How do we manage post-OLT redundant bile duct?

AIM: To address endoscopic outcomes of post-Orthotopic liver transplantation (OLT) patients diagnosed with a "redundant bile duct" (RBD). METHODS: Medical records of patients who underwent OLT at the Liver Transplant Center, University Texas Health Science Center at San Antonio Texas were retrospectively analyzed. Patients with suspected biliary tract complications (BTC) underwent endoscopic retrograde cholangiopancreatography (ERCP). All ERCP were performed by experienced biliary endoscopist. RBD was defined as a looped, sigmoid-shaped bile duct on cholangiogram with associated cholestatic liver biomarkers. Patients with biliary T-tube placement, biliary anastomotic strictures, bile leaks, bile-duct stones-sludge and suspected sphincter of oddi dysfunction were excluded. Therapy included single or multiple biliary stents with or without sphincterotomy. The incidence of RBD, the number of ERCP corrective sessions, and the type of endoscopic interventions were recorded. Successful response to endoscopic therapy was defined as resolution of RBD with normalization of associated cholestasis. Laboratory data and pertinent radiographic imaging noted included the pre-ERCP period and a follow up period of 6-12 mo after the last ERCP intervention. RESULTS: One thousand two hundred and eighty-two patient records who received OLT from 1992 through 2011 were reviewed. Two hundred and twenty-four patients underwent ERCP for suspected BTC. RBD was reported in each of the initial cholangiograms. Twenty-one out of 1282 (1.6%) were identified as having RBD. There were 12 men and 9 women, average age of 59.6 years. Primary indication for ERCP was cholestatic pattern of liver associated biomarkers. Nineteen out of 21 patients underwent endoscopic therapy and 2/21 required immediate surgical intervention. In the endoscopically managed group: 65 ERCP procedures were performed with an average of 3.4 per patient and 1.1 stent per session. Fifteen out of 19 (78.9%) patients were successfully managed with biliary stenting. All stents were plastic. Selection of stent size and length were based upon endoscopist preference. Stent size ranged from 7 to 11.5 Fr (average stent size 10 Fr); Stent length ranged from 6 to 15 cm (average length 9 cm). Concurrent biliary sphincterotomy was performed in 10/19 patients. Single ERCP session was sufficient in 6/15 (40.0%) patients, whereas 4/15 (26.7%) patients needed two ERCP sessions and 5/15 (33.3%) patients required more than two (average of 5.4 ERCP procedures). Single biliary stent was sufficient in 5 patients; the remaining patients required an average of 4.9 stents. Four out of 19 (21.1%) patients failed endotherapy (lack of resolution of RBD and recurrent cholestasis in the absence of biliary stent) and required either choledocojejunostomy (2/4) or percutaneous biliary drainage (2/4). Endoscopic complications included: 2/65 (3%) post-ERCP pancreatitis and 2/10 (20%) non-complicated post-sphincterotomy bleeding. No endoscopic related mortality was found. The medical records of the 15 successful endoscopically managed patients were reviewed for a period of one year after removal of all biliary stents. Eleven patients had continued resolution of cholestatic biomarkers (73%). One patient had recurrent hepatitis C, 2 patients suffered septic shock which was not associated with ERCP and 1 patient was transferred care to an outside provider and records were not available for our review. CONCLUSION: Although surgical biliary reconstruction techniques have improved, RBD represents a post-OLT complication. This entity is rare however, endoscopic management of RBD represents a reasonable initial approach.

The Mirizzi syndrome: multidisciplinary management promotes optimal outcomes.

The Mirizzi syndrome (MS) is a rare cause of obstructive jaundice produced by the impaction of a gallstone either in the cystic duct or in the gallbladder, resulting in stenosis of the extrahepatic bile duct and, in severe cases, direct cholecystocholedochal fistula formation. Sixteen patients were treated for MS in our center over the 12-year period 1993--2005 for a prevalence of 0.35% of all cholecystectomies performed. One patient was diagnosed only at the time of cholecystectomy. The other 15 patients presented with laboratory and imaging findings consistent with choledocholithiasis and underwent preoperative endoscopic retrograde cholangiopancreatography, which established the diagnosis in all but one patient. All patients underwent cholecystectomy. An initial laparoscopic approach was attempted in 14 patients, of whom 11 were converted to open procedures. MS was recognized operatively in 15 patients with definitive stone extraction and relief of obstruction in 13 patients. T-tubes were placed in 10 patients and 1 patient required a choledochoduodenostomy. Two patients required postoperative laser lithotripsy via a T-tube tract to clear their stones; and in another patient, MS was detected and treated via postoperative endoscopic retrograde cholangiopancreatography (ERCP). MS remains a serious diagnostic and therapeutic challenge for endoscopists and biliary surgeons.

Safety and efficacy of metallic stents in the management of colorectal obstruction.

BACKGROUND: The use of self-expandable metallic stents in the management of obstructing colorectal cancer has been described with increasing frequency in the literature. Our goal was to evaluate the efficacy and associated morbidity of the use of self-expandable metallic stents to relieve colorectal obstruction at our institution. METHODS: A retrospective chart review of patients who underwent colorectal stent placement between December 2001 and December 2003 in a tertiary referral center was performed. RESULTS: Stents were placed successfully in 17 of 21 patients (81%) with colorectal obstruction. Placement was achieved endoscopically in 13 patients and radiologically in 4. Ten self-expandable metallic stents were used as a bridge to surgery, and 7 were used for palliation. The obstructions were located in the sigmoid colon (11 patients), the rectosigmoid (3), the splenic flexure, the hepatic flexure, and the rectum. Malignant obstruction was noted in 14 patients. One patient with malignancy experienced a sigmoid perforation, and 2 patients with benign disease had complications (1 stent migration and 1 re-obstruction). Stent patency in obstruction secondary to colonic adenocarcinoma was 100% in our follow-up period (range, 5 to 15 months). CONCLUSIONS: The use of stents as a bridge to surgery is associated with low morbidity, allows for bowel preparation, and thus avoids the need for a temporary colostomy. Long-term patency suggests that stents may allow for the avoidance of an operation in patients with metastatic disease and further defines their role in the palliation of malignant obstruction. Further prospective randomized studies are necessary to fully elucidate the use of stents in the management of colorectal cancer.

Contrast sensitivity in dyslexia.

Contrast sensitivity was determined for dyslexic and normal readers. When testing with temporally ramped (i.e. stimuli with gradual temporal onsets and offsets) gratings of 0.6, 4.0, and 12.0 cycles/deg, we found no difference in contrast sensitivity between dyslexic readers and controls. Using 12.0 cycles/deg gratings with transient (i.e. abrupt) onsets and offsets, we found that dyslexic individuals had, compared to controls, markedly inferior contrast sensitivity at the shortest stimulus durations (i.e. 17, 34, and 102 ms). This deficit may reflect more sluggish temporal summation. There was no difference in sensitivity to 0.6 cycles/deg gratings with transient onsets and offsets. Under these conditions, the two groups showed a consistent and equal increase in sensitivity relative to the ramped baseline condition at 0.6 cycles/deg at the longer stimulus durations. This demonstrates that dyslexic readers have no deficit in their ability to detect stimulus transients, a finding which appears to be inconsistent with a transient system deficit. That detection of the low-frequency stimuli was mediated by the transient system is further indicated by the fact that these stimuli were more susceptible to forward masking than were the high-frequency stimuli. The effects of masking of both high and low spatial-frequency stimuli were about equal for dyslexic readers and controls. This is not in agreement with the transient system deficit theory, according to which one would expect there to be less masking of high spatial-frequency stimuli in the case of dyslexic readers.

Temporal lobe surface area measurements on MRI in normal and dyslexic readers.

In a neuroanatomical study of dyslexia, measurements were made of the superior surface of the temporal lobe (SSTL) on MRI scans in a sample of 17 dyslexics and 21 non-dyslexic subjects. Both anterior and posterior halves of the SSTL area showed significant leftward asymmetry in non-dyslexics, but showed symmetry in dyslexics. The total SSTL area showed greater leftward asymmetry in non-dyslexics than in dyslexics. The dyslexics also revealed a significant correlation (r = 0.69, P = 0.005) between Woodcock-Johnson Passage Comprehension scores and posterior SSTL asymmetry, such that those with higher scores had more leftward asymmetry. This suggests that among dyslexics the direction of SSTL asymmetry may serve as a risk factor and/or a marker for the severity of reading comprehension problems.

Familial dyslexia: genetic and medical findings in eleven three-generation families.

In addition to providing information on the inheritance of dyslexia, the present study of eleven three-generation families has provided a unique opportunity to compare affected and unaffected family members at all ages. The data presented here are based on pedigree information, a questionnaire administered to all participating family members in relation to sex ratio, handedness, the severity of dyslexia by sex, pre- and perinatal complications, medical complications, years of education and earning ability, and a battery of standardized tests to define the presence or absence of dyslexia. The pattern of inheritance was consistent with the postulated autosomal dominant mode of inheritance and penetrance was found to be > 90 percent. Of 73 individuals determined to have a gene leading to dyslexia, seven were classified as obligate carriers and six as compensated adults who had no current symptoms or diagnostic evidence of dyslexia. The sex ratio (1.06) was not different from the expected ratio of 1.04. Left-handedness, major pre- and perinatal complications, and autoimmune disorders and allergy were not more common in dyslexics than non-dyslexics. The number of years of education and average income were similar in affected and unaffected family members. Compensated adults and obligate carriers were similar to unaffected family members in each of these parameters.

Speech perception in adult subjects with familial dyslexia.

Speech perception was investigated in a carefully selected group of adult subjects with familial dyslexia. Perception of three synthetic speech continua was studied: /a/-/e/, in which steady-state spectral cues distinguished the vowel stimuli; /ba/-/da/, in which rapidly changing spectral cues were varied; and /sta/-/sa/, in which a temporal cue, silence duration, was systematically varied. These three continua, which differed with respect to the nature of the acoustic cues discriminating between pairs, were used to assess subjects' abilities to use steady state, dynamic, and temporal cues. Dyslexic and normal readers participated in one identification and two discrimination tasks for each continuum. Results suggest that dyslexic readers required greater silence duration than normal readers to shift their perception from /sa/ to /sta/. In addition, although the dyslexic subjects were able to label and discriminate the synthetic speech continua, they did not necessarily use the acoustic cues in the same manner as normal readers, and their overall performance was generally less accurate.

Positron emission tomographic studies during serial word-reading by normal and dyslexic adults.

Positron-emission tomography (PET) was used to study regional cerebral metabolic activity during oral reading in right-handed adult males with, and without a childhood and family history of developmental dyslexia. Significant group differences in normalized regional metabolic values were revealed in prefrontal cortex and in the lingual (inferior) region of the occipital lobe. Lingual values were bilaterally higher for dyslexic than normal readers. In contrast to the asymmetry observed in prefrontal and lingual regions in nondyslexic subjects during reading, the dyslexic pattern was more symmetric. These results demonstrate that individuals who suffered from familial developmental dyslexia as children, activate different brain regions during reading as adults, as compared to individuals without such childhood history.

Neuroanatomic differences between dyslexic and normal readers on magnetic resonance imaging scans.

The areas of six bilateral brain segments in the right and left hemispheres, on a horizontal brain section, and the area of subdivisions of the corpus callosum, on a midsagittal brain section, were measured on magnetic resonance images obtained from 21 dyslexic and 29 control subjects. In the entire group, the frontal half of the horizontal brain section showed asymmetry, with the right side being larger, whereas posteriorly only the occipital polar segment was asymmetrical, with the left side being larger. Dyslexic subjects exhibited asymmetry, with the right side greater than the left side, in contrast to the relatively symmetrical pattern that is normally observed in the midposterior segment that corresponds to the angular gyrus. In the corpus callosum, dyslexic subjects were found to have a larger splenium than nondyslexic subjects, and dyslexic female subjects were found to have a larger splenium than dyslexic male subjects. Because transcallosal pathways connecting the left and right angular gyrus regions traverse through the splenium of the corpus callosum, the above findings in dyslexic subjects suggest an anatomic abnormality in the angular gyrus region.

Dyslexia subtypes: genetics, behavior, and brain imaging.

This study was designed to identify inherited subtypes of specific dyslexia and to characterize these types by a variety of studies. A previous linkage study in large three-generation families resulted in a LOD score of 3.24 at a 13% recombination frequency between dyslexia and normal variations for the short arm of chromosome 15. The odds for linkage with chromosome 15 markers are better than 1,000 to 1. We estimate that 30% of an extended series of families show linkage to chromosome 15 polymorphisms. Other linkages remain to be identified. PET scanning is being used to examine measures of regional cerebral glucose metabolism during two types of reading by (adult) dyslexics and normal readers. MRI is also being used to examine pertinent brain structures. Behavioral tests are also in progress. The long-term goals of this study are to develop specific genetic and other diagnostic techniques that can be used to test children before beginning school and to develop sufficient understanding of the abnormal brain function of each subtype so that specific and effective remedial programs can be developed.

Behavioral activation and the variability of cerebral glucose metabolic measurements.

Variability in cerebral glucose metabolism was examined between and within subjects when paired studies were performed in the resting state or in a behaviorally activated state. Both normal and demented subjects were studied twice each, from 1 to 6 weeks apart, under near-identical conditions, using positron emission tomography (PET) and [18F]fluorodeoxyglucose. Resting state studies were repeated in nine normal and four demented subjects. A picture-viewing test, used for activation during PET, was used repeatedly in seven normal and five demented subjects. Within-subject variability, as assessed by the percent difference in metabolic rates in paired studies, was reduced by 60-70% for activation state compared to resting state studies in normals. It is concluded that PET studies of brain metabolism, which are designed to study the active brain, should indeed be performed in functionally activated states, as in addition to demonstrating metabolism during a defined functional state, activation studies show reduced variability of cerebral metabolic measures.

Phenotype of adult familial dyslexia: reading of visually transformed texts and nonsense passages.

Oral reading is less disrupted by mirror-image and upside-down text transformations for individuals affected by familial dyslexia than for non-affected readers. An analysis of errors made during oral reading of nonsense passages showed that most readers substituted real words for nonsense words, often of similar visual configurations. These findings were discussed in the context of what is known about cerebral functioning during reading. One interpretation of the present study is that affected readers used a reading strategy apparently mediated more by right than left hemisphere mechanisms, than did nonaffected readers.

Evidence for deficit in interhemispheric transfer of information in dyslexic boys.

Visual thresholds for identification of briefly flashed, lateralized letters were obtained for dyslexics and normal readers, age 11-15 years. Subjects were also tested for ability to localize tactile stimuli on the fingers and transfer information intermanually, a task failed by callosal agenesis patients (Dennis, 1976). Dyslexics differed significantly from normals on both tasks. Half the dyslexics demonstrated high threshold asymmetry across hemifields and many tactile localization errors, a pattern suggesting an "interhemispheric transfer deficit" as a cause of reading failure. Despite equally severe initial handicaps, dyslexics showing low, symmetric thresholds and few tactile errors, showed more reading improvement than did the others.