Pathogenic FBN1 variants in familial thoracic aortic aneurysms and dissections.

Marfan syndrome (MFS) due to mutations in FBN1 is a known cause of thoracic aortic aneurysms and acute aortic dissections (TAAD) associated with pleiotropic manifestations. Genetic predisposition to TAAD can also be inherited in families in the absence of syndromic features, termed familial TAAD (FTAAD), and several causative genes have been identified to date. FBN1 mutations can also be identified in FTAAD families, but the frequency of these mutations has not been established. We performed exome sequencing of 183 FTAAD families and identified pathogenic FBN1 variants in five (2.7%) of these families. We also identified eight additional FBN1 rare variants that could not be unequivocally classified as disease-causing in six families. FBN1 sequencing should be considered in individuals with FTAAD even without significant systemic features of MFS.

Operative outcomes using a side-branched thoracoabdominal aortic graft (STAG) for thoraco-abdominal aortic repair.

BACKGROUND: Pre-manufactured branched grafts now allow an endovascular approach to the repair of thoraco-abdominal aortic aneurysm (TAAA) with visceral vessels' involvement. Similar grafts have been employed in open surgery, generally as a second choice for TAAAs, which are not amenable to patch/inclusion technique for visceral vessel attachment. Results with branched grafts have not been reported in series of open TAAA repairs. The purpose of this report is to describe perioperative risks and outcomes in a consecutive series of patients with pre-manufactured side-branched thoracoabdominal aortic grafts (STAGs) for surgical TAAA repair. METHODS: Between 1996 and 2009, pre-manufactured STAGs were used in 50 patients with TAAA that required reattachment of the visceral and renal arteries. Operative details, perioperative mortality and ischaemic complications were examined. RESULTS: Mean age was 53 years; 18 patients were females. The cases included redo (n = 24), patients affected by genetic disorder (Marfan) (n = 20) and patients with aortic dissection (n = 27). The mean clamp time was 84.1 min. Perioperative mortality was 12.0% (6/50). Neurologic deficits occurred in 2% (1/50). Postoperative renal dysfunction was detected in 19 patients (38%). CONCLUSION: The use of a STAG produced acceptable mortality, bowel and neurological ischaemic risks. Improved strategies to prevent renal ischaemia before and during repair of TAAA with visceral involvement are needed.

Serum myoglobin and renal morbidity and mortality following thoracic and thoraco-abdominal aortic repair: does rhabdomyolysis play a role?

OBJECTIVES: The intractability of renal dysfunction following thoracic and thoraco-abdominal aortic repair leads us to believe that the accepted mechanisms of renal injury - ischaemia and embolism - are incompletely explanatory. We studied postoperative myoglobinaemia and renal dysfunction following aortic surgery. METHODS: Between September 2006 and February 2008, we studied serum myoglobin in 109 patients requiring thoracic/thoraco-abdominal repair for three postoperative days. Forty-two of the 109 (38%) patients were female. The median age was 67 years (range 23-84 years). As we have focussed more attention on renal function, our independent renal consultants have dialysed more aggressively. We divided dialysis into: (1) creatinine indication, (2) non-creatinine indication and (3) no dialysis. RESULTS: Thirteen of the 109 (12%) patients met creatinine indication for dialysis (>4 mg dl(-1)) and an additional 28 (26%) were dialysed for other reasons. Overall mortality was 12 out of 109 (11%) cases: 11 out of 41 (27%) in dialysed patients and one out of 68 (1.5%) in non-dialysed patients. Mortality did not differ between the indications for dialysis. Predictors of mortality were baseline glomerular filtration rate (GFR), postoperative myoglobin and dialysis. The only predictor of dialysis was postoperative myoglobin. CONCLUSION: A strong relationship between postoperative serum myoglobin and renal failure suggests a rhabdomyolysis-like contributing aetiology following thoraco-abdominal aortic repair. We postulate a novel mechanism of renal injury for which mitigation strategies should be developed.

[Acute hematogenous osteomyelitis of the obturator rim in seven children]. / L'ostéomyélite aiguë hématogène du pourtour du foramen obturé chez l'enfant : à propos de sept cas.

PURPOSE OF THE STUDY: Acute osteomyelitis of the rim of the obturator foramen is rarely reported. The clinical presentation is atypical, making diagnosis a difficult task. We report a series of seven cases of osteomyelitis of the obturator rim which illustrate the different features of this localization. MATERIAL AND METHODS: The series included seven boys with osteomyelitis involving the obturator foramen. We reviewed the clinical history, the diagnostic approach and management. Complications and anatomic outcome were noted at mean three years follow-up (range one to 10 years). RESULTS: Mean age was 9.5 years (five to 12 years). Bilateral involvement was noted in one boy. Mean time from symptom onset to consultation was five days and mean time from consultation to hospitalization was eight days. No specific clinical presentation could be identified. Fever was not a constant feature. Mean body temperature was 38.6 degrees C and was not greater than 38.5 degrees C in four children. Symptoms were limited to hip pain in five cases and abdominopelvic pain was noted in two. Physical examination failed to trigger exquisite ischial or pubic pain in two patients. The osteomyelitis involved the ischiopubic ramus in four cases, the ischium in two with one bilateral case, and the pubis in one. Certain diagnosis was established as follows: MRI findings plus isolation of the pathogenic agent (n=4) ; the plain x-ray showed a defect in the ischiopubic ramus, MRI showed signs favoring osteomyelitis of the ischiopubic ramus and surgery evacuated a purulent collection (n=1) ; strong uptake of the obturator rim on scintigraphy (n=2). Medical treatment was given in all cases and surgery was performed in six patients. Outcome was noted at three years follow-up, range one to 10 years. All patients recovered normal function. There were no complications. DISCUSSION: Hematogenous osteomyelitis of the pelvis is exceptional (2-11 % of cases of osteomyelitis). Localization in the obturator rim is rare. We discuss the specific diagnostic and therapeutic features of this localization. Despite the controversy concerning the treatment of pelvic osteomyelitis and in particular cases involving the obturator rim, prognosis is generally good. No complications have been described in the literature specifically associated with osteomyelitis of the obturator rim.

[Acute hematogenous osteomyelitis of the neck of the femur in children: 28 cases]. / L'ostéomyélite aiguë hématogène du col du fémur chez l'enfant : à propos de 28 cas.

PURPOSE OF THE STUDY: Osteomyelitis of the neck of the femur is uncommon, often with a misleading clinical presentation. We report a series of 28 cases of osteomyelitis of the femoral neck to illustrate the particular clinical and imaging findings related to this localization. MATERIAL AND METHODS: This was a series of 28 children treated in our unit from 1990 through 2004: 17 boys and 11 girls, mean age eight years (range one month to 14 years). We analyzed the data in this series using a standard checklist, which noted the diagnostic and therapeutic measures. Results were analyzed by studying the complications, anatomic and functional outcome at mean follow-up of 3.5 years. RESULTS: Time from symptom onset to consultation was five days on average with a delay of 4.5 days from consultation to hospitalization. Intense pain was noted for eight patients (28%) and total functional incapacity of the limb was noted for 15 (53%). Hip stiffness was observed in 11 patients (39%). The diagnosis of osteomyelitis of the femoral neck was established on the basis of imaging (MRI or scintigraphy) in three patients with bacteriological proof in two, of operative findings which confirmed the neck localization in 19, and on changes in the X-ray image of the neck in six. A positive bacteriology was noted in 71%. The germ was isolated from blood cultures and local samples obtained by arthrotomy in five patients (same germ), only in blood cultures for four, and only in local samples in 11. Met-S Staphylococcus aureus was isolated in 18 patients, Met-R S. aureus in one and a Streptococcus in one. All patients were given medical treatment and 25 underwent surgery. There were five thromboembolic complications and five patients who developed femoral pandiaphysitis. Results were analyzed at mean 3.5 years (range four months to 14 years). Complete hip motion was recovered in 78%. There were four cases of hip stiffness and two cases of ankylosis. Partial cephalic necrosis was noted in two hips and total necrosis of the head and neck in two. DISCUSSION: Little data is available in the literature on isolated osteomyelitis of the femoral neck. Based on the pathogenic mechanisms known for osteomyelitis, an isolated localization in the neck of the femur, with no other site in the hip joint, is quite possible in an early stage of infection. We discuss the specific clinical and imaging features of this localization. Analysis of our findings show that the prognosis of femoral neck osteomyelitis is directly related to time to management. Outcome is poorer when treatment is started late. Prognosis is poor if pandiaphysitis develops.

[Hematogenous osteomyelitis of the calcaneus in children: 26 cases]. / L'ostéomyélite hématogène du calcanéum chez l'enfant: à propos de 26 cas.

PURPOSE OF THE STUDY: Osteomyelitis is rarely observed in the calcaneus; about 3 to 10% of the bone infections in children. The diagnosis is often established late because of the less pronounced symptoms in long-bone localizations. We report a series of 26 cases of osteomyelitis of the calcaneus observed in children. MATERIAL AND METHODS: We studied the clinical history, the diagnostic process and the treatments delivered. Outcomes were assessed in terms of complications, anatomy and function at mean two years follow-up (range one to seven years). RESULTS: There were 15 boys and 11 girls, mean age was seven years (range one month to 13 years). Mean time from symptom onset to consultation was 13 days and mean time from consultation to hospital admission was four days, range one to 29 days. The clinical presentation was not specific. Body temperature was not above 38.5 degrees C in 45% of patients. Symptoms were fever, pain in the rear foot and functional impotency of the lower limb. Eight patients (30%) complained of moderate pain, 18 (70%) of intense pain. The pain was focused far from the calcaneus in six patients, retarding the diagnosis. Laboratory tests did not always reveal signs of inflammation. White cell counts above 10,000 were noted in only 61% of patients. The diagnosis of osteomyelitis of the calcaneus was based on: the plain X-ray, which revealed a defect in the calcaneus (n=12), ultrasound (performed in 19 patients) which revealed calcaneal subperiosteal detachment (n=6), collections in the rear foot (n=3) and soft-tissue thickening (n=4). Bone scintigraphy was performed in one child and showed intense uptake in the calcaneus. Magnetic resonance imaging, performed in one patient, demonstrated an anomalous signal in the calcaneus (high-intensity T(2) and low-intensity T(1) with presence of a subperiosteal abscess). Bacteriology was positive in 53% of the children. Medical treatment was delivered for all patients and 23 underwent a surgical procedure. For one of the three patients treated medically, the diagnosis of osteomyelitis of the calcaneus was clinical, since the plain X-ray was normal, the ultrasound yielded no evidence of abscess formation and the bacteriology was negative; but after two months of antibiotic treatment, bone remodelling was in favour of osteomyelitis of the calcaneus. For the two other patients treated medically, the plain X-ray showed a defect in the calcaneus, which had filled after two months of antibiotics. For the 23 patients treated surgically, the procedure was an evacuation of a subperiosteal abscess for 13 (n=6 nonruptured and 7 ruptured). Surgery revealed a bone lesion in nine children allowing curettage of the defect. Articular involvement was noted in eight cases: subtalar osteoarthritis (n=6) and tibiotarsal arthritis (n=2). Two surgical explorations failed to find any abscess formation; blood cultures confirmed the diagnosis and enabled isolation of the causal germ. Outcome was assessed with a mean follow-up of two years, range one to seven years. Nineteen patients (73%) were free of sequelae. Seven patients (27%) presented poor outcome with significant limitation of motion in the rear foot and ankle ankylosis. Seven patients developed chronic fistules, with persistent discharge at last follow-up. The poor results were observed in patients treated late with mean 17 days before consultation. Six of the seven cases of poor outcome were associated with arthritis involving a calcaneal joint (subtalar and tibiotarsal in two patients and subtalar in four). DISCUSSION: The same pathophysiological phenomenon as observed in long-bone localizations is noted for osteomyelitis of the calcaneus; the calcaneus has an apophysis, which is equivalent to the metaphyseal region of long bones, leading to the bone's vulnerability to hematogenous infection. Late diagnosis can be related to the notion of trauma, the manifestations of osteomyelitis being attributed to ligament injury. The positive diagnosis of osteomyelitis of the calcaneus is often established late because of late consultation (13 days in our series) or the minimal expression of general signs. Magnetic resonance imaging contributes significantly to diagnosis by showing an abnormal bone signal; it can also disclose associated abscess formation. Authors differ in their descriptions of the complications. The analysis of our results shows that the prognosis of osteomyelitis of the calcaneus is related to early diagnosis and management. Associated septic arthritis is an element of poor prognosis.

Thoracic aortic aneurysms.

Remarkable progress has been made in the surgical treatment of thoracoabdominal aortic aneurysms. The decline in mortality and complication rates can be attributed to improvements in perioperative care and in surgical technique, particularly the adoption of adjunct distal aortic perfusion and cerebrospinal fluid drainage. Neurologic deficit is no longer a major threat to patients, as the use of adjuncts has brought the incidence down to 2.4% for all thoracoabdominal aortic aneurysms. However, we continue to pursue research to improve organ preservation, particularly for the most troublesome extent II thoracoabdominal aortic aneurysm.

[Fracture of the ulna and bilateral congenital dislocation of the head of the radius: A case report]. / Fracture de l'ulna et luxation congénitale bilatérale de la tête radiale: à propos d'un cas.

We report a case of bilateral congenital dislocation of the radial head discovered at the time of a fracture of the ulna. The dislocation was missed initially and when considered as part of the Monteggia fracture, raised a problem concerning the therapeutic approach. The purpose of this report is the emphasize the importance of careful physical examination before undertaking treatment of any lesion.

Staged repair of extensive aortic aneurysms: morbidity and mortality in the elephant trunk technique.

BACKGROUND: Extensive aortic aneurysms (ascending aorta, aortic arch, and descending or thoracoabdominal aorta) require innovative surgical techniques. Some surgeons advocate a single procedure with long periods of profound hypothermia, whereas others use a staged approach. We adopted a two-staged procedure (elephant trunk technique) in 1991 for elective repair of extensive aortic aneurysms. METHODS AND RESULTS: Between February 1991 and May 2000, we performed a total of 1146 aortic aneurysm operations. Of these, 182 (15.9%) operations were first- or second-stage elephant trunk procedures, performed in a total of 117 patients. Stage 1 was completed in all 117 patients. Stage 2 was completed in 65 (55.6%) of 117 patients. Thirty-day mortality rate for the first stage was 5.1% (6 of 117). Mortality rate during the interval between operations was 3.6% (4 of 111), of which 75% (3 of 4) were the result of aneurysm rupture. Thirty-day mortality rate for the second stage was 6.2% (4 of 65). A total of 43 patients did not return for second-stage repair. Among these patients, within an average period of 3.4 years (range, 1.5 months to 4.9 years), 13 of 43 (30.2%) died, 4 of 13 (30.8%) as the result of rupture. Two of 117 (1.7%) first-stage patients had postoperative stroke. No spinal cord dysfunction occurred in second-stage patients. CONCLUSIONS: Extensive aortic aneurysms can be repaired with acceptable morbidity and mortality rates through the use of the elephant trunk technique. Death was most commonly the result of rupture, both in interval patients awaiting scheduled second-stage repair and in patients who did not return. After the first stage, prompt treatment of the remaining segment is crucial to the success of staged repair.

Pathologic correlates of aortic plaques, thrombi and mobile "aortic debris" imaged in vivo with transesophageal echocardiography.

OBJECTIVES: This study sought to evaluate the pathologic correlates of aortic atheromas, thrombi and mobile "aortic debris" imaged in vivo by transesophageal echocardiography (TEE). BACKGROUND: Atherosclerotic plaques with various complexity, thrombi and debris are frequently identified by TEE during imaging of the aorta. However, pathologic data to characterize these lesions imaged in vivo are lacking. METHODS: Intraoperative TEE was performed prospectively in 31 patients undergoing repair of aortic aneurysm or dissection. TEE was used to guide the surgeon to mark aortic areas of interest that were sent for pathologic examination. A four-point scoring system was used for both TEE and pathologic evaluation to grade the degree of involvement of the aortic wall with atheroma. Ultrasound video intensity of the aortic wall lesions was measured and compared with quantitative measures of wall composition at pathologic examination. The presence of thrombi and mobile aortic debris by TEE was noted and compared with pathologic findings. RESULTS: Histologic-TEE correlations were possible in 62 aortic segments. There was 73% exact agreement between TEE and pathologic grading. Discrepancies were mostly in the inability of TEE to detect superficial ulcerations. However, separation of normal aorta and minimal intimal thickening (grades I and II) from more complex atheromas (grades III and IV) was observed in 93%. For identification of thrombus, TEE had a sensitivity of 91% (29 of 32 segments) and a specificity of 90% (27 of 30 segments). Mobile aortic debris were identified in six aortic segments and were confirmed at pathologic examination to be thrombi. Ultrasound video intensity increased with worsening complexity of atheroma and related significantly to aortic plaque composition at pathologic evaluation (r = 0.80, p < 0.0001). Ultrasound intensity of thrombi and mobile debris was similar and was lower than that of complex atheromas. CONCLUSIONS: Thus, in the evaluation of aortic pathologic segments, TEE can assess aortic plaque complexity and identify thrombus formation, findings that may have important therapeutic implications.

The reduction of dose in paediatric panoramic radiography: the impact of collimator height and programme selection.

OBJECTIVES: The aim of this work was to estimate the doses to radiosensitive organs in the head of a young child undergoing panoramic radiography and to establish the effectiveness of a short collimator in reducing dose. METHODS: Thermoluminescent dosemeters were used in a paediatric head phantom to simulate an examination on a 5-year-old child. The panoramic system used was an Instrumentarium OP200 D (Instrumentarium Dental, Tuusula, Finland). The collimator height options were 110 and 140 mm. Organ doses were measured using exposure programmes intended for use with adult and child size heads. The performance of the automatic exposure control (AEC) system was also assessed. RESULTS: The short collimator reduced the dose to the brain and the eyes by 57% and 41%, respectively. The dose to the submandibular and sublingual glands increased by 32% and 20%, respectively, when using a programme with a narrower focal trough intended for a small jaw. The effective dose measured with the short collimator and paediatric programme was 7.7 µSv. The dose to the lens of the eye was 17 µGy. When used, the AEC system produced some asymmetry in the dose distribution across the head. CONCLUSIONS: Panoramic systems when used to frequently image children should have programmes specifically designed for imaging small heads. There should be a shorter collimator available and programmes that deliver a reduced exposure time and allow reduction of tube current. Programme selection should also provide flexibility for focal trough size, shape and position to match the smaller head size.

Contemporary management of blunt aortic trauma.

Blunt thoracic aortic injury (BTAI) remains a common cause of death following blunt mechanisms of trauma. Among patients who survive to reach hospital care, significant advances in diagnosis and treatment afford previously unattainable survival. The Society for Vascular Surgery (SVS) guidelines provide current best-evidence suggestions for treatment of BTAI. However, several key areas of controversy regarding optimal BTAI care remain. These include the refinement of selection criteria, timing for treatment and the need for long-term follow-up data. In addition, the advent of the Aortic Trauma Foundation (ATF) represents an important development in collaborative research in this field.

Partial cardiopulmonary bypass, hypothermic circulatory arrest, and posterolateral exposure for thoracic aortic aneurysm operation.

Partial cardiopulmonary bypass, profound hypothermia, and circulatory arrest were used in the treatment of 25 patients with thoracic aortic aneurysms exposed through left posterolateral incisions. Indications included aortic clamp laceration (4 patients), pulmonary artery tear (1), treatment of ruptured aneurysm without clamping (5), right-sided arch (2), exposure of proximal aorta in a patient with a large aneurysm (1), inability to expose the proximal aorta for clamping (3), to permit removal of both arch and distal aorta (4), and to avoid distal arch clamping because of atheromatous disease (5). Aortic segments ranging from the upper descending thoracic aorta to most of the aorta were replaced, with early survival in 21 patients. Cerebral protection was satisfactory.

Surgical treatment of aneurysm and/or dissection of the ascending aorta, transverse aortic arch, and ascending aorta and transverse aortic arch. Factors influencing survival in 717 patients.

Ascending aorta and/or aortic arch reconstruction by composite valve graft (281, 39%), separate valve graft (117, 16%), graft only (256, 36%), and other procedures (63, 9%) was used for aneurysm or dissection caused by trauma (6), infection (20), aortitis (46), dissection (261: acute 72, chronic 189), and medial degeneration (384) in 717 patients during the 9-year period between Jan. 11, 1980, and Jan. 16, 1989. Of these, 150 had 173 previous heart or aortic operations and needed reoperation for progression or recurrence of aneurysm, rupture, valvular insufficiency, aortocutaneous or aorta-heart chamber fistulas, great vein or airway obstruction, and infection. Concurrent distal aneurysmal disease was present or developed in 267 (37%) patients, being most prevalent in patients with arch involvement (211/395, 53%). These patients were treated either simultaneously or later. The ages ranged from 10 to 88 years, median 61. Aneurysm symptoms were mild or absent in 593 (83%) and severe in 124 (17%). The 30-day survival rate was 91%. The independent determinants predictive of 30-day death were increasing age, severe aneurysm symptoms, diabetes, previous proximal aortic operation, need for cardiac support, postoperative tracheostomy, postoperative heart dysfunction, and stroke. Of the 319 patients who had none of the four preoperative factors, 308 (97%) survived. Survival decreased to 74% in those with two or more factors. After a total of 1193 operations, the entire aorta was replaced in 53, near total in 35, total thoracic replacement in 78, and total aorta except arch in 27. Late survival rates (Kaplan-Meier) were 66% and 57% at 5 and 7 years. Independent predictors of death were severe aneurysm symptoms, preoperative angina, extent of proximal replacement, associated residual distal aneurysm, balloon pump, renal dysfunction, cardiac dysfunction, and stroke. Five-year survival rates varied with the incidence of the four preoperative variables and age in a single patient: 78% in 413 patients with up to one variables, 57% in 193 patients with two or three, and 39% in 111 patients with three or four (p less than 0.0001).

The impact of distal aortic perfusion and somatosensory evoked potential monitoring on prevention of paraplegia after aortic aneurysm operation.

Temporary distal aortic perfusion and somatosensory evoked potential monitoring were attempted prospectively in 198 patients to prevent neurologic complications from occurring after operation for descending thoracic and thoracoabdominal aortic aneurysm. These 198 patients were divided into two groups. Group 1 consisted of 99 (50%) patients in whom adequate (60 mm Hg) distal bypass was achieved and combined with somatosensory evoked potential monitoring. Group 2 consisted of 99 (50%) in whom this could not be achieved. Of the latter, four patients were excluded because of operative death in one and preexisting neurologic deficits in three. The rates of early and delayed neurologic complications were 8% and 12%, respectively, in the former and 7% and 8%, respectively, in the latter. Using the logistic regression method of statistical analysis, adjusting for the difference in patient mix, we found no statistical difference in the incidence of neurologic complications in the two groups. The incidence of false negative somatosensory evoked potential response was 13% and false positive response 67%. Localization of critical spinal arteries for reattachment was not possible. Thus, the method had no significant impact upon the prevention of neurologic deficits, which varied from mild or transient to severe and which either occurred during the operation or were delayed from 12 hours to 21 days.

Surgery for acute dissection of ascending aorta. Should the arch be included?

Thirty-day and 1-, 5-, 10-, and 20-year overall survivorships among 82 patients undergoing replacement of the ascending aorta with or without the arch for acute aortic dissection between 1968 and May 1989 were 79%, 66%, 56%, 46%, and 30%, respectively. The multivariably determined risk factors for death were the inclusion of the arch in the replacement, the year of the operation, the predissection New York Heart Association functional class, diabetes, and concomitant coronary artery bypass grafting. The current 30-day survivorship predicted by the multivariable equation when the operation involves only the ascending aorta is 97%, and the 10- and 20-year predicted survivorships are 61% and 39%, respectively. When the current era the replacement involves the arch as well as the ascending aorta, the predicted 30-day survivorship is 84%, and the 10- and 20-year ones are 48% and 31%. In 1990 sixteen additional patients (one hospital death) underwent ascending aortic replacement, and six (no hospital deaths) ascending aorta and arch replacement. The predictions for 1990 from the multivariable equation were similar to these actual experiences (Ps for differences were 0.6 and 0.4). Seventy percent of surviving patients with DeBakey type I dissection were free of a second aortic operation for aneurysmal dilation of the distal false channel, but this occurred in none of nine patients in whom an intimal tear in the transverse arch was included in the resection.

Deep hypothermia with circulatory arrest. Determinants of stroke and early mortality in 656 patients.

We have retrospectively evaluated our results after aortic surgery in adults using deep hypothermia with circulatory arrest to determine the patient predictors of early death and postoperative stroke by logistic regression analysis. Of the 656 patients operated on between July 7, 1979, and January 30, 1991, 43% (n = 283) were female, the median age of the patients was 64 years (range 10 to 88 years), 12% (n = 77) had acute dissection, 26% (n = 173) had previously undergone either cardiac or ascending aortic operations, and 13% (n = 85) had a history of cerebrovascular disease. Eighty-four patients underwent elephant trunk procedures. The median circulatory arrest time was 31 minutes (range 7 to 120 minutes). The univariable predictors of transient or permanent stroke, defined as clinical evidence of neurologic injury, either global or hemiparetic, which occurred in 44 patients (7%), were as follows (p < 0.05): increased age; a history of cerebrovascular disease; circulatory arrest time (7 to 29 minutes = 12/298 [4%], 30 to 44 minutes = 15/201 [7.5%], 45 to 59 minutes 9/84 [10.7%], 60 to 120 minutes 7/48 [14.6%]; cardiopulmonary bypass time; and concurrent descending thoracic aorta repair. The multivariably determined predictors were as follows (p < 0.05): a history of cerebrovascular disease; previous aortic surgery distal to the left subclavian artery; and cardiopulmonary bypass time. A history of aortic valve incompetence, however, was associated with a lower risk of stroke (adjusted odds ratio 0.42, p = 0.015). The multivariably determined predictors for increased risk of early death (p < 0.05), which occurred in 66 (10%) patients, were as follows: increased age; Marfan syndrome; concurrent distal aortic aneurysm; previous ascending aortic operation; cardiopulmonary bypass time; cardiac complications; renal complications; and stroke. In this study, the occurrence of stroke was observed to increase after 40 minutes of circulatory arrest; furthermore, the mortality rate increased markedly after 65 minutes of circulatory arrest. Thus the "safe" period for strokes not developing appeared to be limited to approximately 40 minutes. We conclude that deep hypothermia with circulatory arrest is a safe technique for the repair of complex aortic problems provided both the circulatory arrest and the cardiopulmonary bypass times are not excessive. In addition, the clinical characteristics of the patients are important determinants of stroke and death.

Nosocomial transmission of tuberculosis infection in pediatrics wards.

Analysis of restriction fragment length polymorphisms is a well-established method of "DNA fingerprinting" that has been used to trace the transmission of particular strains of Mycobacterium tuberculosis during investigations of outbreaks. This report describe the use of restriction fragment length polymorphisms and arbitrarily primed polymerase chain reaction analysis to investigate two outbreaks of tuberculosis that affected six children who attended two pediatric wards in our hospital. In both outbreaks a history of household exposure to an adult with M. tuberculosis was obtained and suspected tuberculous contacts were identified. We have demonstrated unequivocally the strain relationship among the isolates in all the cases by restriction fragment length polymorphisms and arbitrarily primed polymerase chain reaction analysis. These techniques are very useful for performing epidemiologic studies of tuberculosis in children where natural history of tuberculosis infection is different from that in adults in that it is almost always primary infection rather than reactivation.

External support modulates G protein expression and receptor coupling in experimental vein grafts.

BACKGROUND: Intimal hyperplasia remains the leading cause of vein graft failure. Various external stenting devices have been shown to reduce the development of intimal hyperplasia in vein grafts. Mitogenic and mechanotransduction signals are known to be mediated by G protein-coupled receptors. Therefore in this study we examined the alterations in G protein expression and receptor coupling in vein grafts stented with external tube support. METHODS: Thirty New Zealand White male rabbits had a right carotid interposition bypass graft with use of the ipsilateral jugular vein. Fifteen animals received external support and 15 were controls. In a subset the animals either had removal of the external support or a sham-control neck exploration at 14 days after the initial implantation (n = 5 per group). RESULTS: External support reduced G alpha i3 proteins by 30% in vein grafts without changes in G alpha s by Western blot. Vein grafts with external support were significantly less sensitive to pertussis toxin inactivation than controls were in response to both norepinephrine and serotonin. A 24% decrease in intimal thickness was maintained after withdrawal of the initial external support. CONCLUSIONS: The placement of an external support is associated with alternations in G protein expression and receptor coupling function in vein grafts. The results of this study suggest that the development of vein graft intimal hyperplasia may involve G protein-mediated events.

Spinal cord protection in descending thoracic and thoracoabdominal aortic repair.

BACKGROUND: During simple cross-clamp repair of the descending thoracic or thoracoabdominal aorta, the likelihood of neurologic complications increases greatly after only 30 minutes of spinal cord ischemia. At greatest risk are patients with type II thoracoabdominal aortic aneurysms. METHODS: We reviewed our experience of simple cross-clamp repair and procedures accompanied by adjuncts, paying particular attention to the outcome of patients who had type II thoracoabdominal aortic aneurysms. Between February 1991 and March 1998, 508 patients had descending thoracic and thoracoabdominal aortic repair, 255 (50.2%) of whom received the adjuncts of cerebrospinal fluid drainage and distal aortic perfusion. RESULTS: Fifteen patients died on the day of operation and could not be evaluated for neurologic deficit. The overall incidence of neurologic deficit was 33 of 493 patients (6.7%). In patients who received adjuncts, neurologic deficit occurred in 9 of 247 (3.6%) overall; in types I and II it was 8 of 164 (4.9%), and in type II alone, 7 of 87 (8.1%). Neurologic deficit in simple cross-clamp patients was 24 of 246 (9.8%) overall; in types I and II it was 15 of 99 (15.2%), and in type II alone, 13 of 44 (29.6%). CONCLUSIONS: With the surgical adjuncts of cerebrospinal fluid drainage and distal aortic perfusion, the probability of neurologic deficit is lowered appreciably.