Subclavian steal syndrome from high-output brachiocephalic arteriovenous fistula: a previously undescribed complication of dialysis access.

A 28-year-old dialysis-dependent man presented with episodic vertebrobasilar insufficiency. Noninvasive studies demonstrated an estimated 5.8 L/min flow through the arteriovenous fistula in his left arm and reversal of flow in the left vertebral artery. Surgical reduction of fistula flow resulted in the elimination of symptoms and the return of antegrade flow in the left vertebral artery. intraoperative invasive monitoring corroborated the pressure gradient responsible for his subclavian steal syndrome.

CO2 and gadopentetate dimeglumine as alternative contrast agents for malfunctioning dialysis grafts and fistulas.

BACKGROUND: Hemodialysis grafts and native fistulas are frequently evaluated angiographically utilizing iodinated contrast material to determine the cause of malfunction. Occasionally, patients are not able to receive iodinated contrast material due to a history of previous severe allergic reaction or concern that iodinated contrast material could worsen renal function requiring premature initiation of permanent dialysis. We set out to test the feasibility of gadopentetate dimeglumine as an alternative contrast agent in conjunction with carbon dioxide (CO2) angiography in the evaluation and treatment of hemodialysis grafts and native fistulas in patients who have a contraindication to iodinated contrast material. METHODS: Six patients with a malfunctioning hemodialysis graft and native fistula were evaluated. Four patients were successfully evaluated using carbon dioxide and gadopentetate dimeglumine. Two additional patients underwent balloon angioplasty using gadopentetate dimeglumine alone as the alternative contrast agent. RESULTS: All six patients successfully were evaluated and treated using gadopentetate dimeglumine either alone or as a supplement to CO2 angiography. Five of these patients had lesions successfully treated using gadopentetate dimeglumine alone or in combination with CO2 as the angiographic contrast agents. One patient underwent a successful diagnostic angiogram using gadopentetate dimeglumine and CO2 as alternative contrast agents and was subsequently treated with surgical revision. The gadopentetate dimeglumine angiograms identified the arterial anastomosis and more clearly identified stenotic lesions and venous outflow anatomy compared to carbon dioxide angiograms. CONCLUSION: Gadopentetate dimeglumine is useful as an alternative contrast agent in conjunction with CO2 in patients with malfunctioning hemodialysis grafts and fistulas, who have a contraindication to the administration of iodinated contrast material.

Intraoperative urinary cyclic AMP monitoring in primary hyperparathyroidism.

OBJECTIVE: This study examined the utility of intraoperative urinary cyclic 3'5' adenosine monophosphate (UcAMP), an indicator of parathyroid (PTH) hormone end-organ activity, as a "biochemical frozen section," signaling the real-time resolution of PTH hyperactivity during surgery for primary hyperparathyroidism. SUMMARY BACKGROUND DATA: The unsuccessful initial neck exploration for primary hyperparathyroidism, leaving the patient with persistent hyperfunctioning parathyroid tissue, results in part from the surgeon's inability intraoperatively to correlate a gland's gross appearance and size estimation with physiologic function. Preoperative imaging, intraoperative imaging, and intraoperative histologic/cytologic surveillance have not resolved this dilemma. METHODS: Twenty-seven patients underwent a prospective intraoperative UcAMP monitoring protocol. The patients all had a clinical diagnosis of primary hyperparathyroidism and an average preoperative serum calcium of 12.0 +/- 0.3 mg/dl. UcAMP was assayed intraoperatively using 20-minute nonequilibrium radioimmunoassay providing real-time feedback to the operating team. RESULTS: All patients had an elevated UcAMP confirming PTh hyperactivity at the beginning of the procedure. One patient, subsequently found to have an supernumerary ectopic adenoma, had four normal glands identified intraoperatively, and his intraoperative UcAMP values corroborated persistent hyperparathyroidism, the UcAMP of the remaining 26 patients decreased from 7.0 +/- 1.1 to 2.7 +/- 0.7 nm.dl GF (p < .00005) after complete adenoma excision, and they remain normocalcemic. The protocol provided useful and relevant information to the operating team, and aided in surgical decision-making, in 10 of the 27 cases (37%). CONCLUSION: Intraoperative biochemical surveillance with ucAMP monitoring reliably signals resolution of PTH hyperfunction. It is a useful adjunct to the surgeon's skill, judgment, and experience in parathyroid surgery.

Aspergillus flavus wound infection following repair of a ruptured duodenum in a non-immunocompromised host.

Aspergillus flavus is generally considered to be an opportunistic organism, rarely causing clinical infections in the immunocompetent host. We present a case of a 79-year-old man without history of immunocompromise who developed a severe aspergillus wound infection in an open wound following repair of a traumatic duodenal perforation. Despite aggressive treatment, this invasive infection contributed significantly to his eventual demise.

Experimental inhalation injury with concomitant surface burn: dextran resuscitation improves lung water and oxygenation.

UNLABELLED: The role of extravascular lung water (EVLW) in the pathogenesis of inhalation injury (INH) when associated with concomitant major burn (B) remains controversial. Previous experimental models have investigated isolated INH without surface burn. This study measured the effects of isolated and combined INH on EVLW and pO2 in a porcine experimental model. The beneficial effects of early resuscitation with dextran-40 (DEX) were assessed, using a control group receiving standard Parkland formula (LR). In the first part of the study (INH vs. INH + B), a group of animals with a standardized INH was compared to a group also receiving a standardized 40% BSA third-degree surface burn (n = 8, each group). With serial measurements for 5 hours, EVLW was only modestly increased unless INH was accompanied by surface burn: 20.3 +/- 4.2 vs. 32.0 +/- 4.1 ml/kg at 5 hours (p less than 0.01). Similarly, pO2 fell much more dramatically in the INH + B group, 61 +/- 5 vs. 37 +/- 5 torr (p less than 0.05). The second part of the study compared standard Parkland crystalloid resuscitation with dextran-40 resuscitation in animals receiving a combined INH + B injury (LR vs. DEX, n = 8, each group). DEX resuscitation resulted in substantially lower accumulation of EVLW out to 5 hours, 34.1 +/- 5.0 vs. 13.1 +/- 3.0 ml/kg (p less than 0.01), and significantly better pO2, 35 +/- 5 vs. 64 +/- 4 torr (p less than 0.01). CONCLUSIONS: Inhalation injury did not dramatically increase EVLW in this animal model unless accompanied by concomitant major surface burn. The deterioration in EVLW and pO2 seen in the combined injury was significantly improved with DEX resuscitation when compared to standard crystalloid resuscitation. Further study is indicated and clinical trials may be warranted.

Differentiating pancreatic pseudocyst and pancreatic necrosis using computerized tomography.

Ten per cent of patients with acute pancreatitis will develop pancreatic complications. Differentiating pancreatic pseudocyst formation from pancreatic necrosis may be difficult based on clinical grounds. The purpose of this study was to evaluate the role of computerized tomography in differentiating these processes. A retrospective analysis was performed of 40 patients who developed pancreatic complications following an episode of acute pancreatitis and who subsequently underwent operation for drainage of their pancreatic fluid collections. All 40 patients had abdominal CT scans performed before surgery and the patients were then categorized on the basis of CT findings as having (1) a pseudocyst with a well-defined cyst wall, (2) peripancreatic fluid marked by the absence of a cyst wall, and (3) a combination of a pseudocyst as well as free peripancreatic fluid. Patients with pseudocysts had an average hospital stay of 14 +/- 2 days, a hospital morbidity rate of 16%, and a hospital mortality rate of 0%. In contrast, patients with peripancreatic fluid collections had an average hospital stay of 43 +/- 4 days (p less than 0.01) and hospital morbidity and mortality rates of 74% (p less than 0.01) and 22% (p less than 0.05), respectively. Patients with both pseudocysts and peripancreatic fluid collections behaved in a similar fashion to patients with peripancreatic fluid alone as characterized by a prolonged hospital stay and a high incidence (80%) of postoperative complications. At one year follow-up, 89% of the patients with pseudocysts were asymptomatic, whereas only 13% (p less than 0.01) of patients with peripancreatic fluid were symptom free. These data demonstrate that pseudocyst and peripancreatic fluid collections have markedly different biologic characteristics both in their short-term and long-term behavior. The results suggest that CT scanning can differentiate these processes and may help in directing the appropriate surgical therapy.

Indications for emergency intravenous pyelography (IVP) in blunt abdominal trauma: a reappraisal.

Renal imaging in the diagnostic evaluation of blunt abdominal trauma is a valuable adjunct, but its indications remain controversial. Classic indications for the use of emergency intravenous pyelography (IVP) have been liberal, but more recently the medical need, cost effectiveness, and potential risks of this approach have been questioned in favor of a more selective approach. This retrospective study was undertaken to reassess the value of emergency IVP in blunt abdominal trauma and to test the hypothesis that post-traumatic microscopic hematuria, without other physical or laboratory findings, can safely be managed by observation alone. With the aid of the computerized Trauma Registry at the University of Virginia Medical Center, 50 consecutive patients undergoing emergency IVP for blunt abdominal trauma were identified over a 1-year period. A significantly abnormal IVP was found in six of seven patients with gross hematuria (86%). No patient of 43 with microscopic hematuria had a clinically significant abnormality (p less than 0.001, Chi-square). Three patients in the latter group (7%) had IVP findings which were anatomically abnormal but clinically insignificant, while an equal number (7%) had IVP's which were inadequate or misleading. Emergency IVP is useful in patients with specific indications and gross hematuria, but patients with post-traumatic microscopic hematuria alone may be safely followed by observation. Abdominal CT scanning is emerging as a more useful study than IVP for renal imaging in the stable patient with blunt abdominal trauma.

Evaluation of insulin secretion after pancreas autotransplantation by oral or intravenous glucose challenge.

Segmental pancreatic autotransplantation is accompanied by surgical alterations to the pancreas that may have consequences for carbohydrate metabolism. Four mongrel dogs were evaluated before operation and sequentially until 40 weeks after total pancreatectomy and autotransplantation of the splenic lobe of the pancreas with bolus intravenous and oral administration. Intravenous glucose tolerance test (IVGTT) (0.5 g/kg) revealed maintenance of fasting euglycemia for as long as 40 weeks after operation. Peak glucose and integrated glucose values did not show significant changes as a result of autotransplantation. Following transplantation, a delayed peak insulin response was seen; however, basal, peak, and integrated insulin values were largely unaltered. Only K values, a measure of glucose disposal, showed severe alterations (2.44 +/- 0.21 before operation to 1.24 +/- 0.30 at 40 weeks after operation). Oral glucose tolerance tests (OGTT) (2.0 g/kg) demonstrated an increased peak hyperglycemic response after autotransplantation with increased integrated glucose responses. Insulin levels remained at those levels seen before operation, and glucose-dependent insulinotropic polypeptide (GIP) responses were unchanged during the OGTT as late as 20 weeks after operation. In conclusion, pancreas autotransplantation after total pancreatectomy results in significant metabolic alterations that the IVGTT fails to detect with absolute glucose or insulin levels. However, K values are significantly lowered, which indicates alterations in cellular glucose transport. The OGTT demonstrates hyperglycemia without increased insulin or GIP levels, which suggests an altered beta cell response to the enteric stimulus of insulin release. These changes are nonetheless well tolerated by animals that have remained clinically healthy and euglycemic in the basal state.

Effects of indomethacin on blood flow in the normal pancreas in conscious dogs.

In anesthetised animals basal pancreatic blood flow, both in the normal gland and in acute pancreatitis, and basal renal blood flow have been shown to be dependent on prostaglandins (PGs). However, in conscious dogs it has been demonstrated that the reliance of basal renal blood flow on PGs is only apparent, and probably due to the effect of anesthesia and surgery stimulating PG synthesis through enhanced stimulation of the sympathetic nervous system. This study was undertaken to investigate the changes in mean blood pressure, cardiac output, and pancreatic arterial blood flow, relative to the cardiac output, in the normal pancreas, with and without PG synthesis inhibition (indomethacin) in conscious dogs. Blood flows were measured with electromagnetic flow probes. The effects of indomethacin were measured over a 2-hr period and compared to a control group. The results show that the relative pancreatic blood flow is not affected by doses of indomethacin which decrease cardiac output (P less than 0.5). It is suggested that PGs may have no effect on blood flow in the normal pancreas in conscious animals.

Effectiveness of normal saline solution, dextran 40 or dextran 75, and aprotinin (Trasylol) on renal blood flow preservation during acute canine pancreatitis.

A decrease in renal blood flow is believed to be important in the genesis of the acute renal failure of acute pancreatitis. In some instances, this decrease is undoubtedly due to hypovolemia, whereas in other instances, a circulating vasotoxic agent, possibly trypsin, has been incriminated. Using a canine model of pancreatitis induced by retrograde injection of bile along the pancreatic duct, the effects on renal blood flow of correcting the hypovolemia or administering aprotinin (a trypsin inhibitor) were studied using externally applied flow probes. Correcting the hypovolemia with N saline solution had no effect; the renal blood flow continued to decrease (p less than 0.05). When dextran 40 or dextran 75 was employed, the decrease in renal blood flow was prevented. After the administration of aprotinin, the renal blood flow actually increased (p less than 0.025) compared with preadministration values. It appears that aprotinin may have played a role in preventing this serious complication of pancreatitis.

Experimental acute pancreatitis in dogs and effects of steroids. A light and electron microscopic study with reference to pathogenesis.

Acute pancreatitis was induced in 39 dogs by injecting 10 ml of autologous bile into the pancreatic duct system. Of these dogs, 19 received hydrocortisone. As control, used were two normal dogs and six that were injected with 10 ml of normal saline solution into the pancreatic duct. Of all, 14 dogs were examined by electron microscope. All dogs that were injected with bile developed acute pancreatitis and histologically the lesion produced was acute necrotizing pancreatitis. Dogs treated with steroids showed an improved survival and a reduction in the severity of the acinar lesion. Ultrastructurally, pancreatic changes in these animals were mainly in the acinar cells and capillaries. Although ultrastructural lesions were similar in animals treated with steroids, steroid therapy appeared to be associated with an improved structural preservation of the acinar cells. These results suggest that the bile infusion method is reliable in producing acute necrotizing pancreatitis and that steroid administration is associated with an improved survival and reduction of the severity of the pancreatic lesion. The pathogenetic mechanism in this model and the mode of action of steroids were suggested by the ultrastructural study.

Does edematous pancreatitis exist in biliary-related pancreatitis? A hemodynamic and histologic study of the progression of bile-induced pancreatitis.

The progression of pancreatitis induced in dogs by either single or hourly injections of two different bile solutions was monitored to determine whether acute necrotizing pancreatitis developed through an earlier mild interstitial form. In this model of biliary-related pancreatitis, acute interstitial pancreatitis could not be produced. The earliest lesion produced, although having the macroscopic appearance of edematous pancreatitis, was histologically a mild necrotizing form of the disease. If the bile solution was of sufficient concentration, then further injections resulted in progression of the pancreatitis from this mild form of scattered areas of focal acinar necrosis through coalescence of these areas to areas of parenchymal hemorrhage. Pancreatic blood flow, measured through its arterial inflow, increased during the earliest phase of the disease, but then decreased as the disease progressed.