Biomedical subjects

Marco Catani

Publications and source records attributed to Marco Catani.

24 records · Page 2Linked to original sources

PubMed2002

Spatial normalization and averaging of diffusion tensor MRI data sets.

Diffusion tensor magnetic resonance imaging (DT-MRI) is unique in providing information about both the structural integrity and the orientation of white matter fibers in vivo and, through "tractography", revealing the trajectories of white matter tracts. DT-MRI is therefore a promising technique for detecting differences in white matter architecture between different subject populations. However, while studies involving analyses of group averages of scalar quantities derived from DT-MRI data have been performed, as yet there have been no similar studies involving the whole tensor. Here we present the first step towards realizing such a study, i.e., the spatial normalization of whole tensor data sets. The approach is illustrated by spatial normalization of 10 DT-MRI data sets to a standard anatomical template. Both qualitative and quantitative approaches are described for assessing the results of spatial normalization. Techniques are then described for combining the spatially normalized data sets according to three definitions of average, i.e., the mean, median, and mode of a distribution of tensors. The current absence of, and hence need for, appropriate statistical tests for comparison of results derived from group-averaged DT-MRI data sets is then discussed. Finally, the feasibility of performing tractography on the group-averaged DT-MRI data set is investigated and the possibility and implications of generating a generic map of brain connectivity from a group of subjects is considered.

Adult↗

PubMedDate not supplied

[Treatment of esophageal perforations. Considerations on a clinical case].

The Authors describe a rare case of esophageal perforation occurred after Transoesophageal echocardiography in 68 years old patient and review the literature relating to the causes and management of this pathology. Transoesophageal echocardiography, which is a semi-invasive investigation increasingly used in cardiology and cardiac surgery and intensive care units, is a rare though extremely dangerous cause of such complications. Perforation of the esophagus continues to present a formidable diagnostic and therapeutic challenge. The diagnosis depends on a high degree of suspicion and on the recognition of clinical features and is confirmed by contrast esophagography. The outcome after esophageal perforation depends on the location of the injury, the presence or otherwise of concomitant esophageal disease and the time elapsing between the injury and inititian of treatment. Reinforced primary repair of the perforation is the procedure most frequently employed and preferred for the surgical management of the esophageal perforation. In the case reported here, early diagnosis and prompt surgical treatment consisting in primary repair of the esophageal perforation contributed to the successful management of this serious pathology.

Aged↗

PubMedDate not supplied

["Low-pressure" laparoscopic cholecystectomy in high risk patients (ASA III and IV): our experience].

The insufflation pressure used for laparoscopic cholecystectomy is usually 12-15 mm Hg, and a pneumoperitoneum with carbon dioxide has a significant effect on both cardiovascular and respiratory function. These effects are transient in young, healthy patients, but may be dangerous in ASA III and IV patients with a poor cardiac reserve. This study was designed to assess the feasibility of performing laparoscopic cholecystectomy at 6.5-8 mm Hg insufflation pressure in "high-risk" patients. Thirteen patients, 10 ASA III and 3 ASA IV, with cholelithiasis, were included in this study The insufflation pressure was 6.5-8 mm Hg, with a 10 degrees anti-Trendelenburg position. The cardiovascular and blood gas variables studied were: mean arterial blood pressure, heart rate, respiratory rate, and end-tidal CO2 pressure. The authors reported no conversions and no intra- or postoperative complications. During insufflation heart rate and mean arterial blood pressure increased minimally if compared with laparoscopic cholecystectomy at 12-15 mm Hg. Pa CO2 increased after insufflation (+5 mm Hg), and the end-tidal CO2 pressure gradient was moderate (3.5 mm Hg) and unchanged during surgery. A low-pressure pneumoperitoneum is feasible for laparoscopic cholecystectomy and minimizes the adverse haemodynamic effects of peritoneal insufflation.

Aged↗

PubMedDate not supplied

[Ergonomic and cosmetic aspects of laparoscopic appendectomy: personal technique].

We analyzed our case series in order to evaluate the evolution of our laparoscopic technique in ergonomic and cosmetic terms, leading to the right compromise between these aspects. We retrospectively analyzed 136 diagnostic laparoscopies for suspected appendicitis, using scheme A in the first 98 cases (one 10/12-mm umbilical trocar for the optics and two 5-mm operative trocars placed above the pubis on the right and left side) and scheme B in the other 38 cases (one 10/12-mm umbilical trocar for the optics and two 5-mm operative trocars, one placed over the pubis and the other one on the right hip, just on the umbilical line). The diagnosis of appendicitis was confirmed in 117 patients, while other diseases were present in 19 patients. There were no differences between the two groups in mean operative time (45 min), postoperative complications (0.7%) and clinical course (hospital stay: 36 hours on average). We believe that the right compromise between ergonomic and cosmetic considerations is the one shown in scheme B. In this way it is possible to perform all diagnostic and therapeutic manoeuvres such as pulling the appendix out through the umbilical trocar and using suprapubic trocars as an access route for a possible drainage.

Appendectomy↗

PubMedDate not supplied

Is there a place for intraperitoneal onlay mesh repair (IPOM) of inguinal hernia among laparoscopic techniques?

BACKGROUND/AIMS: The Authors report their experience on laparoscopic hernioplasty using the intraperitoneal onlay mesh repair in 56 patients. METHODOLOGY: Thirty patients had a monolateral hernia, 9 of which were recurrent and 26 had a bilateral hernia, 6 of which were recurrent. Overall, a total of 90 hernias were treated. The hernia repair was performed by using "GORETEX Dual Mesh Plus biomaterial with holes" in the first 32 cases and the latest "Corduroy" type in the following 24 cases. The prostheses were fixed with titanium spiral tacks (Protack, Auto Suture, Tyco Healthcare). RESULTS: No intraoperative complications occurred and no conversion was necessary. Five minor postoperative complications (5.5%), 2 seromas and 3 transient paresthesias, were observed. Four patients (7.1%) needed analgesics after the first 24 hours. Mean hospital stay was 36 hours with a minimum of 24 and a maximum of 48. Mean resumption of normal activity was 8 days with return to work within two weeks. At an average 18 months follow-up, 3 recurrences were recorded (3.3%). CONCLUSIONS: The results of this study as well as the meta-analysis of the series presented in the literature, indicate that the intraperitoneal onlay mesh repair may be a feasible, safe and effective procedure in the treatment of recurrent and bilateral hernias or when a hernia repair is performed during other laparoscopic procedures. The intraperitoneal onlay mesh repair has in fact been shown to be faster and easier than the other more commonly performed laparoscopic hernioplasties (trans-abdominal preperitoneal repair and total extra-peritoneal repair). These data may also suggest utilizing this technique in particular cases of primitive hernia such as very active young males or heavy-duty workers. However the limited series and the short follow-up ask for randomized prospective long-term studies to definitely ascertain the true incidence of recurrence and therefore the effectiveness of this attractive procedure.

Adult↗

PubMedDate not supplied

[New orientations in the management of advanced, metastatic gastrointestinal stromal tumors (GIST): combination of surgery and systemic therapy with imatinib in a case of primary gastric location].

Gastrointestinal stromal tumours (GIST) are rare neoplasms originating from connective tissue in the digestive tract with an incidence of less than 1% and account for most non-epithelial primitive digestive tumours. Metastasis diagnosed at the time of disease discovery confirms GIST malignancy. Kit protein, a trans-membrane tyrosine kinase receptor of staminal cells, is characteristically expressed by GIST. Most GIST have a mutation in the kit proto-oncogene. Resistance to conventional chemotherapy is commonly shown by malignant GIST. Most patients with advanced malignant GIST achieve clinical benefit with imatinib mesilate, an orally administered selective inhibitor of the tyrosine kinase receptor. We treated a 43-year-old male patient suffering from a gastric GIST diagnosed during a surgical emergency operation for peritonitis caused by gastric perforation. At the time of the first operation the patient had lost 10 kg body weight over the previous months and was seriously cachectic. During the emergency operation the perforation was sutured. The biopsy results showed the presence of CD1 17 (c-kit) and CD34 markers. A total body CT scan documented the substantial size of the gastric wall lesion, an increased volume of abdominal lymph nodes and compression of the splenic vein with alternative collateral circulation. The liver presented no less than 5 large metastases distributed in both the left and right lobes. There was also a pulmonary metastasis. Because of frequent spontaneous bleeding and starvation the patient was seriously anaemic. Considering the action mechanism of imatinib and the extent of the lesion we decided to perform a total gastrectomy procedure. At the time of the operation the stomach seemed to have a modified volume and shape: it appeared to be divided into two sacs, the larger and deeper of which was the original gastric cavity, while the superficial, smaller one seemed to be a protrusion of the organ. The stomach was indistinguishable from the spleen, the transverse colon and the distal pancreatic tract. The neoplasm was directly linked to the left liver and to the inferior diaphragmatic surface. We performed total gastrectomy and resection of the tail of the pancreas, the spleen, and the transverse colon all in one and the same session. The patient was discharged on postoperative day 8 and commenced imatinib therapy 30 days after the operation with 4 tablets per day. In the following months the patient repeated the CT scan to monitor the progressive volume reduction of the liver and lung lesions and a PET scan confirmed that the lesions were not active; the patient experienced a 13 kg body weight increase. One year after the operation the outcome appears to be lasting and the patient has tolerated the drug treatment well.

Adult↗