Comparison of 111In-[DTPA0]Octreotide Versus Non Carrier Added 177Lu- [DOTA0,Tyr3]-Octreotate Efficacy in Patients With GEP-NET Treated Intra-arterially for Liver Metastases.

AIM: In patients with progressive, metastatic neuroendocrine tumors (NET), intra-arterial radionuclide infusions with high activities of In-[DTPA]-octreotide and more recently with non-carrier added (nca) Lu-[DOTA,Tyr]-octreotate have been performed with encouraging results. However, the affinity profiles (IC50) of these radiopeptides for human sst2 receptors are markedly different (In-[DTPA]-octreotide, 22 ± 3.6 nM and nca Lu-[DOTA,Tyr]-octreotate, 1.5 ± 4.0 nM). The total administered activity is determined by organ dose limits (kidneys and bone marrow), and our aim therefore was to compare and evaluate the therapeutic efficacy of both radiopeptides in metastatic NETs. METHODS: Thirty patients with gastroenteropancreatic (GEP) somatostatin-positive NETs with liver metastases confirmed on biopsy and In-pentetreotide scan were included. They were treated with In-[DTPA]-octreotide (n = 17) or nca Lu-[DOTA,Tyr]-octreotate (n = 13). Blood samples were collected 2, 4, 8, and 24 hours postadministration to calculate residence time in blood and in red marrow. The maximum percentage uptake in organs and tumors was estimated by region of interest analysis, and tumor dosimetry calculations were performed using OLINDA/EXM/ 1.0 software. RESULTS: ncaLu-[DOTA,Tyr3]-octreotate blood radioactivity, expressed as a percentage of the injected dose, was significantly lower than In-[DTPA]-octreotide (P < 0.05), as clearly depicted from the time-activity curves; the background-corrected tumor uptake was significantly higher than In-[DTPA]-octreotide but without any significant difference in other organs (spleen, kidneys, and liver). CONCLUSIONS: Using Lu-[DOTA,Tyr]-octreotate, a 3-fold higher absorbed dose to tumor tissue was achieved compared with In-[DTPA] octreotide. Residence time of nca Lu-[DOTA,Tyr]-octreotate results in a significantly higher absorbed dose to bone marrow compared with In-[DTPA]-octreotide. However, a drawback of In-[DTPA]-octreotide therapy is that the number of administrations would need to be almost doubled to achieve an equal therapeutic outcome as compared with Lu-[DOTA,Tyr]-octreotate.

Ultrasound imaging of the radial artery following its use for cardiac catheterization.

Our experience suggests transradial arterial access with 5Fr catheters can be used for cardiac angiography with a low incidence of clinical complications, and supports the findings of previous investigators. Subclinical complications at the catheterization site were infrequent in this study (1 patient with asymptomatic radial artery occlusion). The presence of a palpable radial pulse may not be a reliable estimate of artery patency as evidenced by our patient with a palpable pulse due to retrograde flow. The theoretical advantage of the procedure is derived from the dual vascular supply to the hand. Radial artery occlusion, while uncommon, results in no ischemic sequelae in the setting of a patent ulnar artery.

Improved results with resection of extensive thoracoabdominal aneurysms.

Thoracoabdominal aneurysms are the most extensive of aortic aneurysms, and their correction is associated with the greatest number of complications. The introduction of new techniques has reduced the morbidity and mortality of surgery for these formidable lesions. A description of some of these techniques, as applied to 33 patients, is summarized, and the results presented.

Role of magnetic resonance imaging in predicting relapse in residual masses after treatment of lymphoma.

PURPOSE: This prospective study of patients treated at the Royal Marsden Hospital Lymphoma Unit was designed to evaluate the role of magnetic resonance imaging (MRI) in the assessment of residual masses evident on computed tomographic (CT) scanning following treatment of lymphoma. PATIENTS AND METHODS: All patients had MRI, gallium-67 single-photon emission CT (67Ga SPECT), and erythrocyte sedimentation rate (ESR) performed within 3 months of completing therapy. Patients were monitored for 1 year posttreatment and observed for signs of relapse. Investigation results were correlated with disease status, and the sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) calculated. Time-to-relapse curves were derived and the log-rank test used to determine whether patients with a positive result were more likely to have a relapse within the mass than those with a negative result. RESULTS: Thirty-four patients were studied, 14 of whom relapsed, 11 within the area of residual mass. Overall, MRI had a high specificity (90%), PPV (71%), and NPV (75%), but poor sensitivity (45%). The results for 67Ga SPECT were similar, apart from lower sensitivity (33%). ESR had inferior performance in predicting relapse compared with the other tests. MRI was the only investigation to show statistical significance (P = .14) in predicting relapse, and this was particularly evident in Hodgkin's lymphoma (P = .003). Combining results of 67Ga SPECT and MRI did not improve predictive power. CONCLUSION: These data demonstrate that MRI is a valuable tool in the setting of a residual mass after treatment, giving clinically useful prognostic information. 67Ga SPECT also has a role, but is less effective in predicting relapse than MRI.

One-stage segmental resection of extensive thoracoabdominal aneurysms with left-sided heart bypass.

PURPOSE: The purpose of this study is to describe a technique for resection of extensive thoracoabdominal aneurysms, which the authors believe will lower morbidity and mortality rates. METHODS: In an effort to minimize the risk of spinal cord ischemia, we have used a combination of sided heart bypass (left atrium to left femoral artery) with local cooling of the intercostal and visceral arteries and segmental resection of the aneurysm. Segmental resection of the aneurysm allows perfusion of the spinal cord and abdominal viscera as the proximal anastomosis is completed and as each pair of intercostal arteries is reimplanted. An attempt is made to reimplant all pairs of intercostal arteries from T8 to L2. Before the intercostal or visceral arteries are reimplanted, that segment of aorta is cooled with cold crystalloid solution. Thus no segment of the aorta is exposed to warm ischemia for more than 30 minutes. Left-sided heart bypass allows the patient's temperature to be maintained between 35 degrees C and 37 degrees C. RESULTS: We have used this technique in 23 patients with types I and II (Crawford's classification) thoracoabdominal aneurysms. Seven patients (30%) had dissections or rupture associated with their aneurysms and underwent emergency operation. One of these seven patients became paraplegic after operation, for a 4.3% incidence of paraplegia. One patient died of multiple organ failure after operation. No patient had kidney failure requiring dialysis. CONCLUSIONS: We believe that our technique allows the operation to be performed in a deliberate manner with a low incidence of paraplegia and kidney failure.

Angioscope-assisted endovascular occlusion of venous tributaries: preclinical studies.

The feasibility of angioscope-assisted occlusion of venous tributaries from within a vein using a steerable 'shaped-memory' nickel-titanium (nitinol) alloy catheter and occlusion coils was evaluated. An initial series of tests was designed to establish the necessary pressure (275 p.s.i., 1897.5 kPa), time (1.5 s) and volume (2.5 ml normal saline) requirements for hydraulic delivery of platinum occlusion coils from the nitinol catheter through a 3-Fr tracking catheter. In a second series, 25 side branches of the saphenous vein in 11 amputated limbs were visualized angioscopically and cannulated with the nitinol catheter under angioscopic and fluoroscopic surveillance to determine whether the catheter tip could be positioned and coils deployed. In a third series of studies, ten canine femoral vein tributaries were successfully cannulated with an 8-Fr nitinol catheter and 19 occlusion coils delivered under angioscopic surveillance. Fluoroscopy verified coil placement and all embolized venous tributaries were thrombosed. An ideal approach for femoropopliteal in situ saphenous vein bypass would allow the surgeon to divide saphenous vein valves while occluding venous side branches from within the saphenous vein. These initial studies demonstrate that the nitinol catheter can occlude venous tributaries from within a vein by coil embolization. Further development of this technique for clinical investigation is warranted.

Ruptured abdominal aortic aneurysms in a private hospital: a decade's experience (1980-1989).

Despite refinements in elective resection of abdominal aortic aneurysms, morbidity and mortality rates for ruptured abdominal aortic aneurysms (RAAAs) remain high. Between January 1, 1980 and December 31, 1989, we treated 208 patients with RAAAs whose mean age was 70 years. The overall mortality rate was 49.5%. Logistic regression analysis showed that three factors correlated with predicted patient survival. Patients < 70 years old had a survival rate of 65.7% compared with a survival rate of 37.4% in patients > 70 years old (p < 0.001). Among "stable" patients (preoperative blood pressure consistently > 90 mm Hg), 88.9% survived compared with 40.9% of "unstable" patients (blood pressure < 90 mm Hg) (p < 0.001). Of the patients with free intraperitoneal rupture, 38.3% survived compared with a survival rate of 79.6% of patients with rupture confined to the retroperitoneum (p < 0.001). Despite a high overall mortality rate in patients with RAAAs, surgical intervention remains the only hope for survival. We continue to advocate an aggressive surgical approach in this group of patients.

Reduction of Selenate and Selenite to Elemental Selenium by a Pseudomonas stutzeri Isolate.

A Pseudomonas stutzeri isolate rapidly reduced both selenite and selenate ions to elemental selenium at initial concentrations of both anions of up to 48.1 mM. Optimal selenium reduction occurred under aerobic conditions between pH 7.0 and 9.0 and at temperatures of 25 to 35 degrees C. Reduction of both selenite and selenate was unaffected by a number of anions except for sulfite, chromate, and tungstate ions, which inhibited both growth and reduction.

Delayed postoperative bleeding from polytetrafluoroethylene carotid artery patches.

Patch angioplasty of the internal carotid artery after endarterectomy has been advocated as a means of decreasing early postoperative carotid artery thrombosis, as well as reducing the incidence of recurrent carotid artery stenosis. Noninfectious rupture of saphenous vein patches in the early postoperative period has been reported by several authors, leading others to advocate the use of prosthetic patches. This report describes three patients in whom delayed bleeding through needle holes along the suture lines in polytetrafluoroethylene cardiovascular patches occurred between 1.5 and 4 days after operation. All patients required reexploration to control bleeding, and acute respiratory distress from tracheal compression developed in one patient. Although delayed bleeding through needle holes in polytetrafluoroethylene cardiovascular patches appears to be rare, a word of caution may be in order before advocating routine patching of the carotid artery with this particular type of patch.

Septic complications after cardiac catheterization and percutaneous transluminal coronary angioplasty.

Septic complications after cardiac catheterization and percutaneous transluminal coronary artery angioplasty are distinctly uncommon. However, we have recently treated nine patients with sepsis and life-threatening complications after cardiac catheterization alone or after catheterization and subsequent percutaneous transluminal coronary angioplasty. The common denominator in all patients was either repeat puncturing of the ipsilateral femoral artery or leaving the femoral artery sheath in for 1 to 5 days after the procedure. Two patients died as a direct result of their septic complications. One death occurred in a patient in whom bacterial endocarditis with congestive heart failure developed, and the other patient had a large retroperitoneal hematoma that became secondarily infected. Infected aneurysms that were successfully treated developed in three patients. Our study suggests that colonization of the needle tract by skin flora predisposes to septic complications if repeat arterial punctures are required or if a femoral artery sheath is left in place for more than 24 hours. Patients in whom sepsis develops after these procedures should be initially treated with antibiotics effective against gram-positive organisms. CT scanning or angiography should be considered for patients with persistent sepsis, septic emboli, and abdominal or flank pain. Infected aneurysms require resection or ligation because of the propensity of these aneurysms to rupture.

Combined coronary artery bypass grafting and bilateral renal revascularization for unstable angina and impeding renal failure.

The purpose of our article is to describe a patient with severe hypertension and moderate renal insufficiency, unstable angina, and a 6 cm abdominal aortic aneurysm. A previous aortogram had demonstrated severe bilateral renal artery stenoses. Cardiac catheterization demonstrated severe coronary disease. After cardiac catheterization acute renal failure and pulmonary edema requiring dialysis developed in the patient. In addition, evidence of impending myocardial necrosis developed. Because of the critical nature of the myocardial and renal ischemia it was necessary to perform combined myocardial and renal revascularization rather than staged procedures. At the time of coronary artery bypass grafting, a vein graft was anastomosed to the right coronary artery vein graft and tunneled through the diaphragm into the abdomen to revascularize both renal arteries. After surgery renal function gradually improved, and no further dialysis was required. The abdominal aortic aneurysm was repaired at a subsequent operation. At 2-year follow-up all grafts remained patent. The serum creatinine is 1.2 mg/dl. Although most patients with combined coronary artery disease and renal artery disease can be treated with staged operations, our procedure may be of value in patients in whom staged procedure are not feasible and in whom the infrarenal aorta is severely diseased or aneurysmal.

What is the role of carotid arterial resection in the management of advanced cervical cancer?

From 1977 through 1988, 16 patients underwent carotid artery resection and reconstruction or simple ligation in the treatment of advanced cervical carcinomas. Three patients underwent carotid artery ligation, with postoperative transient ischemic attacks, which resolved, in one patient. In the remaining 13 patients, interposition saphenous vein grafts were used to reconstruct the resected carotid arteries. In one of these 13 patients, the previously unresected carotid artery ruptured and was treated by carotid artery resection with interposition vein grafting and coverage by a myocutaneous flap. There were two immediate postoperative strokes, with excellent neurologic recovery in one, and one late postoperative stroke (6 months). There was one postoperative death. Adjunctive intraoperative irradiation (1500 to 2000 rad) was employed in 15 patients to decrease the risk of recurrent disease. Since 1982, pectoralis major muscle flaps have been constructed in all patients to cover the vein grafts, with no subsequent carotid artery blowouts. Seven patients are free of cancer more than 1 year after surgery. In conclusion, carotid artery resection for the treatment of advanced cervical carcinomas may be accomplished with acceptable morbidity and mortality rates in carefully selected cases. Coverage of the vein graft by a myocutaneous flap appears to protect against carotid artery blowout. Intraoperative irradiation appears to decrease significantly the local recurrence rate of these aggressive tumors.

The continuous recovery of uranium from biologically leached solutions using immobilized biomass.

The potential of uranium recovery from the dilute uranium ore bioleach solutions of the Elliot Lake district of Canada was examined using immobilized microbial biomass. Batch and continuous laboratory scale pilot plant experiments were carried out. The results have shown that the immobilized microbial biomass can successfully recover all of the uranium from dilute (less than 300 mg U/L) solutions. The uranium can subsequently be eluted producing a high uranium concentration eluate perhaps exceeding 5000 mg U/L. The biomass maintained its biosorption capacity of about 50 mg U/g over 12 examined successive adsorption-elution cycles with no apparent indication of failure.

Upper-extremity vascular injuries.

Although upper-extremity injuries alone are usually not life-threatening, they can produce significant immediate or long-term morbidity, especially if there is an associated nerve injury. The diagnosis of an arterial injury may be readily apparent, but the excellent upper-extremity collateral circulation may create palpable distal pulses despite a significant proximal arterial injury. Therefore, a high index of suspicion and the liberal use of arteriography are necessary to avoid missing these injuries. Compression of the brachial plexus by a hematoma can produce a serious neurologic deficit. Prompt evacuation of the hematoma may significantly reduce the deficit, another fact that supports an aggressive surgical approach in these patients. The long-term results of upper-extremity vascular injuries are usually determined by the extent of any associated nerve injuries.