Management of a catecholamine-secreting paraganglioma requiring aortic reconstruction

INTRODUCTION

Retroperitoneal paragangliomas are rare extraadrenal pheochromocytomas that can involve major vascular structures.

RESULTS AND DISCUSSION

A case of periaortic catecholamine-secreting paraganglioma was reviewed and literature search performed to summarize the current surgical management of this disease process.

CONCLUSION

Resection for cure of retroperitoneal paragangliomas with vascular reconstruction can be performed with acceptable morbidity and mortality with the use of current vascular techniques.

Inferior vena cava aneurysm

Aneurysms of the inferior vena cava (IVC) are exceedingly rare; less than 50 cases have been reported in the world literature. Owing to the paucity of data regarding the natural history of IVC aneurysms, there is no consensus on their treatment. This case report describes the evaluation of an IVC aneurysm in a 56-year-old male, briefly discusses the embryologic development of the IVC, and revisits the question of whether surgical intervention is indicated in these patients.

Laparotomy for Visceral Ischemia and Gangrene

In the six centuries since mesenteric ischemia was first described, multiple factors have been investigated as predictors of bowel viability with little consensus. We retrospectively examined all cases of exploratory laparotomy for suspected bowel ischemia over an 8.5-year period. Patients were grouped into those who had a “positive laparotomy” with findings of bowel ischemia, bowel gangrene, or both (PL) and those who had a “negative laparotomy” with no evidence of compromised bowel (NL). Of the 114 patients, 86 (75%) were in the PL group and 28 (25%) in the NL group. The significant differences between the two groups were the higher prevalence of females in the PL group versus the NL group [71% vs 50% ( P = 0.04)] and the younger age in the NL group versus the PL group [64 ± 19 vs 76 ± 14 ( P = 0.0002)]. The groups did not significantly differ with respect to preoperative comorbidities and results of laboratory studies. Two patients in NL group had pneumatosis intestinalis on abdominal CT. One patient in PL group had a negative visceral angiogram. There was no difference in mortality between the groups. No single preoperative study reliably predicted positive findings at laparotomy in our series.

Laparotomy for visceral ischemia and gangrene

In the six centuries since mesenteric ischemia was first described, multiple factors have been investigated as predictors of bowel viability with little consensus. We retrospectively examined all cases of exploratory laparotomy for suspected bowel ischemia over an 8.5-year period. Patients were grouped into those who had a "positive laparotomy" with findings of bowel ischemia, bowel gangrene, or both (PL) and those who had a "negative laparotomy" with no evidence of compromised bowel (NL). Of the 114 patients, 86 (75%) were in the PL group and 28 (25%) in the NL group. The significant differences between the two groups were the higher prevalence of females in the PL group versus the NL group [71% vs. 50% (P = 0.04)] and the younger age in the NL group versus the PL group [64 +/- 19 vs. 76 +/- 14 (P = 0.0002)]. The groups did not significantly differ with respect to preoperative comorbidities and results of laboratory studies. Two patients in NL group had pneumatosis intestinalis on abdominal CT. One patient in PL group had a negative visceral angiogram. There was no difference in mortality between the groups. No single preoperative study reliably predicted positive findings at laparotomy in our series.

Transposed Arteriovenous Fistulae: Do the Results Justify the Effort?

Transposed arteriovenous fistulae have been utilized in clinical scenarios where simple arteriovenous fistulae have failed or their construction was not possible for anatomical reasons. Despite variability in published reports, transposed arteriovenous fistulae have acceptable patency rates and outperform prosthetic arteriovenous grafts in patency, frequency of intervention to maintain patency, and complication rates.

Evaluation of the efficacy of the transposed upper arm arteriovenous fistula: A single institutional review of 190 basilic and cephalic vein transposition procedures

INTRODUCTION

Although autogenous brachial-basilic upper arm transpositions (BVT) have been extensively utilized, there has been significant disparity in published patency rates. Very little is known about the efficacy of autogenous brachial-cephalic upper arm transpositions (CVT). We evaluated our experience with transposed upper arm arteriovenous fistulas (tAVF) in order to assess patency and identify factors that affect efficacy. We then compared our tAVF patients with a cohort of upper arm arteriovenous grafts (AVG).

METHODS

A retrospective review was conducted of tAVF performed at our institution from 1998 to 2004. The tAVF group consisted of 119 BVT and 71 CVT procedures. We compared these with 164 AVG. tAVF were placed only for veins >/=2.5 mm in diameter by duplex ultrasonography.

RESULTS

Mean follow-up was 28 months. With the exception of mean vein diameter, the patients in the BVT and CVT groups had similar demographic parameters and complication rates. Primary and secondary patency rates were 52% and 62% at 5 years for BVT and 40% and 46% at 5 years for CVT, respectively (P = NS). Multivariate analysis revealed that hemodialysis dependence at the time of fistula placement and history of previous upper arm access independently affected primary patency. History of upper torso dialysis catheters independently affected secondary patency. Comparison of the tAVF and AVG groups revealed that tAVF patients were significantly younger, more likely to be male, less likely to be African American (AA) and less likely to have a history of previous AV access. The primary patency rate for tAVF was significantly higher than for AVG: 48% vs 14% at 5 years (P < .001). The secondary patency rate for tAVF was also significantly higher than for AVG: 57% vs 17% at 5 years (P < .001). Among the tAVF procedures, 9% required one or more revisions to maintain secondary patency, compared to 51% with the AVG group (P < .001). Multivariate analysis revealed that presence of AVG and a history of previous upper arm access negatively affected primary and secondary patency.

CONCLUSIONS

Autogenous BVT and CVT have similar, high patency rates. Transposed upper arm arteriovenous fistulas have higher patency rates than upper arm AVG and require significantly fewer revisions. Our data strongly support the contention that as long as the patient is a candidate for an upper arm tAVF, based on anatomical criteria, a tAVF should always be considered before an AVG.

Concordant F-18 FDG PET and Y-90 Bremsstrahlung scans depict selective delivery of Y-90-microspheres to liver tumors: confirmation with histopathology

Selective Internal Radiation Therapy using yttrium-90 (Y-90) microspheres is a novel method for the treatment of advanced liver cancer. The procedure involves intrahepatic arterial delivery of the Y-90 microspheres. Since hepatic tumors derive their blood supply mainly from the hepatic arteries, it is assumed that the microspheres will be preferentially delivered to tumor cells. However, this has not been confirmed at histology. We report a case of hepatic metastasis from an unknown primary, where treatment with Y-90 microspheres was the only available option due to inoperability and low tolerance to chemotherapy. Pretherapy F-18 FDG-PET scan defined the distribution of the active tumor within the liver. Following the injection of Y-90 microspheres, Bremsstrahlung imaging showed uptake only in the F-18 FDG-PET-defined tumor area. Post therapy debulking surgery was performed and histopathology of tumor samples confirmed the preferential distribution of the injected microspheres in the hepatic tumor circulation with very little in the healthy liver tissue. The case confirms the preferential blood flow to hepatic tumors as depicted by the distribution of Y-90 microspheres injected directly in the hepatic arteries. It also demonstrates that concordance between F-18 FDG-PET and Y-90 Bremsstrahlung scans can be a useful clue to the in vivo distribution of microspheres.

Clinical and imaging experience with yttrium-90 microspheres in the management of unresectable liver tumours

INTRODUCTION

Selective internal radiation therapy (SIRT) is emerging as a new therapeutic modality in recent years for management of non-resectable hepatic malignancies. Our experience in clinical application of this treatment is reported here.

MATERIAL AND METHODS

From June 2004, patients whose liver tumours were no longer amenable for any conventional treatment with either chemotherapy or surgery were considered for yttrium-90 microspheres treatment after discussion at our multidisciplinary meeting. A pre-treatment planning was carried out with visceral angiography and technetium-99m macroaggregated albumin (MAA) for assessment of both tumour volume and extrahepatic shunting in addition to a baseline PET and CT scans, respectively. Two weeks later, a second visceral angiogram was performed to deliver the calculated dosage of microspheres into the arterial system supplying the tumour. Patients were then followed up with tumour markers, repeat PET and CT scans of abdomen at 6 weeks and 3 monthly thereafter.

RESULT

Twenty-one patients (F=11, M=10; age range 40-75 years, mean=58 years) received yttrium-90 microspheres consisting of liver metastases from colorectal primary (n=10) and non-colorectal primaries (n=8), and primary liver tumours (n=3). One patient received 2 treatments. The mean administered activity of microspheres delivered was 1.9 GBq (range 1.2-2.5 GBq). Injection of microspheres had no immediate effect on either clinical haematology or liver function tests. At follow-up, 86% of patients showed decreased activity on PET scan at 6 weeks (p=0.01). The mean pre-treatment SUV was 12.2+/-3.7 and the mean post-treatment SUV was 9.3+/-3.7, indicating a significant improvement measured with PET activity. Only 13% showed a reduction in the size of tumour on CT scan. For patients with colorectal liver metastases, there was no significant reduction in CEA level (127+/-115 vs 75+/-72 micro/l, p=0.39). Complications were seen in 4 patients (19%) including radiation hepatitis (n=2), cholecystitis (n=1) and duodenal ulceration (n=1). All resolved without surgical intervention. Seven patients died at follow-up from progressive extrahepatic disease (33%).

CONCLUSION

SIRT should be considered for patients with advanced liver cancer. It has a significant effect on liver disease in the absence of extrahepatic disease. PET imaging has an integral role in the assessment of patients treated with yttrium-90 SIR-Spheres.

Trapped electromagnetic modes and scaling in the transmittance of perforated metal films

We describe measurements and simulations of the enhanced transmittance by subwavelength hole arrays in silver films. The array period and hole size are systematically varied to give peak transmittances at wavelengths spanning a factor of 14. The spectra coincide when scaled using the array geometry and substrate refractive index alone, thus showing no significant dependence on the dielectric function of the metal. We argue that the spectra can be explained by interference of diffractive and resonant scattering. The resonant contribution comes from electromagnetic modes trapped in the film vicinity.

CT angiography in penetrating neck trauma reduces the need for operative neck exploration

The evaluation of penetrating neck injury has evolved dramatically from mandatory operative exploration of Zone II injuries that penetrate the platysma to selective management based on physical examination and adjunctive studies. More recently, CT angiography has emerged as an efficient, noninvasive method of evaluating penetrating neck injury. We retrospectively reviewed our experience over 10 years with the management of penetrating neck injury. One hundred thirty cases were reviewed with 34 undergoing CT angiogram (Group CTA) and 96 with no CT angiogram (Group nCTA). Group CTA had significantly fewer neck explorations, 1 (3%) versus 32 (33%), P < 0.001. Negative explorations were significantly higher in nCTA as well, with a rate of 22 per cent versus 0 in CTA (P < 0.01). The use of angiogram and esophagram was also significantly lower in CTA versus nCTA (P = 0.02 and P = 0.04). Of the 34 patients in CTA, 4 (12%) also underwent angiography and 4 (12%) received a contrast esophagram. Of the 64 patients in nCTA who did not undergo a neck exploration, 19 (29%) underwent angiography, and 17 (26%) received a contrast esophagram. The use of CT angiogram increased over time with a concomitant decrease in the rate of neck explorations.

CT Angiography in Penetrating Neck Trauma Reduces the Need for Operative Neck Exploration

The evaluation of penetrating neck injury has evolved dramatically from mandatory operative exploration of Zone II injuries that penetrate the platysma to selective management based on physical examination and adjunctive studies. More recently, CT angiography has emerged as an efficient, noninvasive method of evaluating penetrating neck injury. We retrospectively reviewed our experience over 10 years with the management of penetrating neck injury. One hundred thirty cases were reviewed with 34 undergoing CT angiogram (Group CTA) and 96 with no CT angiogram (Group nCTA). Group CTA had significantly fewer neck explorations, 1 (3%) versus 32 (33%), P < 0.001. Negative explorations were significantly higher in nCTA as well, with a rate of 22 per cent versus 0 in CTA ( P < 0.01). The use of angiogram and esophagram was also significantly lower in CTA versus nCTA ( P = 0.02 and P = 0.04). Of the 34 patients in CTA, 4 (12%) also underwent angiography and 4 (12%) received a contrast esophagram. Of the 64 patients in nCTA who did not undergo a neck exploration, 19 (29%) underwent angiography, and 17 (26%) received a contrast esophagram. The use of CT angiogram increased over time with a concomitant decrease in the rate of neck explorations.

Chronic lithium treatment of B lymphoblasts from bipolar disorder patients reduces transient receptor potential channel 3 levels

Chronic lithium treatment of B-lymphoblast cell lines (BLCLs) from bipolar-I disorder (BD-I) patients and healthy subjects ex vivo attenuates agonist- and thapsigargin-stimulated intracellular calcium (Ca(2+)) responses. As these findings suggest that chronic lithium treatment modifies receptor (ROCE) and/or store-operated Ca(2+) entry (SOCE) mechanisms, we determined whether chronic lithium treatment of BLCLs modified the expression of two members of the transient receptor potential channels (TRPC1 & 3), which participate in ROCE/SOCE. Chronic lithium treatment significantly reduced BLCL TRPC3 immunoreactivity (repeated-measures ANOVA, P=0.00005), with interaction effects of diagnosis (P=0.037) and sex (P=0.040). The lithium-induced decrease was greatest in BLCLs from female BD-I patients compared with those from healthy females (-27%) and with vehicle-treated BLCLs from female BD-I patients (-33%). However, lithium treatment did not affect TRPC1 and 3 mRNA levels, and TRPC1 immunoreactivity. Downregulation of TRPC3 may be an important mechanism by which lithium ameliorates pathophysiological Ca(2+) disturbances as observed in BD.

Is sildenafil failure in men after radical retropubic prostatectomy (RRP) due to arterial disease? Penile duplex Doppler findings in 174 men after RRP

Sildenafil is frequently the first-line treatment for post-radical retropubic prostatectomy (RRP) erectile dysfunction (ED) with maximum treatment satisfaction rates of 43%-80%. The etiology of erectile dysfunction after RRP has been attributed to psychogenic, vascular, veno- occlusive or nerve injury causes. The purpose of this study was to gain insight into the penile duplex Doppler arterial parameters in men with ED after RRP who failed sildenafil. The purpose was to assess whether sildenafil failure after RRP is associated with underlying corporal arterial disease. A total of 174 consecutive men presenting with sildenafil refractory ED after nerve-sparing RRP underwent color duplex penile Doppler evaluation with vasoactive injection. Mean age was 59.6 y and mean time from surgery was 11.6 months. Some 81% (141/174) of the men had no pre-operative ED (PED). Significant differences in penile duplex Doppler parameters for arterial disease were seen between men with and without PED. In men without PED, 19% (27/141) manifested arterial insufficiency. However, in men with PED, 50% (16/33) demonstrated arterial disease. Nerve sparing status did not affect the presence of arterial disease. Sildenafil refractory erectile dysfunction after RRP in men without PED is not predominantly associated with penile Doppler parameters consistent with arterial insufficiency.

Differential synthesis of beta-tubulin isotypes in gerbil nasal epithelia

Compartmentalization of beta-tubulin isotypes within cells according to function was examined in gerbil olfactory and respiratory epithelia by using specific antibodies to four beta-tubulin isotypes (beta(I), beta(II), beta(III), and beta(IV)). Isotype synthesis was cell-type-specific, but the localization of the isotypes was not compartmentalized. All four isotypes were found in the cilia, dendrites, somata, and axons of olfactory neurons. Only two isotypes (beta(I) and beta(IV)) were present in the cilia of nasal respiratory epithelial cells. The beta(IV) isotype, thought to be an essential component of cilia, was present in olfactory neurons and respiratory epithelial cells, which are ciliated, but was not found in basal cells (the stem cells of olfactory sensory neurons, which have no cilia). Olfactory neurons therefore do not synthesize beta(IV)-tubulin until they mature, when functioning cilia are also elaborated. The failure to observe compartmentalization of beta-tubulin isotypes in olfactory neurons sheds new light on potential functions of the beta-tubulin isotypes.

Antiproliferative B cell translocation gene 2 protein is down-regulated post-transcriptionally as an early event in prostate carcinogenesis

B cell translocation gene 2 (BTG2) is a p53 target that negatively regulates cell cycle progression in response to DNA damage and other stress. The objective of this study was to examine the expression, regulation and tumor suppressor properties of BTG2 in prostate cells. By immunohistochemistry BTG2 protein was detected in approximately 50% of basal cells in benign glands from the peripheral zone of the human prostate. BTG2 was expressed in all hyperproliferative atrophic peripheral zone lesions examined (simple atrophy, post-atrophic hyperplasia and proliferative inflammatory atrophy), but was undetectable or detectable at very low levels in the hyperproliferative epithelial cells of HGPIN and prostate cancer. BTG2 mRNA was detected in non-malignant prostate epithelial (PE) cells and in LNCaP cells, but not in PC-3 cells, consistent with p53-dependent regulation. In PE cells BTG2 protein was detected in areas of cell confluence by immunohistochemistry. BTG2 protein in LNCaP cells was undetectable by immunohistochemistry but was detected by immunoblotting at 8- to 9-fold lower levels than in PE cells. BTG2 protein levels were shown to be regulated by the ubiquitin-proteosome system. Forced expression of BTG2 in PC-3 cells was accompanied by a decreased rate of cell proliferation and decreased tumorigenicity of these cells in vivo. Taken together, these findings suggest that BTG2 functions as a tumor suppressor in prostate cells that is activated by cell quiescence, cell growth stimuli as part of a positive feedback mechanism and in response to DNA damage or other cell stress. The low steady-state levels of BTG2 protein in HGPIN and prostate cancer, a potential consequence of increased proteosomal degradation, may have important implications in the initiation and progression of malignant prostate lesions. Furthermore, these findings suggest that a significant component of the p53 G(1) arrest pathway might be inactivated in prostate cancer even in the absence of genetic mutations in p53.