A Conserved Mechanism of Cardiac Hypertrophy Regression through FoxO1

The heart is a highly plastic organ that responds to diverse stimuli to modify form and function. The molecular mechanisms of adaptive physiological cardiac hypertrophy are well-established; however, the regulation of hypertrophy regression is poorly understood. To identify molecular features of regression, we studied Burmese pythons which experience reversible cardiac hypertrophy following large, infrequent meals. Using multi-omics screens followed by targeted analyses, we found forkhead box protein O1 (FoxO1) transcription factor signaling, and downstream autophagy activity, were downregulated during hypertrophy, but re-activated with regression. To determine whether these events were mechanistically related to regression, we established an in vitro platform of cardiomyocyte hypertrophy and regression from treatment with fed python plasma. FoxO1 inhibition prevented regression in this system, while FoxO1 activation reversed fed python plasma-induced hypertrophy in an autophagy-dependent manner. We next examined whether FoxO1 was implicated in mammalian models of reversible hypertrophy from exercise and pregnancy and found that in both cases FoxO1 was activated during regression. In these models, as in pythons, activation of FoxO1 was associated with increased expression FoxO1 target genes involved in autophagy. Taken together, our findings suggest FoxO1-dependent autophagy is a conserved mechanism for regression of physiological cardiac hypertrophy across species.

Local chromatin fiber folding represses transcription and loop extrusion in quiescent cells

A longstanding hypothesis is that chromatin fiber folding mediated by interactions between nearby nucleosomes represses transcription. However, it has been difficult to determine the relationship between local chromatin fiber compaction and transcription in cells. Further, global changes in fiber diameters have not been observed, even between interphase and mitotic chromosomes. We show that an increase in the range of local inter-nucleosomal contacts in quiescent yeast drives the compaction of chromatin fibers genome-wide. Unlike actively dividing cells, inter-nucleosomal interactions in quiescent cells require a basic patch in the histone H4 tail. This quiescence-specific fiber folding globally represses transcription and inhibits chromatin loop extrusion by condensin. These results reveal that global changes in chromatin fiber compaction can occur during cell state transitions, and establish physiological roles for local chromatin fiber folding in regulating transcription and chromatin domain formation.

Characterizing concentrations of diethylene glycol and suspected metabolites in human serum, urine, and cerebrospinal fluid samples from the Panama DEG mass poisoning

CONTEXT

Diethylene glycol (DEG) mass poisoning is a persistent public health problem. Unfortunately, there are no human biological data on DEG and its suspected metabolites in poisoning. If present and associated with poisoning, the evidence for use of traditional therapies such as fomepizole and/or hemodialysis would be much stronger.

OBJECTIVE

To characterize DEG and its metabolites in stored serum, urine, and cerebrospinal fluid (CSF) specimens obtained from human DEG poisoning victims enrolled in a 2006 case-control study.

METHODS

In the 2006 study, biological samples from persons enrolled in a case-control study (42 cases with new-onset, unexplained AKI and 140 age-, sex-, and admission date-matched controls without AKI) were collected and shipped to the Centers for Disease Control and Prevention (CDC) in Atlanta for various analyses and were then frozen in storage. For this study, when sufficient volume of the original specimen remained, the following analytes were quantitatively measured in serum, urine, and CSF: DEG, 2-hydroxyethoxyacetic acid (HEAA), diglycolic acid, ethylene glycol, glycolic acid, and oxalic acid. Analytes were measured using low resolution GC/MS, descriptive statistics calculated and case results compared with controls when appropriate. Specimens were de-identified so previously collected demographic, exposure, and health data were not available. The Wilcoxon Rank Sum test (with exact p-values) and bivariable exact logistic regression were used in SAS v9.2 for data analysis.

RESULTS

The following samples were analyzed: serum, 20 case, and 20 controls; urine, 11 case and 22 controls; and CSF, 11 samples from 10 cases and no controls. Diglycolic acid was detected in all case serum samples (median, 40.7 mcg/mL; range, 22.6-75.2) and no controls, and in all case urine samples (median, 28.7 mcg/mL; range, 14-118.4) and only five (23%) controls (median, < Lower Limit of Quantitation (LLQ); range, < LLQ-43.3 mcg/mL). Significant differences and associations were identified between case status and the following: 1) serum oxalic acid and serum HEAA (both OR = 14.6; 95% C I = 2.8-100.9); 2) serum diglycolic acid and urine diglycolic acid (both OR > 999; exact p < 0.0001); and 3) urinary glycolic acid (OR = 0.057; 95% C I = 0.001-0.55). Two CSF sample results were excluded and two from the same case were averaged, yielding eight samples from eight cases. Diglycolic acid was detected in seven (88%) of case CSF samples (median, 2.03 mcg/mL; range, < LLQ, 7.47).

DISCUSSION

Significantly elevated HEAA (serum) and diglycolic acid (serum and urine) concentrations were identified among cases, which is consistent with animal data. Low urinary glycolic acid concentrations in cases may have been due to concurrent AKI. Although serum glycolic concentrations among cases may have initially increased, further metabolism to oxalic acid may have occurred thereby explaining the similar glycolic acid concentrations in cases and controls. The increased serum oxalic acid concentration results in cases versus controls are consistent with this hypothesis.

CONCLUSION

Diglycolic acid is associated with human DEG poisoning and may be a biomarker for poisoning. These findings add to animal data suggesting a possible role for traditional antidotal therapies. The detection of HEAA and diglycolic acid in the CSF of cases suggests a possible association with signs and symptoms of DEG-associated neurotoxicity. Further work characterizing the pathophysiology of DEG-associated neurotoxicity and the role of traditional toxic alcohol therapies such as fomepizole and hemodialysis is needed.

Esophageal pneumatic dilation for postfundoplication dysphagia: safety, efficacy, and predictors of outcome

OBJECTIVE

Persistent dysphagia occurs in 5-10% of patients after fundoplication. The cause is obscure in most cases, and the management has not been well established. The aim of this study is to evaluate the clinical outcomes and the predictors of success for esophageal pneumatic dilations in patients with dysphagia after fundoplication.

METHODS

We retrospectively reviewed 14 patients who underwent pneumatic dilation for persistent postfundoplication dysphagia. All patients had esophageal manometry before dilations.

RESULTS

There were nine responders to pneumatic dilations (30-40-mm balloons). The nadir lower esophageal sphincter (LES) relaxation pressure was the only significant predictor for successful dilation and was higher among the responders than nonresponders (median 10 mm Hg vs 5 mm Hg). All six of 14 patients with nadir LES pressure > or = 10 mm Hg had a good response. There was no significant difference in the LES basal pressure between the responders and nonresponders (median 20 mm Hg vs 12 mm Hg). The median distal peristaltic amplitude (74 mm Hg vs 69 mm Hg), percent of failed peristalsis (8% vs 45%), and ramp pressure (19 mm Hg vs 17 mm Hg) did not differ significantly between the responders and nonresponders. No perforations occurred.

CONCLUSIONS

Pneumatic dilation is a reasonably safe and effective treatment for patients with postfundoplication dysphagia. Raised nadir LES relaxation pressure seems to be a useful predictor of successful outcome.

Functional outcome after Heller myotomy and fundoplication for achalasia

This study aims to provide longitudinal prospective data on symptomatic outcome following Heller myotomy with fundoplication and to examine variables that might predict a poor outcome. Patients were prospectively followed by means of a biannual mailed questionnaire that assessed symptoms, satisfaction with the procedure, medication, and need for further intervention. Patients were classified as achieving a good or poor outcome based on predetermined criteria. Duration of clinical remission was determined using Kaplan-Meier curves. Between 1992 and 1999, 62 patients with at least 12 months' follow-up were categorized as having either a good outcome (41 patients) or a poor outcome (21 patients). The cumulative probability of a good outcome at 7 years was 37%. Dysphagia significantly increased over the follow-up period despite initial resolution. Patient variables (age, sex, symptom duration, esophageal dilatation, manometric findings) and operative factors (myotomy length, wrap type, case number mucosal perforation, primary therapy) were not demonstrated to influence outcome at 3 years. A comparison of Nissen fundoplication with partial fundoplication suggested increased dysphagia and chest pain in the Nissen group. Despite initial symptomatic relief, patients with achalasia suffer a progressive decline with recurrent dysphagia and regurgitation. The type of fundoplication used may contribute to these poor results.

Mirizzi syndrome: an extra hazard for laparoscopic surgery

BACKGROUND

Mirizzi Syndrome (MS) is an important but uncommon complication of gallstones characterized by narrowing of the common hepatic duct (CHD) due to mechanical compression or inflammation. This study aimed to assess the impact of preoperative and intraoperative diagnosis of MS on the performance, safety and efficacy of laparoscopic cholecystectomy.

METHODS

From a consecutive series of 1,281 patients having surgery for gall bladder disease between 1990 and 1998, nine patients with MS were identified from a prospective database and their clinical progress examined.

RESULTS

Five out of the nine patients with MS presented with pain (2/5 were also jaundiced), and four presented with acute cholecystitis. Liver function tests were abnormal in all patients. Preoperative diagnosis of MS based on ultrasound was made in only two patients, and in a third on findings of a nasobiliary cholangiogram. In six patients, the diagnosis was intraoperative. In seven patients cholecystectomy was completed by laparoscopy. Two patients needed conversion to open cholecystectomy. In two patients the common bile duct was mistaken for the cystic duct and the error was recognized on relaxation of traction on the gall bladder in one, but in the other a duct injury occurred that was not recognized until the postoperative period.

CONCLUSIONS

Preoperative diagnosis of MS is difficult, and a high index of suspicion is necessary to avoid serious complications. Once the diagnosis is known, successful laparoscopic management is possible but care should be taken to avoid duct injury.

Cirrhosis and laparoscopic cholecystectomy

Although cirrhosis has been regarded as a contraindication to laparoscopic cholecystectomy, there is increasing evidence that patients with mild to moderate cirrhosis may safely undergo laparoscopic cholecystectomy with results superior to those of open cholecystectomy. A prospective evaluation and comparison of outcome in 25 consecutive patients with cirrhosis and 1275 patients without cirrhosis undergoing laparoscopic cholecystectomy was undertaken. Fourteen patients with Child's A cirrhosis, nine with Child's B, and two with Child's C underwent laparoscopic cholecystectomy. After surgery, one patient with Child's C cirrhosis died. The median length of stay was 4 days. Postoperative morbidity occurred in 52% of patients and included hemorrhage (8%), thromboembolism (4%), wound complications (24%), intraabdominal collections (12%), and cardiopulmonary complications (8%). Major comorbidity was present in 60% of patients and contributed to complication rate and prolonged stay. Hemorrhage (P = 0.04) and wound complications (P = 0.02) occurred more frequently in patients with cirrhosis than in patients without cirrhosis. Laparoscopic cholecystectomy in patients with cirrhosis is associated with significant but acceptable morbidity and mortality rates, and complications are frequently related to comorbid conditions.

Hyaluronan supports recombinant human bone morphogenetic protein-2 induced bone reconstruction of advanced alveolar ridge defects in dogs. A pilot study

BACKGROUND

Prosthetic-driven implant dentistry requires predictable procedures for alveolar ridge augmentation. The objective of this pilot study was to evaluate bone regeneration in mandibular, full-thickness, alveolar ridge, saddle-type defects following surgical implantation of recombinant human bone morphogenetic protein-2 (rhBMP-2) in a novel hyaluronan (HY) sponge carrier. This sponge was fabricated from auto-crosslinked HY.

METHODS

Alveolar ridge defects (approximately 15 x 10 x 10 mm), 2 per jaw quadrant, were surgically prepared in each of 3 young adult American fox hounds. Four defects were immediately implanted with rhBMP-2/HY. Three defects were implanted with rhBMP-2 in an absorbable collagen sponge (ACS) carrier (positive control). The rhBMP-2 solution (1.5 ml at 0.2 mg/ml) was soak-loaded onto the HY and ACS sponges. Three defects were implanted with HY sponges soak-loaded with buffer without rhBMP-2 (negative control), while 2 defects served as surgical controls. The animals were euthanized at 12 weeks postsurgery for histometric analysis.

RESULTS

Clinically, alveolar ridge defects receiving rhBMP-2/ACS exhibited a slight supracrestal expansion, while defects receiving rhBMP-2/HY were filled to contour. In contrast, the HY and surgical controls exhibited ridge collapse. rhBMP-2/HY-treated defects exhibited a dense bone quality without radiolucent regions observed in defects treated with rhBMP-2/ACS. The histometric analysis showed 100% bone fill for the rhBMP-2/ACS defects and 94%, 58%, and 65% bone fill for the rhBMP-2/HY, HY, and surgical control defects, respectively.

CONCLUSIONS

The conclusions are based on data from 2 of 3 animals in the study. In one animal, no response to rhBMP-2 was observed with either carrier, and the animal may have been a non-responder of unknown nature. With this limitation, the observations herein suggest that: 1) HY supports significant bone induction by rhBMP-2; 2) the rhBMP-2-induced bone assumes qualities of the immediate resident bone; 3) HY alone exhibits no apparent osteoconductive potential; and 4) HY appears to resorb within a 12-week healing interval in the absence or presence of rhBMP-2. Thus, HY appears to be a suitable candidate carrier for rhBMP-2.

Dysphagia after antireflux surgery

BACKGROUND

Dysphagia is experienced by many patients after antireflux surgery. This literature review examines factors associated with the development, prediction and management of postoperative dysphagia.

METHODS

Published studies examining issues related to dysphagia, gastro-oesophageal reflux and fundoplication were reviewed.

RESULTS

Postoperative dysphagia is usually temporary but proves troublesome for 5--10 per cent of patients. Technical modifications, such as a partial wrap, division of short gastric vessels and method of hiatal closure, have not conclusively reduced its incidence. There is no reliable preoperative test to predict dysphagia.

CONCLUSION

It is uncertain whether postoperative dysphagia arises from patient predilection or is largely a consequence of mechanical changes created by fundoplication. Anatomical errors account for a significant proportion of patients referred for correction of dysphagia but these are uncommon in large single-institution studies. Abnormal manometry cannot predict dysphagia and, on current evidence, 'tailoring' the operation does not prevent its occurrence.

A randomized controlled trial assessing the effect of heated carbon dioxide for insufflation on pain and recovery after laparoscopic fundoplication

BACKGROUND

Insufflation with heated gas for laparoscopy may reduce postoperative pain. This study assessed the effect of heated gas on outcome after fundoplication.

METHODS

A blinded, randomized trial compared the effect of heated or standard carbon dioxide (CO2) on core temperature, postoperative pain, analgesic requirement, and postoperative recovery. Pain scores were assessed with a 100 mm visual analog scale (VAS). Recovery was assessed with a patient diary and clinical follow-up assessment at 8 days and 1 month postoperatively.

RESULTS

For this study, 40 patients were randomized to heated CO2 (n = 19) and standard CO2 (control) (n = 21) groups. The heated CO2 group increased core body temperature from 35.9 degrees to 36.1 degrees C, (p = 0.008), whereas the control group maintained core temperature at 35.8 degrees C. The control group had lower analgesic requirements and pain scores, significant at 12 h (VAS: 20 vs 36 mm; p = 0.04). There was no difference between the groups in terms of late recovery. The heated CO2 group showed a significant correlation between operative duration and requirement for postoperative morphine (p = 0.01).

CONCLUSIONS

Heated gas provides no benefit for patients and may be associated with increased early pain. The elevation of core body temperature observed with heated CO2 is of little clinical significance.

A randomized controlled trial comparing cholecystocholangiography with cystic duct cholangiography during laparoscopic cholecystectomy

BACKGROUND

The rate of intraoperative cholangiography fell after the advent of laparoscopic cholecystectomy due to the perceived difficulty of cystic duct cannulation. It is suggested that cholecystocholangiography (CCC) is a valid and easier alternative. The present study compares cystic duct cholangiography (CDC) to CCC with evaluation of procedural time, success rate, image quality, cost and radiation exposure.

METHODS

Patients undergoing laparoscopic cholecystectomy were randomized to CCC (n = 40) or CDC (n = 36). Details of operative times, radiation exposure, and use of disposable equipment were recorded prospectively. Cholangiograms were performed using image intensification and were scored from 0 to 6 according to adequacy of images. Data were analysed on an intention-to-treat basis with the chi-squared test, t-test or Fisher's exact test.

RESULTS

The success rate for CDC was 100% and for CCC it was 72% (P = 0.0005). Patients with a failed CCC went on to have CDC for a success rate in the CCC arm of 92.5%. Comparing CDC to CCC, there was no significant difference in cost ($30.16 vs $33.36: P = 0.11), operative time (1 h 13 min vs 1 h 3 min; P = 0.19) or cholangiogram time (8 vs 9 min: P = 0.39). There was a significant difference in screening time (0:41 vs 1:33 min; P < 0.0001), adequate image quality (100 vs 72.5%, P = 0.0005) and procedure-related complications (0 vs 5; P = 0.03).

CONCLUSIONS

A significant number of CCC fail. Successful CCC provides inferior image quality and greater radiation exposure. It provides no benefit in time or cost and cannot be recommended for operative cholangiography.

Laparoscopic Heller myotomy for achalasia

BACKGROUND

Laparoscopic Heller myotomy provides similar results to open Heller myotomy for the treatment of oesophageal achalasia with the advantage of quicker recovery. The present series examines the evolution of operative technique, postoperative outcome and the effect of the 'learning curve' in a group of 70 consecutive patients.

METHODS

Between 1992 and 1999, details of all patients undergoing oesophagogastric myotomy for achalasia were prospectively entered on a database. Patients were followed with a biannual postal symptom questionnaire and scores were obtained for dysphagia, heartburn, regurgitation and chest pain. Comparison between preoperative and postoperative symptom scores, and case number and operative complications was made using Fisher's exact test or Mann-Whitney U-test where appropriate.

RESULTS

The indication for surgery was as a primary procedure in 20 cases; after failed endoscopic treatment in 48 cases; and after a 'failed' fundoplication in two cases. Myotomy was combined with a 360 degrees fundoplication in 57 patients and with an anterior fundoplication in 13 patients. Mucosal perforation occurred intraoperatively in 11 cases. Conversion to an open procedure was required in seven patients. Seven patients required a second operation. At a mean follow up of 2.9 years, symptom scores were significantly improved from preoperative values for dysphagia, regurgitation and chest pain (P < 0.001). There was no increase in the postoperative score for heartburn. The 'learning curve' contributed significantly to the length of the procedure, and the need for reoperation.

CONCLUSIONS

Laparoscopic Heller myotomy is a technically challenging procedure that provides good early palliation of the symptoms associated with achalasia.

Management of esophageal perforation after pneumatic dilation for achalasia

Current management of esophageal perforation after pneumatic dilation for achalasia is thoracotomy and repair with myotomy. This study aims to assess the outcome of patients managed by laparotomy, and the role of laparoscopic repair. The study was carried out by means of retrospective case review and prospective follow-up with a symptom questionnaire. Results were compared with results in patients undergoing elective Heller myotomy. Over a 20-year period, 445 dilations for achalasia were performed in 371 patients. There were 10 esophageal perforations. Nine patients were referred for surgery and were successfully managed with a transabdominal repair. Laparoscopic repair was attempted in four patients but was successful in only one because of the perforation site. After a mean follow-up of 5.4 years, grade 1 or 2 Visick scores were recorded in all patients. Residual symptoms of dysphagia occurred in 67% in the emergency group and 88% in the elective group. There was an increased incidence of heart-burn compared to elective myotomy. Early operation after perforation provides good results for treatment of achalasia. Mild dysphagia persists and there is an increasing sensation of heartburn. The site of perforation is typically posterolateral, which makes laparoscopic repair difficult.

Gangrenous cholecystitis in the laparoscopic era

BACKGROUND

We reviewed our data of laparoscopic cholecystectomies between 1990 and 1997 with reference to gangrenous cholecystitis.

METHODS

In a consecutive series of 1304 patients having laparoscopic cholecystectomies, prospective data collection has permitted analysis of the relationship between gangrenous cholecystitis (GC), acute (non-gangrenous) cholecystitis (AC) and non-acute cholecystectomies (NAC).

RESULTS

Twenty-five patients had gangrenous cholecystitis and 238 had acute cholecystitis. We found that patients with GC were significantly older (65.4 years vs 56.1 years (AC) and 52.7 years (NAC), P < 0.05) and had a higher M: F ratio (1.5:1 vs 1:2.6 (AC) and 1:2.8 (NAC), P < 0.05). Cardiac disease was found to be a significant factor but not diabetes. Preoperative ultrasonography correctly identified only 17 patients with acute inflammatory changes. Seven patients had an absent sonographic Murphy's sign. The gall bladder wall was generally thicker (4.11 mm vs 3.8 mm (AC) and 2.7 mm (NAC), P < 0.05) but there was marked overlap between the three groups. The common bile duct (CBD) was more dilated (6.1 mm vs 4.8 mm (AC) and 4.6 mm (NAC), P < 0.006) and there was increased incidence of CBD stones in the GC group. Our conversion rate was 8.7% with minimal complications and no operative mortality.

CONCLUSION

Patients with GC were generally older, more likely to be male and had increased incidence of cardiovascular disease. Preoperative ultrasound cannot accurately identify those patients with gangrenous cholecystitis, but with conversion rates of 8.7% and no operative mortality, they can generally be managed safely with laparoscopic surgical techniques.

Palliation of hilar biliary obstruction from colorectal metastases by endoscopic stent insertion

BACKGROUND

In patients with hepatic metastases from colorectal carcinoma there is a distinct subgroup in whom jaundice is not due to hepatic replacement but rather biliary obstruction. We reviewed our experience with stent insertion in patients with malignant proximal biliary obstruction from metastatic colorectal carcinoma.

METHODS

Thirty-three patients were treated between July 1992 and December 1996. Placement of a single stent was attempted at initial endoscopic retrograde cholangiopancreatography. Hilar biliary obstruction was classified according to Bismuth's classification.

RESULTS

Successful stent placement was possible in 94% overall and at initial endoscopic retrograde cholangiopancreatography in 39% of patients. Successful stent placement occurred significantly more often in patients with a type I stricture. Cholangitis was the principal complication occurring in 24% of patients. The 30-day mortality rate was 24%, with death occurring significantly less often in patients with a type I or II stricture. Overall, 45% of patients had a 30% fall in bilirubin at 1 week. The median survival was 81 days, with significantly longer survival seen in patients with a type I or II stricture.

CONCLUSIONS

Endoscopic stent placement offers effective palliation in most patients with hilar obstruction from colorectal metastases. A subset of patients with type III strictures and greater than 3 intrahepatic metastases often do not benefit from stent insertion.

Pain after laparoscopic cholecystectomy

BACKGROUND

Although laparoscopic cholecystectomy (LC) results in less pain than open chole-cystectomy, it is not a pain-free procedure. Many methods of analgesia for pain after laparoscopy have been evaluated.

METHODS

Forty-two randomized controlled trials assessing interventions to reduce pain after LC are reviewed, as are the mechanisms and nature of pain after this procedure.

RESULTS

Non-steroidal anti-inflammatory drugs, wound local anaesthetic, intraperitoneal local anaesthetic, intraperitoneal saline, a gas drain, heated gas, low-pressure gas and nitrous oxide pneumo-peritoneum have been shown to reduce pain after LC. The clinical significance of this pain reduction is questionable.

CONCLUSION

Pain after LC is multifactorial. Although many methods of analgesia produce short-term benefit, this does not equate with earlier discharge or improved postoperative function. However, single trials evaluating low-pressure insufflation, heated gas and multimodal analgesia suggest that clinically relevant benefits can be achieved.

Role of relaparoscopy in the management of minor bile leakage after laparoscopic cholecystectomy

BACKGROUND

Bile leakage in the absence of major ductal injury may occur from the liver bed or from the cystic duct remnant after cholecystectomy. The early limitations of minimally invasive surgery led to reliance on endoscopic methods to manage this complication. However, repeat laparoscopy permits drainage of the bile collection and direct control of the site of leakage in selected situations.

METHODS

Details of 15 patients with bile leakage after laparoscopic cholecystectomy were recorded prospectively and are reviewed.

RESULTS

Postoperative bile leakage occurred after 15 (0.8 per cent) of 1779 laparoscopic cholecystectomies. Two patients with bile in drainage fluid had spontaneous resolution. Ten patients with a subvesical duct leak had repeat laparoscopy. The leak was successfully controlled by suturing in eight patients, and by a laparoscopically placed drain in two. One patient required a subsequent laparotomy for a loculated pelvic collection. Three patients had cystic duct stump leakage. This was managed successfully by laparoscopy in one case but required endoscopic management in two.

CONCLUSION

Laparoscopy is useful in the management of minor bile leaks after laparoscopic cholecystectomy. Selection of appropriate patients relies on a characteristic clinical presentation after an otherwise uncomplicated cholecystectomy.

Cricopharyngeal myotomy does not increase the risk of esophagopharyngeal acid regurgitation

OBJECTIVE

It is not known whether cricopharyngeal myotomy predisposes to esophagopharyngeal regurgitation. Using ambulatory, dual pharyngeal, and esophageal pH monitoring before and after cricopharyngeal myotomy, our aim was to determine the effect, if any, of myotomy on the frequency of esophagopharyngeal acid regurgitation.

METHODS

We studied prospectively 18 patients who underwent cricopharyngeal myotomy for pharyngeal dysphagia (10 Zenker's, eight neurogenic dysphagia), of whom 17 agreed to undergo dual pH monitoring preoperatively, and 10 who agreed to both pre- and postoperative monitoring.

RESULTS

Symptoms of gastroesophageal reflux disease were present in 30%. Cricopharyngeal myotomy significantly reduced basal upper esophageal sphincter pressure by 49%, from 37+/-5 mm Hg to 19+/-3 mm Hg (p = 0.007). Esophagopharyngeal regurgitation was a rare event and the frequency of it did not differ between patients and healthy controls. Preoperatively, three regurgitation events in two patients did not differ from the postoperative frequency of a total of two events in the same two patients.

CONCLUSIONS

Increased esophageal acid exposure is common and esophagopharyngeal regurgitation is rare in unselected patients undergoing cricopharyngeal myotomy for pharyngeal dysphagia. Myotomy does not increase the frequency of esophagopharyngeal acid regurgitation in such patients.

Preoperative esophageal transit studies are a useful predictor of dysphagia after fundoplication

Fundoplication performed for gastroesophageal reflux disease may be complicated by postoperative dysphagia despite successful reduction in reflux symptoms. This is more likely in those patients with reflux who have concurrent esophageal dysmotility. The aim of this study was to establish whether esophageal transit studies using a technetium-99m jello bolus (jello esophageal transit) could detect the presence of motility disorders preoperatively and hence predict surgical outcome. Transit studies in 33 healthy volunteers yielded a normal range of 2 to 24 seconds using ninety-fifth percentile distribution. In the second phase of the study, 26 patients accepted for laparoscopic fundoplication were enrolled: jello esophageal transit, manometry, and endoscopy were attempted preoperatively in all subjects. A clinical dysphagia score was assigned from a questionnaire. Six months after surgery, five patients had dysphagia and of these four were found to have abnormal preoperative jello esophageal transit, for a sensitivity of 80%. Of the 21 patients who had no dysphagia after surgery, 20 patients had normal preoperative jello esophageal transit, showing a specificity of 95%. This esophageal transit study is noninvasive, reliable, and sensitive. When performed prior to fundoplication, it appears to be of significant value in detecting a subtle functional motility disorder that predisposes to postoperative dysphagia. Jello esophageal transit may assist the surgeon in planning treatment of gastroesophageal reflux disease.

Autogenous bone harvesting: a chin graft technique for particulate and monocortical bone blocks

The use of the mandibular symphysis for harvesting intraoral autografts in implant reconstruction cases is based on the ample supply of donor material, the proximity to the recipient site, and the ease of access to the tissue. This article discusses the technique of successful bone harvesting from the mandibular symphysis. As with other harvesting techniques, morbidity can occur. This report demonstrates a low morbidity rate and presents guidelines to help accomplish this.

Predictors of outcome following cricopharyngeal disruption for pharyngeal dysphagia

The indications for, and predictors of outcome following cricopharyngeal disruption in pharyngeal dysphagia are not clearly defined. Our purpose was to examine the symptomatic response to cricopharyngeal disruption, by either myotomy or dilatation, in patients with oral-pharyngeal dysphagia and to determine pre-treatment manometric or radiographic predictors of outcome. Using simultaneous pharyngeal videoradiography and manometry, we studied 20 patients with pharyngeal dysphagia prior to cricopharyngeal dilatation (n = 11) or myotomy (n = 8), and 23 healthy controls. We measured peak pharyngeal pressure, hypopharyngeal intrabolus pressure, upper esophageal sphincter diameter, and coordination. Response rate to sphincter disruption was 65%. The extent of sphincter opening was significantly reduced in patients compared with controls (p = 0.004), but impaired sphincter opening was not a predictor of outcome. Increased hypopharyngeal intrabolus pressures (> 19 mmHg for 10 ml bolus; > 31 mmHg for 20 ml bolus) was a significant predictor of outcome (p = 0.01). Neither peak pharyngeal pressure nor incoordination were predictors of outcome. In pharyngeal dysphagia, hypopharyngeal intrabolus pressure, and not peak pharyngeal pressure, is a predictor of response to cricopharyngeal disruption. The relationship between intrabolus pressure and impaired sphincter opening is an indirect measure of sphincter compliance which helps predict therapeutic response.

Common bile duct stones in non-dilated bile ducts? An ultrasound study

In a consecutive series of 870 patients having cholecystectomy performed by the laparoscopic technique in a single surgical unit, prospective data collection has permitted analysis of the relationship between common bile duct (CBD) diameter, as measured pre-operatively by ultrasound (US) examination, and the frequency of CBD stones. Overall, 85 patients (9.8%) have been shown to have CBD stones; the interval frequency for CBD size 0-4, 4.1-6, 6.1-8, 8.1-10 and > 10 mm, was 3.9, 9.4, 28, 32 and 50%, respectively. Because most patients have small ducts (736 with CBD size < 6.1 mm) almost half (42) of those with CBD stones came from this group. In reporting CBD size as "not dilated', radiologists should remind clinicians that this does not equate with "no CBD stones'.

A prospective audit of selective cholangiography for laparoscopic cholecystectomy

BACKGROUND

With the introduction of laparoscopic cholecystectomy (LC) there has been a reduction in the use of operative cholangiography. The practice of selective cholangiography (SC), where the common bile duct (CBD) is imaged only in those patients where the surgeon believes there is a significant risk of CBD stones has contributed to this reduction. Selective cholangiography has been criticized by advocates of routine cholangiography who argue that there will be more CBD stones missed and more CBD injuries.

METHODS

This prospective study reports the outcome in a series of 457 patients who had LC performed between 1990 and 1992 where cholangiography was used according to a strict protocol relying on clinical history, CBD size and pre-operative liver function tests. There were no CBD injuries. Twenty-nine patients (6.4%) had CBD stones.

RESULTS

Follow up by structured questionnaire at 12-24 months detected 6 patients (1.3%) with CBD stones. Three of these 6 patients had cholangiograms. Of the 3 patients with missed stones and no X-ray, 2 were protocol breaches and only 1 patient from 307 (0.3%) with no indication for SC was subsequently found to have a CBD stone.

CONCLUSION

We believe that this study validates a policy of SC.

Esophageal achalasia and coexistent upper esophageal sphincter relaxation disorder presenting with airway obstruction

Acute airway obstruction associated with esophageal achalasia is an uncommon but life-threatening complication. The pathophysiology of this phenomenon has not been fully defined. A fully documented case of coexistent esophageal achalasia and upper esophageal sphincter relaxation abnormality presenting with airway obstruction is reported. The patient was initially treated with Heller's myotomy but had a recurrence of respiratory distress. She was successfully treated by cricopharyngeal myotomy. The causes of gas entrapment and respiratory distress are likely to be due to failure of both swallow- and distention-induced upper esophageal sphincter relaxation. Cricopharyngeal myotomy is an effective treatment for this complication, probably by facilitating esophagopharyngeal gas venting.

The measure and mismeasure of the tibia: implications for stature estimation

Trotter and Gleser's stature estimation formulae, based on skeletons of the Terry collection and on WWII casualties, have been widely used in forensic work. Our work with the Terry and WWII data yielded tibia lengths too short compared to other data sets. Using Trotter's original measurements, we discovered that she consistently mismeasured the tibia. Contrary to standard practice and her own definitions, she omitted the malleolus from the measurement. Trotter's measurements of the tibia are 10 to 12 mm shorter than they should have been, resulting in stature estimations averaging 2.5 to 3.0 cm too great when the formulae are used with properly measured tibia. We also examined tibia lengths of Korean War casualties, which were measured by technicians rather than by Trotter. Korean tibia measurements are also too short, but by a smaller amount than Terry and WWII. Since the Korean tibia are unavailable for restudy, it is unclear how they were measured. Estimation of stature from Trotter and Gleser's tibia formulae is to be avoided if possible. If necessary, the 1952 formulae could be used with tibia measured in the same manner that Trotter measured, excluding the malleolus.

A simple and effective way to reduce postoperative pain after laparoscopic cholecystectomy

The aims of this study were to see if laparoscopic cholecystectomy is associated with a similar postoperative pain pattern to gynaecological laparoscopy and to see whether the use of a suprahepatic suction drain makes recovery from laparoscopic cholecystectomy more comfortable. After routine laparoscopic cholecystectomy and insertion of a suprahepatic suction drain, patients were randomized to suction or no suction on the drain. The time course of the severity of wound, abdominal and shoulder tip pain was assessed by visual analogue scales administered in the morning and afternoon of the first 3 postoperative days. The control group had a high incidence of shoulder tip pain similar to that after gynaecological laparoscopy. Patients in the treatment group reported significantly less shoulder tip pain than the control group (O.R. 0.16, 95% CI, 0.06-0.40). There was a tendency for the treatment group to report reduced abdominal and, to a lesser extent, wound pain. The authors recommend suprahepatic suction as a simple and more effective way to improve patient comfort after laparoscopic cholecystectomy.

Is laparoscopy associated with a lower rate of postoperative adhesions than laparotomy? A comparative study in the rabbit

This trial set out to test the hypothesis that there is no difference in the incidence of intra-abdominal adhesions after a stereotyped intraperitoneal injury created via laparoscopy or laparotomy. Twenty New Zealand White rabbits had a 2 x 2 cm area of peritoneum stripped off their caecum and adjacent parietal peritoneum, either by laparotomy or laparoscopy. Outcome was assessed by the incidence of adhesions to the test site and the wound. There was no difference in the rate of adhesions at the test site in the two groups. The rate of adhesions to the wound was different in the two groups (70% laparotomy, 0% laparoscopy; P = 0.003). In a rabbit model, comparing laparoscopy and laparotomy in a strictly controlled operative environment, a stereotyped intraperitoneal injury results in similar rates of postoperative adhesions. Laparoscopy is, however, associated with a much lower incidence of wound adhesion. The potential for postoperative adhesions is real after laparoscopic surgery.

Bacteremia associated with operative decompression of a small bowel obstruction

BACKGROUND

Intraoperative decompression of the small bowel has been advocated as a method of aiding recovery of both the patient and the intestine. However, the methods proposed (retrograde stripping or enterotomy) require vigorous handling of bacteria-laden small bowel, possibly giving rise to a bacteremia.

STUDY DESIGN

A small bowel obstruction was created in 31 rats by means of a ligature. Twenty-four hours later, the obstruction was relieved, and the rats were divided into three groups: relief of obstruction alone, relief with retrograde stripping, and relief with enterotomy plus suction. Blood cultures were taken before and after manipulation of the bowel.

RESULTS

In blood cultures taken before and after manipulation there was a significant increase of Escherichia coli bacteremia in the two manipulation groups compared with the relief of obstruction only group.

CONCLUSIONS

Bacteremia may be an effect of operative decompression of obstructed bowel, which at times outweighs its supposed benefits.

Venous stasis during laparoscopic cholecystectomy

The objectives of this research were (a) to determine the effect of insufflation at laparoscopic cholecystectomy to 12 mm Hg on femoral venous blood flow; and (b) to assess the function of intermittent pneumatic compressors (IPC) and intermittent electric calf stimulators (IECS) in the presence of a pneumoperitoneum. Measures of baseline venous blood flow velocity, femoral vein diameter, and maximum blood flow velocity achieved by IPC or IECS were made in the presence or absence of a pneumoperitoneum of 12 mm Hg. The ICP and IECS were randomly allocated to either leg. All measures were made by an experienced sonologist. Insufflation to 12 mm Hg caused a statically significant decrease in femoral blood flow velocity and was accompanied by a significant increase in femoral vein diameter. The IPC and IECS were able to achieve pulsatile venous blood flow despite the presence of a pneumoperitoneum, but they had no effect on the depressed baseline blood flow velocity. We concluded that insufflation to 12 mm Hg causes significant venous stasis in the lower limb and that IPC and IECS cannot completely eliminate this stasis. Further research needs to be done to clarify the optimal methods of prophylaxis in view of the implications for deep venous thrombosis.

Lower limb venous hemodynamics during laparoscopy: an animal study

To assess the impact of raised intra-abdominal pressure associated with laparoscopy on venous return, we have used an animal model (pig) to study the effect of progressive increases in insufflation pressure on femoral venous blood outflow. As a second variable, the effect on flow of the reverse Trendelenburg position was also assessed. Evidence of any adaptation in venous blood flow to the increased intra-abdominal pressure was assessed during a prolonged surgical procedure. These studies have shown that femoral venous blood outflow in the pig is markedly depressed at insufflation pressures of 10 to 20 mm Hg. The reverse Trendelenburg position accentuates this reduction in flow, and there was no sign of adaptation to this depressed flow during a laparoscopic Nissen fundoplication. These findings have clear implications for the potential of deep venous thrombosis/pulmonary embolism (DVT/PE) following prolonged therapeutic laparoscopy.

Laparoscopic management of pneumatic dilatation resistant achalasia

Three patients with achalasia, who were successfully managed by laparoscopic Heller myotomy and Nissen fundoplication, are described. Each patient had failed to respond to two pneumatic dilatations of the oesophagus.

Endoscopic drainage of esophageal suture line leaks

Suture line leaks after esophageal or gastric surgery are associated with high morbidity and mortality rates. We report a new approach to the management of this problem, which has been used successfully in the treatment of nine patients with such leaks who were treated at or referred to our unit. The suture line defect is first visualized by endoscopy, after which a sump nasogastric tube is advanced down the esophagus and out through the defect into the abscess cavity. The tubes are irrigated intermittently to achieve patency and maintained with continuous suction. Separate pleural or subphrenic collections are drained by conventional techniques. After the injection of contrast down the tube, serial radiologic studies are used to monitor progress and to guide the slow withdrawal of the tube as the cavity collapses.

Laparoscopic cholecystectomy. A prospective analysis of the potential causes of failure

Most experienced laparoscopic units suggest a rate of conversion to open cholecystectomy of about 5%. Some failures are predictable preoperatively. We have reviewed the prospective data collected on our first 285 laparoscopic cholecystectomies to provide a basis for advising patients about the likelihood of conversion (failure) if laparoscopic cholecystectomy is attempted. Risk factor analysis was performed to assess the effect on the conversion rate of clinical presentation, preoperative ultrasound features, previous abdominal surgery, and morbid obesity. The overall conversion rate was 4.9%. We identified three preoperative clinical parameters associated with a high risk of failure at laparoscopic cholecystectomy: a contracted gallbladder on ultrasound, gallstone pancreatitis, and a previous history of upper abdominal surgery. Factors that did not predict failure were: an ultrasound report of a thick gallbladder wall, morbid obesity, or acute cholecystitis. It is concluded that laparoscopic cholecystectomy is technically feasible in most patients, but those having the above-mentioned risk factors should be warned of a higher than usual chance of conversion to open cholecystectomy.

Variation among North Amerindians: analysis of Boas's anthropometric data

In the late nineteenth century Franz Boas was responsible for assembling anthropometric data from North Amerindians. Approximately 15,000 subjects were measured, but the data have never been systematically analyzed. Here we describe our efforts to develop a computerized database from Boas's data and present the first systematic analysis of these data. In addition to a general analysis of North Amerindian anthropometric variation, we also present a more detailed analysis of anthropometric variation among tribes located in the American Northwest. In the general analysis we find that anthropometric variation is strongly patterned along geographic lines. We examine geographic and language patterning by grouping tribes by culture area and language phylum. Both have high explanatory power, culture area being the higher. The Northwest analysis shows that both language and geographic location are important in explaining anthropometric variation.

Bile duct emptying in response to fat: a validation study

Fatty meal sonography has been suggested to assess patients with biliary pain after cholecystectomy, but the effects of gallbladder removal on biliary dynamics has not been studied prospectively. Before elective cholecystectomy, 25 patients had their common hepatic ducts' diameter measured by ultrasonography before and after a fat stimulus. In 23, tests were repeated 1 month, 1 year, and 5 years after surgery. In preoperative studies, 5 patients showed dilatation after fat and 2 of these had stones in the common bile duct. However, another 4 patients with stones or sludge in the duct did not show dilatation, so that the response to fat was a poor indicator of patients requiring common bile duct exploration. No patient had major symptoms after surgery. At 1 month and 12 months, the response to fat was variable with more than half of those tested showing no decrease in duct size. A more consistent pattern emerged at 5 years, when 14 of 18 patients tested showed a decrease in common hepatic duct after fat; 3 were unchanged and 1 increased by 1 mm. The response to fat was less consistent and more difficult to measure in the common bile duct, even 5 years after operation. It was concluded that not all patients with indications for exploration of the common bile duct on operative cholangiography show a dilatation response to fat on preoperative testing. Also, fatty meal sonography should be used with caution because the response to fat in asymptomatic patients soon after operation is unpredictable, with occasional patients showing dilation without apparent obstruction. Measurement of common hepatic duct is preferred to common bile duct and increases in diameter of 1 mm are probably not significant.

Costs of magnetic resonance imaging services in public hospitals

Audited cost data from two public hospital installations participating in a trial of the utilisation and efficacy of magnetic resonance imaging are presented. The data cover the period July 1987 to June 1988 when both installations had attained stable patterns of operation. One hospital operated a superconductive system and the other a resistive magnetic resonance imaging unit. Depreciation and salaries represented the major components of cost.

Sex determination in the subadult ilia: an indirect test of Weaver's nonmetric sexing method

The sexing of subadult remains has been an ongoing problem in physical anthropology for many years. This is due in part to the scarcity of subadult collections of known age and sex which are large enough to be used to develop and test analytical methods. Several methods have been devised but few have produced reliable results. In 1980, Weaver presented a method for sexing subadult ilia using a nonmetric trait (the raised versus nonraised auricular surface), which has an accuracy of 75% in fetal females and 92% in fetal males. His method has not been tested for reliability on a different subadult sample. An indirect test of Weaver's method was made on a sample of subadult South Dakota Arikara Indian ilia by comparing the ratio of raised to nonraised auricular surfaces with an expected 1:1 sex distribution. Bimodal sex distributions in the Arikara formed unrealistic sex ratios, following an age-related shift from a 6:1 raised/nonraised ratio in newborns to a 1:4 ratio in young adolescence. Significant age correlations were found both in the present study and in Weaver's published results. The age-to-sex correlations indicated no confounding in the present study. The results of this test suggest that auricular surface morphology is not sex specific in subadult ilia, but may be related to aspects of shape and morphology in pelvic growth.

Pre-operative ultrasound measurement of bile duct diameter: basis for selective cholangiography

In this prospective study, prior to cholecystectomy, the diameter of the common hepatic duct was measured; duct size was then compared with probability of finding stones at operation. Of 115 patients entering the study, 36 had stones removed from the common duct at the time of cholecystectomy but only three (8%) were demonstrated by ultrasonography. No stones were found in ducts less than or equal to 3 mm in size (31% patients). Only two of 26 patients with ducts measuring 4 mm had stones. As duct size increased, so did the probability of stones and all patients with ducts greater than or equal to 9 mm in diameter had stones. It is concluded that pre-operative ultrasound provides a reliable basis for a policy of selective cholangiography.

Endoscopic diagnosis of small flat carcinoma of the colon. Report of three cases

Most small carcinomas arise from polyps. Small lesions with cellular features of malignancy and early invasion, but with no histologic evidence of residual adenoma, are rare. Diagnosed by endoscopy, three such lesions are described. They were recognized as mucosal plaques, measuring between 6 and 8 mm in diameter. In each case, there was either synchronous or metachronous carcinoma elsewhere in the colon, as well as benign adenomatous polyps. Colonoscopic identification of such lesions allows inclusion of that bowel segment in any planned resection.

Angiomyolipoma of the liver

Hepatic angiomyolipoma is a rare tumour of the liver. Its behaviour is benign and this paper reports the first case described in Australia. A review of the literature suggests that the use of ultrasonography, computerized tomography and angiography should enable pre-operative diagnosis to be made with relative certainty, yet the difficulties with histological diagnosis, particularly on needle biopsy, may necessitate resection.

Changes in bile duct diameter after cholecystectomy: a 5-year prospective study

In this prospective study, we have measured with ultrasound the diameter of the common hepatic duct and the common bile duct in a series of 24 patients having elective cholecystectomy. Preoperative measurements by ultrasound were compared with measurements taken directly from operative cholangiograms and excellent correlation was observed (r = 0.938). Studies were repeated 1 mo, 12 mo, and 5 yr after operation. Of 21 patients returning for study at 5 yr, there were 4 patients with 1-mm ducts before surgery who showed an increase in the size of the common hepatic duct but in none was the final measurement greater than 4 mm. Mean common hepatic duct diameter (n = 21) increased from 3.95 mm before to 4.48 mm 5 yr after surgery (p = 0.24, paired t-test). Common bile duct was more easily seen after cholecystectomy and of 13 ducts satisfactorily measured 1 and 5 yr after surgery, 7 showed an increase in size (mean common hepatic duct 1 yr = 4.77 mm, 5 yr = 5.92 mm, p = 0.059, paired t-test). Significant dilatation of the common hepatic duct was seen in only 2 of 21 patients, but a strong trend to minor dilatation was observed in the common bile duct after cholecystectomy.

Recurrent hepatic hydatid disease or prior omentoplasty: diagnostic dilemma

Endocystectomy combined with omentoplasty has become an accepted technique in the treatment of hydatid disease of the liver. Its attractiveness lies in its simplicity, its low frequency of postoperative biliary fistula, and the lack of specific complications related to the omentoplasty itself. However, radiological appearances after this procedure may be confusing. Two patients with upper abdominal pain are described in whom the radiological appearances of a previous omentoplasty could not be distinguished from a recurrent hydatid cyst.

Pylorus-preserving pancreatectomy: functional results

The pylorus-preserving technique is reported as improving the functional results of pancreatectomy but it is complicated in the early postoperative period by delayed recovery of gastric function in a proportion of patients. We have examined early and late gastrointestinal function in a prospective study of 16 patients having this procedure. The late results appear better than reported results for conventional Whipple resection and the delay in early recovery does not appear to have any late sequelae, provided that it does not require gastric bypass for relief.

The role of brushing cytology in the diagnosis of gastric malignancy

The results of endoscopic biopsy and brushing cytology in 234 consecutive patients with established histologic diagnoses of discrete gastric lesions were analyzed. A histopathologic diagnosis of malignancy, established by independent means, was made in 74 patients. Brushing cytology was positive for malignancy in 63, a diagnostic sensitivity of 85%. Endoscopic biopsy was positive in 64, a diagnostic sensitivity of 86%. The sensitivity for combined cytology and biopsy was 91%, which was not significantly greater than for biopsy alone (P = .6). Cytology yielded false-positive results in 5 of 160 patients (3.1%) with confirmed benign disease. There were no false-positive biopsy reports. Although both brushing cytology and biopsy have high diagnostic sensitivities, based on the findings of this study, the routine addition of cytology to biopsy in the endoscopic evaluation of gastric lesions is not recommended. Cytology could be reserved for situations in which difficulty is encountered in obtaining adequate tissue for histologic examination and for cases with a high suspicion of malignancy that have yielded negative biopsies.