Dynamic asymmetries in disparity convergence eye movements

Vergence eye movements have traditionally been considered the product of a single neural control center and are usually studied by combining the movements of each eye into a single 'vergence' response. In the present experiment, disparity-driven eye movements were produced by symmetrical step stimuli, and the dynamic properties of each eye movement were analyzed separately. Although the final positions of the two eyes were symmetrical, large dynamic asymmetries often occurred. The timing between the two eyes showed fair synchrony as they attained maximum velocity at approximately the same time. Since the final static positions were symmetrical, asymmetries occurring during the initial dynamic component must necessarily be compensated by offsetting asymmetries in the latter portion of the response.     

New concepts for endoprostheses of the distal radio-ulnar joint

The primary mechanism and most common cause of hemolytic disease in patients with prosthetic heart valves are mechanical trauma to red blood cells and paraprosthetic valvular regurgitation, respectively. Presenting features in patients with this condition include anemia, congestive heart failure, fatigue, jaundice, dark urine, and a regurgitant murmur. Various laboratory studies can be utilized to diagnose hemolytic anemia and to assess the severity of hemolysis. Transthoracic echocardiography, transesophageal echocardiography, and Doppler studies including color Doppler are useful imaging methods to assess valve function. Treatment is usually medical (oral iron); however, in patients with paravalvular regurgitation, surgery is often required to correct the anemia.     

Surgical anatomy of the distal radio-ulnar joint and the ulno-carpal joint compartment

Variations in length ratios of both radius and ulna directly influence the profiles of the distal radioulnar joint. During pronation and supination, joint surface incongruity of the two forearm bones permits rotational and translational movements. The ulnocarpal discuss is the central part of the ulnocarpal complex. Together with radioulnar and ulnocarpal ligaments, the ulnocarpal meniscus, the tendon sheath of the extensor carpi ulnaris muscle, the ulnar collateral ligament, and accessory fiber strands the complex guides movements such as pronation and supination and stabilizes the proximal and distal carpal joint.     

The indications for and techniques and outcomes of ablative procedures of the distal ulna. The Darrach resection, hemiresection, matched resection, and Sauvé-Kapandji procedure

Several ablative procedures exist for the treatment of distal radio-ulnar joint arthritis. This article describes the indications, techniques, pitfalls, and outcomes for the four most popular procedures: Darrach, hemiresection-interposition, Sauvé-Kapandji, and matched ulnar resection. The authors explain their personal algorithm for treatment selection, emphasizing patient requirements versus the physiologic characteristics of each procedure.     

Tetraplegia after a tracheal resection procedure

We describe a 27-year-old patient who was admitted to our hospital for a tracheal stenosis caused by an adenocystic carcinoma. A tracheal resection procedure was performed and the head was fixed to the anterior chest wall by two sutures. Postoperatively he became tetraplegic, from which he completely recovered after the sutures were removed. We think that the decreased blood flow in the arterial spinal artery with flexion of the neck in combination with hypotension was the direct cause of this major complication.     

Coagulation factor abnormalities after the Fontan procedure and its modifications

OBJECTIVE: Recently we reported the prevalence of thromboembolism in patients who underwent the Fontan procedure and its modifications. Although hemodynamic factors may well contribute to thromboembolism, recent evidence suggests that coagulation factor abnormalities may also play a role. We therefore set out to investigate the coagulation status in a group of patients who had undergone the Fontan procedure. METHODS: The study population consists of 20 children who had undergone the Fontan procedure and its modifications. They were examined for coagulation factor abnormalities. Concentrations of serum albumin, total protein, and liver enzymes were also measured. The median age at the time of the operation was 6.2 years (17 months to 8 years) with a male/female ratio of 2.3:1. The median time from the Fontan repair was 4.9 years (18 to 76 months). RESULTS: Protein C (p < 0.001), protein S (p < 0.02), and factor VII (p < 0.001) were significantly lower than the normal range. The changes in serum albumin and total protein and factors II, IX, and X were not significant. CONCLUSIONS: It is possible that deficiency in protein C, protein S, and factor VII partly account for the prevalence of thromboembolism after Fontan-type repairs. The risk of long-term anticoagulation should be weighed against the best palliative procedure for these patients. We suggest that reduced protein C, protein S, and factor VII levels in this group of patients should be regarded as risk factors and that such patients should be treated with anticoagulants.     

The management of acute fractures involving the distal radio-ulnar joint and distal ulna

The acute management of fractures involving the distal radio-ulnar joint and distal ulna is controversial. The primary goal is recognition and differentiation between stable and unstable fracture patterns. Although an operative approach is adopted in the treatment of these injuries, the optimal management protocol awaits good prospective randomized studies.     

Isolated traumatic dorsal dislocation of the distal radio-ulnar joint. Report of seven cases

The authors report seven cases of isolated dorsal dislocations of the distal radio-ulnar joint. Four were recent dislocations and three were old, chronic dislocations. Acute dislocations were treated surgically. An anatomic study on human cadavers enabled us to define the injuries responsible for radio-ulnar dislocations. An electromyographic study of the extensor carpi ulnaris confirmed its role as a dynamic stabilizer of the ulnar head. Two of the three old dislocations were revised after an attempt at ligamentous reconstruction. These patients benefitted from a resection of the ulnar head. The third patient one underwent a Sauve-Kapandji procedure. Cadaver studies underline the fact that ligamentous reconstruction procedures are actually tenodeses.     

Perioperative conduction and rhythm disturbances after the Ross procedure in young patients

BACKGROUND: The Ross procedure is performed for a variety of left ventricular outflow tract diseases in children. The preoperative hemodynamic burden of pressure or volume overload and associated ventricular hypertrophy can predispose to ventricular arrhythmias. Additional procedures performed with the Ross procedure (eg, Konno) may damage the conduction system. METHODS: Between January 1995 and February 1997, the Ross procedure was performed in 42 patients, 31 (74%) of whom had 71 prior interventions. Concomitant procedures (n = 42 in 23 patients) included 17 annular-enlarging procedures. Screening was performed for perioperative conduction and rhythm abnormalities. RESULTS: There was one postoperative death. Perioperative ventricular tachycardia occurred in 12 patients (29%), with 2 receiving antiarrhythmic medication for ventricular tachycardia at discharge. Transient complete heart block occurred in 3 patients, all of whom had concomitant procedures performed in the subaortic area; all patients were discharged in sinus rhythm and no patient received a permanent pacemaker. CONCLUSIONS: The Ross procedure can be performed successfully in children with complex cardiac disease with low mortality and perioperative morbidity. The incidence of perioperative ventricular tachycardia is high (29%), suggesting the need for vigilant perioperative monitoring and long-term surveillance.     

Radiation-induced temporary epilation after a neuroradiologically guided embolization procedure

A 34-year-old woman underwent embolization of a left paraorbital arteriovenous malformation guided with a bi-plane x-ray system in two sessions separated by 3 days. Imaging included 110 minutes of fluoroscopy and 46 digital subtraction angiography acquisitions. Entrance skin dose rates were determined with measurements performed on a skull phantom. The maximum possible skin dose was estimated to be 6.6 Gy, which is consistent with the temporary epilation in the right occipital region of the skull reported by the patient approximately 5 weeks later.     

Portal vein graft rectal evacuation after Whipple procedure. the Fabrizio's disease

In selected cases, pancreatic resections may be performed "en bloc" with arterial and/or venous segments, which have to be replaced with autologous or synthetic grafts. Rectal evacuation of portal vein graft following a Whipple procedure is described, being a late graft infection supposed to underlie this event. Portal vein graft rectal evacuation has not previously been reported in the literature and it is worth keeping it in consideration when performing a regional pancreatectomy.     

Combined therapies for composite graft infection after Bentall's procedure

We present a patient who suffered from composite graft infection and mediastinitis. After replacement of the infected composite graft, in addition to administration of antibiotics, continuous irrigation of the mediastinum with solutions containing povidone-iodine and cefazolin sodium and transposition of the greater omentum were performed. His postoperative course was uneventful. Combined therapies including mediastinal irrigation and omental transposition should be considered after an operation for composite graft infection complicated with mediastinitis.     

Complement activation and cytokine generation after modified Fontan procedure

BACKGROUND: The modified Fontan procedure separates the systemic and pulmonary circulations in patients born with a functional single ventricle. Delayed recovery is frequently observed after this procedure. It was our hypothesis that complement activation or cytokine generation may contribute to the pathophysiology of this problem. METHODS: We measured activated complement C3, thromboxane B2, interleukin-6, and tumor necrosis factor-alpha levels by immunoassay in 16 patients undergoing Fontan procedure. Patient plasma samples were obtained preoperatively, on initiation of cardiopulmonary bypass, after administration of protamine, and 1, 4, 8, and 24 hours postoperatively. RESULTS: There was no early or late mortality in this cohort of patients. Low cardiac output developed in 3 of 16 patients, and pleural effusions developed in 5. The median length of hospital stay was 9 days. Activated complement C3 levels increased from a baseline of 1,486 +/- 564 to 4,600 +/- 454 ng/mL after cardiopulmonary bypass and administration of protamine, and returned to baseline by 24 hours. The level of interleukin-6 increased from 42 +/- 32 to 176 +/- 22 pg/mL and at 24 hours remained elevated at 71 +/- 15 pg/mL. Neither thromboxane B2 nor tumor necrosis factor-alpha levels increased significantly. CONCLUSIONS: The data demonstrate threefold to four-fold increases in activated complement C3 and interleukin-6, indicating that both humoral and cellular systems are affected. It is our conclusion that complement and cytokine activation may contribute to the delayed recovery observed after Fontan procedure.     

Increased pulmonary flow velocities in oversized homografts in patients after the Ross procedure

OBJECTIVE: Between September 1991 and July 1996, 60 patients (mean age 29.8 +/- 9 years; range 5-57) underwent aortic root replacement with pulmonary autograft, a viable biologic and nondegenerating substitute. The pulmonary root was replaced with cryopreserved homografts from cardiac transplant recipients. The aim of this study was to evaluate differences in early valve function of viable and cryopreserved allografts. METHODS: All patients had Doppler echocardiographic examinations preoperatively, at discharge from hospital and 54 patients at 1 year follow-up. We measured aortic and pulmonary peak flow velocities with continuous and pulsed-wave Doppler, and graded aortic and pulmonary insufficiency (AI, PI) with color Doppler flow (grade 0-IV). Intraoperatively, the diameters of the pulmonary root and the pulmonary homograft were measured with standard valve probes and matched to body surface area. RESULTS: Pulmonary peak flow velocity (PVmax) increased significantly from preoperative 0.87 +/- 0.11 m/s to 1.30 +/- 0.34 m/s postoperatively (P < 0.001). The implanted homografts (mean 25.9 +/- 2.4 mm) were larger than their native pulmonary diameter (mean 23.3 +/- 1.8 mm) in all patients. Homograft size matched for body surface area (BSA) did not correlate with increased PVmax. There was a significant increase of PVmax at follow-up (FU) since discharge, also (1.83 +/- 0.53 m/s; P < 0.001). Pulsed-wave Doppler demonstrates that increase of PVmax is located directly at the homograft leaflets and not at the anastomoses. Aortic peak flow velocities (AVmax) were normal postoperatively and at FU (post = 1.35 +/- 0.35 m/s; FU = 1.17 +/- 0.27 m/s). There was no significant change in AI or PI since discharge (AI FU = 0.8 +/- 0.4; PI FU = 0.7 +/- 0.5). Eight patients with fever and symptoms diagnosed as post-pericardiotomy syndrome had significantly higher PVmax at FU (PVmax = 2.41 +/- 0.40 m/s; P < 0.02). CONCLUSIONS: The Ross procedure leads to normal AVmax but significant increase of PVmax even in oversized cryopreserved homografts immediately after surgery. Further increase of PVmax without changes in AVmax in the first year demonstrates that changes in flow velocities are valve related and not due to increase in cardiac output. Further investigations will be necessary to determine whether this observation is due to valve rejection or early leaflet degeneration and treatment with immunosuppressive therapy is warranted.     

Arthroplasty of the forefoot in rheumatoid arthritis: long-term results after Clayton procedure

The present study aims to evaluate long-term results after Clayton resection arthroplasty in patients with symptomatic arthritis of the forefeet. From 1970 to 1995, 109 patients with a total of 184 rheumatoid forefeet underwent Clayton's procedure at an average age of 60 years. Forty-seven of them returned with 82 operated feet for follow-up by means of patient history, physical examination and radiograph an average of 12.8 years later. Overall outcome was judged as successful in 60 of the 82 cases with complete pain relief, remarkably improved gait capacity and use of normal shoes. Sixteen of the feet were definitely improved, but slight to moderate pain, inadequate balance and contact with the ground, limited walking distance and use of large shoes were signs of decreased operation success. The remaining 5 feet showed recurrent splay-foot deformity with intolerable pain, functional disability and restricted gait capacity even though specially made surgical shoes were used. The Clayton procedure appears to be a suitable method for surgical correction of symptomatic rheumatoid forefeet.     

Operative results after the Cox/maze procedure combined with a mitral valve operation

BACKGROUND: There have been few reports on postoperative morbidity and mortality analyses after concomitant mitral valve operation and the Cox/maze procedure. METHODS: Between April 1993 and August 1995, 87 consecutive patients with chronic atrial fibrillation underwent a mitral valve operation and concomitant Cox/maze procedure at Iwate Medical University. The patients were divided into the replacement group (n = 31) and repair group (n = 56) according to the method of mitral valve replacement. Our initial experience with the combined operative procedures is presented along with the operative mortality and morbidity rates. Univariate analysis on preoperative and intraoperative variables affecting early mortality and morbidity is carried out retrospectively. RESULTS: Total cardiopulmonary bypass time in all patients was 177.2 +/- 70.1 minutes. Total aortic cross-clamp time was 121.7 +/- 30.8 minutes. Total intensive care unit stay was 5.3 +/- 7.9 days. The average intubation period was 55.5 +/- 187.6 hours. The intensive care unit stay and the intubation period of the replacement group were longer than those of the repair group. There were four operative deaths among the 87 patients (4.6%). All repair group patients survived operation, whereas 4 replacement group patients died after operation. In all patients, the New York Heart Association functional class was higher (p = 0.028) in those who died than in those who survived. The overall restoration rate from atrial fibrillation was 79.5% (66 of 83 survivors). Seventeen patients (20.5%) had persistent atrial fibrillation postoperatively. Sick sinus syndrome occurred in 7 patients (8.4%). In the repair group, the restoration rate was 76.8%, whereas in the replacement group it was 85.2% for the survivors. CONCLUSIONS: The Cox/maze procedure can be combined with a mitral valve operation with acceptably low operative risk. Analysis of risk factors of early mortality revealed that the type of mitral valve operation (replacement versus repair) and higher preoperative New York Heart Association functional class were associated with mortality. Long-term results from this combined procedure should be clearly demonstrated before its universal acceptance.     

Late conduit occlusion after modified Fontan procedure with classic Glenn shunt

A number of patients with complex congenital heart disease who were initially palliated with a classic Glenn shunt subsequently underwent modified Fontan procedures. This report discusses the operative management of complete occlusion of right atrial-to-right ventricular conduits in patients with patent classic Glenn shunts. The literature is reviewed regarding similar patients, and alternative treatment strategies are discussed.     

Superior mesenteric vein thrombosis after the Whipple procedure: an aggressive, combined treatment approach

It is now recognized that occlusion of the mesenteric veins not only may complicate a number of disease processes but may occur as a life-threatening complication after abdominal surgery. A 32-year-old woman had mesenteric venous thrombosis after resection of a duodenal inflammatory pseudotumour by pancreatoduodenectomy. She recovered fully after treatment, which consisted of thrombectomy, flushing with urokinase and intravenous administration of heparin. Papaverine infused for 4 days substantially improved bowel viability. Current concepts in mesenteric vein occlusion and the principles of clinical management are reviewed.     

Chromosome analysis of single- and multipronucleated human zygotes proceeded after the intracytoplasmic sperm injection procedure

The incidence of amblyopia in the normal population is 2-6%, whereas among patients with congenital ptosis it can be as high as 50%. We reviewed 146 cases of congenital ptosis in patients aged between 5 months and 15 years and compared them to a control group of 34 age- and sex-matched patients. In 78 children (156 eyes) reliable optotype visual acuity could be obtained. Fifty-three eyes (34%) were amblyopic. Ametropia was responsible for 34% and anisometropia for 28.3% of the amblyopia cases. In 25.4% of cases strabismus, and in 11.34% stimulus deprivation, was the reason for the development of amblyopia. Children with congenital ptosis should have retinoscopy done in cycloplegia, and refractive errors should be corrected early. Controlled patching therapy should also be started early. Since stimulus deprivation amblyopia is rare, congenital ptosis need not be corrected early in life.