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Biomedical subjects

G Navarra

Publications and source records attributed to G Navarra.

At least 19 recordsLinked to original sources
PubMed2006

Palliative antecolic isoperistaltic gastrojejunostomy: a randomized controlled trial comparing open and laparoscopic approaches.

Gastric outlet obstruction is a common, often preterminal, event for patients with inoperable neoplasms of the distal stomach, duodenum, and biliopancreatic area. It can be surgically managed by open or laparoscopic gastrojejunostomy. This study aimed to compare the results of open and laparoscopic palliative gastrojejunostomy for patients with gastric outlet obstruction resulting from inoperable neoplasms. A total of 24 patients were randomized prospectively to undergo laparoscopic (12 patients) or open (12 patients) palliative laterolateral antecolic isoperistaltic gastrojejunostomy. All the procedures were completed as planned. The mean duration of surgery was not significantly different between the two groups (p = 0.75). The mean intraoperative blood loss was significantly less after laparoscopic gastrojejunostomy (LGJ) (p = 0.0001). Time to oral solid food intake was longer after open gastrojejunostomy (OGJ) (p = 0.04). Two patients in the OGJ group experienced postoperative delayed gastric empting, whereas no patients in the LGJ group experienced such a complication (p = 0.04). The mean postoperative stay was shorter in the LGJ group, but the difference did not reach statistical significance (p = 0.65). No readmissions were registered after a minimum follow-up period of 2 months. The findings show that LGJ is a safe, feasible, and effective alternative to OGJ. However, because the current data involved only a small number of patients, large studies still are required for further evaluation of the this operation's effectiveness.

Aged↗
PubMed2005

Detection and imaging of atmospheric radio flashes from cosmic ray air showers.

The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing.

Journal Article↗
PubMed2005

Short- and-long term results of intraoperative radiofrequency ablation of liver metastases.

BACKGROUND: Surgical resection is the only therapeutic option with curative effect on malignant liver tumours, but in over 70% of cases, this is not a feasible option. A prospective study was performed to assess the short- and long-term effects of intraoperative radiofrequency ablation on unresectable liver metastases. PATIENTS: Between 1997 and 2001, 57 patients (mean age 61.9 years; range 31-83 years) with 297 unresectable liver metastases (colorectal adenocarcinoma, n=38; carcinoid tumour, n=4; malignant melanoma, n=3; other metastases, n=12) underwent intraoperative radiofrequency ablation. RESULTS: No mortality was observed in patients managed solely with radiofrequency ablation. Eight postoperative complications occurred in eight patients (14%). Three occurred when radiofrequency ablation was combined with resection. Of the 33 patients completely ablated, 30 patients are still alive and 21 are disease-free after a median follow-up of 18.1 months (range 2-43). Ten patients underwent more than one intraoperative radiofrequency ablation episode. Overall survival was 72.5% at 1 year and 52.5% at 3 years. Complete ablation and the number of lesions were significant independent prognostic factors for survival, with p<0.001 and p<0.0001, respectively. CONCLUSION: Radiofrequency ablation is a safe and effective option for patients with inoperable liver metastases without extra hepatic disease. Prospective controlled trials comparing the results of different treatments are required to assess which patients will benefit best from this emerging new treatment.

Adult↗
PubMed2003

Laparoscopic radiofrequency-assisted liver resection.

Laparoscopic liver resection has not yet gained wide acceptance among hepatic surgeons, mainly because of the difficulties encountered in dealing with possible intraoperative bleeding. A new technique of laparoscopic liver resection is presented. A 43-year-old man with a large and symptomatic hemangioma underwent a laparoscopic radiofrequency energy-assisted liver resection. After induction of pneumoperitoneum, four trocars were introduced and intraoperative ultrasonography and coagulative desiccation were performed along a plane of tissue 1 cm away from the edge of the lesion using the Cool-Tip radiofrequency probe and a 500-kHz, radiofrequency generator. The necrosed band of parenchyma then was divided and the specimen removed. The operative time was 300 min with a resection time of 240 min. The intraoperative blood loss was 75 ml. The postoperative course was uneventful and the patient was discharged on postoperative day 6. Laparoscopic radiofrequency-assisted liver resection is feasible, and with greater experience may contribute to the wider use of mini-invasive video-assisted liver surgery.

Adult↗
PubMed2003

Mucous cystadenoma of the appendix: is it safe to remove it by a laparoscopic approach?

Mucinous cystadenoma is an uncommon neoplasm of the appendix usually discovered intraoperatively. Its clinical significance lies in the possible rupture and consequent spillage of mucin into the peritoneal cavity, leading to pseudomyxoma peritonei. Even if laparoscopy has been successfully used to perform appendectomy, some concerns exist regarding its use in dealing with mucinous secreting lesions because of possible spillage of mucin during surgery. We report a case of mucous cystadenoma of the appendix, which was successfully removed using a laparoscopic approach. At a 12-month follow-up assessment, the patient was free of disease. We believe that the laparoscopic approach is safe if surgery can be performed without grasping the lesion, and if the specimen is removed through the abdominal wall using a bag. Conversion to laparotomy should be considered if the lesion must be traumatically grasped, or if the tumor clearly extends beyond the appendix.

Appendiceal Neoplasms↗
PubMed2002

A novel approach to gallbladder cancer in a Jehovah's Witness.

Transfusion of blood or blood products peri- or postoperatively is often necessary in patients undergoing liver resections for hepatic or biliary tract neoplasms. In Jehovah's Witnesses this inevitably poses a difficult dilemma for clinicians. A 66-year-old female Jehovah's Witness with a T1b gallbladder cancer was referred to our specialist unit for further treatment after having had a routine laparoscopic cholecystectomy in another hospital. Although an abdominal computed tomography scan preoperatively showed a normal liver with no evidence of regional lymph node involvement, histologically the tumor was found in the posterior wall of the gallbladder adherent to the liver bed and had a full thickness involvement of the muscular layer, raising suspicion of a local invasion into the liver bed. The patient, having refused liver resection, was treated with a laparoscopic radiofrequency ablation under intraoperative ultrasound guidance using a newly developed "cooled-tip" needle and a 500-kHz radiofrequency generator. A "zone of necrosis" measuring 3.5 cm in diameter was created in the liver bed and adjacent tissues. The procedure lasted 90 min with no blood loss. Postoperatively, the patient was discharged on the third postoperative day and remained disease free at the 9-month follow-up. Although the follow-up in this case was too short to determine the long-term result of this approach, we believe that this is a single unique case posing a challenging problem to clinicians for which radiofrequency ablation may have a role in offering an alternative to major resections.

Aged↗
PubMed2002

Percutaneous vacuum-assisted core breast biopsy with upright stereotactic equipment. Indications, limitations and results.

PURPOSE: To assess the usefulness of stereotactic vacuum-assisted core breast biopsy (VCBB) performed using a stereotactic add-on device and film-screen technology with the patient in an upright seated position. MATERIAL AND METHODS: We reviewed a series of 129 women with non-palpable mammographic abnormalities who required stereotactic VCBB from December 1999 to November 2000. Twenty-seven (20.9%) cases were excluded due to difficulties in keeping the correct position during the procedure, while the other 102 (79.1%) underwent successful VCBB. Patients with lesions consisting of either atypical ductal hyperplasia or lobular carcinoma in situ were considered for excisional biopsy. Patients with either ductal carcinoma in situ or infiltrating breast cancer were referred for definitive surgery. The results of stereotactic VCBB were correlated to the subsequent surgical histology. RESULTS: Stereotactic VCBB was interrupted because of bleeding in 1 case and vasovagal reaction in 5 cases. Two haematomas occurred after the procedure. Overall underestimation rate was 10.5%. No new lesions were discovered after a mean follow-up of 18.7 months. CONCLUSION: Stereotactic VCBB performed using a standard add-on device with the patient in an upright seated position and analog technology is feasible in about 80% of cases, has a low complication rate, is not significantly time-consuming, and can offer the same accuracy as dedicated prone equipment.

Biopsy, Needle↗
PubMed2001

Role of radio-guided surgery in recurrent secondary hyperparathyroidism.

BACKGROUND: The aim of this paper is to state the role of radio-guided surgery (RGS) in case of recurrent secondary hyperparathyroidism. METHODS: Two cases of recurrent secondary hyperparathyroidism were treated using RGS. After a preoperative assessment, which included ultrasonography (US), MRI and (99m)Tc-radiolabelled sestamibi scan, a radio-guided neck re-exploration was planned. On the day of surgery the patients underwent a radionuclide injection. After 90 min, surgery began. RESULTS: Dissection was guided by placing the probe in the wound to localize any increased concentration of radioactivity. In the first case the probe identified the gland located deeply in the right tracheo-esophageal groove; in the other case the probe detected a site of increased uptake in the upper mediastinum. Both lesions were dissected and excised; a frozen section confirmed they were parathyroid glands with diffuse hyperplasia. The operative time was less than 60 min in both cases. The patients were discharged on the first postoperative day. A decrease in serum calcium and PTH was observed subsequently. A minimum follow-up of 6 months did not show any recurrence. CONCLUSION: RGS can help in detecting the parathyroid tissue in selected cases of renal hyperparathyroidism and makes operation much easier and more predictable.

Humans↗
PubMed2001

[Pleuro-pneumo-phreno-pericardiectomy with pericardial and diaphragmatic plasty].

Aim of the paper is to evaluate 43 extrapleural pneumonectomy performed from 1988 to May 2000. Criteria for extrapleural pneumonectomy were pleural biopsy by thoracoscopy, potentially completely resectable unilateral disease by computed tomography and predicted postresection forced expiratory volume >1,3 L/sec. The resections regarded 33 pleural mesothelioma, 9 pleural lung-carcinosis and 1 pleural melanoma effusion. The perioperative mortality rate was 2,2% (1 death) and morbidity 21,4%.

Diaphragm↗
PubMed2000

Effect of nepadutant at tachykinin NK(2) receptors in human intestine and urinary bladder.

We have characterized the action of the tachykinin NK(2) receptor antagonist nepadutant (c¿[(beta-D-GlcNAc)Asn-Asp-Trp-Phe-Dpr-Leu]c(2 beta-5 beta)¿) in the human isolated ileum, colon and urinary bladder. Nepadutant (30-1000 nM) competitively antagonized neurokinin A- or [beta Ala(8)]neurokinin A-(4-10)-induced contractions in all tissues, with pK(B)=8.3 (ileum and colon) and pK(B)=8.5 (bladder). In contrast, the nonpeptide tachykinin NK(2) receptor antagonist SR 48968 (or (S)-N-methyl-N [4-acetylamino-4-phenylpiperidino)-2-(3, 4-dichlorophenyl) butyl] benzamide) (30-1000 nM) produced insurmountable antagonism in all preparations. The tachykinin NK(2) receptor blockade produced by nepadutant in the colon was fully reversed by washout, whereas that produced by SR 48968 was not. Nepadutant (1 microM) greatly reduced (by 70-80%) the nonadrenergic noncholinergic (NANC) contractile off-response evoked by electrical field stimulation in the human ileum, and almost abolished it in the presence of the tachykinin NK(1) receptor antagonist GR 82334 (or: [[(S,S) Pro-Leu (spiro-gamma-lactam)](9,10),Trp(11)]Physalaemin (1-11)) (1 microM). The present results show that nepadutant is a potent, competitive and reversible antagonist at human tachykinin NK(2) receptors and provide further evidence that tachykinins act as excitatory NANC neurotransmitters in the human small intestine.

Aged↗
PubMed2000

Radio-guided surgery in recurrent renal hyperparathyroidism: report of a case.

BACKGROUND: It has been demonstrated that radio-guided surgery offers several advantages in treating primary hyperparathyroidism. Even if it is considered less helpful in renal hyperparathyroidism, it could be of tremendous advantage in the treatment of persistent or recurrent secondary hyperparathyroidism. METHODS: We report a case of recurrent secondary hyperparathyroidism treated by the use of radio-guided surgery. The preoperative assessment consisting of ultrasonography, magnetic resonance imaging, and 99mTc-sestamibi scintigraphy identified a parathyroid in the upper mediastinum. The patient underwent a radio-guided neck re-exploration that allowed a rapid localization and excision of the ectopic gland, which was located in the anterosuperior mediastinum, in front of the trachea, between the innominant and the left common carotid artery. RESULTS: The operative time was 45 minutes. The patient was discharged on the first postoperative day. A decrease in serum calcium and parathyroid hormone was observed subsequently. A follow-up of 6 months did not show any recurrence. CONCLUSIONS: The case reported indicates that radio-guided surgery can help surgeons detect parathyroid tissue in selected cases of renal hyperparathyroidism.

Humans↗
PubMed2000

Evidence that PAR-1 and PAR-2 mediate prostanoid-dependent contraction in isolated guinea-pig gallbladder.

We have investigated the ability of protease-activated receptor-1 (PAR-1), PAR-2, PAR-3 and PAR-4 agonists to induce contractile responses in isolated guinea-pig gallbladder. Thrombin, trypsin, mouse PAR-1 activating (SFLLRN-NH(2)) peptide, and mouse PAR-2 activating (SLIGRL-NH(2)) and human PAR-2 activating (SLIGKV-NH(2)) peptides produced a concentration-dependent contractile response. Mouse PAR-4 activating (GYPGKF-NH(2)) peptide, the mouse PAR-1 reverse (NRLLFS-NH(2)) peptide, the mouse PAR-2 reverse (LRGILS-NH(2)) and human PAR-2 reverse (VKGILS-NH(2)) peptides caused negligible contractile responses at the highest concentrations tested. An additive effect was observed following the contractile response induced by either trypsin or thrombin, with the addition of a different PAR agonist (SFLLRN-NH(2) and SLIGRL-NH(2), respectively). Desensitization to PAR-2 activating peptide attenuated the response to trypsin but failed to attenuate the response to PAR-1 agonists, and conversely desensitization to PAR-1 attenuated the response to thrombin but failed to alter contractile responses to PAR-2 agonists. The contractile responses produced by thrombin, trypsin, SFLLRN-NH(2) and SLIGRL-NH(2) were markedly reduced in the presence of the cyclo-oxygenase inhibitor, indomethacin, whilst the small contractile response produced by NRLLFS-NH(2) and LRGILS-NH(2) were insensitive to indomethacin. The contractile responses to thrombin, trypsin, SFLLRN-NH(2) and SLIGRL-NH(2) were unaffected by the presence of: the non-selective muscarinic antagonist, atropine; the nitric oxide synthase inhibitor, L-NAME; the sodium channel blocker, tetrodotoxin; the combination of selective tachykinin NK(1) and NK(2) receptor antagonists, (S)-1-[2-[3-(3,4-dichlorphenyl)-1 (3-isopropoxyphenylacetyl) piperidin-3-yl] ethyl]-4-phenyl-1 azaniabicyclo [2.2.2] octane chloride (SR140333) and (S)-N-methyl-N-[4-acetylamino-4-phenylpiperidino-2-(3, 4-dichlorophenyl)-butyl] benzamide (SR48968), respectively. The results indicate that PAR-1 and PAR-2 activation causes contractile responses in the guinea-pig gallbladder, an effect that is mediated principally by prostanoid release, and is independent of neural mechanisms.

Animals↗
PubMed1999

Lymphatic mapping for the dissection of the sentinel node in the treatment of breast carcinoma.

The Authors present the preliminary results of a study aimed at verifying the effectiveness of lymphatic mapping for the dissection of the sentinel lymph node in the treatment of breast carcinoma. The lymphoscintigraphy method was used in the study performed on 24 patients to evidence the sentinel lymph node. The sentinel lymph node was identified in 23/24 patients (95,8%), with 100% accuracy, negative predictions were 100% (21/21). Consistently with the low number of cases treated, our results seem to guarantee the same prognostic accuracy obtained using radical lymphadenectomy extended to the third lymph node level.

Adult↗
PubMed1998

Symptomatic abdominal aortic aneurysm and "situs viscerum inversus." Diagnostic and therapeutic approach.

BACKGROUND: We report one case of symptomatic aneurysm of infrarenal abdominal aorta in a patient symptomatic for acute abdomen. METHODS: The patient was accepted at the Emergency Care Unit and the routine admission tests were taken. US of the abdomen revealed a < > (SVI) disposition of the organs and an aneurysm of the abdominal aorta below the renal arteries. Patient underwent an aorto-aortic straight graft CONCLUSIONS: In this case-report we show SVI cannot be considered a problem in the surgical treatment of symptomatic abdominal aortic aneurysms.

Abdomen, Acute↗