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Biomedical subjects

Luigi M Cavallo

Publications and source records attributed to Luigi M Cavallo.

11 recordsLinked to original sources
PubMed2006

Use of equine collagen foil as dura mater substitute in endoscopic endonasal transsphenoidal surgery.

OBJECTIVE: This study describes the use of a novel collagen-based dural substitute in endoscopic endonasal transsphenoidal surgery. METHODS: Operative records were reviewed for a 12-month period for all patients who underwent surgery by means of an endoscopic endonasal transsphenoidal approach since we began using TissuDura (Baxter, Vienna, Austria) collagen-only dural substitute in January 2004. RESULTS: During the 12-month period evaluated, we performed an endoscopic endonasal transsphenoidal operation for a variety of pituitary lesions on 72 consecutive patients. Among these, 15 patients (20.8%) required the implant of the collagen foil. Nine patients (60%) presented an intraoperative CSF leak (3 small weeping of CSF and 6 larger leaks); in these cases, the TissuDura was used against the arachnoid membrane, followed by the other materials used for the repair. In 7 other subjects without any evidence of CSF escape, the collagen foil was used to protect and enforce the arachnoidal membrane descent into the sellar cavity to prevent its possible postoperative rupture and consequent CSF leak. Fibrin glue was used in all cases. A postoperative CSF leak with meningitis occurred in only 1 (6.7%) of the 15 subjects. The patient required a reoperation for CSF fistula repair and intravenous antibiotics. CONCLUSIONS: Even if based on a relatively small patient series, our experience demonstrated that the use of TissuDura in transsphenoidal surgery is safe and biocompatible, as compared with other dural substitutes.

Animals↗
PubMed2006

Age changes the diagnostic accuracy of mean profile and nadir growth hormone levels after oral glucose in postoperative patients with acromegaly.

BACKGROUND: This analytical, retrospective study was designed to select cut-off thresholds of mean GH levels during a diurnal profile and nadir GH levels after oral glucose tolerance test (OGTT) according to age to diagnose surgical remission of acromegaly. METHODS: One hundred forty-one patients (76 women, aged 44 +/- 15 years and 65 men, aged 43 +/- 13 years) were included in this study. For the purpose of this study, remission was based on insulin-like growth factor-I (IGF-I) levels in the normal range for age. Diagnostic accuracy was analysed by receiving-operator characteristics (ROC) curves in the entire series, and in young (20-40 years), middle-aged (41-60 years) and older patients (> 60 years), separately. RESULTS: Sixty patients (42.6%) had normal IGF-I levels after surgery. In the entire series, in young and in middle-aged patients, the ROC analysis showed that optimum cut-off for mean GH levels was 2.3 microg/l (diagnostic accuracy range, 94-97%) whereas that for nadir GH after OGTT were, respectively, 0.85, 0.9 and 0.8 microg/l (diagnostic accuracy range, 90-95%). In the older patients, the optimum cut-off selected for mean GH levels was 1.4 microg/l and that for nadir GH after OGTT was 0.5 microg/l (diagnostic accuracy, 100% for both). The comparative analysis of the ROC curves did not show any significant difference between mean GH and nadir GH after OGTT (P = 0.21). CONCLUSIONS: The criteria currently accepted for diagnosing post-surgical remission of acromegaly have high diagnostic accuracy only in the patients aged below 60 years. In older patients, lower cut-offs (i.e. = 1.4 microg/l for fasting GH and = 0.5 microg/l for nadir GH after OGTT) predict normal IGF-I levels. Mean GH levels during a diurnal profile have similar diagnostic accuracy of nadir GH levels after OGTT. This suggests that OGTT is not necessary to establish surgical cure.

Acromegaly↗
PubMed2006

The endoscopic endonasal approach to the lateral recess of the sphenoid sinus via the pterygopalatine fossa: comparison of endoscopic and radiological landmarks.

OBJECTIVE: The endoscopic endonasal approach offers the opportunity to reach the pterygopalatine fossa, the lateral recess of the sphenoid sinus, and other areas of the cranial base through a minimally invasive approach. This study compares the anatomy of these areas when observed through an endoscopic endonasal view with the anatomy of the same regions as they appear in computed tomographic scans. The aim was to identify and correlate the corresponding anatomic structures, providing the surgeons with anatomic landmarks to guide them when operating in these areas through an endoscopic endonasal approach. METHODS: An anatomic dissection of six fixed cadaver heads was performed by an endoscopic endonasal approach. A step-by-step comparison of endoscopic and radiological images was made to identify the landmarks of the surgical field. RESULTS: The step-by-step comparison of endoscopic and radiological images acquired during the endoscopic endonasal approach to the lateral recess of the sphenoid sinus via the pterygopalatine fossa allowed the identification of all the relevant anatomic landmarks of the procedure. CONCLUSION: The endoscopic endonasal approach via the pterygopalatine fossa offers direct, minimally invasive access to the lateral recess of the sphenoid sinus, which can be monitored in each phase through consistent radiological imagery.

Cadaver↗
PubMed2005

Partial surgical removal of growth hormone-secreting pituitary tumors enhances the response to somatostatin analogs in acromegaly.

CONTEXT: Surgery is a cornerstone in the treatment of acromegaly, but its efficacy in large, invasive tumors is scant. OBJECTIVE: The objective of this study was to investigate whether partial surgical removal of GH-secreting pituitary tumors enhances the response rate to somatostatin analogs (SSA; sc octreotide, slow-release octreotide, and lanreotide). DESIGN: This was a multicenter, open, retrospective study. SETTING: The study was performed at university hospitals. SUBJECTS AND METHODS: Eighty-six patients (42 women and 44 men; age, 42 +/- 14 yr) with acromegaly were studied. INTERVENTIONS: Patients underwent two courses of octreotide, lanreotide, or slow-release octreotide treatments before and after surgery of at least 6 months. MAIN OUTCOME MEASURE: The main outcome measure was normal IGF-I levels for age. RESULTS: Presurgical SSA treatment significantly decreased GH and IGF-I levels in all patients. GH levels were less than 2.5 microg/liter in 12 patients (14%); IGF-I levels normalized in nine (10%). After surgery, GH and IGF-I levels further decreased in all patients; tumor removal was greater than 75% in 50 (58%), 50.1-75% in 21 (24%), 25.1-50% in 10 (12%), and less than 25% in five patients (6%). Preoperatively, pituitary function was impaired in 12 patients (14%). Postsurgical SSA treatment lowered GH levels to less than 2.5 microg/liter in 49 (56%) and normalized IGF-I levels in 48 patients (55%). The success rate was significantly increased compared with that before surgery (P < 0.0001). GH (r = -0.48; P < 0.0001) and IGF-I levels (r = -0.38; P = 0.0003) after postsurgery SSA treatment correlated with the amount of tumor surgically removed. After surgery, pituitary function was impaired in 28 patients (32.6%) and was improved in 12 patients (13.9%). The cumulative prevalence of pituitary deficiency did not change during the study (normal function from 40 to 42%; deficiency from 60 to 58%). CONCLUSIONS: Surgical tumor removal (>75%) enhances the response to SSAs without impairing pituitary function. Our data indicate that surgical debulking has a significant place in the treatment algorithm of acromegaly.

Acromegaly↗
PubMed2005

Endoscopic endonasal surgery of the midline skull base: anatomical study and clinical considerations.

OBJECT: The midline skull base is an anatomical area that extends from the anterior limit of the cranial fossa down to the anterior border of the foramen magnum. Resection of lesions involving this area requires a variety of innovative skull base approaches. These include anterior, anterolateral, and posterolateral routes, performed either alone or in combination, and resection via these routes often requires extensive neurovascular manipulation. The goals in this study were to define the application of the endoscopic endonasal approach and to become more familiar with the views and skills associated with the technique by using cadaveric specimens. METHODS: To assess the feasibility of the endonasal route for the surgical management of lesions in the midline skull base, five fresh cadaver heads injected with colored latex were dissected using a modified endoscopic endonasal approach. Full access to the skull base and the cisternal space around it is possible with this route. From the crista galli to the spinomedullary junction, with incision of the dura mater, a complete visualization of the carotid and vertebrobasilar arterial systems and of all 12 of the cranial nerves is obtainable. CONCLUSIONS: The major potential advantage of the endoscopic endonasal approach to the skull base is that it provides a direct anatomical route to the lesion without traversing any major neurovascular structures, obviating brain retraction. Many tumors grow in a medial-to-lateral direction, displacing structures laterally as they expand, creating natural corridors for their resection via an anteromedial approach. Potential disadvantages of this procedure include the relatively restricted working space and the danger of an inadequate dural repair with cerebrospinal fluid (CSF) leakage and potential for meningitis resulting. These approaches often require a large opening of the dura mater over the tuberculum sellae and posterior planum sphenoidale, or retroclival space. In addition, they typically involve large intraoperative CSF leaks, which necessitate precise and effective dural closure.

Cadaver↗
PubMed2005

Extended endoscopic endonasal approach to the pterygopalatine fossa: anatomical study and clinical considerations.

OBJECT: The pterygopalatine fossa is an area located deep in the skull base. The microsurgical transmaxillary-transantral route is usually chosen to remove lesions in this region. The increasing use of the endoscope in sinonasal functional surgery has more recently led to the advent of the endoscope for the treatment of tumors located in the pterygopalatine fossa as well. METHODS: An anatomical dissection of three fresh cadaveric heads (six pterygopalatine fossas) and three dried skull base specimens was performed to evaluate the feasibility of the approach and to illustrate the surgical landmarks that are useful for operations in this complex region. The endoscopic endonasal approach allows a wide exposure of the pterygopalatine fossa. Furthermore, with the same access (that is, through the nostril) it is possible to expose regions contiguous with the pterygopalatine fossa, either to visualize more surgical landmarks or to accomplish a better lesion removal. CONCLUSIONS: In this anatomical study the endoscopic endonasal approach to the pterygopalatine fossa has been found to be a safe approach for the removal of lesions in this region. The approach could be proposed as an alternative to the standard microsurgical transmaxillary-transantral route.

Cranial Fossa, Anterior↗
PubMed2004

Dopamine receptor expression and function in clinically nonfunctioning pituitary tumors: comparison with the effectiveness of cabergoline treatment.

The aim of this study was to correlate dopamine receptors and D(2) isoform expression with the cabergoline effect on alpha-subunit secretion in vitro and tumor mass in vivo in clinically nonfunctioning pituitary tumors. Eighteen patients were subjected to neurosurgery, and a tumor sample was used for dopamine receptor and D(2) isoform expression evaluation by RT-PCR and the in vitro functional studies. After neurosurgery, nine of 18 patients with persistent tumor were treated with cabergoline and tumor mass was evaluated before and after 1 yr treatment. D(2) receptor was expressed in 67% of cases. D(2long) was found in 50%, D(2short) in 17%, and both D(2) isoforms in 33% of cases. D(4) receptor was also expressed in 17% of cases. The in vitro inhibition of alpha-subunit concentration was found in 56% of cases and was associated with D(2) expression (chi(2) = 5.6; P < 0.05). After 1 yr of cabergoline treatment, tumor shrinkage was evident in 56% of patients and was associated with D(2) expression (chi(2) = 5.6; P < 0.05). The expression of D(2short) rather than D(2long) isoform is associated with the most favorable response of the tumor to cabergoline treatment. In conclusion, this study demonstrates D(2) receptor expression and function in nearly 70% of cases, suggesting a role of this drug in the treatment schedule of clinically nonfunctioning pituitary tumors.

Adult↗
PubMed2004

The legacy of Pompeii and its volcano.

On August 24, AD 79, a terrible eruption of Mount Vesuvius deranged life in beautiful Pompeii and killed thousands of men, women, and children. They were restored to us by the fact that Mount Vesuvius, with its rain of ashes, proved to be a skilled sculptor, preserving the shape and even the wrinkles in the clothes the Pompeians wore while trying to escape during the day of the tragedy. The detailed description of Plinius the Younger and modern static studies of the eruptive residues have made it possible to reconstruct with great accuracy the various phases of the eruption that took place 2000 years ago, including the hours and days during which the phenomena first became obvious. Today, almost 2000 years later, Pompeii has reawakened and risen from its sepulcher of ashes thanks to the excavations initiated under King Charles III of Bourbon in 1748. Excavations proceeded slowly under the Bourbons, with the aim of enriching the Bourbon Museum of Naples rather than of classifying the ruins and placing them into a historical context. Under Joachim Murat, interest in the town planning and architecture of the uncovered cities reemerged, especially with respect to Pompeii. In 1860, however, with the establishment of the Kingdom of Italy, the excavations, now under the direction of archaeologist Giuseppe Fiorelli, were provided new impetus and, finally, a scientific basis. Today, the excavations are giving us back extraordinary evidence concerning the culture, the everyday life, the habits, the architecture, and the wonderful frescoes of the Roman cities of southern Italy, making possible the statement that Pompeii is "the most alive of the dead cities."

History, 15th Century↗