Cardiac valvular surgery in dialysis patients: comparison of surgical outcome for mechanical versus bioprosthetic valves

Purpose  There has been a changing preference for bioprosthetic valves over mechanical valves in dialysis patients, but there is still much controversy. We reviewed our 17-year experience and assessed the influence of prosthesis choice. Methods  From 1990 to 2007, a total of 63 consecutive dialysis patients who underwent valvular surgery (64 operations including one reoperation) at our hospital were retrospectively reviewed. The mean age of the patients was 58.3 ± 9.0 years. The reasons for dialysis were glomerulonephritis (n = 32) and diabetes (n = 10). The major preoperative diagnosis was aortic stenosis (n = 44). The surgical procedures included aortic valve replacement (n = 44), mitral valve replacement (n = 7), double valvular replacement (n = 7), and mitral valve repair (n = 5). Prostheses for valve replacement were mechanical valves (n = 37) or bioprosthetic valves (n = 22). Follow-up was accomplished in 95.2%, and the mean follow-up period was 49 months. Results  Actuarial survivals at 1, 5, and 10 years were 85%, 64%, and 45% respectively. Freedom from cardiovascular events at 1 and 5 years was 61% and 41%, respectively. Mechanical valve patients had significantly higher early mortality than bioprosthetic valve patients (P = 0.03). However, both mechanical and bioprosthetic valve patients had similar survival and event-free rates (P = 0.87 and P = 0.27, respectively) in the midterm results. The mechanical group had a higher rate of bleeding events. There was no structural valve deterioration up to the 5-year follow-up. Conclusion  The choice of prosthesis did not influence the surgical outcome except for early mortality. Careful consideration of preventive measures against bleeding is important, and prosthesis selection should be based on the patient’s profile as well as the criteria for nondialysis patients.     

Accumulation of Excess Visceral Fat Is a Risk Factor for Pancreatic Fistula Formation After Total Gastrectomy

Background  The effect of obesity on gastrectomy in patients with gastric cancer is controversial. The degree of abdominal fat increases the technical difficulty of abdominal surgery. This study examined the effect of visceral fat on total gastrectomy and risk factors associated with the formation of pancreatic fistula. Methods  Between February 2001 and April 2007, 191 patients with gastric cancer underwent total gastrectomy. The visceral fat area (VFA) was calculated from computed tomography (CT) scans taken at the level of the umbilicus using FatScan Software. Patients were divided into high- (≥100 cm², n = 52) and low-VFA groups (<100 cm², n = 139), and also into high- (≥25 kg/m², n = 47) and low-BMI groups (<25 kg/m², n = 144). Results  Blood loss and incidence of pancreatic fistula were significantly higher in the high- than low-VFA group. However, only blood loss was significantly different between the high- and low-BMI groups. VFA, blood loss, and splenectomy were identified as significant risk factors for pancreatic fistula formation on univariate analysis, and multivariate logistic regression analysis of these factors identified VFA (p = 0.0001) and splenectomy (p = 0.0014) as significant predictors of pancreatic fistula. Conclusions  VFA is a better indicator for pancreatic fistula formation after total gastrectomy than is BMI. Lymph node dissection must be performed carefully, especially in patients with visceral fat accumulation during total gastrectomy with splenectomy.     

Tethered cord syndrome in identical twins

Summary  The diagnosis of tethered cord syndrome (TCS) without typical conus medullaris symptoms and the radiological features such as a low set conus medullaris or dysraphic malformation is difficult. We report 11 year old identical twin brothers with TCS associated with the conus at the normal level. Their presenting symptom was progressive leg pain and both patients underwent surgical interruption of the filum terminale. The pain recurred in one patient treated surgically only after symptom became worse but resolved immediately in the other sibling treated promptly. We indicate the importance of early diagnosis and treatment of TCS to obtain excellent long-term outcome despite the absence of a low set conus or specific symptoms. Furthermore, when a twin or sibling of an affected person has neurological symptoms and the cutaneous signature of spinal dysraphism, radiological examination should be performed to establish the cause.     

Dickkopf-1 Expression as a Marker for Predicting Clinical Outcome in Esophageal Squamous Cell Carcinoma

Background and Objectives  Dickkopf-1 (DKK1) is the inhibitor of the canonical Wnt signaling pathway, however it is highly transactivated in various cancers, suggesting the presence of unknown mechanism. Its implication in human esophageal squamous cell carcinoma (ESCC) has not been sufficiently investigated. Patients and Methods  We evaluated DKK1 protein expression in resected specimens from 170 patients with ESCC by immunohistochemistry. Tumors were categorized as positive or negative for DKK1. The relationships between DKK1 expression in ESCC and various clinicopathological parameters and prognosis (disease-free survival; DFS) were analyzed separately. Results  Immunohistochemically, 72 (42.4%) tumors were DKK1 positive while no significant staining was observed in the normal squamous epithelium except for few basal cells. There was no significant relationship between DKK1 expression in ESCC and any of the clinicopathological parameters tested in this study. Patients with DKK1-positive tumors had poorer DFS than those with negative ESCC (5-year DFS; 31.5% versus 53.6%, P = 0.0062). Univariate analysis showed a significant relationship between pT [hazard ratio (HR) = 2.944, 95% confidence interval (CI) = 1.713–5.059, P < 0.0001], number of pN (HR = 2.836, 95% CI = 1.866–4.309, P < 0.0001), lymphatic invasion (HR = 2.892, 95% CI = 1.336–6.262, P = 0.0070), and DKK1 expression (HR = 1.763, 95% CI = 1.167–2.663, P = 0.0071) and DFS. Multivariate analysis including the above four parameters identified pT (HR = 2.053, 95% CI = 1.157–3.645, P = 0.0140), pN number (HR = 2.107, 95% CI = 1.362–3.260, P = 0.0008), and DKK1 expression (HR = 1.813, 95% CI = 1.195–2.751, P = 0.0052) as independent and significant prognostic factors for DFS. Conclusion  Our data suggest the usefulness of DKK1 as a novel predictor of poor prognosis of patients with ESCC after curative resection and also as a therapeutic target for future tailored therapies against ESCC.     

Surgical treatment of thoracic aortic aneurysm in patients with concomitant coronary artery disease

Objective: Surgical treatment of thoracic aortic surgery in patients with coronary artery disease was investigated. Methods: Between 1990 and April 2003, 330 patients underwent elective thoracic aortic surgery. Fifty-six patients who underwent aortic root reconstruction were excluded and 274 patients were examined. Fifty-four (20%) patients showed concomitant coronary artery disease. Ten had undergone coronary revascularization previously; and 3 underwent coronary revascularization [2 coronary artery bypass grafting (CABG), 1 percutaneous transluminal coronary angioplasty (PTCA)] before aortic surgery. Twenty-three patients underwent elective CABG simultaneously and 2 patients had additional coronary artery bypass because of cardiac ischemia during operation. The number of patients who underwent thoracic aortic surgery including Asc Ao+AVR was 2, hemi arch 1, total arch 15, distal arch 5, distal arch+LV aneurysmectomy 1, and thoracoabdominal Ao 1. Two patients underwent coronary revascularization with arterial grafts and the others with SVG grafts. Results: There was one hospital death (4%). In patients without coronary bypass, 2 patients suffered cardiac ischemic events. Conclusion: Our thoracic aortic operations with concomitant CABG using SVG were overall successful. Our current strategies for thoracic aortic surgery in patients with concomitant coronary artery disease include conducting a dipyridamole myocardial perfusion-imaging test first in patients not at risk of coronary artery disease, and if the test is positive, coronary angiography is performed and aggressive coronary revascularization is conducted where possible.     

Decreased body mass index as an independent risk factor for developing chronic kidney disease

BACKGROUND: Obesity and metabolic syndrome are risk factors for the development of chronic kidney disease (CKD). Few studies have examined the effect of change in body mass index (DeltaBMI) on CKD incidence in a general screening setting. METHODS: Subjects of this study were screenees that participated in the screening program of the Okinawa General Health Maintenance Association in 1993 and 2003 in Okinawa, Japan. Using identification number, birth date, sex, and other recorded identifiers, we identified 33,389 subjects among the 1993 screening participants (N = 143,948) who also participated in the 2003 screening. CKD was defined as estimated glomerular filtration rate <60 ml/min/1.73 m(2), according to the modification of diet in renal disease study equation. Obesity was defined as BMI > or = 25 kg/m(2). RESULTS: CKD prevalence was 13.8% in 1993 and 22.4% in 2003. The incidence of developing CKD in 10 years was 15.5%. The effect of DeltaBMI on CKD incidence was evaluated after considering other confounding factors such as age, sex, blood pressure, BMI, fasting plasma glucose, and proteinuria. Median DeltaBMI was 1.0%. The adjusted odds ratio (95% CI) for the effect of DeltaBMI on CKD incidence was 1.111 (1.026-1.204, P < 0.01; entire study population), 1.271 (1.116-1.448, P = 0.0030; men), and 1.030 (0.931-1.139, NS; women), when DeltaBMI > or = 1% was taken as a reference. DeltaBMI was an independent predictor of CKD incidence. CONCLUSIONS: The present results suggest that there was an inverse relationship between DeltaBMI and CKD incidence among screened subjects. The reasons for this observation are not clear, but careful follow-up for DeltaBMI is necessary, particularly in obese men with proteinuria.     

Surgical treatment of lumbar ossification of the posterior longitudinal ligament. Report of two cases and description of surgical technique

The authors report two cases of patients with lumbar ossification of the posterior longitudinal ligament (OPLL). One patient underwent surgery via the single posterior approach, and the other patient underwent combined anterior-posterior surgery. The authors consider the anterior approach for excision of the ossified lesion to be the most reasonable for treatment of lumbar OPLL. It is extremely important, however, to select the surgical procedure according to the individual patient's condition.     

Prognostic factors in patients with ipsilateral pulmonary metastasis from non-small cell lung cancer.

OBJECTIVE: Pulmonary metastasis of non-small cell lung cancer is classified as an advanced disease stage, with limited indications for surgical treatment. However, the prognosis of patients with pulmonary metastasis of non-small cell lung cancer is better than that of patients with distant metastases. The purpose of the present study was to analyze and detect possible prognostic factors in surgically treated patients with ipsilateral pulmonary metastasis of non-small cell lung cancer. METHODS: Among 1198 patients with non-small cell lung cancer who underwent surgery at Kurashiki Central Hospital (Okayama, Japan) from April 1982 to March 2004, a total of 48 (4.0%) patients with pathologically diagnosed ipsilateral pulmonary metastasis were retrospectively evaluated. The median follow-up time was 20.5 months (range 1-103 months) and 37 patients (77.1%) were completely followed up until their death or more than 5 years after the operation. RESULTS: Among the 48 patients, 31 (64.6%) patients had metastatic nodules in the same lobe as the primary tumor (PM1) and 17 (35.4%) patients had metastatic nodules in different ipsilateral lobes (PM2). There was no significant difference in survival between patients with PM1 and the other patients with pT4-stage IIIB, or between patients with ipsilateral PM2 and the other patients with stage IV. Univariate analysis of postoperative survival stratified according to clinicopathologic factors revealed significant differences for the radicality of resection (complete vs. incomplete), tumor size (0-30 vs. >30mm) and pathological nodal (pN) factor (among pN0, pN1 and pN2-3). Multivariate analysis revealed that tumor size (0-30 vs. >30mm) and pN factor (pN0-1 vs. pN2-3) were independent prognostic factors. CONCLUSIONS: The results of our study suggest that undergoing a complete resection, having a tumor size of 30mm or less and having no mediastinal lymph node metastases were better prognostic factors for surgically treated patients with ipsilateral pulmonary metastasis of non-small cell lung cancer.     

Living donor liver transplantation for biliary atresia complicated by situs inversus: technical highlights.

Living-donor liver transplantation (LDLT) has become an established technique to treat children with end-stage liver disease. Biliary atresia (BA), one of the most common indications for liver transplantation in children, can be associated with situs inversus (SI). In the past, the presence of SI has been considered to be an absolute contraindication for liver transplantation because of the technical difficulties. Recently, some reports of successful diseased-donor liver transplantation in patients with BA complicated by SI have been published; however, few reports of that with LDLT exist. The technical difficulties involved with LDLT for such cases have not been described. Herein, we present 4 successful cases of LDLT for BA with SI. Complex anomalies associated with SI, such as a hepatic artery arising from the supraceliac aorta, a preduodenal portal vein, and absence of the retrohepatic inferior vena cava, increase the technical difficulties involved with the operation. Additional caution is required in LDLT because a living-donor graft has short vessels and the availability of vascular grafts from the donor is limited. In conclusion, LDLT for BA complicated by SI can be managed successfully with technical modifications and scrupulous attention. This series represents the largest reported group of patients with BA complicated by SI who underwent a successful LDLT procedure.     

Flexion Model Simulating Spinal Cord Injury Without Radiographic Abnormality in Patients With Ossification of the Longitudinal Ligament: The Influence of Flexion Speed on the Cervical Spine

Background/Objective:

It is suspected that the speed of the motion of the spinal cord under static compression may be the cause of spinal cord injury (SCI). However, little is known about the relationship between the speed of the motion of the spinal cord and its stress distributions. The objective was to carry out a biomechanical study of SCI in patients with ossification of the longitudinal ligament without radiologic evidence of injury.

Methods:

A 3-dimensional finite element spinal cord model was established. After the application of static compression, the model underwent anterior flexion to simulate SCI in ossification of the longitudinal ligament patients without radiologic abnormality. Flexion of the spine was assumed to occur at 1 motor segment. Flexion angle was 5°, and flexion speeds were 0.5°/s, 5°/s, and 50°/s. Stress distributions inside of the spinal cord were evaluated.

Results:

Stresses on the spinal cord increased slightly after the application of 5° of flexion at a speed of 0.5°/s. Stresses became much higher at a speed of 5°/s and increased further at 50°s.

Conclusions:

The stress distribution of the spinal cord under static compression increased with faster flexion speed of the spinal cord. High-speed motion of the spinal cord under static compression may be one of the causes of SCI in the absence of radiologic abnormality.