A Criterion for the Formation of Fibrillar Layers in Injection Molded Parts

It is quite well known that the morphology of an injection molded part made by a semicrystalline polymer presents several layers. In particular spherulitic structures are found in the core region, a layer characterized by highly oriented fibrillar morphology (the shear layer) usually follows and a skin layer is often observed at the sample surface. The thickness of the fibrillar layer deeply influences the mechanical properties of the part. In this work, a criterion to predict the thickness of the fibrillar layer is proposed and verified. The criterion is essentially based on the amount of viscous work done when the molecular stretch is higher than a critical value: the molecular stretch should be above a critical value while a critical amount of viscous work is accumulated. In order to tune the parameters, and to validate the criterion, a well characterized polypropylene was chosen as test material, and four different injection molding conditions were analyzed. The criterion is verified by comparing some experimental results with the prediction of the UNISA code (an injection molding software developed at the University of Salerno), good comparison between software predictions and experimental data confirms the suitability of the criterion.

Thirty Years of Modeling of Injection Molding. A Brief Review of the Contribution of UNISA Code to the Field

UNISA code, a software for the analysis and modeling of injection molding, was born at the University of Palermo in Italy in the 1980s. Afterwards, in the 1990s, it was rewritten and expanded at the University of Salerno (Italy) and continuously improved over the years. It is a study code, aimed at understanding rather than simulating. It has the unique characteristic of describing, since the early versions, the morphology of the molded samples. Furthermore, it always implemented the interrelationships among the different material properties (crystallinity, viscosity, density). In this work, the evolution of the software is reviewed, placed in the background, underlining the contribution given to the understanding of polymer processing and morphology evolution. Eventually, the future challenges of modeling are presented.

Relevance of Crystallisation Kinetics in the Simulation of the Injection Molding Process

Modelling of the injection moulding process is carried out in this work on the basis of Williams and Lord model and its recent extensions to post filling stages. The emphasis is devoted to identifying the role of crystallisation kinetics in the process simulation. Data of pressure histories during injection moulding of an iPP are taken as reference to the analysis. Crystallisation kinetics of the material was described by means of a non-isothermal formulation of Avrami model whose parameters where determined either by accounting for only of calorimetric results or by describing also final density data of thin samples subjected to characterised quenching histories. Predictions of pressure histories are analysed in relation to the crystallisation kinetics adopted. The effect of pressure on crystallisation is also discussed.

On the Simulation of Thermoplastic Injection Moulding Process

The relevance of enhancement of crystallisation kinetics by effect of shear flow and rheology during polymer solidification to the phenomena taking place during the injection moulding process has been shown by means of simulations performed on the basis of Lord and Williams [1, 2] model and its recent extensions [3 to 5]. A key point of the simulation was the solidification criterion based on a critical crystallization index; on the basis of simple calorimetric and rheological tests in the limit of zero shear rate, values of a few percent were given to the solidification crystallinity value.

Many experimental features of pressure history both in the runner and in the cavity are recovered by model predictions, if both effects mentioned above are properly accounted for. However, predictions for gate sealing time, although improved, still have a sensitivity to gate thickness lower than that shown by the experiments. Similar conclusions, obviously, regard also the mass entering in the mould during holding.

Another mechanism which sums up to shear stresses to accelerate thin gate solidification has still to be identified.

On the Simulation of Thermoplastic Injection Moulding Process

Numerical simulation of the injection moulding process of thermoplastic polymers has been performed on the basis of the Williams and Lord model and its recent extensions. The aim of the simulation was to identify material properties which play a relevant role to process modelling, including post filling stages. Predictions improve significantly by taking into account the effect of pressure on both viscosity and crystallisation kinetics. Several features, however, are not satisfactorily predicted. Also the relevance of convection during packing has been evidenced especially with reference to gate sealing time. As highly oriented crystalline structures are present in the final moulded object, the enhancement of crystallisation kinetics by the effect of flow is suggested as the phenomenon to be accounted for in order to gain a quantitative description of the whole process.

[Treatment of biliary lithiasis with the advent of new technologies in Italy in the Lazio and Abruzzo regions over the past 15 years. Comparison between the patient series in a Roman university hospital and in a number of hospitals in the Abruzzo region]

Biliary lithiasis is a disease with a high incidence in the western world and a high social cost. To evaluate the impact of new technologies--mainly laparoscopic cholecystectomy and radiological and endoscopic techniques--in the treatment of biliary lithiasis, a statistical study was conducted on the surgical interventions performed over the past 15 years in Italy in the Lazio and Abruzzo regions. From 1985 to 1999, 150,000 cases of hepatobiliary lithiasis were hospitalized every year in Italy with a mean hospital stay of 7.8 days (13,000 in Lazio and 6,000 in Abruzzo). 100,000 cholecystectomies were performed every year in Italy in public hospitals, 30% of which by conventional laparotomy and 70% laparoscopically. Ten percent of these operations on average were performed in the Lazio region and 3% in the Abruzzo region. 10,615 cases of main bile duct stones were treated in 1999, 6,502 of which by ERCP and the others with open procedures and radiologically. The mortality was 0-0.1% for laparoscopic cholecystectomy as against 0-0.5% in open procedures.

Alterations in serum anti-alpha-galactosyl antibodies in patients with Crohn's disease and ulcerative colitis

Anti-galactosyl alpha1-3-galactosyl (anti-Gal) is a natural serum antibody abundantly produced in humans in response to immune stimulation by enteric bacteria. Marked elevation of its titer has been detected in parasitic diseases and in some autoimmune disorders. Because persistent intestinal infection and defective mucosal barrier have been suggested as potential etiologic agents of inflammatory bowel disease, the aim of this study was to analyze the sera levels of anti-Gal antibodies in patients with Crohn's disease and ulcerative colitis. An ELISA assay was performed to analyze circulating antibody using the disaccharide Gal (alpha 1-3)Gal coupled to human serum albumin as antigen and alkaline phosphatase-conjugated rabbit anti-human immunoglobulin G, A, M as antibody. Immunoglobulin classes were assayed using class-specific antibodies. The optical densities of sera from Crohn's disease (1.83 +/- 0.63) and ulcerative colitis (1.45 +/- 0.7) were significantly higher (P < 0.0001 and P < 0.0005, respectively) than those of the control group (0.97 +/- 0.39). In Crohn's disease the increase was distributed among the three immunoglobulin classes; in ulcerative colitis a significant increase was observed only for immunoglobulin A. The increased levels of circulating antibodies against Gal (alpha 1-3)Gal in the presence of intestinal bacterial strains expressing antigenic epitopes and breakdown of mucosal barrier could contribute to the dysregulated immune response observed in inflammatory bowel disease.

ERCP and acute pancreatitis

Acute biliary pancreatitis (ABP) is a serious complication of biliary stones disease and is associated with significant morbidity and mortality. The role of ERCP in the management of ABP has been the focus of discussion in recent years. In this report, we evaluated a protocol of emergency Endoscopic retrograde Cholangiopancreatography (ERCP) (within 24 hours) and early ERCP (within 72 hours). From July 1997 to July 2000, were observed 45 patients (19 man and 26 women) with acute biliary pancreatitis. Mean age of patients was 63.4 years (range 21-87 years). Diagnosis of ABP was based on anamnesis and clinical assessment and was confirmed by specific laboratory data (hyperamylasemia, hyperlipasemia, total and fractionated bilirubinemia, gamma-GT, transaminase, alkaline phosphatase, hypocalcemia, hyperglycemia, leukocytosis). Ultrasound scanning within 24 h of admission was performed in 45 patients (100%) and it revealed gallbladder stones and muddy bile in 39 patients (87%). Computed tomography (CT) performed in all patients, showed a severe acute pancreatitis in the second or subsequent week following admission. The severity of acute pancreatitis was established by Glasgow's criteria and by clinical details of patients. ERCP and Endoscopic Sphinterotomy (ES) was performed in all 45 patients with acute biliary pancreatitis. Twenty-six patients (57%) were classified as having a severe attack (> 4) 19 as having a mild attack by Glasgow's criteria. ERCP associated with ES was performed within 24 hours in 22 patients (49%), 11 (50%) showed a severe attack and 11 (50%) showed a mild attack. A total of 2 complications (4%) occurred and the mortality was of 2 patients (4%). In 23 patients (51%) ERCP and ES was performed within 72 hours after conservative therapy, 8 (35%) showed a mild attack and 15 (65%) showed a severe attack. A total of 5 complications (9%) occurred and the mortality was of 3 patients (6%). Our study showed that ERCP with endoscopic sphincterotomy can be performed safely by skilled endoscopist, without adverse consequences soon after the onset of acute biliary pancreatitis even within the first 24 hours and it showed that is better than ERCP within 72 hours after conservative therapy.

Two-trocar laparoscopic cholecystectomy: a reproducible technique

Laparoscopic cholecystectomy is usually performed with a four-trocar technique. From December 1998 to March 1999, 25 of 42 admitted patients underwent a two-trocar laparoscopic cholecystectomy. In our technique, after establishing umbilical carbon dioxide pneumoperitoneum, a 30 degree scope was inserted, and a second 5-mm trocar was positioned below and to the left of the xiphoid process. Then two stitches with nonabsorbable sutures were passed: one at the fundus to pull up the gallbladder, and the second through the neck of the gallbladder to expose the structure of the Calot triangle. Intraoperative cholangiography was performed with a percutaneous catheter in 15 patients. Retrograde cholecystectomy was performed and the gallbladder was extracted through the umbilical port. Scars were closed with glue, and bupivacaine was injected to reduce pain. The technique was feasible in approximately 84% (25 of 30) of patients. The mean operative time was 42 minutes, and the mean hospital stay was 1.6 days. We conclude that this method is similar to four-port laparoscopic cholecystectomy in terms of safety and operation time. This technique seems to be well reproducible and offers better results in terms of postoperative pain, hospital stay without considering better cosmetic results, and cost-effectiveness.

Effector Th-1 cells with cytotoxic function in the intestinal lamina propria of patients with Crohn's disease

A large body of evidence points to a pivotal relationship between Th-1 cells and mucosal inflammation in Crohn's disease (CD). The aim of the present study was to assess whether CD is associated with specific functional activity of lamina propria T lymphocytes (LPT), particularly purified CD4, such as cytotoxic activity and specific cytokine-secreted profile. The results showed that CD4 LPT in patients displayed a chronically activated memory-like surface phenotype and, when compared to controls, had a significantly enhanced antibody-redirected cytotoxicity. Interestingly, the ratio of perforin expression in CD4 LPT was higher compared to controls, and a redirected lysis of human RBC mediated by a CD4 subset of intestinal lamina propria was evident, suggesting a cytolytic pore-forming mechanism. Moreover, a unique Th-1 cytokine profile pattern in the CD4 cells from CD was defined. These effector cells produced 12 times more IFN-gamma, two times more TNF-alpha, and three times less IL-4 than controls. In contrast, no increase in IL-2 was detected, while IL-5 was undetectable. Our studies suggest that these preexisting in vivo activated CD4 LPT may play an important role in the inflammatory process in CD, thus directly contributing to the intestinal lesions.

Effector Th-1 cells with cytotoxic function in the intestinal lamina propria of patients with Crohn's disease

A large body of evidence points to a pivotal relationship between Th-1 cells and mucosal inflammation in Crohn's disease (CD). The aim of the present study was to assess whether CD is associated with specific functional activity of lamina propria T lymphocytes (LPT), particularly purified CD4, such as cytotoxic activity and specific cytokine-secreted profile. The results showed that CD4 LPT in patients displayed a chronically activated memory-like surface phenotype and, when compared to controls, had a significantly enhanced antibody-redirected cytotoxicity. Interestingly, the ratio of perforin expression in CD4 LPT was higher compared to controls, and a redirected lysis of human RBC mediated by a CD4 subset of intestinal lamina propria was evident, suggesting a cytolytic pore-forming mechanism. Moreover, a unique Th-1 cytokine profile pattern in the CD4 cells from CD was defined. These effector cells produced 12 times more IFN-gamma, two times more TNF-alpha, and three times less IL-4 than controls. In contrast, no increase in IL-2 was detected, while IL-5 was undetectable. Our studies suggest that these preexisting in vivo activated CD4 LPT may play an important role in the inflammatory process in CD, thus directly contributing to the intestinal lesions.

Imipenem/cilastatin (1.5 g daily) versus meropenem (3.0 g daily) in patients with intra-abdominal infections: results of a prospective, randomized, multicentre trial

An open-label prospective, randomized, parallel multicentre study was undertaken to compare the efficacy and tolerability of 1.5 g/day intravenous imipenem/cilastatin with 3 g/day intravenous meropenem in the treatment of intra-abdominal infections. A total of 287 patients were enrolled: 201 patients, divided between the 2 treatment groups, were evaluable. Clinical outcome, bacteriological outcome, untoward microbiological effects, and clinical and laboratory adverse experiences were evaluated. 98% of patients receiving imipenem/cilastatin therapy were cured, with 96% showing eradication of infection. 95% of those on meropenem were cured, with 98% showing eradication. These differences in clinical and bacteriological outcome between the 2 treatments were not statistically significant. Two patients receiving imipenem/cilastatin and 5 receiving meropenem had untoward microbiological effects. There was a 0.7% frequency (1/139 patients) of possibly or probably drug-related clinical or laboratory adverse experiences with imipenem/cilastatin and a 2.7% frequency (4/148) with meropenem. The mean time to defervescence was significantly less for patients in the imipenem/cilastatin treatment group than for those receiving meropenem. This study shows that 1.5 g/day of imipenem/cilastatin is equivalent to 3.0 g/day meropenem in clinical and bacteriological outcome, as well as in incidence of side effects.

Magnetic resonance-cholangiopancreatography in the diagnosis of biliopancreatic diseases

BACKGROUND

Magnetic resonance cholangiopancreatography (MRCP) is a new, noninvasive imaging technique for the visualization of the biliary ducts with cholangiographic images similar to those obtained with endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography. No contrast medium injection is used. The aim of this study was to assess the feasibility of MRCP versus ERCP in the diagnosis of biliary tract and pancreatic diseases.

PATIENTS AND METHODS

One hundred and thirty-six patients were submitted to MRCP. They were referred to MR study according to four inclusion criteria: (1) evidence or suspicion of choledocholithiasis, (2) benign or malignant bile ducts stenosis, (3) follow-up of patients submitted to biliary-enteric anastomosis, and (4) chronic pancreatitis with Wirsung duct dilatation. The MRCP was performed with a 0.5T superconducting magnet (Philips Gyroscan T5). When neoplastic disease was detected, additional images on axial planes were acquired. MRCP allowed images of diagnostic value to be obtained in all the cases.

RESULTS

In choledocholithiasis, MRCP showed 91.6% sensitivity, 100% specificity, and overall diagnostic accuracy 96.8%. Of 48 patients with stenotic lesions, 16 were correctly characterized as benign and 30 as malignant. Two cases of focal chronic pancreatitis were misdiagnosed as pancreatic head carcinoma. In the patients submitted to biliary-enteric anastomosis, MCRP was able to detect the dilatation of the intrahepatic ducts, the stenosis, and associated stones in all 8 positive cases. In the remaining 7 patients with mild signs of cholangitis, MCRP showed irregular aspects of the biliary tree in the main ducts. In the 11 patients with chronic pancreatitis, MCRP was able to depict the dilated Wirsung duct and the stenotic tract, although the fine details of the secondary ducts were not evaluated due to the low spatial resolution as compared with conventional films.

CONCLUSIONS

MRCP can be considered a technique able to completely replace diagnostic ERCP. Further studies are necessary for a better evaluation of the potential advantages and disadvantages of this technique.

[The role of surgery in the treatment of appendicular abscesses]

The management of appendiceal abscesses is still discussed and many different approaches are nowadays adopted. The aim of this study was to analyze retrospectively our experience with this disease to value the results of drainage of the abscess and appendectomy in one stage in presence of appendiceal abscesses. We studied 44 patients consecutively observed in our Department of General Surgery all submitted to drainage of the abscess and appendectomy for acute appendicitis with periappendiceal abscess. Preoperative ultrasonography showed an accuracy of 85.7% in detecting the presence of an abscess. Mean size of the abscesses were 5 cm (from a minimum of 3 cm to a maximum of 9 cm). The mean duration of surgical operation was 48 minutes (min 35'-max 95'), with a mean in-hospital stay of 6.2 days. Morbidity rate was 9% and was due in 75% of cases to wound infection and in 25% of cases to wound dehiscence. Neither major morbidity nor mortality were observed. In consideration of the results the authors conclude that even in presence of an appendiceal abscess, appendectomy with abscess drainage is not only a safe operation with a low morbidity rate but the procedure of choice allowing a significative reduction of hospitalization and health cost.

[Fistulectomy with closure by first intention in the treatment of perianal fistulae]

The authors report in a retrospective study their experience in the treatment of anal fistulas suggesting the total exercises of the fistula with primary closure of external and internal anal sphincters and rectal mucosa. In our department of surgery between 1987 and 1993, 36 patients (22 males and 14 females) with anal fistulas (17 intersphincteric, 15 trans-sphincteric and suprasphincteric) were treated with this technique. Postoperative in-hospital stay ranged between 2 and 5 days (mean 3.1) and surgical healing needed 12-15 days. A dehiscence of distal tract was observed in 3 cases (8.2%). in these cases secondary closure of the wound needed 24-28 days. All the patients controlled at follow-up (it lasted at least 1 year) did not show rectal incontinence for gas or stools. The authors conclude that total exeresis with primary closure is a safe procedure indicated in the treatment of anal fistula not associated to inflammatory bowel disease in consideration of earlier healing and minor costs.

ESWL experience in the therapy of difficult bile duct stones

In recent years, alternatives to surgery for difficult bile duct stones have been developed. Routine endoscopy fails in about 10% of patients. To verify the role of extracorporeal shock wave lithotripsy in residual CBD stones, we treated 32 patients by HM4 or MPL 9000 Dornier lithotripters. Ten (34.4%) patients needed two extracorporeal shock wave lithotripsy sessions, and 3 (10.3%) patients three. Complete clearance was achieved in 29 patients (90.6%) after one or more sessions either by endoscopic (20 pts) or percutaneous (9 pts) extraction of the debris; of the remaining 3 patients, in 2 a bilioduodenal stent was placed and in 1 electrohydraulic lithotripsy was performed. Eighteen and seven-tenths percent transient mild hemobilia, 12.5% microhematuria, and no mortality were observed. It is possible to state that in site- or size-related difficult biliary stones, extracorporeal shock wave lithotripsy is a rapid, safe, and highly effective treatment as an additional nonoperative option to resolve the failure of routine endoscopic measures.

[Risk factors for recurrence of Crohn disease after intestinal resection]

From 1965 to 1990, postoperative risk factors (age, sex, preoperative history of CD, initial location of CD, length of affected intestinum, extent of bowel resection) for recurrence of Crohn's Disease (CD) were retrospectively analysed from data of 172 patients (104 men, 68 women; age 14 to 65 yrs.) with primary bowel resection and compared with the international literature. The mean follow-up interval was 10 (1-21) years. Additionally full thickness biopsies from resection margins of 66 consecutive ileocecal specimen (45 men, 21 women; age 21-70 years) with ileitis were studied, histopathologically classified into 3 groups and correlated with the rate, manifestation and onset of early recurrence. The cumulative CD recurrence rate was 69% after 10 years and 86.4% after 15 years. There was no statistically significant correlation between recurrence rate and age, sex, initial location or extent of bowel resection, only an higher rate with an preoperative duration of CD longer than 5 years (p < 0.05). The histopathology of the ileocecal resection specimen showed no statistically significant differences of the recurrence rate within the 3 groups. Surgery cannot minimize the recurrence rate of CD after resection but do clearly improve the quality of life.

Primary gastric lymphoma: a 15-year review

BACKGROUND/AIM

Between 1976 and 1991, 25 patients underwent surgical therapy for primary gastric lymphoma. Clinical records were reviewed retrospectively to evaluate prognostic factors and impact of treatment on survival.

RESULTS

Diagnostic sensitivity of endoscopic biopsy was 68%, positively of barium contrast studies for tumor was 33%. The overall 5-year survival rate was 67.3% (51.7% "free disease"): it was for stage I E 88.9%, for stages II 1E and II 2E respectively 68.6% and 44.4% and for stage IV 33.4%. Patients with tumors smaller than 5 cm had a 5-year survival rate of 80.8% whereas for patients with larger lesions survival rate was 44% (p < 0.05). Patients with low grade malignancy tumors had a 5-year survival rate of 81.9% versus 37.5% for high grade malignancy tumors (p < 0.03). Chemotherapy as adjuvant therapy was used in 17 cases (68%). 53% of them are "free disease" at minimum 4 years from the operation.

CONCLUSIONS

We conclude that, surgical management of primary gastric lymphoma is mandatory but a planned multimodality therapy may produce complete remission and long-term "free disease" survival rate even in patients with relapse.

["Occult" carcinoma of the thyroid: clinical, morphological, and biologic characteristics for a correct therapeutic regime]

The "occult" carcinoma of the thyroid is still a highly controversial topic. The controversies not only regard its diagnosis, treatment, natural history and, therefore, its biological potential, but also aspects of a nosological nature in that there is still no unequivocal acceptance of its originality, thus leading to discussions focused on its precise definition. On the basis of our experience and other published data, we have reached the following conclusions: a) the term "occult" carcinoma of the thyroid must be used to describe a neoplasia which does not exceed 1.5 cm in diameter, irrespective of the presence or otherwise of laterocervical adenopathy, and leaving aside the fact that it can be identified using clinical and instrumental tests; b) high-resolution echography and echo-guided FNA are fundamental instruments for a correct and early preoperative diagnosis; c) the clinical, morphological and, above all, biological (a very slowly evolving neoplasia) characteristics make the occult carcinoma of the thyroid seem to be a tumour with its own nosological identity; d) on the strength of the latter, and in particular in view of its natural history, conservative surgery (lobectomy with isthmectomy), in the differentiated forms, might play a primary role in the treatment of occult carcinoma of the thyroid in the very near future. However, at present complete thyroidectomy represents the treatment of choice even in differentiated forms, whereas lobectomy is only reserved for incidental cases of occult carcinoma discovered during the final histological test; e) lymphadenectomy is indicated in the event of lymph node involvement, not to achieve a longer survival rate but to reduce the incidence of recidivation in the form of lymph node metastases. In these cases, even the mere removal of macroscopically damaged lymph nodes is sufficient to ensure the virtual absence of recidivation on which, it is worth noting, metabolic radio-iodotherapy is efficacious in the large majority of cases.

[Anorectal functional study. The state of the art]

Disturbances of anal continence and evacuation are frequent. Numerous techniques are now available to measure anorectal function. There is also a better understanding of the anatomy and physiology of the pelvic floor which has a major role in anorectal function. ANORECTAL MANOMETRY. Manometry of the anal canal is an index of the resistance of sphincters to the passage of faeces. Resting pressure is due mainly to the internal anal sphincter whereas voluntary contraction is due mainly to the external anal sphincter. Anorectal manometry is essential in measuring the length of the anal canal and in establishing the presence of the rectoanal inhibitory reflex. Several techniques are employed to evaluate anorectal manometry which is useful in the investigation of patients with faecal incontinence and constipation. PUDENDAL LATENCIES: Pudendal latencies are valuable in the study of the innervation of the external anal sphincter. Pudendal latencies are measured thanks to the stimulation of the S2-S4 nerves lying in the proximity of the ischial spine through the use of a special glove (St Mark's glove). Prolonged pudendal latencies are typical of neurogenic faecal incontinence but it can be brought about by childbirth, rectal prolapse, obstructed defecation and old age. ELECTROMYOGRAPHY. Electromyography is useful in the study of the function of the pelvic floor. This technique can be performed with single fibre needles which make it possible to measure the action potentials and the fibre density of the muscular fibres. Fibre density is raised in neurogenic faecal incontinence and the action potentials are polyphasic in this condition. Concentric needles are employed to map the anal sphincters and this is useful for evaluating the extent of the damage caused by traumatic events like a third degree tear. ANAL ENDOSONOGRAPHY. Anal ultrasound is very effective in the study of the morphology of the anal sphincters and it requires a rectal probe fitted with a 7-MHz transducer. It is as accurate as electromyography in evaluating the damage to the anal sphincters but it is not painful and it is more acceptable to the patient. DEFECOGRAPHY. This radiological test is a dynamic study of the pelvic floor during defecation. It is very useful for investigating the function and the morphology of the rectum and the pelvic floor during defecation. Important parameters like: the anorectal angle, the opening of the anal canal, the position of the pelvic floor and the descent of the perineum can be evaluated with this test. Defecography is useful in the study of patients with rectal prolapse and constipation. CONCLUSION. All these tests provide extremely useful information on the pelvic floor and are reproducible. They can be of great help in evaluating patients with pelvic floor disorders but they are no substitute for clinical judgement.

[Intraoperative digital cholangiography during laparoscopic cholecystectomy interventions]

In the last years, laparoscopic cholecystectomy has become the method of choice in the surgical treatment of gallbladder stones. Recently, the same laparoscopic approach has been used to remove choledochus stones. This surgical procedure needs the accurate intraoperative study of the biliary tree with diagnostic imaging modalities to better define the anatomy of the biliary ducts and the possible presence of choledochus stones. To this purpose, transcutaneous and endolaparoscopic US with dedicated probes and intraoperative cholangiography can be performed. In this study, we performed 30 laparoscopic cholecystectomies during which all the patients were submitted to intraoperative cholangiography with a digital fluoroscopic unit. The maneuvers for catheter insertion in the cystic duct and the examination as a whole took 3 to 5 minutes. Intraoperative cholangiography demonstrated choledochus stones in 3 patients, while preoperative US detected them in 2 patients only. In 8 cases the dynamic study, carried out with digital image acquisition, allowed to refer the biliary duct filling defects to artifacts caused by the presence of air bubbles. In conclusion, intraoperative cholangiography, also during endolaparoscopic cholecystectomy, plays a major role in the surgical assessment of the biliary tree. When the procedure was performed with a digital fluoroscopic unit, its diagnostic accuracy was higher and the images on the TV monitor were better visualized.

[The role of intraoperative echography in laparoscopic cholecystectomy]

On the basis of recent technological improvements, the laparoscopic approach has become the method of choice during cholecystectomy. This surgical procedure, however, needs that cholangiography be performed simultaneously to better define the anatomy of the biliary ducts and the possible presence of choledochus stones. The use of intraoperative US during cholecystectomy is nowadays advocated for the unquestionable advantages offered by this technique--i.e., its non-invasiveness, high spatial resolution and no need of contrast agent administration. In this study, we examined 30 patients with cholelithiasis who underwent laparoscopic cholecystectomy and were submitted to endolaparoscopic US besides routine intraoperative cholangiography. In all cases, both techniques allowed optimal visualization of the biliary tree, clearly demonstrating choledochus stones in 2 cases. Intraoperative US proved to be more accurate in two cases. In one case which was positive at intraoperative cholangiography, the method allowed the biliary duct filling defect to be referred to an artifact caused by the presence of an air bubble. In another case, the lack of opacification of the hepatic ducts at cholangiography was referred, after US, to extrinsic gallbladder compression. US also allowed the adjacent parenchymal organs, such as the liver and the head of pancreas, to be studied. A limitation of this technique was represented by the difficult assessment of the choledochus in the patients with anatomical abnormalities or adhesions of the intestinal loops of the upper abdomen. In conclusion, endolaparoscopic US proved to be a reliable technique in the intraoperative study of the biliary ducts and can be considered as a procedure complementary to intraoperative cholangiography.

Role of magnetic resonance imaging (MRI) in detecting liver changes after gallstone extracorporeal shock wave lithotripsy (ESWL)

Recently published literature on biliary extracorporeal shock wave lithotripsy (ESWL) has shown that high-energy ESWL utilizing high kV is more effective than the low-energy ESWL and low kV used previously. Prior studies have not reported injury to the gallbladder or adjacent liver following ESWL. Our study evaluated 29 patients that were treated with high kV ESWL. Magnetic resonance imaging (MRI) was used to study the gallbladder and adjacent liver for possible injury resulting from the high-energy treatment. The patients, selected using the Dornier MPL-9000 United States protocol, underwent ESWL using 18-24 kV (average 21 kV). MRI was done both pre and post-ESWL in all 29 patients. Ten patients had a second treatment to reduce fragment size and, subsequently, had an additional MRI examination. Spin echo MRI images were obtained at the level of the gallbladder fossa using a 0.5-Tesla ESATOM RM 5000 (ESAOTE Biomedica, Genva, Italy.) superconductive unit. Both T1- and T2-weighted images were obtained. In 26 patients the hepatic parenchyma was normal post-ESWL. Two patients had a hyperintense region on T1-weighted images post-ESWL that was felt to be related to pericholecystic fat. A third patient had an abnormality detected on T2-weighted images that was thought to be due to hepatic edema or microhemorrhage. No significant changes were shown by laboratory or concurrent ultrasound examinations. Repeat MRI examinations in these three patients were normal. High-energy ESWL appears as safe as low-energy ESWL in the treatment of patients with symptomatic gallstones.

Plasma opioid levels during extracorporeal gallstone lithotripsy

Plasma levels of beta-endorphin (beta-EP), met-enkephalin (met-ENK), ACTH, cortisol, and prolactin were measured in 20 patients who underwent extracorporeal gallstone lithotripsy (ESWL) before the treatment, at 500 shock waves (SW) (15-20 min), at 1000 SW (40-50 min), and 10 min after the end of ESWL. According to the Visual Analog Scale, nine patients had no pain, seven patients had pain from level 1 to 5, and four patients had pain from 5 to 10. No complications were observed. Plasma beta-EP values increased during the treatment, both in patients without pain and in those with pain. Only in the former group was the increase significant (baseline values (pmol/L): no pain = 4.04 +/- 1.3; pain 1-5 = 3.6 +/- 1.06; pain 5-10 = 2.9 +/- 0.5. Peak values: no pain = 6.6 +/- 1.2 (p < 0.005); pain 1-5 = 4.6 +/- 2.5; pain 5-10 = 4.5 +/- 2.2). Moreover, a negative correlation between beta-EP levels and individual pain scores during ESWL has been observed (CC = -0.64, p < 0.003). Plasma met-ENK levels reached the peak at 1000 SW and declined 10 min after the end of the treatment, although they were always higher than basal values (baseline values (pg/ml): no pain = 45 +/- 12; pain 1-5 = 38 +/- 10; pain 5-10 = 48 +/- 8. Peak values: no pain = 112 +/- 42 (p < 0.005), pain 1-5 = 114 +/- 48 (p < 0.005), pain 5-10 = 85 +/- 10 (p < 0.005). This behavior has been the same, regardless of the presence or absence of pain. We conclude that during ESWL, a rise of beta-EP and met-ENK occurs, and the increase of the former can be responsible for induction of analgesia because of its inverse correlation with pain intensity.

[Trends in the incidence of acute appendicitis in Italy during the past 30 years]

The incidence and mortality rate of acute appendicitis for the years 1955 and 1987 were calculated on the basis of data used by ISTAT. In 1955 the incidence was 5.7 per 1000 whereas in 1987 this had fallen to 3.7 per 1000. In both years examined there was a prevalence of females (in 1987 females accounted for 4.3 per 1000 in comparison to 3 per 1000 recorded for for males). In 1987 the lowest incidence was recorded in the over 60 years olds, whereas the highest incidence was in males between 1 and 14 years old (7.57 per 1000) and females between 15 and 24 years old (12.17 per 1000). Mortality diminished from 0.42% in 1955 to 0.05% in 1987. The highest rate of mortality was recorded in those patients over 60 years old (1.5%).