Characterization of the polycaprolactone melt crystallization: complementary optical microscopy, DSC, and AFM studies.

The first stages of the crystallization of polycaprolactone (PCL) were studied using several techniques. The crystallization exotherms measured by differential scanning calorimetry (DSC) were analyzed and compared with results obtained by polarized optical microscopy (POM), rheology, and atomic force microscope (AFM). The experimental results suggest a strong influence of the observation scale. In particular, the AFM, even if limited on time scale, appears to be the most sensitive technique to detect the first stages of crystallization. On the contrary, at least in the case analysed in this work, rheology appears to be the least sensitive technique. DSC and POM provide closer results. This suggests that the definition of induction time in the polymer crystallization is a vague concept that, in any case, requires the definition of the technique used for its characterization.

Transduodenal papillostomy as a routine procedure in managing choledocholithiasis.

The purpose of this study was to evaluate the results of transduodenal papillostomy as a routine procedure in managing choledocholithiasis in treating common bile duct (CBD) stones. From 1973 to 1978, 117 patients underwent transduodenal papillostomy for CBD lithiasis. The operation was carried out in standard manner, and all patients had preoperative telecholangioscopy, cholangiography, and biliary manometry. The mean age of patients was 53.7 years, and women predominated in a ratio of 4.5:1.0. Papillostomy was performed together with cholecystectomy for CBD stones in 111 patients (group 1). In five patients, we had to perform a choledochotomy to remove the stones after an unsuccessful papillostomy (group 2). Eight patients who previously had cholecystectomies underwent papillostomy for retained or recurrent stones (group 3), and three patients had a choledochoduodenostomy for recurrent stones after a previous cholecystectomy and papillostomy (group 4). Complications included two deaths in group 1 (1.9%). No mortality was observed in groups 2 and 4. Moreover, the overall morbidity was due to six cases of wound infection, one case of postoperative bleeding, one case of phlebitis, and three cases of cholangitis. The mean length of hospital stay was 12.9 days, considering all the groups. Lack of confidence with this procedure may explain the different results reported in the literature for transduodenal papillostomy, which on the basis of this study has been shown to ba a valid alternative to supraduodenal choledochotomy in treating CBD stones.

Intrahepatic lithiasis. Study of thirty-six cases and review of the literature.

In 2,700 operations for biliary tract stones, intrahepatic lithiasis (stones located proximal to the confluence of the main hepatic ducts) was discovered in 36 patients (1.3 per cent). The diagnosis of intrahepatic lithiasis was determined only via intraoperative chalangiography in thirty-two cases (88.9 er cent); in 23 per cent of our cases of intrahepatic lithiasis, jaundice was never observed. This confirms that intraoperative cholangiography should be performed routinely in every case of biliary lithiasis. The removal of stones was generally performed by an indirect approach (papillostomy and/or choledochotomy). In 16.7 per cent of our cases, a direct approach was indicated. It is extremely important, after removal of calculi, to assure ample bilioenteric flow. Our surgical approach was therefore based mostly on the caliber of the biliary tract. When the tract was dilated less that 2 cm (in 20 cases), choledochohepaticotomy with papillostomy was most often performed (12 cases, 60 per cent). When the dilatation was more that 2 cm (12 cases), Roux-en-Y hepaticojejunostomy was performed in all. There was no operative mortality, although the long-term follow-up results were poor in 9.6 per cent of the cases.

Elevated plasma levels of vasoactive intestinal polypeptide in short bowel syndrome.

Short bowel syndrome is a complex disease that is almost always seen with diarrhea. VIP is known to act powerfully on gut motility, and elevated VIP plasma levels have been reported in several diarrheal conditions. In this study VIP plasma levels were measured by radioimmunoassay in 8 patients with short bowel syndrome versus 30 healthy control subjects under basal conditions. VIP plasma levels were significantly higher in the short bowel syndrome group (p less than 0.05). The explanations that could account for these elevated levels are (1) an increased gastric acid load in the residual bowel, (2) a compensatory increase in blood supply to the gut, (3) removal of an inhibitory factor arising from the small intestine, or (4) mucosal stress due to unadsorbed food. An etiologic role of VIP in the occurrence of diarrhea in patients with short bowel syndrome seems to be an unproved hypothesis.

Retained antral mucosa in pancreaticoduodenectomy patients.

Thirteen patients with pancreaticoduodenectomy were studied. In three patients presenting with stomal ulcer or bleeding stomitis, endoscopic biopsies showed the presence of retained antral mucosa (RAM). No disease and no RAM was present in the remaining ten patients. Bombesin (BBS) infusion augmented both gastric acid and gastrin secretion in the group with RAM, whereas no change was apparent in the remaining ten patients. The BBS infusion test is useful in detecting stomal ulcer high risk pancreaticoduodenectomy patients.

Cimetidine and antacid prophylaxis of acute upper gastrointestinal bleeding in high risk patients. Controlled, randomized trial.

A randomized, controlled clinical trial was performed to compare the efficacy of prophylactic cimetidine treatment, antacid treatment and no treatment in high risk patients. Sixty patients received cimetidine (200 mg every 6 hours), 52 patients received antacids (Maalox, 10 ml/hour), and 56 patients received no treatment. One hundred thirty-five patients completed the study. Eight patients in the control group and one patient in the antacid-treated group presented with upper gastrointestinal bleeding. No bleeding occurred in the cimetidine-treated group. Patients considered at low risk had no bleeding. Cimetidine or antacid prophylaxis significantly decreased the incidence of upper gastrointestinal bleeding in the high risk patients.

Management and long-term results in patients with two-thirds gastrectomy and stomal ulcer.

In 67 patients with two-thirds gastrectomy and endoscopically proven stomal ulcer, serum gastrin levels were measured under basal conditions and after intravenous infusion of bombesin (15 ng/kg/min), calcium (4 mg/kg/hour) and secretion (2 units/kg). All patients underwent medical or surgical therapy. The long-term results were evaluated according to the Visick grading system (average follow-up, 3.1 years).

Relationship between pancreatic and serum amylase in basal conditions and during stimulation in man. Report of a new intraoperative technique.

The correlation between serum amylase and pancreatic amylase secretion was studied in two patients. Both patients underwent sphincterotomy, and the pancreatic duct was cannulated with a polyethylene tube. The tube was left in place for 15 to 21 days. The rate of amylase secretion over 7 days was studied in response to (1) a standard meal, (2) duodenal acidification, (3) scalar doses of cholecystokinin, (4) scalar doses of secretin, and (5) scalar doses of secretin with simultaneous infusion of cholecystokinin. Blood samples were collected during the tests to measure serum amylase. No significant correlation was shown between blood concentration and output of amylase in any of the tests. Our findings show that under normal conditions serum amylase levels are not influenced by pancreatic secretion and suggest that serum amylase concentration is not related to pancreatic exocrine secretion.

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.

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.

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.

Action of famotidine and ranitidine on prostaglandin E2 (PGE2) content of fundic and duodenal mucosa in duodenal ulcer patients.

PGE2 plays an important role in gastric cytoprotection. Previous experience has shown that H2-blocker drugs may have a role in gastric cytoprotective mechanisms. The effects have been compared of ranitidine and famotidine on PGE2 content in duodenal ulcer patients. Twenty patients were treated for 4 weeks as follows: group A, ranitidine (150 mg twice daily); group B, famotidine (40 mg daily). The patients underwent EGDS before and after therapy. The results show that both famotidine and ranitidine significantly increase the PGE2 content of fundic mucosa (from 112.3 +/- 73 to 210.7 +/- 106 ng/g wet wt and from 109.6 +/- 52.4 to 230.2 +/- 104.6 ng/g wet wt, respectively) in duodenal ulcer patients (p less than 0.01). Similarly, the PGE2 content of duodenal mucosa significantly increases after famotidine treatment (from 51.9 +/- 27.5 to 105.3 +/- 55.6 ng/g wet wt) as well as ranitidine treatment (from 53.8 +/- 24 to 172.6 +/- 72.9 ng/g wet wt) (p less than 0.01). It is concluded that these drugs play an important role in gastric and duodenal cytoprotection.

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.

[Risk factors for recurrence of Crohn disease after intestinal resection]. / Risikofaktoren des Morbus-Crohn-Rezidivs nach Darmresketion.

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.

[Anaerobic infections in surgery]. / Infezioni anaerobie in chirurgia.

In the past few years the incidence of anaerobes in the aetiology of surgical infections has definitely increased due to a distinct increase in anaerobic flora and to the noticeable improvement in isolation and culture techniques which have drastically decreased the incidence of so-called "sterile pus". The development of the toxi-infective shock due to Gram negative anaerobes, presents the most serious clinical problems, being the shock with the highest mortality rate. A paradigmatic example of shock due to surgical infections is the shock complicating peritonitis. A correct postoperative behaviour includes peritoneal lavage through drainages placed during surgery. The AA. personal experience with 50 hospitalized patients treated surgically and with cefoxitin, a new cephamycin semisynthetic antibiotic resistant to beta-lactamases, is reported.

[The gastric mucosa barrier and gastropathy]. / Barriera mucosa gastrica e gastropatie.

In addition to a layer of mucus, the gastric mucosa barrier is mainly formed of a tight junction consisting of the surface membranes of epithelial cells. It is this that mainly impedes the flowback of H+ ions. Buffers conveyed by the blood neutralise the small numbers of ions that do flow back, even under physiological conditions. Damage to the barrier results in a considerable backflow of ions that enhance acid secretion and release of histamine and other vasoactive substances, so that further mucosal lesions occur. Such damage may be of exogenous or endogenous origin. Alcohol and acetylsalicylic acid are two examples. The latter is undissociated and hence liposoluble in the highly milieu of the stomach and can easily enter the cells and damage them. Severe hypovolaemia, stress and sepsis are instances of endogenous sources of damage. In the final analysis, the damage caused by sepsis is linked to cell anoxia.

[Anorectal functional study. The state of the art]. / Studio della funzione anorettale. Orientamenti attuali.

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.

["Occult" carcinoma of the thyroid: clinical, morphological, and biologic characteristics for a correct therapeutic regime]. / Il carcinoma "occulto" della tiroide: caratteristiche cliniche, morfologiche e biologiche per una corretta programmazione terapeutica.

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.

[Fistulectomy with closure by first intention in the treatment of perianal fistulae]. / La fistulectomia con chiusura per prima intenzione nel trattamento delle fistole perianali.

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.

[The role of surgery in the treatment of appendicular abscesses]. / Il ruolo della chirurgia nel trattamento degli ascessi appendicolari.

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.