laser-assisted anastomosis of small vessels is possible, that early tensile strength and patency are excellent, but that long-term aneurysm formation is excessive. In addition, CO2 laser injury of the arterial intima leads to a marked increase in atheromata formation in animal models of atherosclerosis; this may be eliminated with the excimer laser. We have begun using the excimer laser to open obstructed peripheral and coronary arteries. New technology is emerging which allows dual fiber catheters which allow identification of tissue in an artery, ie calcium, atheromata, clot, media, etc. and instantaneous computer sensing/integration which initiates "fire" or "no fire" signals in the enclosed laser system, thus decreasing the chance of vessel perforation. These technologies, in association with balloon angioplasty, intravascular stents, and atherectomy devices are offering exciting alternate therapy for patients with obstructing atherosclerosis.

Cardiac Surgical Procedures↗
PubMed1990

Clinical experience with portable cardiopulmonary bypass in cardiac arrest patients.

To evaluate the use of portable cardiopulmonary bypass as a resuscitative tool and its impact on long-term survival of patients in cardiac arrest, we reviewed the results of 32 consecutive patients resuscitated by cardiopulmonary bypass for cardiac arrest or severe hemodynamic compromise at Northwestern Memorial Hospital over a 2-year period. Overall survival was 12.5%. Only 1 (3.4%) of the 29 patients who had cardiac arrest survived and left the hospital. All 3 patients who had severe hemodynamic compromise but not cardiac arrest were long-term survivors. Our study suggests that portable cardiopulmonary support systems used as a resuscitative tool do not prolong the survival of most cardiac arrest patients but may be useful for patients with shock due to mechanical causes and for those with profound hemodynamic compromise due to ischemia or myocardial infarction. Portable heart-lung machines can provide patients with excellent hemodynamic support; however, neurological or cardiac recovery is unlikely once cardiac arrest occurs.

Cardiopulmonary Bypass↗
PubMed1990

Aerodynamic evaluation of crystalloid and colloid flush perfusion for lung preservation.

To assess the effectiveness of pulmonary perfusion we evaluated the lung mechanics of 36 canine lungs in an isolated perfused working lung (IPWL) model. Four groups of lungs (n = 9 each) were preserved by pulmonary artery flushing with either high-potassium colloid (UW), high-potassium crystalloid (EuroCollins', EC), low-potassium crystalloid control (lactate), or low-potassium substrate-enhanced crystalloid (RPMI) followed by 130 +/- 10 min of cold storage. Ventilation remained constant (TV 10 ml/kg at 14 breaths/min with 5 cm H2O PEEP). Assessed data included lung resistance (R), timed expiratory volume (EV0.3 sec as %TV), lung compliance (C), elastic work (Wel), and flow-resistive work (Wres). Immediately following storage, R and Wel were similar for all groups (16 +/- 3 cm H2O/liter/sec and 149 +/- 18 gm/min). UW preserved lungs were less compliant (1.5 +/- 0.1 X 10(-2) liter/cm H2O) and required more inspiratory work (Wres 5.8 +/- 0.8 gm/min) compared to the low-potassium crystalloid (Lactate) group (2.0 +/- 0.1 X 10(-2) liter/cm H2O and 3.4 +/- 0.6 gm/min, respectively, P less than 0.05). For 3 hr of reperfusion, crystalloid lungs showed no significant change in R, C, Wel, or Wres. In contrast, R of the UW group increased significantly to 32 +/- 5 and 40 +/- 8 cmH2O/liter/sec at 1 and 3 hr, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Interposition of the thymus as a pedicled flap in tracheal reconstructive surgery.

Thymus was interposed in six patients following tracheal reconstruction: three tracheo-innominate fistula repairs, two resections for stenosis, and one repair of a membranous tear during esophagectomy. The two resections for stenosis were elective; the others were emergent repairs. This gland, readily accessible in the upper mediastinum, is easily dissected from the pleura and pericardium and separated into two lobes. Pedicles based at the thoracic inlet measure between 15 and 20 cm by 4 cm. Each lobe receives independent arterial blood supply and venous drainage which remains intact even if the innominate vein must be divided to effect tracheal repair. All patients survived the perioperative period. The patient with the tracheo-innominate fistula died 1 month later. No patient had evidence of further vascular complications or tracheal anastomotic leak even though one patient developed a long segment of necrotic trachea. Reinforcement following tracheal reconstruction is important in preventing complications from anastomotic leak or vascular erosion. The pedicled thymus gland is an excellent, readily available interposition flap for emergent or elective tracheal reconstruction.

Brachiocephalic Veins↗
PubMed1990

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.

Bronchial Arteries↗
PubMed1990

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.

Adenocarcinoma↗
PubMed1990

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.

Adult↗