Preservation of Muscular and Elastic Artery Distensibility After an Intercontinental Cryoconserved Exchange: Theoretical Advances in Arterial Homograft Generation and Utilization

While the situation of tissue donation and transplantation differs between Latin American and European countries, a common problem is tissue deficiency. Hence, at present, there is a pressing need to generate alternatives so as to increase the possibilities of obtaining the requested materials. Consequently, it would be of significant interest to establish an intercontinental network for tissue exchange, to improve international cooperation, and to help patients that need tissue transplantation, and to evaluate the feasibility of using an intercontinental network for the exchange of cryopreserved arteries (cryografts), preserving the arterial distensibility and ensuring a reduced native artery–cryograft biomechanical mismatch. Distensibility was studied in ovine arteries divided into three groups: intact (in vivo tests, conscious animals), fresh control (in vitro tests immediately after the artery excision, Uruguay), and cryografts (in vitro tests of cryopreserved-transported-defrosted arteries, Spain). Histological studies were performed so as to analyze changes in the endothelial layer and elastic components. The comparison between fresh control and cryografts showed that neither the cryopreservation nor the exchange network impaired the distensibility, despite the expected histological changes found in the cryografts. The comparison between intact and cryografts showed that the cryografts would be capable of ensuring a reduced biomechanical mismatch. The cryopreservation and the intercontinental network designed for artery exchange preserved the arterial distensibility. It could be possible to transfer cryografts between Latin America and Europe to be used in cardiovascular surgeries and/or for tissue banking reprocessing, with basic biomechanical properties similar to those of the fresh and/or native arteries.     

Glutathione peroxidase 1 (GPX1) genetic polymorphism, erythrocyte GPX activity, and prostate cancer risk

Glutathione peroxidase 1 (GPX1) is a ubiquitously expressed selenium-dependent enzyme that protects cells against oxidative damage by reducing hydrogen peroxide and a wide range of organic peroxides. Some epidemiological studies have correlated low GPX activity or particular GPX1 polymorphisms with enhanced risk of cancer, although these correlations have not been consistently observed in all populations. Therefore, we conducted the present study to evaluate the possible association of GPX1 Pro198Leu polymorphism and erythrocyte GPX activity with the risk of developing prostate cancer and to clarify whether erythrocyte GPX activity levels were correlated with the GPX1 Pro198Leu genotype in the Macedonian population. The GPX1 Pro198Leu genotype was determined in 82 prostate cancer cases and 123 control individuals. We found an overall protective effect of the variant Leu allele of the GPX1 polymorphism on the prostate cancer risk. Heterozygous carriers of the variant Leu allele had a significantly lower risk of prostate cancer compared with homozygous wild-type individuals (OR, 0.38; 95% CI, 0.20–0.75; P = 0.004). Erythrocyte GPX activity was analyzed in 73 cases and 91 controls. The erythrocyte GPX activity in the cancer group was lower than in the healthy controls. Additionally, we compared the erythrocyte GPX activity in the control group of 90 subjects and found no significant differences by genotype. These findings suggest that individual susceptibility of prostate cancer may be modulated by GPX1 polymorphism and that the combination of genetic factors involved in oxidative response with environmental carcinogens may play an important role in prostate carcinogenesis.     

Establishment of a minimally invasive program at a Veterans' Affairs Medical Center leads to improved care in colorectal cancer patients

Background

Despite significant advantages to patients, less than 5% of all colorectal surgeries for cancer are performed laparoscopically. A minimally invasive colorectal cancer program was created in our Veterans' Affairs hospital with the intent of increasing access and improving quality of patient care while maintaining patient safety and oncologic standards.

Methods

Sixty consecutive laparoscopic colorectal cancer resections and 60 age-matched open resections were identified. Our prospective database was queried for demographic, clinical outcomes, and oncologic data.

Results

Patients undergoing laparoscopic resections experienced a shorter hospital stay and a quicker return of bowel function. Both groups had similar intraoperative blood loss and surgical times. Laparoscopic resections achieved equivalent lymph node retrieval and resection completeness compared with open resections. Laparoscopic resections resulted in fewer wounds and fewer complications requiring reoperation.

Conclusions

Establishment of a minimally invasive colorectal cancer program in a Veterans Affairs Medical Center leads to increased access to laparoscopic colorectal resections and improved patient care while maintaining patient safety.     

Arteriovenous fistula of the superior gluteal artery as a complication of posterior iliac crest bone graft harvesting: 3D-CT angiography and arterial embolization

Superior gluteal artery injuries are rare, but potentially serious complications that occur during posterior iliac crest bone graft harvesting. The authors reported an arteriovenous fistula of the superior gluteal artery, which occurred as a complication during posterior iliac crest bone graft harvesting and was diagnosed with 3D-CT angiography, then treated with arterial embolization.     

Intramuscular myxoma of the cervical paraspinal muscle

Myxoma is a neoplasm of mesenchymal origin composed of undifferentiated stellate cells in a myxoid stroma. This tumor can develop in a variety of locations. Myxomas that arise from skeletal muscles are called intramuscular myxomas. They usually occur in large skeletal muscles. Only ten cases of these benign tumors involving the neck muscles were reported in literature. Of them, only three were located at the paraspinal muscles. A 64-year-old woman presented with occiptal and neck pain over 5 years noted an expansive painful lesion located at posterior cervical region with progressive volume increase in the last 12 months. Image exams revealed a large mass located in the left posterior region of the neck in contact with the C2, C3 and C4 laminae with no invasion of the vertebrea. Tumor total removal was performed through normal muscle margins and the vertebral periosteum was scraped. The tumor was encapsuleted, lobulated with a gray-white appearance. The histological examination yielded the diagnosis of intramuscular myxoma. Follow-up at 1 year showed complete resolution of preoperative symptoms and no evidence of local recurrence. In conclusion, although rare, intramuscular myxoma should be included in differential diagnosis of cervical paraspinal tumors. We reported the fourth case of intramuscular myxoma in the paraspinal musculature of the neck. Despite its benign characteristics, local recurrence was reported after subtotal resection. Tumor total removal should be the goal of surgery.     

High Hospital Volume Is Associated with Better Outcomes for Breast Cancer Surgery: Analysis of 233,247 Patients

Background: The relationship between hospital volume and outcomes needs to be further elucidated for low-risk procedures such as surgical therapy of localized breast cancer. The objective of this investigation was to assess the relationship between hospital volume and outcomes for breast cancer surgery. Methods: A total of 233,247 patients who underwent breast-conserving therapy (BCT) and breast-ablative therapy (BAT) for localized breast cancer were extracted from 13 years (1988–2000) of the Nationwide Inpatient Samples. Hospital volume was classified as low (<30 cases/year), intermediate (≥ 30 to <70cases/year), and high (≥ 70 cases/year). Multiple linear and logistic regression analyses were used to assess the risk-adjusted association between hospital volume and outcomes. Results: In risk-adjusted analyses, patients operated on at low-volume hospitals were 3.04 (p = 0.03) times more likely to die after BCT compared with patients operated on at high-volume hospitals. Similarly, low-volume hospitals had a significantly higher likelihood of postoperative complications (odds ratio [OR] = 1.73, p = 0.01 for BCT; OR = 1.44, p < 0.001 for BAT) compared with high-volume hospitals. Compared with low-volume hospitals, length of hospital stay was significantly shorter and nonroutine patient discharge significantly lower for high-volume providers for both BCT and BAT (all p < 0.001). Patients were also significantly less likely to undergo BCT if operated on in a low- or intermediate-volume hospital compared with a high-volume provider (p < 0.001). Conclusions: High-volume hospitals had significantly lower nonroutine patient discharge, postoperative morbidity and mortality, shorter length of hospital stay, and higher likelihood of performing BCT. Referral of patients with localized breast cancer to high-volume hospitals may be justified.     

Changes in C-reactive protein predict insulin sensitivity in severely obese individuals after weight loss surgery

The production of inflammatory mediators by abdominal adipose tissue may link obesity and insulin resistance. We determined the influence of systemic levels of interleukin-6 and C-reactive protein on insulin sensitivity after weight loss via Roux-en-Y gastric bypass surgery. Severely obese individuals (n 5 15) were evaluated at baseline and at 6 months after surgery. Insulin sensitivity was determined by frequently sampled intravenous glucose tolerance testing at the same time points. Visceral and subcutaneous adipose tissue volumes were quantified by computed tomography. Interleukin-6 and C-reactive protein were measured by enzyme-linked immunoassay in plasma and in adipose tissue biopsies. Correlation analysis was used to determine associations between insulin sensitivity and other outcome variables. Significance was set at P < 0.05. Plasma interleukin-6 concentrations were significantly correlated to the IL-6 content of subcutaneous adipose tissue (r = 0.71). At 6 months postsurgery, subcutaneous and visceral adipose tissue volumes were significantly reduced (34.7% and 44.1%, respectively) and insulin sensitivity had improved by 160.9%. Significant longitudinal correlations were found between insulin sensitivity and plasma C-reactive protein (r = 20.61), but not plasma interleukin-6 at 6 months. These findings offer insights that link obesity and insulin resistance via the activity of inflammatory mediators. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation). Supported by National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Diseases 1R03 DK067167-01A1 (N.G.), the Emory University Research Committee Grant (N.G.), and the National Institutes of Health/National Center for Research Resources General Clinical Research Center Grant M01 RR00039 (N.G., E.L.).     

Molecular absorbent recirculating system for the treatment of acute liver failure in surgical patients

The Molecular Adsorbent Recirculating System (MARS) represents an attractive artificial liver support system for the treatment of liver insufficiency. However, neither indications for MARS treatment (i.e., after extended liver resection) nor criteria for discontinuation of therapy have been evaluated. Therefore, we analyzed the clinical data of all our surgical patients who received MARS treatment for acute liver failure (n = 7). The aim of the study was to identify prognostic indicators for survival. Four of 174 patients resected for hepatic malignancy at our institution received a total of 13 MARS treatments. Two additional patients were successfully bridged to orthotopic liver transplantation with seven MARS treatments and one patient was MARS supported after liver transplantation of a steatotic graft with three MARS treatments. Five of the seven patients survived and were dismissed an average of 31 days, ranging from 17 to 47 days, after the final MARS treatment. No technical complications or adverse effects were observed during the MARS treatments. Important prognostic factors for hepatic recovery and survival were indocyanin green plasma disappearance rates greater than 5%/min and an increase in clotting factor V levels after each MARS treatment. We conclude that MARS therapy can be an effective treatment of postoperative liver insufficiency in the surgical hepatobiliary unit. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation).     

Predictive value of intact parathyroid hormone measurement during surgery for renal hyperparathyroidism

Background and aims In contrast to that in patients with primary hyperparathyroidism, the value of intraoperative intact parathyroid hormone (iPTH) measurement is still unclear in patients with renal hyperparathyroidism and was, therefore, evaluated in a large cohort of patients.Patients Intraoperative iPTH measurement was performed in 153 patients with renal hyperparathyroidism (129 with terminal renal failure and 24 with functioning kidney graft). Subtotal and total parathyroidectomy were performed in 123 and 13 patients, respectively, during initial surgery. In patients with recurrent disease (17), the respective hyperfunctioning tissue was removed. Intraoperative blood samples were obtained by puncture of the internal jugular vein before preparation of the parathyroids (PTH₀) and 15 min after parathyroidectomy (PTH₁₅). iPTH was measured with the Elecsys 2010 system. Postoperative iPTH levels (PTH_post) were determined at postoperative days 1 to 3 and at week 2. Patients were arbitrarily divided in four groups according to the postoperative iPTH values: 0–25 pg/ml (group 1), 26–65 pg/ml (group 2), 66–150 pg/ml (group 3) and more than 150 pg/ml (group 4).Results The mean PTH₀ value was 869±57 pg/ml, which decreased to 167±15 pg/ml at PTH₁₅. The mean relative PTH₁₅ value was 21.6±1.7%. Postoperatively, iPTH decreased to 42±9 pg/ml. The postoperative iPTH value of the 129 patients with terminal renal failure was 25 pg/ml or less in 99 patients, 26–65 pg/ml in 11 patients, 66–150 pg/ml in eight patients and higher than 150 pg/ml in 11 patients. Two successive criteria of iPTH decrease were used: first, a PTH₁₅ of 150 pg/ml or, second, a relative PTH₁₅ of 30% less was used. Fifteen patients did not fulfil both criteria. In 13 of them (86.7%) iPTH_post was higher than 65 pg (true failure to decline). Of 114 patients who fulfilled the criteria, 108 (94.7%) had normal postoperative iPTH values (true decline). Absolute PTH₁₅ values of less than 150 pg/ml predicted normal postoperative iPTH levels in 77 of 78 patients.Conclusion A PTH₁₅ value of 150 pg/ml or less predicts operative success in patients with renal failure in 98.7% of cases, independently of the relative decay. In contrast, if the relative PTH₁₅ is higher than 30%, high postoperative PTH values are predicted with a probability of 86.7%. Although there remain some borderline cases, intraoperative iPTH measurement is accurate and also can be useful in patients with renal hyperparathyroidism.The paper was presented at the first constitutive meeting of the European Society of Endocrine Surgeons (ESES) in Pisa, Italy, on 14–15 May 2004