Symmetry breaking and effects of nutrient walkway in time-dependent bone remodeling incorporating poroelasticity.

Bone is an extraordinary biological material that continuously adapts its hierarchical microstructure to respond to static and dynamic loads for offering optimal mechanical features, in terms of stiffness and toughness, across different scales, from the sub-microscopic constituents within osteons-where the cyclic activity of osteoblasts, osteoclasts, and osteocytes redesigns shape and percentage of mineral crystals and collagen fibers-up to the macroscopic level, with growth and remodeling processes that modify the architecture of both compact and porous bone districts. Despite the intrinsic complexity of the bone mechanobiology, involving coupling phenomena of micro-damage, nutrients supply driven by fluid flowing throughout hierarchical networks, and cells turnover, successful models and numerical algorithms have been presented in the literature to predict, at the macroscale, how bone remodels under mechanical stimuli, a fundamental issue in many medical applications such as optimization of femur prostheses and diagnosis of the risk fracture. Within this framework, one of the most classical strategies employed in the studies is the so-called Stanford's law, which allows uploading the effect of the time-dependent load-induced stress stimulus into a biomechanical model to guess the bone structure evolution. In the present work, we generalize this approach by introducing the bone poroelasticity, thus incorporating in the model the role of the fluid content that, by driving nutrients and contributing to the removal of wastes of bone tissue cells, synergistically interacts with the classical stress fields to change homeostasis states, local saturation conditions, and reorients the bone density rate, in this way affecting growth and remodeling. Through two paradigmatic example applications, i.e. a cylindrical slice with internal prescribed displacements idealizing a tract of femoral diaphysis pushed out by the pressure exerted by a femur prosthesis and a bone element in a form of a bent beam, it is highlighted that the present model is capable to catch more realistically both the transition between spongy and cortical regions and the expected non-symmetrical evolution of bone tissue density in the medium-long term, unpredictable with the standard approach. A real study case of a femur is also considered at the end in order to show the effectiveness of the proposed remodeling algorithm.

Laparoscopic cholecystectomy in the treatment of acute cholecystitis: comparison of outcomes and costs between early and delayed cholecystectomy.

BACKGROUND: Several trials showed that early laparoscopic cholecystectomy is superior to delayed laparoscopic cholecystectomy for the treatment of acute cholecystitis. However actual practice does not conform to current evidence. The aim of this study is to compare outcomes and total hospital costs between early and delayed laparoscopic cholecystectomy for acute cholecystitis. PATIENTS AND METHODS: A retrospective analysis of patients with acute cholecystitis that underwent a laparoscopic cholecystectomy at our institutions was performed. Patients were divided into 2 groups on the basis of the treatment received and statistical analysis was performed. RESULTS: The study included 91 patients, 52 female and 39 male, with a mean age of 55. Early surgery was performed in 32 cases and delayed surgery in 59 cases. The two groups were comparable for demographics data and severity of disease on admission. There was a no significant difference (p = 0.174) in the mean operative time between early (54.8 min) and delayed group (47.8 min). Conversion rate was higher in the early group (34.3% vs. 20.3%), but difference was not statistically significant (p = 0.223). The overall complications rate was comparable (18.7% early vs. 16.9% delayed, p = 0.941). Length of postoperative stay (4.3 vs. 3.8 days) was similar (p = 0.437), but total hospital stay was significantly 4 days shorter in the early group (p < 0.0001). The mean total cost was higher for the delayed group (4171 vs. 6041), with a significant difference of 1870 Euro (p < 0.0001). CONCLUSIONS: Early laparoscopic cholecystectomy has an outcome comparable to the delayed procedure, with a shorter total hospital stay and lower total costs, and it should be considered as the preferred approach in treatment of acute cholecystitis.

Preoperative risk factors for conversion from laparoscopic to open cholecystectomy.

BACKGROUND: Laparoscopic cholecystectomy has become the standard treatment for symptomatic gallstones. However, a conversion to open surgery is sometimes still required to complete the procedure safely. The aim of this study is to identify the predictive factors of conversion from laparoscopic to open cholecystectomy in both elective and emergency cases. PATIENTS AND METHODS: A retrospective review of all patients underwent laparoscopic cholecystectomy for symptomatic gallstones from January 2011 to October 2013 was performed. Data considered for analysis were: demographic data, comorbidities, preoperative laboratory values, preoperative ERCP, indication for surgery, and the timing of the intervention in acute cholecystitis. Conversion to open cholecystectomy was chosen as the dependent variable for both, univariate and multivariate analysis. RESULTS: 414 patients underwent laparoscopic cholecystectomy. 245 were female (59.1%) and 169 (40.8%) male, with a mean age of 51.7±16.4 years. The indication for surgery was acute cholecystitis in 91 cases (21.9%). Lithiasis of the bile duct was found in 40 patients (9.6%), and it was identified preoperatively in 37 patients, all treated with a preoperative ERCP. Conversion to open occurred in 33 cases (7.9%). Univariate analysis revealed as risk factor for conversion: increased age, acute cholecystitis, comorbidities, elevated white blood cell count, increased level of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma glutamyl transpeptidase, C-reactive protein, and fibrinogen. Multivariate logistic regression analysis showed that acute cholecystitis (OR 5.63) and age > 65 years (OR 3.025) were independent predictive factors for conversion. CONCLUSIONS: These patients should be properly informed of their increased risk of conversion and should be operated by surgeons skilled in laparoscopic procedures to reduce this risk.

Hemoperitoneum as severe and unusual complication in the stapler recto-anopexy for hemorrhoidal prolapse. Case report.

We report unusual but severe complication after Longo recto-anopexy for hemorrhoidal prolapse, i.e. large intramural hematoma of the rectum and subsequent hemoperitoneum. We make some assessment about the technique.

Usefullness of the ultrasonically activated scalpel in laparoscopic cholecystectomy: our experience and review of literature.

Laparoscopic cholecystectomy (LC) actually represents the most used and proper treatment for gallbladder lithiasis, because its many and known advantages in comparison with 'open' abdominal surgery. But there are some problems during and after LC due to the use of the electric scalpel and these have brought to the search of an alternative system of dissection and coagulation. The ultrasonically activated scalpel (Harmonic Scalpel, HS) allows to perform dissection and coagulation with a minimal thermal side effect for surrounding tissues, unlike the electrocoagulation. Furthermore, the use of the HS brings a series of advantages in comparison to the other electromagnetic forms of energy (electro-scalpel, laser). HS cuts and coagulates with the same effectiveness of the electro-scalpel but, unlike this, it doesn't introduce risks of wandering currents. Moreover, HS contributes to have a more clean and clear (smokes-free) field of operation and it reduces the operative time, the bleeding and the costs of the operation without an increase of the complications and of the percentages of 'open' conversion, and perhaps leads to a less negative influence on the postoperative systemic immune response. The Authors report their experience that confirm these observations, according also with results reported in a brief review of the recent scientific literature, and support wider diffusion and technical development of this ultrasonically-operating surgical team.

Intestinal obstruction due to idiopathic sclerosing encapsulating peritonitis. Clinical report and review of literature.

The sclerosing peritonitis (SP) is a rare illness secondary to the peritoneal dialysis or due to intraperitoneal chemotherapy or the positioning of a peritoneal-jugular shunt in cirrhotic patient with refractory ascites or due to unknown other factors (idiopathic form) like in our patient. The clinical pattern is various and insidious, but when an intestinal occlusive symptomatology is presents an urgent operation is mandatory. The surgical operation is often not easy and asks for a lot of attention especially in the dialyzed subject or in patients with cirrhosis, due to the possibility of postoperative bleeding and other serious complications that can result in fatal outcome. In this report we describe surgical treatment, pathologic pattern and clinical findings of this rare disease.

About a case of GIST occurring during pregnancy with immunohistochemical expression of epidermal growth factor receptor and progesterone receptor.

The coexistence of gastrointestinal stromal tumors (GISTs) and pregnancy is very rare. We are the first to add to the literature a case report of GIST occurring during pregnancy with immunohistochemical staining for epidermal growth factor receptor (EGFR) and progesterone receptor (PgR). A role of PgR and EGFR in tumor growth should not be excluded, and these findings indicate that the expression of these receptors could provide pertinent biological information required to determine adequate therapeutic regimens. In conclusion, considering that GIST occurring during pregnancy is a rare event, with frequent delay in diagnosis, it is important to consider this diagnosis for early recognition, correct diagnosis, and a better outcome.

Laparoscopic cholecystectomy (LC): predictive role of preoperative ultrasounds.

AIM: We studied several ultrasounds patterns concerning gallbladder, biliary tract and gallstones to identify some predictive signs of difficulties during LC. PATIENTS & METHODS: 112 patients (24 females), 25-75 years old, upper abdomen operated patients not included. From 7 ultrasounds patterns 4 degrees of potential intra-operative difficulty (0-3) were obtained. During the operation 7 conditions of true intra-operative problems were also classified. RESULTS: Patients showing grade 0: regular gallbladder wall stones < 20 mm, regular Main Biliary Tract (MBT) = 62 LC and 2 open surgery conversion (OSC); grade 1: wall < 4 mm, stones > 20 mm= 24 LC and 7 OSC; grade 2: hydrops, wall > 4 mm, infundibular stone = 6 LC and 6 OSC, grade 3: wall > 4 mm, stones > 20 mm, empyema of gallbladder, MBT > or = 6 mm = 3 LC and 0 OSC. Inflammation near gallbladder and wall > 4 mm were mainly responsible for transition of LC in OSC. CONCLUSION: Several predictive conditions for intraoperative difficulties are often detectable by accurate preoperative ultrasounds examination, with the aim of best surgical planning and to select those patients to entrust to surgeons during their learning phase.

Splenic trauma following colonoscopy.

A case of splenic trauma after colonoscopy is reported. After description of their experience, the Authors report a review of the literature and some considerations about clinical diagnosis and surgical or medical therapy for this pathology.

Stress of routine follow-up in colorectal cancer operated patients.

Postoperative follow-up is the logical consequence of cancer treatment, but colorectal cancer follow-up does not achieve all its goals. These unfavourable findings induced us to assess whether follow-up also causes negative psychological stress in our colorectal cancer patients. In this trial 100 colorectal cancer follow-up patients were asked to compile three questionnaires: 1) the McGil Pain Questionnaires; 2) Profile of Mood Status; and 3) Locus of Control. The questionnaires were handed to the patients at follow-up and were compiled immediately. In addition, the patients were asked to answer the firsts two tests spontaneously 30 days after follow-up and mail the questionnaires. Our results showed that only 41% of the patients complied the tests 30 days after follow-up. The scores for pain and mood disorders were greater in women, especially during the "before follow-up" period. The third test revealed a prevalence of subjects with internal-type reinforcement. Our data revealed that: 1) patients tend to repress the problem; 2) women are affected by greater stress and anxiety; 3) subjects with internal-type reinforcement have a positive attitude during follow-up and this enables the ego to bear the anguish, process it and dilute it to anxiety, thus favouring future life experiences.

Giant esophageal polyp: a rare and benign neoplasm.

Giant esophageal polyp is a very rare neoplasm, usually benign but often demanding both for diagnostic and/or therapeutical procedures and for dramatic symptomatologic onset in the patient (regurgitation and asphyxia). The authors present a brief clinical report of a patient with a 20 cm.-long esophageal polyp removed by left lateral cervicotomy and esophagotomy for 8 cm. below the upper esophageal sphincter (histologic examinations showed a pedicled polypoid fibrolipoma with a remarkable presence of myxoid and vascular components). The authors also describe diagnostic and therapeutic methods to manage this rare disease and they gave a brief review of recent literature.

[Primary lymphoma of the small intestine. A clinical case report and review of the literature]. / Il linfoma primitivo dell'intestino tenue. Descrizione di un caso clinico e revisione della letteratura.

The authors present a case of small bowel primitive lymphoma found in a 66-years-old female. After having briefly reviewed the literature they direct their attention to the clinical-instrumental diagnostic difficulties of this neoplasm which is often discovered only when it has already invaded various organs. Therefore surgical therapy is not always radical. This fact in addition to the fatally rapid postoperative course led the authors to discuss the problems involved in a correct treatment of this pathology.

[Ileal and axillary metastasis of primary unknown site melanoma. Clinical case]. / Metastasi ileale ed ascellare da melanoma primitivo a sede ignota. Caso clinico.

The incidence of Cutaneous Melanoma is 4-5% of all the tumors of the skin. This incidence increases several folds in the last years. Metastases of Melanoma involve lungs, skin, soft tissue, liver, bone, brain, but in 20-30% of the patients involve gastrointestinal (GI) tract. In 60-70% of the cases GI metastases involve small bowel, in 15-20% stomach, in 10-20% large bowel, in 5% esophagus. In 8% of the patients the primary cutaneous melanoma is not known. The prognosis of the patients with metastatic melanoma is poor with an average survival of 5 months. One patient male, 51 years old, underwent surgery for metastases from melanoma in the lymph nodes of the right axilla and in the gastrointestinal tract (ileum). An ileo-ileo anastomosis and a lymphoadenectomy of the nodes of the right axilla were performed. After a first chemotherapy with DTIC (800 mg/m2) + a-IFN(3MU three times every week) and another with CDDP (30 mg/m2 day 1-3), DTIC (250 mg/m2 day 1-3) and VDS (2.5 mg/m2 day 1) with no response, the patient was treated with chemo-immunotherapy sec. Bernengo, slightly modified: CDDP 75 mg/m2; IL-2 18 MU (9MU b.d.) day 3-6 and 17-21; a-IFN 5MU three times every week. This therapy had a partial response of short-course (three months) and the patient died 15 months after surgery. The authors hope that immunotherapy and genetic therapy improve the survival of the patients with metastatic melanoma in the next years.

[Low ileorectal anastomosis in the surgery of ulcerative rectocolitis]. / L'ileorettoanastomosi bassa nella chirurgia della rettocolite ulcerosa.

The authors report their experience of 23 patients with ulcerative colitis treated with surgery from 1991 to 1994. At admission 8 patients had a high-grade illness, 10 patients had a middle-grade illness, 5 patients had a toxic megacolon. All the patients were treated with systemic medical management (mesalazine + methylprednisolone) and topical medical management with rectal steroid (methylprednisolone) and rectal mesalazine by enema, and with nutritional support (Total Parenteral Nutrition). The 5 patients with toxic megacolon, after 48 hours of unsuccessful medical management, underwent surgery with deferred urgency; the other 18 patients underwent surgery after one-four months. The authors prefer the ileorectal anastomosis (IRA), since the rectal lesions are more susceptible to topical therapy. A single-stage IRA was performed in 17 patients. A sigmoid resection has been employed in the first stage in the 18th patient with a local development of the disease in the sigma; a following relapse of the lesions required a total colectomy with a low ileorectal anastomosis. A first-stage subtotal colectomy with ileostomy and Hartmann closure of the rectum with low ileorectal anastomosis at a later date was performed in the 5 patients with toxic megacolon. One of these, 18 years old, died after a heart failure. After surgery, as soon as the patients start moving their bowels all of these had again a systemic therapy with mesalazine for a short period and after they had a topical therapy with mesalazine + methylprednisolone by enema, for a long period. The average postoperative period of admission was 16.3 days. The functional results have been encouraging with an average of 1.6 bowel movements daily and an average of 0.4 nocturnal bowel movements. All the patients had a normal anal sphincter function with an acceptable stool frequency. In male patients there no urinary or sexual defects. In one case of these, there was a low grade of dysplasia, revealed by endoscopic biopsy. The authors conclude that today surgical treatment of ulcerative colitis is not well established.

[Peritoneal mesothelioma. A case report]. / Il mesotelioma peritoneale. Caso clinico.

Peritoneal mesothelioma is a rare neoplasm (annual incidence: 1-2 cases per million in the general population) and forms about 10% of all mesotheliomas. The authors report a case of malignant mesothelioma of the peritoneum in a male, 61 years old. After laparotomy the patient was treated with intraperitoneal administration of cisplatin (40 mg/m2 day 1-2-3-29-30-31) and intravenous administration of mitomycin C (10 mg/m2 day 1). The renal toxicity was avoided with the GSH and with prehydration before and after administration of the cisplatin. The bone marrow toxicity was avoided with the subcutaneous administration of G-CSF (300 mg three times each week) and erythropoietin (10.000 U three times a week). After the first cycle, with the reduction of the ascites, the cisplatin was administered intravenously too. After six cycles of chemotherapy (18 months after laparotomy) the patient is alive and he has a performance status of 1 (ECOG/WHO). The chemotherapy with cisplatin and mitomycin C must be preferred to the anthracycline in all the patient with cardiologic involvement. The cisplatin administered by intracavitary route give a quick response with less systemic toxicity. A review of the literature confirms the rarity of this pathology, linked epidemiologically with exposure to asbestos, and the difficulty of the preoperative diagnosis: in fact cytologic assay and ultrasonographic and TC scan always don't permit to discover a mesothelioma. The laparotomy and the laparoscopy are useful in the P.M. for the possibility of the biopsies and the apposition of the catheters for intracavitary therapy. The response of peritoneal mesothelioma to treatment is poor. The median survival after the appearance of the symptom is less than 18 months.

[Leiomyosarcoma of the inferior vena cava: description of a new case and review of the literature]. / Leiomiosarcoma della vena cava inferiore: descrizione di un nuovo caso e revisione della letteratura.

A case of primary leiomyosarcoma of the inter-renal vena cava is reported. This tumor is rare and up to date no more than 100 cases have been reported. Surgical treatment consisted in the removal of vena cava from the iliac veins to the suprahepatic veins with right nephrectomy. Restoration of vena cava and left renal vein continuity was not necessary because of the presence of collateral venous circulation at the time of operation. Venous ligation was haemodynamically well tolerated and the patient is disease-free at one year from operation. However, despite surgical radicality, prognosis remains poor given the frequency of metastases reported in more than 35% of cases.

[Liposarcoma in the submandibular region. Clinical case]. / Liposarcoma della regione sottomandibolare. Caso clinico.

The authors report a case of liposarcoma in the sub-mandibular region, and they describe the histological species and the way of spreading. They suggest a surgical, non-demolitional therapy, that they carried radical if it is related to a strict follow-up. Anatomical and functional results, after demolishing surgical therapy, are sometimes unacceptable if the real benefits in terms of survival are considered. No supporting therapy has been used because of the presumed insensibility of the neoplasm to the chemo-radiotherapeutic treatments. At 2 years from surgical treatment no local relapses, on distance metastasis have been related.

[Probable correlations ultrastructural anomalies of the central nervous system and hyperammonemia following portacaval anastomosis in rats]. / Corrélations probables entre les anomalies ultrastructurelles du système nerveux central et l'hyperammoniémie après anastomose porto-cave chez le rat.

The correlation between hyperammonemia, during porto-systemic encephalopathy, and brain's lesions in patients died for porto-systemic encephalopathy is not demonstrated. The aim of this study has been to try a demonstration. A histological study of the brain, cerebellum, brainstem, and spinal cord was made in 60 rats: in 40 rats 1, 3 and 6 months after portocaval shunt, and in 20 rats sham operated. The brain, cerebellum, brainsteam and spinal cord have been fixed with paraformaldehyde (4%) and then sectioned for optical and electronic microscopic study. Ammonemia was measured regularly in the 40 rats with portocaval shunt, all the rats have been hyperammonemia since 10 weeks, after this period in 4 rats ammonemia was normal. In 20 rats sham-operated ammonemia was always normal. One month after surgery electronic microscopy revealed changes in the astrocytes characterized by nuclear swelling and lobulation. Three months after surgery this lesion was increased. After six months most lesions were noted in the hyperammoniemic rats. No similar lesions were observed in control rats. These results suggest that hyperammonemia is responsible of nuclear changes in the astrocytes of the patients died from hepatic encephalopathy.

[Staplers in surgery: state of the art]. / Le suturatrici meccaniche in chirurgia: stato dell'arte.

After a review of the technical development and application of staplers from their introduction to the present day, the indications to the use of this instrument in all gastroenterological areas from the oesophagus to the rectum as well as in chest, gynaecological and urological surgery specified. The advantages offered by staplers in the creation of intestinal anastomoses are undeniable, but these instruments must be considered alternatives to traditional surgery, the techniques of which should be well known to all surgeons. In certain areas (gastric, ileal and colonic resections etc.), the now widespread return to single thread manual stitches sheds a new light on staplers and reflects the fact that an anastomosis can be performed just as quickly by hand but will be softer and less rigid than a stapled one. It is only in oesophageal and lower rectal surgery that staplers offer a significant advantage, solving problems where hand suturing cannot.

Radiologic anatomy of the genital venous system in female patients with varicocele.

The diagnosis of varicocele in a female patient is difficult clinically. Until recently, only celioscopy and uterine phlebography were helpful. We have developed a new method for diagnosis of the pelvic varicocele using retrograde phlebography of the ovarian and iliac veins. Thirty-three women with pelvic pains and disorders of the menstrual cycle have been studied. In 15 patients, an insufficiency of the left ovarian vein was revealed. In three of the patients, an analogous insufficiency of the right ovarian vein was also recognized, along with chronic bilateral stasis in the pampiniform plexes. An insufficiency of the left iliac vein was present in seven of the patients without ovarian varicocele. The average age of the women without ovarian reflux was lower (22.5 years) than that of women with reflux (36.6 years) (p less than 0.01). In this last group of patients, the number of pregnancies was greater (30 children) than in the group without reflux (two children) (chi-square = 12.75; p less than 0.001). This indicates how parity plays an important role in the determination of the appearance of a varicocele. We conclude that the diagnosis of pelvic varicocele may be made by a new diagnostic method represented by retrograde phlebography of the ovarian and iliac veins. The use of it in patients with chronic pelvic pains and disorders of the menstrual cycle of unknown nature can be done routinely.