Herniation of the lung after video-assisted thoracic surgery

We report a case of lung herniation occurring following video-assisted thoracic surgery. Although lung hernias are rare, the widespread application of video-assisted thoracic surgery to patients at risk for lung hernia will likely result in more reports in the future. Consequently, pulmonologists and thoracic surgeons must be aware of this condition, risk factors for development, and potential methods of prevention in order to minimize the occurrence of this complication.

Rodeo related large animal injury: is protective head-gear warranted?

To compare rodeo associated large animal injuries to large animal associated trauma from other aetiologies in order to determine whether mandatory protective head-gear during rodeo is warranted. Retrospective analysis related to injury involving large animal admissions between 1 January 1990 and 31 December 1995. The setting is at the University of New Mexico Health Science Center, a level 1 trauma centre. All patients admitted with Injury Severity Scores of 1 or higher following large animal associated injuries. There were 140 admissions for which mechanism of injury was known. Thirty-nine occurred during rodeo competition and 101 occurred during other activities. Bovine associated activities were the aetiology in 34 (87%) of rodeo related injuries while equine related activities were the aetiology in 97 (96%) of non-rodeo related injuries (P<0.001). Rodeo related injuries involved the head and neck in five patients (13%) compared to 42 patients (42%) in non-rodeo activities (P=0.001). Mean Regional Injury Severity Score head and neck was 0.4 for injured rodeo riders and 1.5 for injured non-rodeo riders (P<0.001). Mean admission Glascow Coma Scale was 14.9 for rodeo-injured patients and 13.3 for non-rodeo-injured patients (P<0.001). Total ISS was significantly lower for rodeo injured patients (9.1 vs. 11.7, P=0.03). No rodeo injured patient died as a result of head injury. Mechanism of injury, ISS head, GCS, total ISS, and outcome differ between rodeo and non-rodeo injuries. While routine helmet use during non-rodeo events appears justified, mandatory use of helmets in rodeo events is unwarranted. Orthotics to protect the chest and abdomen are more likely to reduce morbidity and mortality for rodeo participants.

The lingula is an appropriate site for lung biopsy

BACKGROUND

Lung biopsy is commonly performed for diagnosis of diffuse pulmonary disease. The lingula offers technical advantages for biopsy, however the quality of tissue obtained by lingula biopsy has been questioned. We sought to determine whether lingula biopsy was a satisfactory site for biopsy in terms of diagnostic yield, therapeutic interventions, and survival results.

METHODS

All diagnostic lung biopsies performed for diffuse lung disease at 3 university affiliated hospitals between July 1, 1992 and December 31, 1998 were retrospectively reviewed. Patients were divided into 2 groups, depending upon site of biopsy: patients with lingula biopsy only and those with biopsies from other sites.

RESULTS

There were 75 patients; 20 underwent biopsy of the lingula alone, 48 had biopsy of other sites with or without biopsy of the lingula, and location of biopsy was unknown in 7 patients. Histologic diagnosis was achieved in all patients. Significant beneficial therapeutic changes were made in 14 lingula patients, and consisted of immunosuppression in 12 cases. Three patients died in the hospital or within 30 days. Fourteen patients survived 1 year. There was no significant difference between patients that had biopsy of the lingula alone and those that had biopsies from other sites in urgency, technique, histologic diagnosis, rate of therapeutic interventions, hospital mortality, or 1 year survival.

CONCLUSIONS

Lung biopsy of the lingula compared to other anatomic sites has equivalent diagnostic yield, therapeutic significance, and survival. Given the technical ease of biopsy, when disease is present radiographically it is the preferred site for lung biopsy.

Competitive NMDA receptor antagonists and spinal-cord ischemia

Ischemic neuronal death is associated with excitatory amino acid (EAA) release. Their action is mediated by N-methyl-D-aspartate (NMDA) receptors. Blockade of the receptors before the ischemic insult can decrease neuronal damage. Accordingly, we investigated the protective effect during spinal cord ischemia of two competitive antagonists, 4-(3-phosphonopropyl)-2-piperazine-carboxylic acid (CPP) and cis-4-(phosphonomethyl)-2-piperidine-carboxylic acid (CGS). Male Sprague-Dawley rats underwent intrathecal administration of 10 microL saline, CGS, and CPP 10 mM solutions, in a randomized blinded fashion, and were subjected to balloon occlusion of the thoracic aorta. Proximal aortic pressure was lowered to a mean of 40 mm Hg by partial exsanguination. In the acute protocol, 21 rats divided in 3 groups of 7 (saline, CPP, and CGS) were used to calculate the aortic occlusion time (AOT) resulting in paraplegia in 50% of animals (P50). In the chronic study, 24 rats divided in 4 groups of 6 (saline, CPP, CGS, sham) underwent 12-min occlusion. The chronic animals were scored daily for 28 days and submitted to histology of the cord. In the acute study, the P50 of CGS (10 min 48 s) and CPP (11 min 11 s) was longer than saline (10 min 27 s). In the chronic groups, analysis of variance of neurologic (p = .66) and histologic (p = .66) scores did not disclose differences between CGS, CPP, and saline. In conclusion, blockade of NMDA receptors with CPP or CGS may afford some protection for durations of occlusion around the P50, but it is not beneficial when ischemic injury is more protracted.

Heterotopic pancreas of the esophagus masquerading as Boerhaave's syndrome

Heterotopic pancreas (HP) of the esophagus is rare. We report a patient with HP of the esophagus and review the presentation, treatment, and results of the nine previously reported cases. Two patients had cancer. This high incidence raises concerns that HP of the esophagus may be premalignant. Because surveillance endoscopy is not possible, all known or suspected esophageal HP should be treated surgically.

Transhiatal esophagectomy in a patient with aberrant right subclavian artery

During transhiatal esophagectomy, the esophagus is generally safely and easily dissected posteriorly. However, in 1% to 2% of patients, an aberrant right subclavian artery passes between the esophagus and spine. We demonstrate that transhiatal esophagectomy may be safely performed in these patients when recognition and careful dissection are performed. Thoracic surgeons must be aware of this anomaly in order to prevent laceration of the aberrant right subclavian artery with catastrophic hemorrhage.

Lung biopsy: is it necessary?

OBJECTIVE

Lung biopsy is associated with substantial mortality rates. We reviewed our experience with this operation, primarily in patients with immunocompetence, to determine whether the results justify the continued performance of this procedure.

METHODS

We conducted a retrospective review of all diagnostic lung biopsies performed at 3 university-affiliated hospitals between July 1, 1992, and December 31, 1998.

RESULTS

There were 75 patients: 25 patients were treated electively, 17 were treated on an urgent basis, 27 patients on an emergency basis, and the urgency was unclear in 6 patients. Significant beneficial therapeutic changes were made in 15 of 25 elective procedures (60%), in 16 of 17 urgent procedures (94%), and in 11 of 27 emergency procedures (41%; P =.001). Significant beneficial therapeutic changes consisted of immunosuppression in 13 of 15 (87%) patients treated on an elective basis, in 9 of 16 (56%) treated on an urgent basis, and in 9 of 11 (82%) treated on an emergency basis in whom therapy was altered (P =.14). Operative death was 0 of 25 for elective operations (0%), 3 of 17 for urgent operations (18%), and 14 of 26 for emergency operations (54%). Multivariable analysis of operative death showed urgency to be the only significant predictor of death (P =.002).

CONCLUSIONS

In patients with immunocompetence, elective and urgent lung biopsies have acceptable operative mortality rates and frequently result in important beneficial therapeutic changes. Consequently biopsies are appropriate in these patients. Emergency biopsies are associated with high operative mortality rates and rarely result in a therapeutic change other than immunosuppression. These patients should not undergo lung biopsy if they are in stable condition and should be treated empirically with immunosuppression without operation if their condition is deteriorating.

Catastrophic hemorrhage on sternal reentry: still a dreaded complication?

BACKGROUND

To define the incidence of catastrophic hemorrhage (CH) during reoperations, the experience of the University of New Mexico was reviewed and compared with the practice of surgeons contacted by questionnaire.

METHODS

At the University of New Mexico, 610 reoperations were reviewed and 210 deemed high risk because of multiple reoperation, aneurysm, patent grafts, chamber's enlargement, conduit or previous mediastinitis. In the questionnaire, we asked about reentry technique, occurrence and outcome of CH, and precautions for high-risk patients.

RESULTS

At the University of New Mexico there were 4 CH with 1 death, and in the questionnaire there were 2,046 CH with 392 deaths. Our rate per surgeon was lower than that of the questionnaire. Rate of CH according to the saw was 2.09 for reciprocating, 2.0 for sagittal, and 1.74 for stryker in the questionnaire. Our rate was lower (0.65) with a micro sagittal saw. High-risk category predicted CH during sternotomy (p = 0.01) but only conduit (p = 0.005) was significant by univariate analysis.

CONCLUSIONS

The risk of CH could be as high as 1%. The sagittal micro oscillating saw is the safest reported to date. Presence of a conduit increases the risk by 2.5 fold.

Retrograde perfusion of the spinal cord during aortic crossclamping: initial observations in the swine model

BACKGROUND

Retrograde perfusion has emerged as a useful technique for the preservation of the heart and brain when arterial circulation is interrupted. Herein, this study was designed to test the hypothesis that retrograde perfusion of the azygos vein is sufficient to maintain viability of the spinal cord during aortic occlusion in the swine model.

METHODS

Female swine, 17 to 22 kg, underwent left thoracotomy, creation of a shunt between the aortic arch and the azygos vein, and aortic crossclamping for 60 minutes: the shunt was open in the retrograde perfusion group (n = 5) and closed in the control group (n = 4). The animals were evaluated for neurologic function for 8 days and killed. Spinal cords were processed for histologic examination. Additional animals underwent left thoracotomy and injection of a casting solution in the azygos vein (n = 2), left thoracotomy and angiography of the azygos vein (n = 2), and a compartmentalization procedure to separate the azygos vein from the caval system followed by angiography (n = 2).

RESULTS

Differences in the neurologic (2-sample t test, P =.11) and histologic (2-sample t test, P =.65) scores of retrograde perfusion and control groups were likely due to chance. Casting and angiography groups showed extensive collaterals between azygos and caval systems, only partially interrupted by compartmentalization.

CONCLUSIONS

Retrograde perfusion does not protect the spinal cord from ischemic injury. The collateral network between the azygos and caval systems prevents the oxygenated blood from reaching the cord. Surgical separation between the 2 systems was only partially successful in this study.

Selective protection of gray and white matter during spinal cord ischemic injury

BACKGROUND

Ischemic injury in the gray matter is associated with excitatory amino acid neurotransmitters (EAA) release, and in the white matter is associated with intracellular sodium accumulation. We investigated the protective effect during spinal ischemia of the EAA antagonist, 2-carboxypiperazinyl-propylphosphonic acid (CPP), and the sodium channel blocker (2,6-dimethylphenylcarbamoylmethyl) triethylammonium bromide (QX).

METHODS

Sprague-Dawley rats were randomized in four groups, received intrathecally 10 microL of saline, CPP, QX, or QX/CPP, and underwent balloon occlusion of the aorta. Proximal pressure was lowered by exsanguination. In the acute protocol, 28 rats were used to calculate the length of occlusion, resulting in paraplegia in 50% of animals (P50). In the chronic study, 60 rats underwent 11' occlusion. The chronic animals were scored daily for 28 days and submitted to cord histology.

RESULTS

The P50 of QX (11'22") and QX/CPP (11'54") were longer than saline (10'39"), suggesting a beneficial effect. Neurologic scores of all treatment groups (p = 0.0001) and histologic scores of CPP (p = 0.003) and QX/CPP (p = 0.002) were better than saline.

CONCLUSIONS

Protection of spinal cord during ischemia can be achieved with intrathecal administration of selective agents directed to the gray and white matter.

Cyanotic congenital heart disease with decreased pulmonary blood flow in children

Of the "five T's" of cyanotic congenital heart disease--tetralogy of Fallot, TGA, TAPVC, truncus, and tricuspid valve abnormalities (tricuspid atresia, stenosis, and displacement)--the first and last are commonly associated with diminished PBF. The four features that comprise tetralogy of Fallot--right ventricular hypertrophy, VSD, overriding aorta, and subpulmonary stenosis--are all secondary to a single morphogenetic defect: failure of expansion of the subpulmonary conus. This also explains the variability in clinical presentation. When neonates need intervention, shunts are usually performed. Coronary arterial anatomy must be defined before repair, which is usually done after these infants are 3 months of age. Although children with repaired tetralogy of Fallot are not completely "normal," markedly increased longevity and improvement in quality of life can be achieved. When major associated defects are present, such as atrioventricular canal defect, diminutive pulmonary arteries or collateral vessels, or left heart lesions, the prognosis changes from excellent to merely good. Tetralogy of Fallot with absent pulmonary valve syndrome is physiologically different from other tetralogy of Fallot conditions and characterized primarily by airway obstruction from massive dilatation of the central and perihilar pulmonary arteries; repair with pulmonary artery reduction is necessary. Tricuspid valve abnormalities include atresia, hypoplasia (i.e., pulmonary atresia with intact ventricular septum), and displacement (i.e., Ebstein anomaly). The pathophysiology that dictates these children's clinical condition (and prognosis) relates to three factors: (1) status of the tricuspid valve, (2) presence and size of a VSD, and (3) TGA or normally related great arteries. Virtually all children with tricuspid valve abnormalities can be palliated; reparative options include repair using two-ventricle, one-ventricle, or 1-1/2 ventricle repair. Children with critical pulmonary stenosis generally have a normal tricuspid valve and right ventricle. Balloon dilation is usually the only therapy necessary.

Posterior ventricular septal rupture: an anatomical reconstruction

Rupture of the ventricular septum following posterior myocardial infarction is an uncommon, but lethal, injury that requires prompt repair. Surgical reconstruction can be complex, demanding, and unfamiliar. Conventional techniques, as described in the literature, are associated with a variety of potential pitfalls. An alternative method we have successfully used in our last four patients is presented in detail. The procedure uses two composite (felt/pericardium) patches: an internal patch to reconstruct the left ventricular geometry and an external patch to repair the subtotal infarctectomy. For maximal security, all suture lines sandwich myocardium between two continuous felt surfaces. Specific transition stitches are described, which reliably anchor the entire repair at the critical, but poorly visualized, areas where the ventricular septum makes its transition to left and right ventricular free walls. This technique offers immediate hemostasis and a more anatomical left ventricular geometry. The method also reduces the risk of systemic thromboembolism, residual VSD, and repair disruption.

Choosing a prosthetic heart valve

Although most of the available prosthetic heart valves function remarkably well, the variety of available choices attests to the inability of any single one to fulfill the requirements of the ideal valve substitute. The mechanical prostheses include the caged-ball, tilting-disc, and bileaflet valves. Tissue valves available in the United States are the Carpentier-Edwards and Hancock porcine heterograft valves and the Carpentier-Edwards pericardial valve. Review of several large comparative studies on valve performance reveals that the overall results with tissue and mechanical valves are about equal at the end of 10 years. The characteristics of each type of valve substitute dictate the selection of one prosthesis in preference to others for a particular patient. Mechanical prostheses are recommended for patients without contraindications for anticoagulants. Tissue valves are reserved for patients over 65 years of age or for patients in whom anticoagulation is contraindicated. Multiple other patient-related factors need to be considered in selecting the appropriate valve, including the psychosocial situation and patient preference.

Mediastinitis without antecedent surgery

The study evaluates the results of aggressive surgical treatment for mediastinitis without antecedent surgery, after retrospectively reviewing all patients with mediastinitis, excluding patients with prior cardiac, esophageal or mediastinal operations, treated between June 1, 1992 and August 1, 1996. 8 patients were treated. 7 were male, mean age was 58 years. The etiology was Boerhaave's syndrome in 4, iatrogenic injury in 2 and descending necrotizing mediastinitis in 2 patients. The mean number of operations was 2.5. The initial operation was through thoracotomy in 5 patients and sternotomy in 2 patients. 4 patients underwent neck drainage, 1 as primary treatment and 3 combined with transthoracic drainage. 1 patient received laparotomy. Mean hospitalization was 52 days (excluding 1 death). Complications included mechanical ventilation greater than 48 hours in 7 patients, 2 or more operations in 5 patients, multisystem organ failure in 5 patients and other complications in 6 patients. Death occurred in one patients. Mediastinitis without antecedent surgery is associated with significant morbidity, however, with aggressive surgical drainage 87% of patients survived.

Fissureless lobectomy

Traditional lobectomy techniques describe division of pulmonary parenchyma within the fissures for access to the pulmonary artery. This results in air leaks, which may prolong chest tube drainage and hospitalization times. We describe a technique for lobectomy in which all lung parenchyma is divided using a stapler.

Sequestration of the lung arising from the circumflex coronary artery

Sequestration is an unusual pulmonary malformation. Systemic blood supply is commonly from the thoracic aorta, but arteries may occasionally arise from other sites including the abdominal aorta or the intercostal vessels. We report a rare form of sequestration with origin from the circumflex coronary artery. Knowledge of uncommon vascular origins, particularly from coronary arteries, is important to avoid injury and possible ischemia, infarction, exsanguination, or death.

Videothoracoscopic treatment of hepatic hydrothorax

Hepatic hydrothorax occurs frequently in ascites arising from communications in the diaphragm between peritoneal and pleural cavities. Numerous treatments have been described but are of limited utility due to invasiveness and poor success rate. We describe a case of hepatic hydrothorax in which the pore in the diaphragm was documented photographically and in which successful resolution was achieved with videothoracoscopic suture ligation and talc pleurodesis.

Head, face, and neck trauma from large animal injury in New Mexico

BACKGROUND

Head, face, and neck injuries (HFNI) occur during animal-related trauma. We compared patients with HFNI and without HFNI after animal-related injuries to determine the significance of these injuries.

METHODS

Retrospective review of admissions for animal injuries between January 1, 1990, and December 31, 1995, by age, gender, mechanism, animal, Glasgow Coma Scale (GCS) score, Injury Severity Score (ISS), Abbreviated Injury Severity score for head and neck (AIS Head/Neck), AIS score for face (AIS Face), intensive care unit stay, hospitalization length, morbidity, and mortality.

RESULTS

There were 153 admissions: 61 HFNI and 92 no HFNI. Significant differences occurred in gender, animal, activity, GCS, and ISS. HFNI had higher AIS Head/Neck, AIS Face, and mortality. HFNI were from horses in 87% and occurred during recreation in 89%; 39% of patients with HFNI were 18 years or younger.

CONCLUSION

HFNI occur in females and young people and produce lower GCS score, higher ISS, higher AIS Head/Neck, higher AIS Face, and higher mortality. Most occur during recreational horseback riding. Protective headgear should be mandated.

Aortoesophageal fistula after repair of descending aortic dissection

The development of aortoesophageal fistula after aortic repair is rare. We describe a patient who presented with hematemesis 4 months after emergent repair of a descending thoracic aortic dissection using a prosthetic graft. Diagnosis was supported by computed tomographic, angiographic, and endoscopic findings. Resection of the involved graft was performed through a left thoracotomy after placement of an ascending aorta-to-abdominal aorta conduit through an anterior approach. The patient died of uncontrollable bleeding a few hours after the procedure. Surgical intervention offers the potential for cure in this otherwise uniformly fatal condition. But like medical therapy, operative management has thus far been associated with 100% mortality.

Intrapleural fibrinolytics in management of empyema thoracis

STUDY OBJECTIVE

To determine the success and complication rates of fibrinolytic therapy (FL) in the treatment of thoracic empyema.

DESIGN AND PATIENTS

Between December 1992 and November 1994, all patients referred with empyema thoracis (ET) were offered FL. FL consisted of streptokinase (275,000 +/- 170,000 IU) or urokinase (121,000 +/- 57,000 IU) daily for a mean of 6.2 +/- 2.1 days.

SETTING

The University of New Mexico Health Sciences Center and the Albuquerque Veterans Affairs Medical Center.

RESULTS

Twenty-six patients were treated. Sixty-two percent (16/26) had complete resolution (CR) of symptoms, near or complete normalization of chest radiographic findings, and required no surgery or empyema tubes. Eight percent (2/26) had relief of symptoms and partial resolution (PR) of radiographic abnormalities and were discharged from the hospital with empyema tubes in place. All patients with PR had empyema tubes removed within 30 days of hospital discharge. Thirty-one percent (8/26) of patients failed to completely improve clinically or radiographically (nonresponse) and were treated with decortication or empyema tubes for greater than 30 days. Bleeding occurred in a single patient (4%). There was no mortality associated with FL use.

CONCLUSIONS

The use of FL is associated with resolution of ET in 69% (18/26) of patients. This modality is safe, effective, and spares most patients with empyema the morbidity and mortality of thoracotomy.

Multiple polyposis and adenocarcinoma arising in Barrett's esophagus

Adenomatous polyps of the esophagus are rare in comparison with those of the lower gastrointestinal tract. Like adenomatous colon polyps, they have been associated with malignancy. We describe a case of early adenocarcinoma and multiple polyposis of the esophagus arising in a Barrett's epithelium, treated with surgical resection.

Osteogenesis imperfecta and cardiovascular diseases

Aortic and mitral valvular insufficiency in patients with osteogenesis imperfecta result from an underlying defect in connective tissue formation. The surgical cases reported in the literature have included mechanical and bioprosthetic valve replacement as well as attempts at repair and reconstruction. Despite complications related to bleeding and tissue friability, acceptable results have been obtained. In this report, we describe aortic regurgitation secondary to osteogenesis imperfecta treated with homograft replacement. The unique cardiovascular complications of osteogenesis imperfecta and the available therapeutic options are discussed in light of the literature review.

Esophago-airway fistula in AIDS

Fistula formation between the esophagus and airway in acquired immunodeficiency syndrome is extremely unusual. We report 2 cases, the first in a patient who did not undergo definitive surgical management and died shortly after diagnosis. The second patient was managed successfully for 5 months by insertion of a Celestin endoesophageal prosthesis. This procedure can be performed with low morbidity and mortality, and may become the treatment of choice for this complex problem.

Experimental delayed postischemic spinal cord hypoperfusion after aortic cross-clamping

BACKGROUND

As in the brain, recent evidence has suggested a defect in the microcirculation during the reperfusion period after spinal cord ischemia. This investigation was undertaken in order to delineate blood flow dynamics in the postischemic spinal cord of the rat.

METHODS

Male Sprague-Dawley rats underwent cross-clamping of the aorta and subclavian arteries (XC) for 11 minutes. Spinal cord blood flow (SCBF) was measured by autoradiography in the gray and white matter of cervical (Ce), thoracic (Th) and lumbar (Lu) regions during XC, 1 h, 6 h and 24 h (XC n = 8, 1 h n = 9, 6 h n = 9, and 24 h n = 11, groups) after XC. Control groups underwent surgical manipulations and SCBF measurement but no XC (Sham 1, n = 8), or clamping of the subclavian arteries only (Sham 2, n = 8).

RESULTS

In Ce cord, there was no difference between SCBF of 1 h, 6 h, 24 h and Sham 1. In Th cord, SCBF was reduced during XC (P < 0.003 vs. Sham 2), 1 h, 6 h (P < 0.04 and P < 0.01 vs. Sham 1). In Lu cord, SCBF was not detectable in XC, and depressed in 1 h (P < 0.003) and 6 h (P < 0.003). There was no difference between 24 h and Sham 1 in Ce, Th, and Lu cords.

CONCLUSIONS

The study demonstrated a period of delayed postischemic hypoperfusion in the white and gray matter of Th and Lu cord segments lasting 6 h after XC. The phenomenon may play an important role in the ultimate fate of neural elements with borderline viability after ischemic injury.

Internal fixation of high tracheal stents

A technique for internal fixation of a silicone elastomer tracheal stent is described. This technique allows the use of a short stent in situations where complex stent placement otherwise would be necessary. The procedure was used successfully to manage a postresection stricture in the subglottic trachea.

Degeneration of axons in the corticospinal tract secondary to spinal cord ischemia in rats

Occlusion of the thoracic aorta and both subclavian arteries (XC) in the rat model produces spastic paraplegia. In order to characterize the lesion of white matter, 14 male Sprague-Dawley rats underwent XC for 10.5 to 12 min, were observed for 32 days and assessed with a lesion score. A sham group of eight underwent surgical manipulations without XC. The spinal cords were studied by optical microscopy and electron microscopy. An additional group of normal animals (n = 8) underwent spinal cord blood flow measurement with the autoradiographic technique. Optical microscopy showed normal histology in sham operated rats and rats with aortic cross-clamp and lesion score = 2-4 (n = 5), rare changes in the white matter of rats with lesion score = 8 (n = 2), and demyelination of the anterior and lateral tracts of the white matter and motor neuron loss in the gray matter of rats with lesion score = 13-15 (n = 7) and spastic paraplegia. In this last group, electron microscopy disclosed severe axonal degeneration of corticospinal tracts. In the same region spinal cord blood flow was higher than the remaining white matter. This study confirms that spastic paraplegia observed in the rat model after XC is due to degeneration of the pyramidal tracts, perhaps more susceptible to injury due to the high spinal cord blood flow.

Mycotic aneurysm of the ascending aorta after coronary revascularization

A mycotic aneurysm developed at the aortic cannulation site after coronary revascularization and subsequent mediastinitis. Treatment required hypothermic circulatory arrest and patch repair. Review of the literature revealed 40 cases, 11 after various open heart procedures and 10 after either heart or heart and lung transplantation. Postoperative mediastinitis was present in 12. Nine of 12 patients operated on electively survived, versus 4 of 10 who had rupture. Mycotic aneurysms of the ascending aorta are rare but do occur after heart operations, especially in transplant patients.

Ascending aorta to right pulmonary artery interposition shunt in critically ill infants

In spite of a trend toward earlier complete repair, some neonates and infants with complex cyanotic heart disease continue to require interim palliation with systemic-to-pulmonary artery shunts. A variety of shunt procedures have been proposed, each with inherent advantages and disadvantages. We have found a prosthetic interposition shunt between the ascending aorta and right pulmonary artery (AA-RPA) to be effective in very young infants with small vessels. Over a 15-year period, 51 patients, mean weight 3.33 kg and mean age 59 days, underwent this procedure with a 13% perioperative mortality and a 78% 2-year overall shunt patency rate. We conclude that the AA-RPA interposition shunt is a safe, effective procedure in these infants.

Surgical repair of atrial septal rupture due to blunt trauma

We report a case of atrial septal rupture and surgical cure after blunt chest trauma. Review of the literature indicates that this rare lesion results from severe forces applied to the chest and is often associated with other serious and life-threatening injuries. The defect may not be recognized for several months or even years in patients who survive concomitant initial trauma. When operative repair is undertaken, a favorable outcome can be anticipated.

Pseudocoarctation of the aorta presenting as a mediastinal mass with dysphagia

Pseudocoarctation is an uncommon anomaly thought to be caused by congenital elongation and kinking of the aorta. We report a case of pseudocoarctation of the aorta presenting as a superior mediastinal mass causing dysphagia. Aortography and echocardiography revealed dilatation of the aorta and an aneurysm below the level of the pseudocoarctation. The patient underwent operative repair of the pseudocoarctation and associated aneurysm with good symptomatic relief. Review of the literature and experience with this case demonstrate that pseudocoarctation of the aorta cannot necessarily be regarded as a benign condition. Surgical treatment is recommended for all symptomatic patients and for those with associated aneurysm formation.

Selective vulnerability of white matter during spinal cord ischemia

The long-term effects of spinal cord ischemia were studied in 21 rats by lesion scores (LS, n = 21), somatosensory evoked potentials (SEP, n = 16), electromyographic measurements (EMG, n = 12) and histology of the spinal cord (n = 21) 48.5 +/- 57.2 days after 10- to 12-min occlusion of the thoracic aorta and subclavian arteries. All the animals were initially paraplegic with a spastic presentation but seven recovered within 2 days (group A), demonstrating low LS (3.4 +/- 1.05) normal EMGs (n = 3) and unremarkable histology. The 14 paraplegic animals presented relevant findings of the lumbar cord consisting of white matter lesions only (group B, n = 7) or white and gray matter lesions (group C, n = 7). Group B animals showed severe deficit (LS = 11.8 +/- 2.93) without denervation on EMG (n = 5) or muscle atrophy on histology. Group C animals displayed equal impairment (LS = 14.4 +/- 0.71), denervation on EMG (n = 4), and muscle atrophy. Resting motor unit activity of groups B and C were significantly different from group A (p < 0.001), while LS of groups B and C did not differ (p = 0.083). These data underscore the nature and the extent of white matter lesions during spinal cord ischemia, a finding which has generally been eclipsed by emphasis on gray matter lesions in previous studies.

Repair of atrial septal defect due to penetrating trauma

We report a case of stab wound to the heart resulting in an atrial septal defect and perforation of the anterior leaflet of the mitral valve, which we repaired successfully 7 years after the injury. To our knowledge, repair of an atrial septal defect due to penetrating trauma has never before been reported. Investigation of possible valvular heart disease in a patient with a history of chest trauma should be aimed at identifying both intracardiac shunts and valvular abnormalities, so that a complete repair can be performed.

Efficacy, complications, and cost of a comprehensive blood conservation program for cardiac operations

We reviewed blood use in 118 consecutive patients who underwent primary, elective cardiac operations in 1989. In June 1989 we initiated a blood conservation program that included attempts to limit preoperative aspirin use, intraoperative phlebotomy and hemodilution, use of a cell conservation device (Electromedics, Inc., Englewood, Colo.) to concentrate residual oxygenator contents, reinfusion of chest drainage, and acceptance of a minimum hemoglobin level of 8.0 gm/dl in stable patients. Patient characteristics were similar for patients operated on both before (n = 58) and after (n = 60) initiation of the blood conservation program, except for age and preoperative aspirin use (both greater in postconservation patients). Fewer blood products were transfused (5.8 +/- 5.7 units per patient before conservation versus 4.0 +/- 7.4 units per patient after conservation; p = 0.005). More complete data were available for 82 patients (40 patients before conservation and 42 after conservation). In the postconservation patients, 20 of 42 had 575 +/- 140 ml of blood withdrawn before cardiopulmonary bypass and reinfused afterward, 26 of 42 had 806 +/- 376 ml of blood processed with the cell conservation device returned, and 21 of 42 patients had an average of 287 +/- 127 ml of chest drainage reinfused. Chest tube drainage, postoperative hematologic parameters, and the prevalence of complications were not significantly different between groups. Stepwise linear regression analysis identified intraoperative withdrawal of blood before cardiopulmonary bypass, bypass duration, and preoperative hematocrit value as predictors of blood use. Intraoperative withdrawal of blood before cardiopulmonary bypass is an important conservation measure, and its use should be expanded.

Pulmonary artery sling with severe tracheobronchial stenosis: repair in infancy by tracheal resection and pulmonary artery reimplantation

Pulmonary artery sling is an unusual anomaly. The results of surgical therapy have been unsatisfactory in the past because of poor long-term left pulmonary artery patency and failure to address concomitant primary tracheobronchial stenoses. Refinement of suture materials and microsurgical techniques have allowed earlier surgical treatment of tracheal stenosis and have led to improved pulmonary artery patency rates. Intermediate results of primary one-stage repair with tracheal resection and left pulmonary artery reimplantation or translocation in early childhood have been promising. It remains to be seen whether late anastomotic tracheal stenosis will be a problem. This constitutes the first report of a case of one-stage repair with tracheal resection and left pulmonary artery reimplantation in an infant.

latrogenic pseudoaneurysm of the innominate artery

Central venous cannulation by the subclavian approach is a commonly performed procedure with an overall complication rate of up to 11%. In the English literature, however, there has been no previous documentation of pseudoaneurysm of the innominate artery as a complication of right subclavian vein catheterization. We report a case of a 55-year-old woman on chronic hemodialysis admitted to the hospital with pneumonia and sepsis who underwent multiple attempts at placement of a right subclavian vein catheter. These were unsuccessful and resulted in arterial puncture. The patient was discharged, but returned to the hospital 2 weeks later with shortness of breath and stridor. Evaluation revealed a pseudoaneurysm of the innominate artery with compression of the airway, which was successfully repaired.

Choosing a prosthetic heart valve

Although most of the available prosthetic heart valves function remarkably well, the variety of available designs attests to the inability of any single one to fulfill the requirements of the ideal valve substitute. The mechanical prostheses include the caged-ball, tilting-disc, and bileaflet valves. Tissue valves available in the United States are the Carpentier-Edwards and Hancock porcine heterograph valves. Review of several large comparative studies on valve performance reveals that the overall results with tissue and mechanical valves are about equal at the end of 10 years. The characteristics of each type of valve substitute dictates the selection of one prosthesis in preference to others for a particular patient. Mechanical prostheses are recommended for patients without contraindications for anticoagulants. Tissue valves are reserved for patients over 70 years of age or for patients in whom anticoagulation is contraindicated. Multiple other patient-related factors need to be considered in selecting the appropriate valve, including the psychosocial situation and patient preference.

Blood conservation in cardiac surgery

We reviewed current blood conservation techniques and their use in cardiac surgery. Avoidance of aspirin preoperatively is an important blood conservation measure. Patients scheduled for an elective operation should participate in autologous predonation programs. With careful monitoring, patients with major coronary artery disease can safely donate blood preoperatively. Intraoperative processing of blood withdrawn before cardiopulmonary bypass provides autologous platelet-rich plasma for infusion after reversal of heparin sodium. Blood collected from the field during operation and blood remaining in the oxygenator after bypass can also be processed to yield washed and concentrated red blood cells for reinfusion. Randomized, prospective studies document that postoperative autotransfusion is both safe and effective in reducing homologous blood use. Aprotinin reduces plasma protein activation and platelet damage during bypass. The integration of available blood conservation techniques into a comprehensive program combined with careful consideration of the indications for transfusion may allow more patients to avoid transfusion entirely.

Arteriovenous and capillary hemangiomas of the interventricular septum

The case of a patient with two extremely unusual types of hemangioma is presented. The arteriovenous and capillary hemangiomas of the interventricular septum were discovered on coronary angiography performed for chest pain. Echocardiography confirmed the diagnosis. Successful surgical excision was performed.

Observations on flow characteristics of passive external aortic shunts

Extraluminal heparin-bonded shunts have been recommended to support the distal circulation and decompress the proximal vascular bed during procedures that require interruption of flow through the thoracic aorta. Shunts that originate in either the left ventricle or the proximal aorta are generally viewed as hemodynamically similar, despite incomplete documentation of their flow characteristics. The present study was conducted to further define these hemodynamic properties. Identical extraluminal shunts were placed from the left ventricular apex and aortic arch to the distal thoracic aorta in mongrel dogs. Simultaneous pressure and Doppler flow velocities were recorded in the carotid and femoral arteries. Computer-enhanced composite waveforms were used to assist data analysis. When compared to ventricular cannulation, aortic cannulation provided improved proximal decompression and increased mean distal flow. In addition, significant diastolic flow reversal was recorded in the distal circulation when ventricular cannulation was employed. On the other hand, ventricular cannulation was associated with the preservation of pulsatile flow, whereas flow generated by aortic cannulation was linear. It is concluded that extraluminal shunts that originate in the left ventricle and the proximal aorta have distinct hemodynamic properties. These differences may be clinically important in specific situations.

Lung cancer--current concepts and controversies

The recent literature contains a variety of controversial management alternatives for patients with pulmonary malignancy that affect all aspects of the lung cancer problem. Revisions in the classification system have been advanced in which the prognostic implications of specific ultrastructural and histochemical information are acknowledged. Computed tomography and, to a lesser extent, nuclide scanning have revolutionized the staging process, but limitations in these procedures are emerging. Improved survival following aggressive surgical treatment has challenged the adequacy of the standard staging system. The palliative role of radiotherapy is becoming more widely appreciated. Results of immunotherapy are equivocal and gains from chemotherapy are modest. Combinations of treatment modalities will require further documentation before they can be recommended with confidence.

Use of a sagittal oscillating saw for repeat sternotomy: a safer and simpler technique

A method of repeat sternotomy using a microsagittal oscillating saw is described. We have found this method to be safer and simpler than previously described techniques. We have used this technique in more than 50 repeat sternotomies without a single complication related to the mediastinal reentry procedure.

Unusual complication of direct left atrial pressure monitoring line

We are here reporting the case of a left atrial pressure monitoring line that caused mechanical interference with the functioning of a Björk-Shiley mitral valve. The catheter wedged the disc into a closed position and caused the patient's death.

Use of the pulmonary artery for left ventricular venting during cardiac operations

Data relating to the hemodynamic efficaciousness and mechanism of action of a pulmonary artery catheter or vent used for left ventricular venting during cardiac operations are presented. The pulmonary artery vent is a plastic sump catheter that is introduced into the main pulmonary artery through a purse-string suture and connected via a roller pump to the venous reservoir of the heart-lung perfusion machine. Placement and removal require only a few minutes. The pulmonary artery vent retrieved 85% of a 99mtechnetium-labeled solution placed in the left atrium during aortic cross-clamping, and there was no detectable radioactivity in peripheral or aortic root blood samples. Pulmonary artery vent return during cardiopulmonary bypass in 10 patients undergoing coronary artery bypass averaged 12.5 L. The effectiveness of left ventricular decompression was evaluated in 20 patients also undergoing bypass grafting. Use of the pulmonary artery vent consistently and significantly decreased left heart pressures, compared to the control situation with the vent off, with the aortic cross-clamp applied, and in both the fibrillating and beating heart in the early postischemic reperfusion period. We reached the following conclusions: (1) The pulmonary artery vent withdraws left heart blood via the pulmonary vasculature, in addition to returning right heart spillover and retrieving bronchial flow. (2) Left heart pressures are reduced to levels which reduce oxygen demands and preserve endocardial perfusion, therefore protecting myocardium, during fibrillation and during coronary reperfusion of the beating heart. (3) Because of its effectiveness and safety, especially the impossibility of introducing air into the left ventricle, the pulmonary artery vent is recommended for routine left ventricular venting.

Long-term evaluation of pericardial substitutes

The development of postoperative pericardial adhesions increases the risk of cardiac reoperations because of the danger of damaging the heart, great vessels, or grafts. Several pericardial substitutes have been tested in the past in an attempt to facilitate reoperation, with inconclusive results. This study evaluated eight different materials as pericardial substitutes: six synthetic materials and two different preparations of bovine pericardium. In 32 dogs a 10 by 5 cm piece of pericardium was excised through a right thoracotomy and the defect closed with a measured patch. Each material tested was implanted in four dogs that were put to death at 3, 6, 9, and 12 months. At autopsy the development of adhesions and epicardial reaction were graded as none, minimal, moderate, and severe. Histologic studies of the patch, the epicardium, and the suture line were performed. Our results suggest that both types of bovine pericardium were an excellent substitute. Although minimal adhesions developed, these were easily dissected. The underlying anatomy was clearly recognizable because of the lack of epicardial reaction. Silicone rubber-coated polyester fabric was an acceptable material for the prevention of adhesions, but a severe fibrous epicardial reaction impeded the recognition of the coronary arteries. Both silicone-filled and high-porosity polytetrafluoroethylene (PTFE) films reduced adhesions but caused a severe epicardial reaction. The other synthetic materials were considered inferior because of severe epicardial reaction and/or structural deterioration.

Traumatic avulsion of the innominate and left carotid arteries: successful repair

Traumatic rupture of the aorta or the arch vessels is a rare and frequently fatal injury. This lesion should be considered in all cases of severe chest trauma. Early aortography is essential for accurate diagnosis. Nineteen cases of avulsion of the innominate artery have been previously reported. In only two of them a second aortic arch branch had an associated injury. The case presented here is the first successful repair of a combined avulsion of both the innominate and the carotid arteries from the aortic arch. Cerebral circulation was maintained during the operation with a heparin-coated shunt from the ascending aorta to the right common carotid artery. Reconstruction was accomplished by inserting a bifurcated Dacron prosthesis from the aorta to the innominate and left carotid arteries. The use of a heparin-bonded shunt maintained cerebral perfusion, and greatly simplified the operation and avoided the risk of extracorporeal circulation and systemic anticoagulation in a patient with multiple trauma.

Intra-aortic closure of the calcified patent ductus: a new operative method not requiring cardiopulmonary bypass

Diffuse and circumferential calcification of the patent ductus arteriosus is a rare finding frequently associated with severe pulmonary artery hypertension. Under this circumstance, closure of the patent ductus arteriosus by ligation in continuity or by division and suture is hazardous if not impossible. Endoaortic closure of the ductus with a prosthetic patch has been proposed as an alternate and safer procedure. This paper describes an improved operative technique for intra-aortic closure of a calcified patent ductus arteriosus employing a heparin-coated shunt to permit aortic cross-clamping and an intraluminal baloon catheter to control bleeding from the pulmonary artery. Extracorporeal circulation and systemic heparinization are avoided. Minimal manipulation of the ductus and pulmonary artery is required.