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.

Primary mediastinal malignancies in children: report of 22 patients and comparison to 197 adults.

PURPOSE: Examine a contemporary series of patients with primary pediatric malignant mediastinal tumors and determine epidemiology, histology, treatment, and survival. Patients and Methods. All malignancies diagnosed between January 1, 1973 and December 31, 1995 were analyzed. RESULTS: Twenty-two patients, age 18 years or less, with pediatric primary mediastinal malignancies were identified from a database of 110,284 patients with primary malignancies. During the same period, 197 adult patients with primary mediastinal malignancies were identified. Fifty-nine percent of the pediatric patients were male. Median age was 11 years. Lymphoma was present in 55%, neurogenic malignancies in 23%, malignant germ cell tumors in 18%, and sarcoma in 5%. Neurogenic tumors presented in infants and lymphomas and germ cell tumors presented in teens (p = 0.005). In treated children, surgery was used more often in neurogenic tumors and germ cell tumors than in lymphomas (p = 0.002). Five-year survival was 74% for lymphomas, 67% for neurogenic tumors, 25% for germ cell tumors, and 61% overall (p = 0.23). Compared to adults, children had more neurogenic tumors (p < 0.001) and fewer thymomas (p = 0.0499). There were no significant differences in staging or survival between children and adults. CONCLUSIONS: Pediatric mediastinal malignancies occurred with a frequency of 1/5,013 patients with malignant tumors. Lymphoma, neurogenic tumors, and germ cell tumors predominated. Compared to adults, children had more neurogenic tumors and fewer thymomas. Within the pediatric group, differences were found in age of presentation between histologic groups. These differences between adults and children, and between infants and teens, should be considered when evaluating a patient suspected of having mediastinal malignancy.

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.

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.

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.

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.

Esophageal rupture after regional anesthesia: report of two cases.

Esophageal perforation after anesthesia is rare. It is usually secondary to esophageal instrumentation. Only one case of barogenic rupture after regional anesthesia has been reported. We report two additional cases and present possible mechanisms for this unusual entity. Neither patient had anatomic abnormalities by history or preoperative endoscopy. However, both patients and the previously reported patient had esophageal dysmotility resulting from advanced age, alcoholism, intraoperative medications, and preexisting disease. Each patient experienced at least one episode of emesis with subsequent perforation of the distal one third of the esophagus. The previously reported patient died; both of our patients underwent successful surgical repair and are alive 2 years later. Intraoperative or postoperative emesis in patients with esophageal dysmotility appears to be the principal factor causing esophageal rupture after regional anesthesia. Prevention of nausea and vomiting and recognition of this high-risk population may minimize this complication in the future.

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.

Primary mediastinal malignancies: findings in 219 patients.

The purpose of this study was to determine the demographics, histology, methods of treatment, and survival in primary mediastinal malignancies. We did a retrospective review of the statewide New Mexico Tumor Registry for all malignant tumors treated between January 1, 1973 and December 31, 1995. Benign tumors and cysts of the mediastinum were excluded. Two hundred nineteen patients were identified from a total of 110,284 patients with primary malignancies: 55% of tumors were lymphomas, 16% malignant germ cell tumors, 14% malignant thymomas, 5% sarcomas, 3% malignant neurogenic tumors, and 7% other tumors. There were significant differences in gender between histologies (P < 0.001). Ninety-four percent of germ cell tumors occurred in males, 66% of neurogenic tumors were in females; other tumors occurred in males in 58% of cases. There were also significant differences in ages by histology (P < 0.001). Neurogenic tumors were most common in the first decade, lymphomas and germ cell tumors in the second to fourth decades, and lymphomas and thymomas in patients in their fifth decades and beyond. Stage at presentation (P = 0.001) and treatment (P < 0.001) also differed significantly between histologic groups. Five-year survival was 54% for lymphomas, 51% for malignant germ cell tumors, 49% for malignant thymomas, 33% for sarcomas, 56% for neurogenic tumors, and 51% overall. These survival rates were not statistically different (P > 0.50). Lymphomas, malignant germ cell tumors, and thymomas were the most frequently encountered malignant primary mediastinal neoplasms in this contemporary series of patients. Demographics, stage at presentation, and treatment modality varied significantly by histology. Despite these differences, overall five-year survival was not statistically different.

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.

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.

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.

Successful treatment of adults with severe Hantavirus pulmonary syndrome with extracorporeal membrane oxygenation.

OBJECTIVE: To describe our experience with the use of extracorporeal membrane oxygenation (ECMO) as a rescue therapy in adult patients with severe cardiopulmonary failure from Hantavirus pulmonary syndrome. DESIGN: Case series. SETTING: Tertiary referral center. PATIENTS: Patients with confirmed Hantavirus infection, who developed severe cardiopulmonary failure in which conventional therapy was assessed as being unsuccessful. INTERVENTIONS: Records of previous patients treated for Hantavirus pulmonary syndrome were reviewed and findings consistent with 100% mortality were found. MEASUREMENTS AND MAIN RESULTS: Findings associated with a 100% mortality rate were a) cardiac index of <2.5 L/min/m2; b) serum lactate concentration of >4.0 mmol/L (normal range 0.0 to 2.2); c) pulseless electrical activity or ventricular fibrillation or ventricular tachycardia; and d) refractory shock despite fluid resuscitation, and vasoactive medications. From 1994 to 1996, seven patients were admitted with confirmed Hantavirus pulmonary syndrome and severe cardiopulmonary failure. Three of the seven patients had at least two of the four criteria for a 100% mortality rate listed above, and appeared to be failing optimal conventional therapy. These three patients received support with venoarterial ECMO. The first patient was placed on ECMO during cardiac arrest and died. The next two patients who received ECMO for Hantavirus pulmonary syndrome survived after relatively short, uncomplicated ECMO runs, and were discharged without complications. CONCLUSIONS: ECMO successfully provided cardiopulmonary support in two patients with severe Hantavirus pulmonary syndrome who survived with a good outcome. Our experience suggests that ECMO is a beneficial therapy for patients critically ill with Hantavirus pulmonary syndrome.