Comparing Shared Patient Networks Across Payers.

BACKGROUND: Measuring care coordination in administrative data facilitates important research to improve care quality. OBJECTIVE: To compare shared patient networks constructed from administrative claims data across multiple payers. DESIGN: Social network analysis of pooled cross sections of physicians treating prevalent colorectal cancer patients between 2003 and 2013. PARTICIPANTS: Surgeons, medical oncologists, and radiation oncologists identified from North Carolina Central Cancer Registry data linked to Medicare claims (N = 1735) and private insurance claims (N = 1321). MAIN MEASURES: Provider-level measures included the number of patients treated, the number of providers with whom they share patients (by specialty), the extent of patient sharing with each specialty, and network centrality. Network-level measures included the number of providers and shared patients, the density of shared-patient relationships among providers, and the size and composition of clusters of providers with a high level of patient sharing. RESULTS: For 24.5% of providers, total patient volume rank differed by at least one quintile group between payers. Medicare claims missed 14.6% of all shared patient relationships between providers, but captured a greater number of patient-sharing relationships per provider compared with the private insurance database, even after controlling for the total number of patients (27.242 vs 26.044, p < 0.001). Providers in the private network shared a higher fraction of patients with other providers (0.226 vs 0.127, p < 0.001) compared to the Medicare network. Clustering coefficients for providers, weighted betweenness, and eigenvector centrality varied greatly across payers. Network differences led to some clusters of providers that existed in the combined network not being detected in Medicare alone. CONCLUSION: Many features of shared patient networks constructed from a single-payer database differed from similar networks constructed from other payers' data. Depending on a study's goals, shortcomings of single-payer networks should be considered when using claims data to draw conclusions about provider behavior.

Efficacy of immune checkpoint inhibitors in alveolar soft-part sarcoma: results from a retrospective worldwide registry.

BACKGROUND: Conventional cytotoxic drugs are not effective in alveolar soft-part sarcoma (ASPS). Immune checkpoint (programmed cell death protein 1/programmed death-ligand 1) inhibitors (ICIs) are promising drugs in ASPS. A worldwide registry explored the efficacy of ICI in ASPS. MATERIALS AND METHODS: Data from adult patients diagnosed with ASPS and treated with ICI for advanced disease in expert sarcoma centers from Europe, Australia and North America were retrospectively collected, including demographics and data related to treatments and outcome. RESULTS: Seventy-six ASPS patients, with a median age at diagnosis of 25 years (range 3-61 years), were registered. All patients received ICI for metastatic disease. Immunotherapy regimens consisted of monotherapy in 38 patients (50%) and combination in 38 (50%) (23 with a tyrosine kinase inhibitor). Among the 68 assessable patients, there were 3 complete responses and 34 partial responses, translating into an overall response rate of 54.4%. After a median follow-up of 36 months [95% confidence interval (CI) 32-40 months] since the start of immunotherapy, 45 (59%) patients have progressed on ICI, with a median progression-free survival (PFS) of 16.3 months (95% CI 8-25 months). Receiving ICI in first line (P = 0.042) and achieving an objective response (P = 0.043) correlated with a better PFS. Median estimated overall survival (OS) from ICI initiation has not been reached. The 12-month and 24-month OS rates were 94% and 81%, respectively. CONCLUSIONS: This registry constitutes the largest available series of ASPS treated with ICI. Our results suggest that the ICI treatment provides long-lasting disease control and prolonged OS in patients with advanced ASPS, an ultra-rare entity with limited active therapeutic options.

Identification of potentially mobile and persistent transformation products of REACH-registered chemicals and their occurrence in surface waters.

Transformation of industrial chemicals might be a significant source of hitherto unknown persistent and mobile organic contaminants (PMOC, PM chemicals) present in the aquatic environment. Herein we depicted a three-step strategy consisting of (I) the prioritization of potential PMOC precursors among REACH-registered chemicals, (II) their lab scale transformation through hydrolysis, photolysis, MnO2 oxidation, and biotransformation and subsequent structural elucidation of derived transformation products, and finally (III) the assessment of their environmental relevance. The proposed procedure was utilized to investigate eleven chemicals, for nine of which a concentration reduction was observed. For six of these chemicals transformation products were at least tentatively identified and partially confirmed with a commercially available reference standard. Retrospective assessment of high-performance liquid chromatography - high-resolution mass spectrometry data as well as a target screening method for the identified TPs and some of the prioritized REACH chemicals revealed the widespread presence of the following chemicals in the environment: 2-pyrrolidone (hydrolysis product of vinylpyrrolidone), TP 216 (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-acetic acid, biotransformation product of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-ethanol), and 1,3-diphenylguanidine (prioritized chemical with experimental evidence of environmental stability). 2-Pyrrolidone was detected in 23/25 investigated surface water samples and present in concentrations of up to 400 ng/L. TP 216 was detected in 20/25 surface water samples and an additional sampling of a waste water treatment plant and the receiving surface water confirmed that TP 216 is formed in waste water treatment plants. The vulcanisation agent 1,3-diphenylguanidine was present in all investigated samples. A leaching experiment with a tire suggested that tires and thus tire wear particles are a potential source of 1,3-diphenylguanidine. With these data the depicted approach was proven successful and suitable for true unknowns like TP 216, and thus an alternative to non-target screenings or suspect-screenings with predicted TPs to identify environmentally relevant transformation products.

Two-dimensional echocardiographic findings in cardiac trauma.

Cardiac contusion is a potentially fatal complication of blunt chest trauma. The diagnosis is obscured because cardiac contusion usually occurs in a setting of multisystem trauma. Furthermore, the electrocardiographic changes are nonspecific. Experience with 2-dimensional echocardiography in evaluating cardiac trauma has not previously been emphasized. This report examines the results of 2-dimensional echocardiographic examinations in 7 patients after significant blunt chest trauma. Generalized right ventricular dilatation was identified in 4 cases; superimposed segmental areas of right ventricular dilatation occurred in 3. Three patients had localized myocardial thinning, and segmental wall motion abnormalities occurred in 2. Additional abnormalities identified included ventricular thrombi (4 right and 1 left ventricular), fibrinous pericardial effusion (1), ruptured tricuspid chordae with flail leaflet (1), and a small aneurysm of the sinus of Valsalva (1). It is concluded that 2-dimensional echocardiography is useful for diagnosing cardiac contusion, for estimating the extent of myocardial damage, and for identifying accompanying cardiac lesions such as thrombi, pericardial effusion, and valvular disruption.

Trauma prophylaxis: every physician's responsibility.

Recognition of trauma as a major national health problem during the past 2 decades has led to concerted efforts to combat the devastating consequences of accidental death and disability. Although many medical advancements in the care of injured patients have been achieved, trauma continues to take its toll. Unfortunately, little has been accomplished in actually reducing the incidence of traumatic events that lead to serious injury. In fact, many types of accidents are becoming more frequent. The time has come to begin treating trauma as any other disease process--that is, prevention is undoubtedly the best cure. Physicians are in a unique position to assume a leadership role in this regard. Armed with anecdotal experiences in the care of trauma victims and with factual, epidemiologic data, all physicians, regardless of specialty, should actively support legislation and changes in social values aimed at trauma prophylaxis.

Changing attitudes toward the management of blunt splenic trauma in adults.

During the past decade, one of the most controversial issues in the surgical literature has been the question of what is the most appropriate management of splenic trauma. An increased understanding of the physiologic importance of splenic function must now be weighed against the life-threatening risk of exsanguinating splenic hemorrhage. In this article, postsplenectomy sepsis and mortality in adults and the selective management of blunt splenic trauma are discussed. Although the risks of postsplenectomy sepsis and serious infection are low, they do exist. A policy of individual assessment of cases is recommended when the merits of splenectomy versus those of splenic preservation are considered. Similarly, in cases of blunt splenic trauma, a policy of individual assessment is not only intellectually attractive but also safe, rational, and effective from a clinical standpoint. In selected cases of blunt splenic trauma, nonoperative management and splenorrhaphy are acceptable alternatives; however, in many instances splenectomy remains the most appropriate and only course of action.

Acute acalculous cholecystitis.

Acute acalculous cholecystitis occurs infrequently, but the incidence seems to be increasing. Its attendant high associated morbidity and mortality dictate prompt diagnosis. Diagnosing this condition is often difficult because of the patient's debilitated medical condition and the limitations of biliary imaging techniques. During a 5-year study period (1981 through 1986), 20 patients underwent assessment and treatment for acute acalculous cholecystitis at our institution. This observation suggests an increase in incidence in comparison with a previously reported review of 28 such patients during a 16-year period at our institution. Initial treatment consisted of cholecystectomy in 18 patients, and percutaneous transhepatic cholecystostomy was successfully used in the other 2 patients. The postoperative mortality and morbidity for these 20 patients were 30% and 55%, respectively. Percutaneous transhepatic cholecystostomy should be explored further as a treatment option for acute acalculous cholecystitis.

Torsion of the gallbladder.

Herein we report two cases of acute torsion of the gallbladder, including an extremely rare instance of torsion of the fundus of the organ. Because symptoms of torsion of the gallbladder are similar to those of other diseases and because of its rarity, preoperative diagnosis is difficult. The cause of this disorder had not been determined. Torsion of the gallbladder may occur as an acute event or be subtle and recurrent. Because of the potentially catastrophic consequences of delayed surgical intervention, an abdominal operation should be performed early in patients with symptoms suggestive of acute cholecystitis, especially if a mass is palpable. The recommended treatment is cholecystectomy.

Subclavian vein. A golden route.

Percutaneous access to the subclavian vein provides a route for the insertion of a variety of devices necessary in the management of severely ill patients. As described in this article, the technique can be easily and safely performed. Special emphasis is given to the more recent applications of the technique in the placement of Swan-Ganz catheters, cardiac pacemakers, and hemodialysis cannulas. With familiarity of the anatomy, careful attention to details, and an awareness of the potential complications, this technique can become a useful tool for the practicing physician in various disciplines.

Aortic graft-enteric fistula.

Fifteen years' experience with 20 patients undergoing 24 operations for intestinal bleeding from aortic graft-enteric fistula at the Mayo Clinic has been reviewed. A review of the English language literature permits analysis of an additional 127 patients who underwent surgical intervention for this condition. Associated operative mortality in our experience and in that of others has been high--55% and 46%, respectively. Long-term survival in both groups remains low--approximately 15%. Consideration has therefore been given to aspects of prophylaxis, diagnosis, and intervention which may minimize future morbidity and mortality.

The clinical usefulness of routine stacked multiplanar reconstruction in helical abdominal computed tomography.

RATIONALE AND OBJECTIVES: The authors evaluate the usefulness of stacked multiplanar reconstructions in routine, thick-section abdominal computed tomography. MATERIALS AND METHODS: Twenty-five routine, thick-section contrast abdominal CTs performed with equivalent technique were reformatted by multiplanar reconstructions in sagittal and coronal planes sequentially from side-to-side and front-to-back. The image sets were submitted, first axial images only followed by axial plus multiplanar reconstructions (MPRs), to 5 separate physician readers including 2 radiologists and 3 nonradiologists. These readers graded the visualization of a variety of normal and up to 5 pathologic lesions per patient on a scale of 1 to 5 (5 = best). RESULTS: The addition of sagittal and coronal multiplanar reconstructions significantly improved the visualization of all normal anatomic structures (mean axial only, 3.8; mean axial plus MPR, 4.1; P < 0.0001). In addition, most pathologic lesions were statistically better visualized with the addition of multiplanar reconstructions (mean axial images only, 3.9; mean axial plus MPR, 4.1; P < 0.0001). All five readers found improved visualization in nearly every category with the addition of the multiplanar reconstructions. However, in only 7% of cases, did a reviewer find new diagnostic information with the addition of MPR images. CONCLUSIONS: Stacked multiplanar reconstructions of routine, thick-section abdominal CT has clinical value in both the display of normal anatomic and pathologic lesions. Further studies, however, are required to confirm these findings before it is commonly used.

Nonoperative management of the ruptured spleen: a revalidation of criteria.

BACKGROUND: Our goal was to revalidate this institution's original criteria for safe nonoperative management of splenic injury. METHODS: This was a prospective series between October 1991 and December 1995 entering all patients with splenic injury to a modified algorithm. Patients were taken to the operating room if hemodynamically unstable (systolic blood pressure less than 90 mm Hg; pulse greater than 110 beats per minute) after 2 liters of fluid resuscitation, positive abdominal examination findings, American Association for the Surgery of Trauma Organ Injury Scale Grade IV or V injuries by computed tomographic scan (unless younger than 15 years old), or associated severe head injuries (unless younger than 15 years old), or age greater than 55. The remainder of the patients were closely observed. RESULTS: One hundred seventy-three patients were entered-six were excluded by death before operating room salvage, and one was excluded because of operation for a ruptured thoracic aorta. Therefore 166 patients were reviewed. Seventy splenectomies and 18 splenorrhaphies were performed, and 78 patients were treated nonoperatively (58% splenic salvage). Two failures occurred in the nonoperative group: a 16-year-old with a grade IV hilar injury was operated on on the eighth day after injury because of a continually falling hematocrit, and a 25-year-old with unresolved tachycardia was operated on at 6 hours (97% success rate). The patients in the operative group had a greater severity of injury as determined by mean Injury Severity Score of 32, 18 deaths, a mean transfusion requirement of 14 units of blood compared with mean injury severity score of 21, two deaths from brain injury, and no transfusions given in 58 of the 78 nonoperative cases. CONCLUSIONS: Prospectively applied, these guidelines allow the safe nonoperative management of patients with blunt splenic injury.

Nonoperative management of blunt hepatic trauma in adults.

Although well accepted in pediatric patients, nonoperative management of blunt hepatic trauma in adults remains controversial. From January 1981 through May 1987, 66 adults were identified with blunt hepatic trauma that had been confirmed by abdominal exploration or abdominal computed tomography (CT): 46 underwent immediate operation, and 20 were initially managed nonoperatively. Patients were considered for nonoperative management only if they were hemodynamically stable and had no significant peritoneal irritation. CT criteria for nonoperative management included contained subcapsular or intrahepatic hematoma, unilobar fracture, absence of devitalized liver, minimal intraperitoneal blood, and absence of other significant intra-abdominal organ injuries. The predominant CT pattern in the 17 patients successfully managed nonoperatively included unilobar right-lobe fracture or intrahepatic hematoma. A small amount of blood in either gutter or in the pelvis did not portend failure of nonoperative management. No delayed complications were noted during an average follow-up of 27 months. Nonoperative management of blunt hepatic injury based on abdominal CT findings is a useful alternative in a select group of hemodynamically stable patients.

The complementary roles of diagnostic peritoneal lavage and computed tomography in the evaluation of blunt abdominal trauma.

To determine the roles of diagnostic peritoneal lavage (DPL) and abdominal computed tomography (CT) in the evaluation of blunt abdominal trauma, we compared our results in the eras before and after the advent of abdominal CT. In the pre-CT era 1977 to 1980 (group 1; 365 patients), DPL was the diagnostic procedure of choice. In the CT era 1983 to 1986 (group 2; 282 patients), DPL was used for unstable, polytraumatized patients, and CT was reserved for stable patients. The rate of delayed recognition of documented visceral injury (7%) was similar for groups 1 and 2. Celiotomy was nontherapeutic in 21 (14%) patients in group 1 and in 5 (5%) in group 2 (p less than 0.02). Despite immediate availability of abdominal CT, clinical examination alone or in combination with DPL was the diagnostic procedure of choice in 41% of those with blunt abdominal trauma in group 2. The complementary use of abdominal CT and DPL in those with blunt abdominal trauma decreased the rate of nontherapeutic celiotomy, did not result in a significant increase in missed injuries, and allowed identification of candidates for nonoperative management of solid organ injury.

Management of retroperitoneal sarcomas.

The records of 116 adult patients who underwent operative treatment for retroperitoneal sarcomas at the Mayo Clinic during the years 1963 to 1982 were reviewed. Clinical, pathologic, and treatment variables were analyzed for their influence on recurrence and death from disease. Leiomyosarcomas, liposarcomas, and malignant fibrous histiocytomas represented 93% of the tumors. The primary tumor was completely excised in 54% of patients. Recurrent tumor developed in 68% of patients (median time to recurrence, 1.3 years). Tumor fixation to adjacent structures (T3 tumor) or a high-grade tumor (G2-4) identified patients at increased risk for recurrent disease. Five-year and 10-year survival rates were 40% and 22%, respectively. Survival was significantly better for patients who had (1) complete surgical excision of their tumors, (2) low-grade tumors (G1), (3) tumors not fixed to adjacent retroperitoneal structures (T1 and T2 sarcomas), and (4) tumors without metastases when initially seen. Complete surgical excision offers patients with retroperitoneal sarcomas the best chance for long-term survival, but recurrent disease remains a vexing problem. The therapeutic challenges in the treatment of retroperitoneal sarcomas continue to be the development of therapy that will increase the rate of complete resection, decrease the rate of local recurrence, and enhance patient survival.

Acute cholecystitis as a complication in surgical patients.

Acute cholecystitis after operation or trauma is associated with reported mortalities of 10% to 50%. During a 16-year period at the Mayo Clinic, Rochester, Minn, 75 such patients were examined, eight of whom had traumatic injuries. The incidence of this complication was approximately one for every 10,000 surgical procedures. In contrast with acute cholecystitis that occurs de novo, elderly men who had other antecedent complications seemed to be at an increased risk. Also, acalculous cholecystitis with associated gangrene and perforation of the gallbladder was more commonly encountered. The diagnosis is difficult to establish in patients who have had recent abdominal operations and is based on physical signs and symptoms, although cholescintigraphy will be of value in future cases. The most common treatment is cholecystectomy. Clinicians must maintain a high index of suspicion and carefully examine any surgical patient in whom abdominal pain or unexplained fever develops. Once the diagnosis is confirmed, early operative intervention is indicated.

Duodenal villous tumors.

The treatment of 36 patients with duodenal villous tumors was reviewed to determine the long-term outcome of various surgical treatment options for specific adenoma histopathology. Duodenal villous tumors were typically solitary and periampullary in location. Villous adenomas contained epithelial atypia in 30% of patients, in situ carcinoma in 14%, and invasive carcinoma in 33%. Treatment consisted of transduodenal submucosal excision in 19 patients and radical pancreaticoduodenectomy in 15. There was no perioperative mortality. Perioperative morbidity for transduodenal excision and pancreaticoduodenectomy was 16% and 47%, respectively. Benign adenomas recurred more than 5 years postoperatively in 17% of patients undergoing transduodenal excision. Five-year survival following radical resection for invasive cancers was 45%. Overall median follow-up was 5.8 years. We conclude that duodenal villous tumors without invasive cancer can be managed successfully by local submucosal excision, but invasive carcinoma requires radical resection.

Hickman catheter implantation in the treatment of acute leukemia.

Between July 1980 and May 1981, 32 permanent indwelling Hickman catheters were implanted in 29 patients. Most of the catheters were placed for treatment of acute leukemia (25 patients) or lymphoma (two patients). Catheters were used for a total of 3,461 patient-days (mean, 108 days). Two patients had infections at the exit site, one seven and the other 11 days after implantation. Four patients had sepsis, but none of those infections appeared to be catheter related. Hickman catheters appear to provide ease of treatment in acute leukemia and are associated with patient satisfaction and an acceptable complication rate.

Closure of abdominal incisions with subcutaneous catheters. A prospective randomized trial.

A preliminary report from our institution suggested that closure of abdominal incisions with subcutaneous, closed-suction catheters intermittently irrigated with antibiotic resulted in decreased wound infection rates. To test this hypothesis, a prospective, randomized, controlled trial was undertaken to compare the results of primary closure, subcutaneous catheter irrigated with saline or antibiotic, and subcutaneous catheter alone. During the two-year trial, 3,282 incisions (type II, III, or IV) were analyzed. Subcutaneous catheter placement alone or with antibiotic or saline irrigation was not superior to primary closure for type II or III incisions. A trend favoring subcutaneous catheter and antibiotic irrigation was observed for type IV incisions. This finding suggests that further clinical trials designed to assess the role of subcutaneous catheter placement and antibiotic irrigation in decreasing wound infection rates are warranted in type IV incisions.

Interaction of HIV Tat model peptides with tRNA and 5S rRNA.

New data are presented on the interaction of model synthetic peptides containing an arginine-rich region of human immunodeficiency virus (HIV-Tat), with native RNA molecules: tRNA(Phe) of Saccharomyces cerevisiae and 5S rRNA from Lupinus luteus. Both RNA species form complexes with the Tat1 (GRKKRRQRRRA) and Tat2 (GRKKRRQRRRAPQDSQTHQASLSKQPA) peptides, as shown by electrophoretic gel shift and RNase footprint assays, and CD measurements. The nucleotide sequence UGGG located in the dihydrouridine loop of tRNAPhe as well as in the loop D of 5S rRNA is specifically protected against RNases. Our data indicate direct interactions of guanine of RNA moieties with arginine residues. These interactions seem similar to those observed in DNA-protein complexes, but different from those previously observed in the TAR RNA-Tat complexes.