Non-linear evaluation of respiratory mechanics during laparoscopic cholecystectomy.

BACKGROUND/AIMS: Laparoscopic cholecystectomy is accompanied by significant increase of the respiratory system elastic and resistive properties. These changes are completely abolished after peritoneal deflation. In the present study we examine the volume and flow dependence of respiratory mechanics during four operation phases. METHODOLOGY: Airway pressure and flow were recorded from 17 patients undergoing laparoscopic cholecystectomy. Measurements were done at 4 distinct phases: 1) Before the induction of pneumoperitoneum. 2) Five minutes after pneumoperitoneum induction at Trendelenburg position. 3) Five minutes after positioning the patient at reverse. Trendelenburg. 4) Five minutes after the peritoneal deflation. Data of airway pressure, flow and volume were treated according to the non-linear regression model: Paw = E1.V + E2.V2 + k1.V' + k2.V'. |V'| + k3.V.V' + EEP. RESULTS: The induction of pneumoperitoneum results in: Significant increase of linear elastance and resistance and significant decrease of flow and volume dependence of resistance. No significant changes are noted in volume dependence of elastance and end-expiratory pressure. CONCLUSIONS: The pneumoperitoneum and not the body position causes the changes in respiratory mechanics and their dependencies during laparoscopic cholecystectomy, which, although important, do not predispose to major risks (lung overdistension, alveolar collapse) and they are reversed after peritoneal deflation.

Respiratory system mechanics during laparoscopic cholecystectomy.

The influence of laparoscopic cholecystectomy (LC) on the mechanical properties of the respiratory system (RS) was examined using multiple regression analysis (MRA). Measurements of airway pressure (PaO) and flow (V') were obtained from 32 patients at four distinct stages of the LC procedure: 1) Immediately before the application of pneumoperitoneum (PP) at supine position, 2) 5 min after the induction of PP at Trendelenburg position, 3) 5 min after the patients position at reverse Trendelenburg, and 4) 5 min after the end ofthe surgical procedure with the patient again in supine position. Evaluated parameters were the RS elastance (Ers), resistance (Rrs), impedance (Zrs), the angle theta indicating the balance between the elastic and resistive components of the impedance, as well as the end-expiratory elastic recoil pressure (EEP). Ers and Zrs increased considerably during PP and remained elevated immediately after abolishing PP Rrs, on the contrary, returned to pre-operative levels right after the operation. Change of body position from Trendelenburg (T) to reverseTrendelenburg (rT) mainly induced a significant change in theta, thus indicating an increased dominance of the elastic component of Zrs on changing fromT to rT. There was no evidence of increased End-Expiratory Pressure during PP

Laparoscopic splenectomy in beta-thalassemia major patients. Advantages and disadvantages.

BACKGROUND: Splenectomy is indicated in patients with thalassemia major when they develop hypersplenism with subsequent need for increased transfusions. Extreme splenomegaly is considered a restrictive factor for laparoscopic splenectomy in these patients. METHODS: Laparoscopic splenectomy was undertaken in 12 beta-thalassemia major patients with massive splenomegaly. The devascularization of the organ was performed with serial ligations of the splenic vessels starting from the lower pole of the organ. The spleen was extracted from the abdominal cavity through a 5-cm incision in the left iliac fossa, which incorporated two port sites. RESULTS: The procedure was concluded laparoscopically in 10 cases, while two patients were converted due to difficulty in controlling bleeding from branches of the splenic vein. The patients tolerated the procedure well and had a postoperative hospital stay of 3-6 days. CONCLUSIONS: From our limited initial experience it seems that laparoscopic splenectomy in the difficult setting of thalassemia major patients is feasible, but extreme care is required in order to avoid hemorrhagic complications.

[Indications for prophylactic ovariectomy in patients with colorectal carcinoma]. / Indicazioni all'ovariectomia profilattica nelle pazienti con carcinoma colorettale.

Metastasis of colorectal cancer to the ovaries presents in 2-8% of patients. Prevention of these metastasis with bilateral oophorectomy at the initial operation is quite simple, but nevertheless it produces an early menopause in premenopausal women and may add the morbility of the operation. Prophylactic oophorectomy is evaluated in a prospective study of 130 women that underwent surgery for adenocarcinoma of the large bowel. Forty-four of these patients underwent unilateral (10 patients) or bilateral (34 patients) oophorectomy along with the large bowel resection. Fifty-five women were submitted to colectomy alone, while 31 with or without oophorectomy were lost to the follow-up. Of the 44 women that underwent oophorectomy, 8 were premenopausal, while 36 were postmenopausal. The tumor was situated at the right colon in 5 out of the 44 patients that underwent oophorectomy and at the left colon in the remaining 39. According to Dukes classification, 5 tumors were Dukes A, 22 Dukes B and 17 Dukes C. Two of the 44 patients were found to harbour metastasis to the ovaries (4.5%). One of these patients was premenopausal (12.5%) and 1 was postmenopausal (2.7%). Of the 55 women that underwent colectomy, only one developed metastasis to the ovaries during the follow-up period (1.8%). No metastasis was detected at the resected ovary or at the remaining ovary during the follow-up period, among the patients that underwent unilateral oophorectomy. No complication directly related to the oophorectomy was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Intra-abdominal desmoplastic small-cell tumours with divergent differentiation. Report of two cases and review of the literature.

Two intraabdominal desmoplastic small cell tumours presenting in young adult males and involving the entire peritoneum, with no evident single primary site, have been studied. The histological pattern was suggestive of a metastatic small cell epithelial neoplasm, but immunohistochemical study revealed strong reactivity for cytokeratins, vimentin and desmin indicating synchronous epithelial and myogenous differentiation. In addition epithelial membrane antigen and neuron specific enolase were also positive. Electron microscopy showed fairly undifferentiated tumour cells with striking desmosome-like junctions, containing prominent paranuclear whorls of intermediate filaments, and a typical myofibroblastic stroma around neoplastic islands. Although the histogenesis of these recently described and rare tumours still remains uncertain, it seems that they constitute a reproducible entity which requires differential diagnosis from other small cell tumours of childhood and young adulthood.