Endoscopic ultrasound rendezvous for bile duct access using a transduodenal approach: cumulative experience at a single center. A case series.

Endoscopic ultrasound (EUS)-assisted biliary access is utilized when conventional endoscopic retrograde cholangiopancreatography (ERCP) fails. We report a 10-year experience utilizing a transduodenal EUS rendezvous via a transpapillary route without dilation of the transduodenal tract, followed by immediate ERCP access. Patients included all EUS-guided rendezvous procedures for biliary access that were performed following ERCP failure. EUS-assisted bile duct puncture was performed via a transduodenal approach and a guide wire was advanced through the papilla without any dilation or bougienage of the tract; ERCP was performed immediately afterwards. EUS-assisted biliary rendezvous was attempted in 15 patients (mean age 66 +/- 18.2 years; malignant = 10, benign = 5). Mean diameter of measured bile ducts was 14.3 +/- 5.17 mm (range 4-23 mm). The reasons for initial ERCP failure were tumor infiltration or edema (n = 9), intradiverticular papilla (n = 2), pre-existing duodenal stent (n = 1), and anatomic anomalies (n = 3). Successful EUS-guided bile duct puncture and wire passage were achieved in all 15 patients (100 %), with drainage being successful in 12 / 15 (80 %). Failures occurred in three patients due to inability to traverse the biliary stricture (n = 2) or dissection of a choledochocele with the guide wire (n = 1); all were subsequently drained via percutaneous methods. Stents placed were metallic in eight patients and plastic in four. Complications consisted of moderate pancreatitis after a difficult ERCP attempt in one patient, and bacteremia after percutaneous biliary drainage in another. There were no instances of perforation, extraluminal air or fluid collections. EUS-assisted biliary drainage utilizing a transduodenal rendezvous approach demonstated a high success rate without any complications directly attributable to the EUS access. Advantages over percutaneous biliary and other methods of EUS biliary access include performance under the same anesthesia, and a very small-caliber needle puncture similar to EUS/fine-needle aspiration.

Endoscopic ultrasound-guided fine-needle aspiration for the diagnosis of extra-pulmonary tuberculosis.

SETTING: The incidence of extra-pulmonary tuberculosis (EPTB) is surprisingly high among certain subgroups of patients in industrialized countries. Diagnosis is often difficult and can require costly invasive workup. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a safe, minimally invasive, accurate, out-patient diagnostic modality for assessing mediastinal and abdominal lymphadenopathy and masses. OBJECTIVE: To evaluate the usefulness of EUS-FNA for diagnosing EPTB. DESIGN: Retrospective 6-year review, including all patients who had evidence of lymphadenopathy or mass on computed tomography scan accessible by EUS and consideration of tuberculosis (TB) in the differential diagnosis. RESULTS: Of 81 potential patients, a total of 20 cases with EPTB diagnosed by EUS-FNA were identified. Necrotizing granulomas had a 58% likelihood of TB vs. 14% for other cytologic findings (P < 0.0001); necrosis was also predictive, with a 44% likelihood of TB vs. 19% (P < 0.0225). EUS-FNA cytology was diagnostic for TB when an African-born patient had necrotizing granulomas (P < 0.0001), and was highly suggestive with necrosis alone (P < 0.0514). Non-necrotizing granulomas were not predictive of TB and an alternative diagnosis was more likely, including sarcoidosis and cancer. CONCLUSION: EUS-FNA is a useful diagnostic modality that should be used early in the diagnostic workup of suspected EPTB.

Accurate diagnosis of pancreas divisum by linear-array endoscopic ultrasonography.

BACKGROUND AND STUDY AIMS: During linear-array endoscopic ultrasonography (EUS), the main pancreatic duct can be followed continuously from the major papilla into the pancreatic body in most patients. Often, the duct can also be seen crossing a sonographic border between the ventral and dorsal pancreatic anlagen. It was hypothesized that the presence of either feature excludes pancreas divisum, whereas the absence of these features suggests complete pancreas divisum. PATIENTS AND METHODS: Pancreas divisum was sought during all linear-array EUS examinations conducted between July 1999 and June 2003. Charts were reviewed retrospectively, and patients who underwent endoscopic retrograde pancreatography after, but not before, EUS were included in the study. RESULTS: A total of 162 patients had EUS before ERCP. Adequate evaluation of the pancreatic duct was possible in 78 % of the patients. The prevalence of pancreas divisum was 13.6 %. In patients with adequate duct visualization, the sensitivity, specificity, and positive and negative predictive values for EUS were 95 %, 97 %, 86 %, and 99 %, respectively. The overall accuracy of EUS for identifying pancreas divisum was 97 % in this subgroup. CONCLUSION: Adequate EUS evaluation of pancreas divisum was possible in most cases. Linear-array EUS is a promising diagnostic test for pancreas divisum.

Endoscopic ultrasound-guided pancreatic duct aspiration: diagnostic yield and safety.

BACKGROUND AND STUDY AIMS: Endoscopic ultrasound (EUS)-guided fine-needle aspiration provides useful diagnostic material in solid and cystic pancreatic lesions. It is logical that EUS-guided pancreatic duct aspiration may be useful in cases of suspected intraductal or duct-obstructing tumors. We evaluated the safety and efficacy of EUS-guided pancreatic duct aspiration. PATIENTS AND METHODS: Twelve patients with dilated pancreatic ducts underwent EUS-guided duct aspiration. Aspirates were submitted for cytology and mucin staining. Patients were followed for up to 13 months. RESULTS: There were no procedure-related complications. Cytology was diagnostic in nine of the 12 patients (six with intraductal papillary mucinous tumor, one with pancreatic clonorchiasis, and two with obstructing solid pancreatic adenocarcinomas). Cytology in the remaining three patients, all with solid obstructing masses, was nondiagnostic. Overall, the diagnostic yield was 75%; however, the yield was 100% in patients without extrinsic obstruction. CONCLUSION: This preliminary experience suggests that EUS-guided pancreatic duct aspiration is safe and can provide diagnostic material in a significant number of patients with unexplained pancreatic duct dilation.

Effects of 10-hydroxycamptothecin, delivered from locally injectable poly(lactide-co-glycolide) microspheres, in a murine human oral squamous cell carcinoma regression model.

This study investigated whether local delivery of 10-hydroxycamptothecin provides effective inductive chemotherapy as assessed by significant tumor reduction. Established tumorigenic human oral squamous cell carcinoma cells were used for these experiments. The experimental groups were comprised of: control (blank (no drug) poly(lactide-co-glycolide) (PLGA) microspheres), intraperitoneal 10-hydroxycamptothecin delivery + blank microspheres, local bolus 10-hydroxycamptothecin + blank microspheres, and PLGA controlled-release microspheres. The 10-hydroxycamptothecin dose administered was 12 mg/kg (bolus-intraperitoneal, local) or controlled-release over 10 days. Regardless of delivery route, 10-hydroxycamptothecin significantly reduces tumor volume. However, PLGA microspheres provide significantly higher intratumor-drug concentrations (approximately 10 and 100 fold higher) relative to local bolus and intraperitoneal routes, respectively. Also, only the PLGA microspheres significantly reduced tumor weights. Camptothecin clinical applications are limited by drug inactivation at physiological pH and the need for sustained infusions. However, due to their acidic, camptothecin-stabilizing microclimate, PLGA microspheres could provide a novel delivery system for camptothecin-based induction chemotherapy.

Current status of diagnostic and therapeutic endoscopic ultrasonography.

Endoscopic ultrasonography is firmly established as an imaging modality that can be used for diagnosing and staging both malignant and nonmalignant disorders of the pancreas, gastrointestinal tract, biliary tree, and mediastinum. In the future, as more physicians are trained and as technologic developments continue to advance, endosonography will likely assume a greater role in therapeutic management.

The reliability of EUS for the diagnosis of chronic pancreatitis: interobserver agreement among experienced endosonographers.

BACKGROUND: Endoscopic ultrasound (EUS) is a minimally invasive, low risk method of diagnosis for chronic pancreatitis (CP). The degree to which endosonographers agree on the features and diagnosis of CP is unknown. For EUS to be considered an accurate test for CP, there must be good interobserver agreement. METHODS: Forty-five pancreatic EUS examinations were videotaped by 3 experienced endosonographers. Examinations from 33 patients with suspected CP based on typical symptoms, as well as 12 control patients without suspected CP, were included. Eleven experienced endosonographers ("experts") who were blinded to clinical information independently evaluated all videotaped examinations for the presence of CP and the following 9 validated features of CP: echogenic foci, strands, lobularity, cysts, stones, duct dilatation, duct irregularity, hyperechoic duct margins, and visible side branches. The experts also ranked (most to least) which features they believed to be the most indicative of CP. Interobserver agreement was expressed as the kappa (kappa) statistic. RESULTS: There was moderately good overall agreement for the final diagnosis of CP (kappa = 0.45). Agreement was good for individual features of duct dilatation (kappa = 0.6) and lobularity (kappa = 0.51) but poor for the other 7 features (kappa < 0.4). The expert panel had consensus or near consensus agreement (greater than 90%) on 206 of 450 (46%) individual EUS features including 22 of 45 diagnoses of CP. Agreement on the final diagnosis of CP was moderately good for those trained in third tier fellowships (kappa = 0.42 +/- 0.03) and those with more than 1100 lifetime pancreatic EUS examinations (kappa = 0.46 +/- 0.05). The presence of stones was regarded as the most predictive feature of CP by all endosonographers, followed by visible side branches, cysts, lobularity, irregular main pancreatic duct, hyperechoic foci, hyperechoic strands, main pancreatic duct dilatation, and main duct hyperechoic margins. The most common diagnostic criterion for the diagnosis of CP was the total number of features (median 4 or greater, range 3 or greater to 5 or greater). CONCLUSIONS: EUS is a reliable method for the diagnosis of chronic pancreatitis with good interobserver agreement among experienced endosonographers. Agreement on the EUS diagnosis of chronic pancreatitis is comparable to other commonly used endoscopic procedures such as bleeding ulcer stigmata and computed tomography of the brain for stroke localization and better than the physical diagnosis of heart sounds.

Controlled-release of doxorubicin from poly(lactide-co-glycolide) microspheres significantly enhances cytotoxicity against cultured AIDS-related Kaposi's sarcoma cells.

Subsequent to the introduction of highly active antiretroviral therapy (HAART), there has been a reduction in HIV viral titers and a concomitant decrease in AIDS-related Kaposi's sarcoma. However, as failure rates of HAART approach 30%, concerns arise regarding resurgence in AIDS-KS. Current AIDS-KS therapies fail to provide sustained remissions and yet also result in significant morbidity. Although partially effective, systemic chemotherapy is particularly debilitating to AIDS patients. In this report, we examined the co-incubation of AIDS-KS cells with doxorubicin which was slowly delivered from biodegradable, locally injectable, controlled-release poly(lactide-co-glycolide) (PLGA) microspheres. Local drug delivery systems such as PLGA microspheres can sustain therapeutic intralesional concentrations while minimizing deleterious systemic side effects, providing a pharmacologic advantage at the treatment site. Our data show that controlled release from PLGA microspheres augments doxorubicin cytotoxicity towards AIDS-KS cells without increasing toxicity in nonlesional cells from the AIDS-KS donors. Electron microscopic analysis revealed that PLGA microspheres possess a strong affinity for cell membranes, facilitating doxorubicin delivery to redox-sensitive cell membrane sites. Consistent with their speculated endothelial cell lineage, some of the AIDS-KS cells appeared to engulf microspheres via phagocytosis. Our results suggest that PLGA controlled-release doxorubicin microspheres have potential clinical applicability in management of AIDS-KS.

Advances in diagnostic and therapeutic endoscopy.

Endoscopy is extremely valuable in the evaluation of disorders of the luminal gastrointestinal tract, pancreas, and biliary system. Endoscopy as a medical discipline continues to evolve and is becoming increasingly therapeutic in nature. Minimally invasive endoscopic intervention now is effective in a wide variety of disorders, including gastrointestinal hemorrhage, obstructive diseases of the intestinal or biliary tree, and early detection or prevention of neoplastic disease of the colon and esophagus. The development of EUS technology has expanded greatly the potential utility of endoscopy as a diagnostic and a therapeutic modality, and further technologic advances are anticipated.

Sustained angiogenesis enables in vivo transplantation of mucocutaneous derived AIDS-related Kaposi's sarcoma cells in murine hosts.

AIDS-related Kaposi's sarcoma (AIDS-KS), the most prevalent HIV-associated malignancy, is a debilitating, potentially fatal disease. Currently, there is a need for development of AIDS-KS therapies that are not only well tolerated, but also capable of providing sustained remission. Preclinical assessment of pharmacological parameters and therapeutic efficacies are dependent upon in vivo parameters. However, there are currently no animal KS models and mucocutaneous KS cell isolates have proved to be non-tumorigenic in animal hosts. This report describes the development of a murine model that enables in vivo transplantation of 'native' low population doubling level AIDS-KS cells from biopsy-confirmed mucocutaneous lesions. The angiogenic phenotype of in situ AIDS-KS lesions is reconstituted via controlled release of a complete angiogenic peptide, recombinant human basic fibroblast growth factor (bFGF), from locally injectable, biodegradable polylactide-co-glycolide implants. Consequential to the sustained local release of bioactive bFGF, a murine vascular network is established, which facilitates the in vivo transplantation of AIDS-KS cells. Desirable aspects of this model include: low cost murine species, transplantation of non-selected patient cells and use of animal hosts that are T cell-deficient. The transplanted human AIDS-KS cells and extensive murine vascular network create lesions that retain a striking resemblance, at both the gross and microscopic levels, to in situ AIDS-KS tumors. Because the bFGF-induced murine vascular network is analogous to the abundant vascularity present in AIDS-KS lesions, this murine model should provide an excellent vehicle for numerous clinically relevant studies, such as assessment of drug clearance at AIDS-KS lesional sites. Finally, applicability of this method is not restricted to AIDS-related malignancies. Establishment and maintenance of an extensive host vascular network should augment success rates for in vivo transplantation of numerous other human cell strains or lines.

Stabilization of vinca alkaloids encapsulated in poly(lactide-co-glycolide) microspheres.

PURPOSE: The purpose of this study was to stabilize the vinca alkaloids, vincristine sulfate (VCR) and vinblastine sulfate (VBL), in poly(lactide-co-glycolide) (PLGA) microspheres and to release the drugs in a sustained manner for more than a month. METHODS: An oil-in-oil emulsion-solvent extraction method was used to encapsulate VCR and VBL in PLGA50/50 microspheres. Stability and release kinetics of the drugs during the incubation at 37 degrees C in PBS/Tween 80 were assessed by HPLC. Degradation products were identified with HPLC-MS. RESULTS: VCR and VBL were encapsulated in PLGA microspheres unchanged. During the microsphere incubation, however, VCR degraded inside the particles with a t1/2 approximately 7.5 days. The degradation product was identified by LC-MS as the deformyl derivative, commonly formed at acidic pH. VBL, which differs only by a stable methyl group in place of the N-formyl group in VCR, was completely stable in the PLGA microclimate. The neutralization of acidic PLGA microclimate by addition of 3-10% Mg(OH)2 completely inhibited deformylation of VCR during release. but introduced a new degradation product formed under the more alkaline conditions used during the preparation. The substitution of Mg(OH)2 with a weaker base, ZnCO3, inhibited the formation of both degradation products resulting in VCR stabilization of >92% for 4 weeks. The optimal formulations of VCR (containing ZnCO3) and VBL (no additives) slowly and continuously released stable drugs for over a month. CONCLUSIONS: VCR and VBL were successfully stabilized and released in a sustained manner from PLGA microspheres. Co-encapsulation of ZnCO3 stabilizes VCR against acid-catalyzed degradation during release from the polymer and minimizes VCR decomposition during encapsulation.

Stabilization of proteins encapsulated in injectable poly (lactide- co-glycolide)

Controlled release from biodegradable polymers is a novel approach to replace daily painful injections of protein drugs. A major obstacle to development of these polymers is the need to retain the structure and biological activity of encapsulated proteins during months of incubation under physiological conditions. We encapsulated bovine serum albumin (BSA) in injectable poly(DL-lactide- co-glycolide) (PLGA) 50/50 cylindrical implants and determined the mechanism of BSA instability. Simulations of the polymer microclimate revealed that moisture and acidic pH (<3) triggered unfolding of encapsulated BSA, resulting in peptide bond hydrolysis and noncovalent aggregation. To neutralize the acids liberated by the biodegradable lactic/glycolic acid-based polyester, we coincorporated into the polymer an antacid, Mg(OH)2, which increased microclimate pH and prevented BSA structural losses and aggregation for over one month. We successfully applied this stabilization approach in both cylinder- and microsphere-injectable configurations and for delivery of angiogenic basic fibroblast growth factor and bone-regenerating bone morphogenetic protein-2.

Interventional endoscopic ultrasonography: current status and future direction.

Although first performed more than 20 years ago, endoscopic ultrasonography (EUS) has only recently been used for interventional/therapeutic purposes. The recognition and application of this versatile procedure by gastroenterologists who perform endoscopy has reached an all-time high, and the demand for symposia and tutorials devoted to EUS rivals that of endoscopic retrograde cholangiopancreatography 20 to 25 years ago. EUS has become an established part of the endoscopic armamentarium for many gastroenterologists. Despite its proved clinical utility for staging gastrointestinal (and lung) cancers, and its use in delineating the nature of "submucosal" tumors of the gastrointestinal tract, EUS has continued to evolve. Within the past 10 years, the safety and efficacy of EUS as a means of guiding tissue acquisition via fine-needle aspiration has been demonstrated, increasing its utility in gastrointestinal oncology. Newer indications currently under clinical investigation include the use of EUS as a delivery mechanism for novel immune-based and viral-based "chemo" therapeutic agents for patients with pancreatic cancer. Finally, the role of EUS as a reliable method to guide therapy to control the often refractory abdominal pain in patients with pancreatic cancer and/or chronic pancreatitis is being verified in clinical trials. The following is a brief overview of the current state-of-the-art in interventional EUS.