A feasibility study into the use of three-dimensional printer modelling in acetabular fracture surgery.

There are a number of challenges associated with the operative treatment of acetabular fractures. The approach used is often extensive, while operative time and perioperative blood loss can also be significant. With the proliferation of 3D printer technology, we present a fast and economical way to aid the operative planning of complex fractures. We used augmented stereoscopic 3D CT reconstructions to allow for an appreciation of the normal 3D anatomy of the pelvis on the fractured side and to use the models for subsequent intraoperative contouring of pelvic reconstruction plates. This leads to a reduction in the associated soft tissue trauma, reduced intraoperative time and blood loss, minimal handling of the plate, and reduced fluoroscopic screening times. We feel that the use of this technology to customize implants, plates, and the operative procedure to a patient's unique anatomy can only lead to improved outcomes.

The differential diagnosis of foot lumps: 101 cases treated surgically in North Glasgow over 4 years.

INTRODUCTION: There are a wide variety of different lesions which present as lumps of the foot. There have been very few studies which look at the presenting characteristics or the differential diagnosis of such lesions. PATIENTS AND METHODS: All patients who underwent excision or biopsy of a foot lump over a period of 4 years were studied in order to determine patient demographics, presenting characteristics, diagnoses encountered and to assess the diagnostic accuracy of the surgeon. RESULTS: In total, 101 patients were identified. Average age was 47.3 years (range, 14-79 years); there was a marked female preponderance with 73 females and 28 males. Thirty different histological types were identified; ganglion cysts were the most commonly encountered lesions and there was only one malignant lesion encountered in this study. Only 58 out of the 101 lumps were correctly diagnosed prior to surgery. Certain lesions were more commonly encountered in specific zones of the foot. CONCLUSIONS: We have shown that there are a wide variety of potential diagnoses which have to be considered when examining a patient with a foot lump. There is a low diagnostic accuracy for foot lumps and, therefore, surgical excision and histological diagnosis should be sought if there is any uncertainty.

Implantable cardioverter defibrillator patch erosion in a heart transplant patient.

A 57-year-old man who had received an automatic implantable cardioverter defibrillator and subsequent orthotopic heart transplant presented to medical attention for hemoptysis. The hemoptysis was caused by the migration of the left ventricular patch of the automatic implantable cardioverter defibrillator, which had been left in place at the time of orthotopic heart transplant. The patch had eroded into the left lung. We recommend that implantable cardioverter defibrillators be removed completely at the time of heart transplantation to prevent subsequent complications.

Concomitant subclavian and coronary artery disease.

BACKGROUND: Proximal subclavian artery occlusive disease in the presence of a patent internal mammary artery used as a conduit for a coronary artery bypass graft procedure may cause reversal of internal mammary artery flow (coronary-subclavian steal) and produce myocardial ischemia. METHODS: We reviewed outcome to determine whether subclavian artery revascularization can provide effective protection from and treatment for coronary-subclavian steal. Between 1985 and 1997, 20 patients had either concomitant subclavian and coronary artery disease diagnosed before operation (group 1, 5 patients) or symptomatic coronary-subclavian steal occurring after a previous coronary artery bypass graft procedure (group 2, 15 patients). Patients in group 1 received direct subclavian artery bypass and a simultaneous coronary artery bypass graft procedure in which the ipsilateral internal mammary artery was used for at least one of the bypass conduits. Patients in group 2 received either extrathoracic subclavian-carotid bypass (5 patients, 33.3%) or percutaneous transluminal angioplasty and stenting (10 patients, 66.7%) as treatment for symptomatic coronary-subclavian steal. RESULTS: All patients were symptom-free after intervention. One patient treated with percutaneous transluminal angioplasty and stenting died of progressive renal failure. Follow-up totaled 58.5 patient-years (mean, 3.1 years/patient). In group 1, primary patency was 100% (mean follow-up, 3.7 years). In group 2, one late recurrence was treated by operative revision, yielding a secondary patency rate of 100% (mean follow-up, 2.9 years). CONCLUSIONS: Subclavian artery revascularization can provide effective protection from and treatment for coronary-subclavian steal with acceptably low operative risk. Midterm follow-up demonstrates good patency.

Cryoablation of incessant ventricular tachycardia: case report and long-term follow-up.

We report the case of a 52-year-old man who had incessant ventricular tachycardia despite treatment with antiarrhythmic agents. Placement of an implantable cardioverter/defibrillator, radiofrequency ablation, and antitachycardia pacing were ineffective. He underwent intraoperative arrhythmia mapping and cryoablation at our institution. Eighteen months later, he remained free of arrhythmia. He was in New York Heart Association functional class II with an ejection fraction of 30%.

Sinus of Valsalva aneurysm or fistula: management and outcome.

BACKGROUND: Few large or long-term series exist regarding the management of patients with sinus of Valsalva aneurysms or fistulas (SVAFs). METHODS: Between 1956 and 1997, 129 patients presented with a ruptured (64 cases; 49.6%) or nonruptured (65 cases; 50.4%) SVAF. The patients included 88 men and 41 women, with a mean age of 39.1 years. Associated findings included a history of endocarditis (42 cases; 32.6%), a bicuspid aortic valve (21 cases; 16.3%), a ventricular septal defect (15 cases; 11.6%), and Marfan's syndrome (12 cases; 9.3%). Operative procedures included simple plication (61 cases; 47.3%), patch repair (52 cases; 40.3%), aortic root replacement (16 cases; 12.4%), and aortic valve replacement/repair (75 cases; 58.1%). RESULTS: There were five in-hospital deaths (3.9%): four due to preexisting sepsis and endocarditis and one that followed dehiscence of the repair in a patient with Marfan's syndrome. Two patients (1.6%) had strokes during the early postoperative period. The survivors were followed up for 661.1 patient-years (5.3 years/patient). The following late complications occurred: prosthetic valve malfunction (5 cases; 3.9%), prosthetic valve endocarditis (3 cases; 2.3%), SVAF recurrence (2 cases; 1.6%), thrombosis (1 case; 0.8%), and anticoagulation-related bleeding (1 case; 0.8%). CONCLUSIONS: Resection and repair of SVAF entails an acceptably low operative risk and yields long-term freedom from symptoms. Early, aggressive treatment is recommended to prevent endocarditis or lesional enlargement, which causes worse symptoms and necessitates more extensive repair.

Right atrial bypass grafting for central venous obstruction associated with dialysis access: another treatment option.

PURPOSE: Central venous obstruction is a common problem in patients with chronic renal failure who undergo maintenance hemodialysis. We studied the use of right atrial bypass grafting in nine cases of central venous obstruction associated with upper extremity venous hypertension. To better understand the options for managing this condition, we discuss the roles of surgery and percutaneous transluminal angioplasty with stent placement. METHODS: All patients had previously undergone placement of bilateral temporary subclavian vein dialysis catheters. Severe arm swelling, graft thrombosis, or graft malfunction developed because of central venous stenosis or obstruction in the absence of alternative access sites. A large-diameter (10 to 16 mm) externally reinforced polytetrafluoroethylene (GoreTex) graft was used to bypass the obstructed vein and was anastomosed to the right atrial appendage. This technique was used to bypass six lesions in the subclavian vein, two lesions at the innominate vein/superior vena caval junction, and one lesion in the distal axillary vein. RESULTS: All patients except one had significant resolution of symptoms without operative mortality. Bypass grafts remained patent, allowing the arteriovenous grafts to provide functional access for 1.5 to 52 months (mean, 15.4 months) after surgery. CONCLUSION: Because no mortality directly resulted from the procedure and the morbidity rate was acceptable, this bypass grafting technique was adequate in maintaining the dialysis access needed by these patients. Because of the magnitude of the procedure, we recommend it only for the occasional patient in whom all other access sites are exhausted and in whom percutaneous dilation and/or stenting has failed.

Concomitant occlusive disease of the coronary arteries and great vessels.

BACKGROUND: Although an increasing number of elderly and high-risk patients, including those with generalized atherosclerosis, are undergoing coronary revascularization, few reports exist regarding the management of patients who have both occlusive disease of the great vessels and coronary artery disease. METHODS: Between 1972 and 1996, 31 consecutive patients (mean age, 56.5 years; 74% men) with multivessel coronary artery disease and symptomatic occlusive disease of the great vessels (25 single-vessel, 80.6%; 6 multiple-vessel, 19.4%) had 40 great vessels reconstructed by transthoracic bypass (n = 17, 42.5%), transthoracic endarterectomy (n = 8, 20%), or extrathoracic bypass (n = 15, 37.5%). All patients had simultaneous coronary artery bypass grafting (mean, 2.6 grafts per patient), and 8 patients had 10 distal carotid bifurcation endarterectomies (6 staged, 4 simultaneous). RESULTS: The early primary patency rate was 100%, and symptoms resolved completely in all 31 patients. There was 1 in-hospital death (3.2%) in a patient who had a respiratory arrest 11 days after operation. Perioperative morbidity included two myocardial infarctions (6.5%) and one opposite-hemisphere, embolic stroke (3.2%). Long-term follow-up of the 30 survivors (167.4 patient-years; mean, 5.6 years per patient) documented 5- and 10-year actuarial survival rates of 88.6% and 60.4%, respectively, with a 100% late brachiocephalic primary patency rate. Ten-year actuarial rates of freedom from the following events were as follows: death, 60.4%; myocardial infarction, 82.5%; stroke, 90.9%; percutaneous transluminal coronary angioplasty or redo coronary artery bypass grafting, 95.2%; and vascular operation or amputation, 78.4%. CONCLUSIONS: Depending on the anatomic distribution of the disease, an integrated approach to great vessel reconstruction that incorporated transthoracic and extrathoracic approaches and techniques of endarterectomy and bypass resulted in few adverse outcomes and excellent long-term patency. Simultaneous revascularization of the great vessels and coronary arteries can produce immediate and long-term, symptom-free outcome with acceptably low operative risk.

Is an integrated approach warranted for concomitant carotid and coronary artery disease?

BACKGROUND: The management of patients with severe, concomitant coronary and carotid artery occlusive disease is controversial. METHODS: Between 1975 and 1996, 512 patients (mean age, 64.9 years; 70% male) were admitted for coronary revascularization; 316 (61.7%) had asymptomatic, severe carotid disease (stenosis > 70%) and 196 (38.3%) had symptomatic carotid disease (159 [31.1%] with transient ischemia and 37 [7.2%] with completed stroke). In group 1, coronary revascularization and carotid endarterectomy were simultaneously performed in 255 patients (49.8%) with unstable angina. In group 2 (staged approach), carotid endarterectomy was performed before coronary revascularization in 257 patients (50.2%) without unstable angina. RESULTS: Before 1986, the incidence of stroke and death was greater in group 1 (n = 149) than in group 2 (n = 156) (14 [9.4%] versus 4 [2.6%]; p < 0.01). Since 1986, outcomes in group 1 (n = 106) and group 2 (n = 101) have been similar for stroke (2 [1.9%] versus 2 [2.0%]), death (4 [3.8%] versus 3 [3.0%]), and myocardial infarction (4 [3.8%] versus 5 [5.0%]). Significant univariate and multivariate predictors of adverse outcome were primarily heart-related (reoperation, intraaortic balloon use, ejection fraction < 0.50, and angina grade 4 for death; age > 70 years and congestive heart failure for stroke). CONCLUSIONS: Despite highly selected populations, contemporary surgical results do not indicate that staged treatment of severe, concomitant coronary and carotid artery occlusive disease has an advantage over simultaneous treatment. Advances in myocardial protection and perioperative hemodynamic management may account for the low incidences of stroke and death in these operations.

Implants in adolescents: a literature review and case reports.

A retrospective review of a limited number of adolescents with implants was conducted to compare the behavior of these implants with studies in which implants had been placed in growing animals. Growth of the facial skeleton is also reviewed. Implants placed in the growing alveolus behave like ankylosed teeth and become submerged as the surrounding bone grows. Cessation of facial growth should occur prior to implant placement in adolescents.

Management of mitral valve stenosis in pregnancy: case presentation and review of the literature.

Severe mitral stenosis is a challenging complication in pregnancy. A case is described in which mitral valve replacement was undertaken immediately following caesarean section at 34 weeks' gestation. A review of the literature discusses the evolution of treatment approaches for mitral stenosis in pregnancy, including open mitral commissurotomy and percutaneous mitral commissurotomy with the use of balloon catheters. With balloon procedures, potential risks to the fetus are minimized because the abdomen and pelvis are shielded. In addition, the use of adjunct transesophageal echocardiography shortens fluoroscopic time. In the case described, neither open nor percutaneous mitral commissurotomy were viable options because of moderate-to-severe mitral regurgitation and a heavily calcified valve. This is one of few such cases reported in the literature to date.

Improved survival after extended bridge to cardiac transplantation.

In the past, left ventricular assist device (LVAD) support was frequently plagued by complications; thus, bridge to transplantation times were kept short. Increasing evidence suggests that extended bridging provides greater benefit due to improved end-organ perfusion and, thus, generally improved physical condition. To assess whether extended bridging translates into improved long-term survival after transplantation, we reviewed our experience with the HeartMate 1000 IP LVAD (Thermo Cardiosystems, Inc, Woburn, MA). Since January 1988, 19 patients (mean age, 45 +/- 9 years) have undergone extended bridging (mean time, 106 +/- 57 days). Their mean weight was 82 +/- 16 kg, and their mean body surface area was 2.0 +/- 0.2 m2. We define "extended" as the length of support necessary for systemic organ recovery after prolonged heart failure. During support, average pump flow indices ranged from 2.3 to 3.3 L.min-1.m-2, and all patients underwent physical rehabilitation. Between the time of LVAD implantation and explantation, the mean serum creatinine value decreased from 1.63 +/- 0.6 to 1.25 +/- 0.6 mg/dL (p = not significant), and the mean serum total bilirubin value decreased from 2.8 +/- 2.0 to 0.63 +/- 0.11 mg/dL (p < 0.05). All but 1 patient improved from New York Heart Association class IV to class I. Device-related complications were minimal. Twelve control patients ("de facto randomized") who did not receive the LVAD also were evaluated: actuarial survival at 1 year was 0% (p < 0.05); 3 (25%) underwent transplantation and died within 2 months; 9 (75%) died before transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunochemical identification of human endothelial cells on the lining of a ventricular assist device.

We are studying the biologic (pseudointimal) lining that forms in the HeartMate (Thermo Cardiosystems, Inc.; Woburn, Massachusetts, USA), a left ventricular assist device with a pusher-plate blood pump, housed in solid titanium with uniquely textured blood-contacting surfaces. Sintered titanium microspheres cover the rigid surface, and integrally textured polyurethane lines the flexing diaphragm. The texture of the blood-contacting surfaces is designed to encourage formation of a biologic pseudointimal lining, which greatly reduces the risk of thromboembolic complications. We performed immunochemical analyses to characterize precisely the pseudointimal lining. Samples were taken from 2 explanted pumps; 1 had supported a patient for 132 days and the other, 189 days. The samples were cultured to detect factor-VIII-related antigen (von Willebrand factor), acetyl low-density lipoprotein receptors, smooth-muscle-cell actin, and surface adhesion molecules specific for monocytes/macrophages. Macrophage cells were predominant in both pumps, but in the 2nd pump, cultures from the center of the diaphragm were positive for acetyl low-density lipoprotein receptor and von Willebrand factor, indicating the presence of endothelial cells. We believe that blood-borne endothelial cells or endothelial cell precursors were deposited on the blood-contacting surfaces, which is an important clinical finding with regard to lowering the risk of thromboembolic complications and reducing the need for systemic anticoagulation in long-term left ventricular assist device patients.

Peripheral organ perfusion augmentation during left ventricular failure. A controlled bovine comparison between the intraaortic balloon pump and the Hemopump.

Despite the use of inotropic therapy and the intraaortic balloon pump (IABP), inadequate peripheral organ perfusion and subsequent multiorgan failure from left ventricular dysfunction is a major cause of death following cardiac surgery. To compare the end-organ perfusion provided by the IABP with that of the recently developed Hemopump Cardiac Assist System, blood flow from visceral organs was measured by ultrasonic flow probes during separate periods of support with each of these pumps. Ten calves underwent coronary artery ligations with beta-receptor blockade; hemodynamic parameters were recorded before the induction of failure, during unsupported cardiac failure, and during Hemopump and IABP support. Improvement in mean cardiac output, mixed venous oxygen saturation, and pulmonary artery wedge pressure was significantly greater (p < 0.05) during Hemopump support than during IABP support. Renal artery flow was significantly greater during Hemopump support (276 +/- 74.2 cc/min) than during IABP support (164 +/- 79.6 cc/min). Hepatic artery flow was significantly greater during Hemopump support (34.7 +/- 25.7 cc/min) than during IABP support (24.4 +/- 18.9 cc/min), and portal vein flow was significantly greater during Hemopump support (1588 +/- 315 cc/min) than IABP support (1259 +/- 310 cc/min). There were no significant differences, however, between carotid artery flow during Hemopump support (292 +/- 171 cc/min) and that during IABP support (317 +/- 204 cc/min). We conclude that renal, hepatic, and mesenteric perfusion provided by the nonpulsatile Hemopump is superior to that of the IABP in this bovine model of left ventricular failure. Therefore, the Hemopump may be more effective in preventing multiorgan failure during recovery of ventricular function.

Improved multiorgan function after prolonged univentricular support.

Eleven cardiac transplant candidates (all male; mean age, 43.3 years) with multiorgan (hepatic, pulmonary, and/or renal) dysfunction were sustained for prolonged periods (> 30 days) with the HeartMate (Thermo Cardiosystems, Inc, Woburn, MA) left ventricular assist device. We evaluated the effect of extended support on end-organ recovery and on the ultimate outcome of cardiac transplantation. In addition to cardiac failure, 9 patients had hepatic dysfunction, 8 had pulmonary dysfunction, and 6 had renal dysfunction (4 of whom required hemodialysis before left ventricular assist device support). Mean duration of support was 115 days (range, 31 to 233 days). All patients underwent successful transplantation; 10 of these patients survived a mean of 24 months. One patient, who had required hemodialysis and ventilatory support during and after support, experienced progressive multiorgan failure and died 7 weeks after transplantation. Two late deaths after transplantation were unrelated to the device. Overall, patients experienced improvement in cardiac functional class status, and most participated in cardiac rehabilitation programs before transplantation. During left ventricular assist device support, hepatic function returned to normal in 8 patients, pulmonary function recovered in 7, and renal function returned to normal in 4. One patient who required hemodialysis underwent renal transplantation after cardiac transplantation and had complete recovery of renal function. In the current era of donor shortages, gravely ill patients can benefit from a strategy of prolonged left ventricular assist device support. This strategy has proved safe, has allowed for reversal of multiorgan dysfunction, and has produced healthier transplant candidates.

Long-term results of the surgical management of symptomatic chronic intestinal ischemia.

We analyzed our surgical experience in 20 patients who underwent revascularization procedures for symptomatic chronic intestinal ischemia caused by atherosclerosis. The group comprised 17 women and 3 men, with an age range of 25 to 71 years (mean 58.6 years). Sixteen patients had postprandial abdominal pain, and 4 had pain not related to eating. The average weight loss was 23.8 lb. Malabsorption and diarrhea were present in 8 patients. The duration of the symptoms was from 4 to 46 months (mean 13.4 months). One patient presented with acute intestinal ischemia following balloon angioplasty reocclusion of a stenotic celiac artery, and 3 underwent surgery for stenosis of a previously placed graft. Five patients had single mesenteric artery involvement, 10 had double-artery involvement, and 5 had significant occlusion in all 3 mesenteric arteries. The major arteries were revascularized whenever technically possible; therefore, 36 arteries were revascularized in 20 patients. Bypass grafts were done in 27 vessels, reimplantation in 7, and endarterectomy with patch angioplasty in 2. The saphenous vein was used in 12 vessels, polytetrafluoroethylene grafts in 8, dacron in 6, and inferior mesenteric vein in 1. The type of revascularization or graft utilized did not affect long-term patency. Two patients had early graft thrombosis and required intestinal resection. All patients survived the operation. At a mean follow-up of 36 months, all 20 patients were alive and asymptomatic with regard to their abdominal complaint. Ten patients (50%) underwent postoperative abdominal angiography; all the grafts were patent.(ABSTRACT TRUNCATED AT 250 WORDS)

Reevaluation of steroid tapering after steroid pulse therapy for heart rejection.

A retrospective analysis was conducted to determine the efficacy and complications resulting from steroid pulse therapy, with or without a steroid taper, in 93 episodes of heart transplant rejection that occurred in 72 patients (58 men, 14 women; mean age, 47.6 years). Each rejection episode was classified according to severity (Texas Heart Institute endomyocardial biopsy scale) and the treatment. Group 1 included 25 episodes of grade 7, 8, 9, or 10 rejection (International Society for Heart Transplantation [ISHT] grade IIIB or IV) that were treated with high-dose methylprednisolone (2.5 to 3.0 gm) and a steroid taper of 1.75 gm over 30 days. Group 2 included 16 episodes of rejection, with the severity of rejection and methylprednisolone pulse therapy being similar to that in group 1, but without a steroid taper. The results of treatment in group 1 were compared with those in group 2. Group 3 included 12 episodes of grade 5, 6, or 7 rejection (ISHT grade IIIA or IIIB) that were treated with moderate-dose methylprednisolone (1.0 to 2.0 gm) and a steroid taper, as described. Group 4 included 40 episodes of rejection, with the severity of rejection and methylprednisolone therapy being similar to that of group 3, but without a steroid taper. The results of treatment in group 3 were compared with those in group 4. No statistically significant differences were found among the groups regarding subsequent episodes of rejection or infection within 3 months of treatment. No statistically significant difference was noted among the groups in the number of rejection episodes requiring additional therapy to control the rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Implantation technique for the HeartMate left ventricular assist device.

The technique for implanting the HeartMate, an intraabdominally placed, pulsatile left ventricular assist device, is described. This device, which has been developed for potential use in patients requiring permanent left ventricular assistance, is currently undergoing clinical investigation in patients requiring temporary support as they await cardiac transplantation. This clinical experience has demonstrated device safety and efficacy, even for patients requiring extended periods of support.

Human intraperitoneal response to a left ventricular assist device with a Ti-6AI-4V alloy surface.

The soft tissue reaction to long-term implantation of an intraperitoneal left ventricular assist device (LVAD) was investigated. The HeartMate 1000 (Thermo Cardiosystems, Inc., Woburn, MA) is a pneumatically driven blood pump with smooth titanium alloy (Ti-6AI-4V) outer surfaces that is placed intraperitoneally in the left upper quadrant and sutured to the anterior abdominal wall. It is being used currently as a bridge to cardiac transplant, which sometimes requires extended support times. We examined the tissue capsule that formed around the rigid circular pump housing of four LVADs (duration of implant: 61, 86, 128, and 153 days) for gross, histologic, immunohistochemical, and ultrastructural analysis. Immunostaining was performed using monoclonal and polyclonal antibodies against cytoskeletal tissue markers (vimentin, desmin, alpha-smooth muscle actin), T and B lymphocytes, carcinoembryonic antigen, factor VIII, and cytokeratins (CAM 5.2 AE1/AE3, 34 beta E12, and 35 beta H11). Direct fluorescent immunolabeling for fibrinogen was also performed to characterize cell and tissue type. Histologic analysis of the 3 to 4 mm thick capsule with white, glistening inner surfaces showed fibrovascular tissue with multipotential subserosal cells (MSCs), capillary endothelium, collagen, and a few mononuclear infiltrates. The immunohistochemical profile of the MSCs differed from myofibroblasts despite a morphologic similarity. Transmission electron microscopy revealed abundant rough endoplasmic reticulum and peripherally arranged myofilaments within the spindle shaped cells. It was hypothesized that capsule formation was initiated by fibrin deposition, followed by proliferation of MSCs and subsequent formation of fibrovascular tissue.(ABSTRACT TRUNCATED AT 250 WORDS)