Impact of pancreatic head resection on direct medical costs in patients with chronic pancreatitis

OBJECTIVE

To quantitate disease-specific hospital-based medical costs in 34 patients with chronic pancreatitis before and after treatment by either duodenal-preserving pancreatic head resection (DPPHR) or pylorus-preserving pancreaticoduodenectomy (PPPD).

SUMMARY BACKGROUND DATA

Pancreatic head resection in selected patients with chronic pancreatitis provides pain relief and improves quality of life, but the effect on healthcare costs is unknown.

METHODS

This observational cohort study comprised 34 selected patients with chronic pancreatitis followed up exclusively at the authors' institution treated by either DPPHR or PPPD between 1992 and 1997.

RESULTS

Twenty-one patients had DPPHR and 13 had PPPD. Patients in the PPPD group were slightly older, but other clinical characteristics were similar. Before surgery, the mean number of admissions per patient per year, days in the hospital per patient per year, and disease-specific hospital-based medical costs per patient per year were not significantly different between groups. After surgery, those three variables were similar between the groups but significantly less than preoperative values. Pain control remained significantly improved after 36 months of follow-up.

CONCLUSIONS

In selected patients with chronic pancreatitis, DPPHR and PPPD are equally effective in providing long-term pain relief and decreasing disease-specific hospital-based costs.

Stages of Reproductive Aging Workshop (STRAW)

A select group of clinicians and investigators met recently for the express purpose of developing a staging system for female reproductive aging. The group also addressed the confusing and redundant nomenclature that is commonly used to describe the late reproductive years. A summary and recommendations are presented.

Roux-en-Y internal drainage is the best surgical option to treat patients with disconnected duct syndrome after severe acute pancreatitis

BACKGROUND

Roux-en-Y (RNY) internal drainage has been our primary surgical strategy to definitively treat disconnected duct syndrome in patients after severe acute pancreatitis (SAP). This study compares the results of internal drainage with the results of distal pancreatectomy-splenectomy (DPS) performed in a contemporaneous group of patients.

METHODS

For 5 years (June 1995 to June 2000), 27 consecutive patients with disconnected duct syndrome after SAP were identified: 13 treated with internal drainage and 14 with DPS. Fistula characteristics, operative management, and clinical outcome were analyzed. Comparisons between groups were made with the Student t test and Fisher exact test, with statistical significance defined as P <.05.

RESULTS

Age, sex, etiology of pancreatitis, comorbid diseases, and prior operations were similar between groups. Internal drainage required less operative time (211 +/- 37 vs 269 +/- 88 minutes, P =.04), blood loss (735 +/- 706 vs 2757 +/- 3062 mL, P =.03), and transfusion requirements (0.69 +/- 1.7 vs 4.21 +/- 8.0 units, P =.05). Clinical outcomes--as measured by postoperative complication rate, reoperation rate, fistula recurrence rate, and death rate--were similar between groups.

CONCLUSIONS

RNY internal drainage, when technically feasible, is the best surgical option to treat disconnected duct syndrome after SAP.

Two dopamine genes related to reports of childhood retrospective inattention and conduct disorder symptoms

The 7-repeat allele of the dopamine receptor D4 gene (DRD4) and the 10 repeat allele of the dopamine transporter gene (DAT1) have shown association and linkage with symptoms of attention deficit hyperactivity disorder (ADHD) in childhood. The parents of ADHD children (clinic group, n = 80 fathers and 107 mothers) and control children (control group, n = 42 fathers and 51 mothers) were the focus of this study. These parents reported retrospectively on their level of ADHD Inattention and Conduct Disorder symptoms in adolescence. In analyses of the relation of symptom levels to the DRD4 and DAT1 genotypes, fathers possessing the 7 repeat DRD4 allele had greater levels of both inattention and conduct disorder symptoms. Mothers with the 10/10 genotype had higher levels of inattention symptoms. Thus, genetic associations found in children may be replicable in their parents.

Selenoprotein oxidoreductase with specificity for thioredoxin and glutathione systems

Thioredoxin (Trx) and glutathione (GSH) systems are considered to be two major redox systems in animal cells. They are reduced by NADPH via Trx reductase (TR) or oxidized GSH (GSSG) reductase and further supply electrons for deoxyribonucleotide synthesis, antioxidant defense, and redox regulation of signal transduction, transcription, cell growth, and apoptosis. We cloned and characterized a pyridine nucleotide disulfide oxidoreductase, Trx and GSSG reductase (TGR), that exhibits specificity for both redox systems. This enzyme contains a selenocysteine residue encoded by the TGA codon. TGR can reduce Trx, GSSG, and a GSH-linked disulfide in in vitro assays. This unusual substrate specificity is achieved by an evolutionary conserved fusion of the TR and glutaredoxin domains. These observations, together with the biochemical probing and molecular modeling of the TGR structure, suggest a mechanism whereby the C-terminal selenotetrapeptide serves a role of a protein-linked GSSG and shuttles electrons from the disulfide center within the TR domain to either the glutaredoxin domain or Trx.

Endoscopic ultrasonography-guided fine-needle aspiration biopsy of suspected pancreatic cancer

BACKGROUND

In many institutions, computed tomography (CT)-guided percutaneous fine-needle aspiration (FNA) has become the procedure of choice for biopsies of pancreatic mass lesions. This method of biopsy and others, such as endoscopic retrograde cholangiopancreatography (ERCP) cytology, are problematic because of a substantial false-negative rate.

OBJECTIVE

To investigate the yield of endoscopic ultrasonography-guided FNA biopsies in patients who had negative results on CT-guided biopsy or negative cytologic findings on ERCP sampling.

DESIGN

Prospective cohort study.

SETTING

Tertiary care university medical center.

PATIENTS

102 patients (median age, 65 years; 58 men and 44 women) with suspected pancreatic cancer who fulfilled the above criteria were prospectively identified and underwent endoscopic ultrasonography-guided FNA biopsy.

MEASUREMENTS

The operating characteristics of endoscopic ultrasonography-guided FNA for diagnosing pancreatic masses were determined. Surgical pathology or long-term follow-up (median, 24 months) was used to identify false-positive or false-negative results.

RESULTS

Median mass size was 3.5 cm x 2.7 cm. A median of 3.4 passes were performed. Cytologic results on endoscopic ultrasonography-guided FNA biopsy were positive in 57 patients, negative in 37, and inconclusive or nondiagnostic in 8. No false-positive results were observed. A diagnosis of pancreatic cancer was subsequently confirmed in 3 patients who had tested negative (false-negative results) and 1 of the 8 patients with nondiagnostic results. Of these 4 patients, 3 had cytologic evidence of chronic pancreatitis on endoscopic ultrasonography-guided FNA biopsy. The 95% CI for the likelihood ratio for a positive test result contained all values greater than or equal to 9.7. The likelihood ratio for a negative test result was 0.05 (CI, 0.02 to 0.15). The posterior probability of pancreatic cancer after a definitely positive result was at least 93.5% by a conservative lower 95% confidence limit; after a definitely negative test result, it was 6.9%. The prevalence of pancreatic cancer was 59.8% (61 of 102 patients). Self-limited complications occurred in 3 of the 102 patients (2.9% [CI, 0.6% to 8.4%]).

CONCLUSION

Endoscopic ultrasonography-guided FNA biopsy may play a valuable role in the evaluation of a pancreatic mass when results on other biopsy methods are negative but pancreatic cancer is suspected.

Impact of endoscopic therapy on the survival of patients with primary sclerosing cholangitis

BACKGROUND

Endoscopic measures such as balloon dilation can relieve obstruction and improve symptoms in patients with primary sclerosing cholangitis (PSC). However, the influence of repeated endoscopy to maintain biliary patency on the survival of patients with PSC is unclear.

METHODS

This study evaluated the impact of endoscopic therapy on the survival of consecutive patients with PSC undergoing endoscopic therapy. During a 6-year period 63 patients underwent endoscopic therapy. After initial therapy, patients were followed for a median of 34 months. Endoscopic therapy primarily consisted of repeated balloon dilation of dominant biliary strictures. The observed survival of this cohort was estimated (Kaplan-Meier). The predicted survival of the cohort was estimated by using the Mayo Clinic survival model based on clinical information obtained within 3 months before first endoscopic therapy. The Mayo Risk Score was calculated by using the equation R = (0.03 Age, years) + (0.54 log(e) Bilirubin mg/dL) + (0.54 log(e) Aspartate aminotransferase U/mL) + (1.24 Bleed history) - (0.84 Albumin gm/dL).

RESULTS

The observed survival over 5 years was significantly higher than the predicted 5-year survival (83% vs. 65%, respectively; p = 0.027).

CONCLUSION

These data suggest that repeated endoscopic attempts to maintain biliary patency may improve the survival of patients with PSC and dominant strictures.

Endoscopic ultrasound-guided celiac plexus block for managing abdominal pain associated with chronic pancreatitis: a prospective single center experience

OBJECTIVE

In our previous randomized trial, we suggested a possible role for endoscopic ultrasound (EUS) guided celiac plexus block in the treatment of abdominal pain associated with chronic pancreatitis. The purpose of this study was to evaluate our prospective experience with EUS-guided celiac plexus block for controlling pain attributed to chronic pancreatitis, including follow-up on response rates and complications.

METHODS

All subjects enrolled had documented chronic pancreatitis by ERCP and EUS criteria and presented with chronic abdominal pain unresponsive to current treatment options. All were treated with EUS-guided celiac plexus block under the guidance of linear array endosonography using a 22-gauge FNA needle (GIP, Mediglobe Inc., Tempe, AZ) inserted on each side of the celiac area, followed by injection of 10 cc bupivacaine (0.25%) and 3 cc (40 mg) triamcinolone on each side of the celiac plexus. Individual pain scores, based on a visual analog scale (0-10), were determined preblock and postblock by a nurse at 2, 7, 14 days and monthly thereafter. Subjects also rated their overall comfort level during the EUS procedure.

RESULTS

EUS-guided celiac plexus block was performed in 90 subjects (40 males, 50 females) having a mean age of 45 yr (range 17-76 yr) between July 1, 1995 and December 30, 1996. A significant improvement in overall pain scores occurred in 55% (50/90) of patients. The mean pain score decreased from 8 to 2 post EUS celiac block at both 4 and 8 wk follow-up (p < 0.05). In 26% of patients there was persistent benefit beyond 12 wk, and 10% still had persistent benefit at 24 wk, including three patients who were pain-free between 35 and 48 wk. Younger patients (<45 yr of age) and those having previous pancreatic surgery for chronic pancreatitis were unlikely to respond to the EUS-guided celiac block. Three patients experienced diarrhea post EUS celiac block, which resolved in 7-10 days; however, it is unclear whether this diarrhea was due to the block or to refractory disease. A cost comparison between the EUS ($1200) and CT ($1400) techniques shows the EUS celiac block to be less costly and perhaps more cost efficient in a subset of subjects.

CONCLUSIONS

EUS-guided celiac plexus block appears to be safe, effective, and economical for controlling pain in some patients with chronic pancreatitis. Younger patients (<45 yr) and those having prior pancreatic surgery for chronic pancreatitis do not appear to benefit from this technique. Prophylactic antibiotics should be considered if acid suppressing agents are being taken.

Therapeutic biliary endoscopy

Therapeutic biliary endoscopy is continuing to evolve; some small but important developments were seen during the last year. Competing techniques are continuing to develop.

Influence of cholangiography on biliary sphincter of Oddi manometric parameters

BACKGROUND

When sphincter of Oddi manometry (SOM) and endoscopic retrograde cholangiopancreatography are performed at the same session, SOM is usually performed immediately before ductography because of concern about the accuracy of the manometric recording after contrast medium injection. However, it would be preferable to inject contrast medium first to identify other causes for a patient's symptoms, allowing selective use of SOM. The aim of this study was to evaluate the effect of cholangiography on sphincter of Oddi (SO) basal pressure.

METHODS

Twenty-five patients with suspected SO dysfunction were prospectively studied. Conventional station pull-through manometry of the biliary part of the sphincter was performed before and after cholangiography. The intraductal pressure and basal sphincter pressure were evaluated.

RESULTS

The mean intraductal pressure was 8+/-5.5 mm Hg before and 13.3+/-6.8 mm Hg after contrast medium injection (p< 0.01). However, the basal sphincter pressure was not significantly altered (52.9+/-42.1 mm Hg vs. 55.1+/-38.1 mm Hg, p = 0.52). Concordance (normal vs. abnormal) between the basal sphincter pressure before and after ductography was seen in 24 of 25 patients (96%).

CONCLUSIONS

Intraductal installation of contrast medium immediately before SOM infrequently alters SO basal pressure in a clinically significant manner. We therefore believe that this sequence can be utilized in clinical practice.

Structural effects of O-glycosylation on a 15-residue peptide from the mucin (MUC1) core protein

To study the effect of O-glycosylation on the conformational propensities of a peptide backbone, the 15-residue peptide PPAHGVTSAPDTRPA (PPA15) from the MUC1 protein core and its analogue PPA15(T7), glycosylated with alpha-N-acetylgalactosamine on Thr7, were prepared and investigated by NMR spectroscopy. The peptide contains both the GVTSAP sequence, which is an effective substrate for GalNAc-T1 and -T3 transferases, and the PDTRP fragment, which is a well-known immunodominant epitope recognized by several anti-MUC1 monoclonal antibodies. Useful structural results were obtained in water upon decreasing the temperature to 5-10 degrees C. The sugar attachment slightly affected the conformational equilibrium of the peptide backbone near the glycosylated Thr7 residue. The clustering of low-energy conformations for both PPA15 and PPA15(T7) within the GVTSAP and APDTRP fragments revealed structural similarities between glycosylated and nonglycosylated peptides. For the GVTSAP region, minor but distinct clusters formed by either PPA15 or PPA15(T7) conformers showed distinct structural propensities of the peptide backbone specific for either the nonglycosylated or the glycosylated peptide. The peptide backbone of the APDTRP fragment, which is a well-known immunodominant region, resembled an S-shaped bend. A similar structural motif was found in the GVTSAP fragment. The S-shaped structure of the peptide backbone is formed by consecutive inverse gamma-turn conformations partially stabilized by hydrogen bonding. A comparison of the solution structure of the APDTRP fragment with a crystal structure of the MUC1 peptide antigen bound to the breast tumor-specific antibody SM3 demonstrated significant structural similarities in the general shape.

Success of ERCP at a referral center after a previously unsuccessful attempt

BACKGROUND

The diagnostic and therapeutic success of endoscopic retrograde cholangiopancreatography (ERCP) depends on a number of factors. When an attempt at ERCP fails, the physician must decide whether to repeat the procedure, rely on another imaging procedure (noninvasive or invasive), or refer to another endoscopist/center. Our aim in this prospective study was to determine the role of a second attempt at ERCP at a referral ERCP center.

METHODS

Five hundred sixty-two patients were referred for ERCP after having undergone a previous unsuccessful attempt to visualize the clinically relevant duct(s).

RESULTS

The overall success in visualizing the desired duct was 96.4% (542 of 562). Advanced techniques for cannulation were used in 41% (229 of 562). Anatomic abnormalities possibly contributing to the previous lack of success were present in 27% of cases. ERCP with or without manometry identified a cause or potential cause for the signs and symptoms in 86% of patients. Sixty complications occurred in 57 patients (10.1%). ERCP was unsuccessful in 20 patients (3.6%).

CONCLUSIONS

The cannulation success rate and diagnostic yield of further ERCP with an acceptable complication rate warrant consideration of referral to centers with available resources and expertise.

Counting cross-overs: characterizing meiotic recombination in mammals

Until recently, most of our understanding of meiotic recombination has come from studies of lower eukaryotes. However, over the past few years several components of the mammalian meiotic recombination pathway have been identified, and new molecular and cytological approaches to the analysis of mammalian meiosis have been developed. In this review, we discuss recent advances in three areas: the application of new techniques to study genome-wide levels of recombination in individual meioses; studies analyzing temporal aspects of the mammalian recombination pathway; and studies linking the genesis of human trisomies to alterations in meiotic exchange patterns.

The method of sib-pair linkage analysis in context of case-control design

We used sib-pair linkage analysis as part of an epidemiologic approach to solving Problem 2 of the GAW10 data set of nuclear families. We recoded the quantitative trait Q1 into a dichotomous trait using Q1 > or = 40 as the cut-point. In a case-control design of sib-pair analysis, the affected siblings of the proband were the case subjects and the unaffected siblings were the control subjects. Case and control subjects were compared with respect to the number of alleles at one or more loci (0, 1, 2) that were identical-by-descent (IBD) with those of the proband. Odds ratios (ORs) and 95% confidence intervals (95% CI) were then computed with subjects sharing no alleles (share-0) serving as the reference group. Significantly high ORs were taken as indication of linkage between a marker locus and a suspected disease-susceptibility locus. The case-control sib-pair analysis identified marker D5G15 as associated with disease susceptibility (OR of sharing two alleles [share-2] = 7.7 [95% CI 2.5-23.9]). Our results were consistent with the results from Kruglyak and Lander's method of complete multipoint sib-pair analysis for linkage. For the marker (D5G15) identified through sib-pair analysis, we examined the effects of other covariates and evaluated gene-environment interaction using conditional logistic regression.

Bias associated with study protocols in epidemiologic studies of disease familial aggregation

The effect of selection bias has not been well evaluated in epidemiologic studies which focus on familial aggregation. The authors illustrate this type of bias for a reconstructed cohort study. With the reconstructed cohort design, cases and controls are first selected from the population and their relatives form the exposed and unexposed cohorts, respectively. The recurrence risk ratio (RRR) is calculated to assess and measure familial aggregation. The ways of utilizing information from relatives affects the estimate of RRR, and the authors show that a traditional method used in epidemiologic studies can yield a severely biased estimate of the RRR. However, this traditional approach can give approximately unbiased estimates under special conditions. A novel selection approach is proposed which yields an unbiased estimate of RRR. In conclusion, when relatives are identified through cases or controls, they should be included and counted in the study cohorts each time a case or control is selected, even if they or other family members have already been included.

Triple-tissue sampling at ERCP in malignant biliary obstruction

BACKGROUND

Procurement of cytologic samples by brushing is common practice at endoscopic retrograde cholangiopancreatography (ERCP) but has low sensitivity for cancer detection. Limited data are available on other techniques, including endoluminal fine-needle aspiration and forceps biopsy. This series reviews the yield of these three stricture sampling methods.

METHODS

In this prospective study, patients with biliary obstruction with a clinical suspicion of malignancy underwent triple-tissue sampling at one ERCP session. Final cancer diagnosis was based on all sampling methods plus surgery, autopsy, and clinical follow-up. Tissue specimens were reported as normal, atypia, or malignant.

RESULTS

A total of 133 patients were evaluated: 104 had cancer and 29 had benign strictures. Tissue sampling sensitivity varied according to the type of cancer; the highest yield was seen in ampullary cancers (62% to 85%). The cumulative sensitivity of triple-tissue sampling in the cancer patients was as follows: sensitivity was 52% if atypia was considered benign and 77% if it was considered malignant. The addition of a second or third technique increased sensitivity rates in most instances. No serious complications occurred from the tissue sampling methods.

CONCLUSIONS

Tissue sampling sensitivity varied according to the type of cancer. Combining a second or third method increased sensitivity; general use of at least two sampling methods is therefore recommended.

Endoscopic ultrasound characteristics of mucinous cystic neoplasms of the pancreas

OBJECTIVE

Mucinous cystic neoplasms of the pancreas have a more favorable prognosis than ductal adenocarcinoma. Management of a subgroup, intraductal papillary-mucinous neoplasms, is controversial. Endoscopic ultrasound (EUS) with fine-needle aspiration biopsy may emerge as the imaging modality of choice. There are few studies describing the EUS features of these tumors.

METHODS

A total of 35 consecutive cases of cystic tumors of the pancreas with an established pathological diagnosis were analyzed for characteristic EUS features.

RESULTS

Mucinous cystadenocarcinomas (n = 14) were more likely to be characterized by hypoechoic cystic/solid mass or complex cyst and were frequently associated with a dilated main pancreatic duct. Benign mucinous duct ectasia (n = 6) were characterized by a dilated main pancreatic duct in conjunction with hyperechoic thickening of the duct wall. The two cases of intraductal mucinous hyperplasia additionally showed a hypoechoic mass. Intraductal papillary carcinoma (n = 11) had features in common with mucinous cystadenocarcinoma but also had echogenic foci in the mass and intraductal hyperechoic lesions. The two cases of microcystic cystadenoma showed either a mixed hypoechoic solid/cystic mass or a complex cyst without the additional features seen in mucinous cystadenocarcinoma.

CONCLUSIONS

EUS features seem to exist that may help to differentiate cystic neoplasms from adenocarcinoma of the pancreas and, thus, to establish the preoperative diagnosis of cystic tumors of the pancreas.

Down syndrome: genetic recombination and the origin of the extra chromosome 21

Despite the clinical importance of trisomy 21, we have been ignorant of the causes of meiotic nondisjunction of chromosome 21. Recently, however, genetic mapping studies of trisomy 21 families have led to the identification of the first molecular correlate of human nondisjunction; i.e. altered levels and positioning of meiotic recombinational events. Specifically, increases in 0 exchange events or in distal-only or pericentromeric exchanges are significantly increased in trisomy 21-generating meioses. These observations have led to the idea that chromosome 21 nondisjunction requires 'two hits': first, the establishment in prophase I of a 'vulnerable' bivalent and second, abnormal processing of the bivalent at metaphase I or II.

Endoscopic measurement of pancreatic tissue perfusion in patients with chronic pancreatitis and control patients

BACKGROUND

Pancreatic blood flow is diminished in experimental models of acute and chronic pancreatitis. We attempted to develop a safe and reliable technique for its measurement in patients and to examine blood flow in patients with chronic pancreatitis and in control subjects.

METHOD

Pancreatic blood flow was measured using the hydrogen gas clearance technique and an endoscopically placed platinum ductal electrode. Pancreatic blood flow was measured in 12 patients with chronic pancreatitis diagnosed clinically and radiographically, and in 11 control patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) for non-pancreatic pathology.

RESULTS

Patients with chronic pancreatitis had a significantly lower pancreatic blood flow compared with control patients (51.5 versus 91.7 mL/min/100 gm, p < 0.01). With secretin stimulation pancreatic blood flow increased in two control patients, whereas this notable rise was not seen in three patients with chronic pancreatitis.

CONCLUSIONS

Measurement of pancreatic blood flow with an endoscopically placed electrode is relatively safe and simple to perform. The scarring and vascular fibrosis associated histologically with chronic pancreatitis is reflected in lower pancreatic blood flow.

Effectiveness of Tizanidine in Neuropathic Pain: An Open-Label Study

The purpose of this research trial is to assess the effectiveness and tolerability of tizanidine in neuropathic pain. In an open-label study, patients with neuropathic pain received 1 to 4 mg of tizanidine once daily for 7 days, followed by weekly dose escalation of 2 to 8 mg to his/her effective or maximum tolerated dose or a maximum of 36 mg over an 8-week period. Treatment effects were assessed, using average weekly pain scores as well as biweekly scores for patient global assessment of pain relief, the neuropathic pain scale, and wisconsin brief pain inventory. Frequency and severity of adverse events were examined also. Twenty-three patients were enrolled. The mean average weekly pain score at baseline was 6.9, which decreased by 1.7 points at the end of week 8 to 5.2 (p < or =.01). A total of 15 patients (68%) reported that their pain relief was improved or much improved with tizanidine therapy, and 2 of these patients became completely pain-free. The following neuropathic pain qualities were significantly lower at week 8 compared with baseline: intense, sharp, hot, dull, cold, sensitive, unpleasant, and deep pain. There was a significant decline in pain quantity and interference of pain on quality of life from baseline to week 8. The mean effective or maximum tolerated dose was 23 mg/day (range 6 to 36 mg/day). Side effects consisted primarily of dizziness/lightheadedness (52%), drowsiness (48%), fatigue/weakness (43%), dry mouth (39%), gastrointestinal upset (30%), and sleep difficulty (22%). One patient developed significant elevation in liver function tests (LFTS) With symptoms at week 4. Tizanidine therapy was discontinued. LFTS returned to normal in 3 weeks. Tizanidine might be an effective treatment for neuropathic pain, offering an alternative for patients poorly responsive to other medications. A larger, randomized placebo-controlled trial is recommended. In addition, comparative studies with alternative agents should be sought.