Biochemical and molecular characterization of the novel BRAFV599Ins mutation detected in a classic papillary thyroid carcinoma

Activating mutations of the BRAF gene are the most common genetic alterations in papillary thyroid carcinomas (PTCs) and the T1799A transversion, resulting in BRAFV600E, appeared virtually unique in this cancer type. Here, we report on the identification in a classic PTC of a novel BRAF mutation, namely a 1795GTT insertion, resulting in BRAFV599Ins, and describe its biochemical and molecular characterization. Kinase assays carried out on BRAFV599Ins and BRAFV600E revealed a three- to five-fold increase in the enzymatic activity of both mutants with respect to BRAFWT. Similarly, evaluation of BRAF-induced phosphorylation of MEK, MAPK and RSK revealed a significant MAPK cascade activation in cells expressing BRAFV599Ins or BRAFV600E, but not in cells expressing BRAFWT. Molecular dynamic simulations showed a destabilization of the inactive conformation of the enzyme in both BRAFV599Ins and BRAFV600E mutants, but not in BRAFWT. The analysis of the interaction energies inside the catalytic site allowed to demonstrate the presence of repulsive electrostatic forces acting on the activation loop and moving from inward to outward of the mutant enzymes. Finally, focus assays in NIH-3T3 cells confirmed a high transformation rate in the cells transfected either with BRAFV599Ins or BRAFV600E. In conclusion, this study demonstrated that BRAFV599Ins, as BRAFV600E, is a 'gain of function' mutation, characterized by a constitutive catalytic activation, which accounts for its causative role in the studied PTC.

Genotyping of an Italian papillary thyroid carcinoma cohort revealed high prevalence of BRAF mutations, absence of RAS mutations and allowed the detection of a new mutation of BRAF oncoprotein (BRAF(V599lns))

OBJECTIVES

The genes RET and RAS, and more recently BRAF, have been shown to be frequently mutated in human papillary thyroid carcinomas (PTC). The aim of this study was to genotype for these mutations a cohort of thyroid tumours collected at our institutions.

DESIGN AND PATIENTS

Thyroid tumours removed from 51 subjects were analysed, including 43 PTC and 8 non-PTC tumours [3 follicular adenomas (FA), 4 follicular carcinomas (FTC) and 1 anaplastic carcinoma (AC)].

MEASUREMENTS

RET/PTC1 and RET/PTC3 expression was evaluated by reverse transcriptase-polymerase chain reaction, whereas screening of BRAF (exon 15) and RAS (HRAS, KRAS2 and NRAS) mutations were performed, respectively, by single strand conformation polymorphism and denaturing high-pressure liquid chromatography.

RESULTS

RET/PTC expressions was positive in 5/43 (11.6%) PTC and in none of the non-PTC tumour. Similarly, BRAF mutations were positive only in PTC, but with a higher prevalence (24/43 positives, 55.8%). All but one BRAF mutation resulted in the prototypic substitution of valine 600 with a glutamic acid. In one case, a somatic in-frame insertion of three bases at codon 599 resulted in the insertion of an additional valine. RET/PTC expression and BRAF mutations were mutually exclusive. Screening of the RAS gene allowed identification of oncogenic mutations in 1/3 (33.3%) FA and 3/4 (75%) FTC. None of the PTCs was positive for RAS.

CONCLUSIONS

These data indicate that BRAF mutations are the most frequent genetic event in PTC and that RAS mutations, besides being a genetic hallmark of follicular tumours, are rare or completely absent in PTC from our area. Together, BRAF mutations and rarer RET rearrangements accounted for a genetic event in two-thirds of PTCs. This study showed a novel and presumably oncogenic mutation of BRAF, which is BRAF(V599Ins).

Recurrent laryngeal nerve damage and phonetic modifications after total thyroidectomy: surgical malpractice only or predictable sequence?

Modifications of phonation occurring after total thyroidectomy (TT) are usually attributed to surgical malpractice, but other causes of voice impairment even in nonoperated subjects should also be taken into account. This study analyzes 208 patients who underwent TT from January 1, 1999 through December 31, 2001. Follow-up ended on December 31, 2003. Only cases in which the surgeon ruled out the possibility of operative damage to the laryngeal nerves were included. All patients underwent pre- and postoperative clinical and instrumental nose and throat examination (NTE). Preoperatively, 86 patients (41%) showed hoarseness or dysphagia: 4 (2%) monoplegia and 12 (6%) hypomobility of the vocal cords due to impaired function of the recurrent laryngeal nerve (RLN); 6 (3%) cord hypotonia due to impairment of the superior laryngeal nerve (SLN); 34 (16%) dysphagia: and 30 (14%) hoarseness due to other causes. At follow-up 1 month after surgery, 71 patients (34%) had an onset of previously absent signs and symptoms: 8 (4%) had palsy of one vocal cord (2% permanent); 6 (3%) had cord hypomobility (all temporary); 12 (6%) had cord hypotonia due to disease of the SLN, 4 of which (2%) were permanent; 44 patients (21%) had symptoms due to scarring and adhesions between the laryngotracheal axis and the prethyroid muscles and between these and the skin. One patient (0.5%) had a nodular cord lesion that occurred after 3 months. Overall, more than one-third of the patients had preoperative voice modifications or swallowing impairment, around one-third had these problems after TT, and less than one-third were free of pre- and postoperative complications. The surgeon's care to avoid damage to the anatomica integrity of the of laryngeal nerves does not exclude functional problems of the nerves and of laryngeal dynamics. In fact, such problems could be referred to outcomes linked to the operation itself (hematoma, edema, scarring adhesion) or to events that only temporarily follow surgery but must be considered as an unavoidable sequel (e.g., neuritis, viral neuritis, myopathy). The patient should undergo a careful clinical and instrumental NTE to detect conditions prior to surgery, and the information provided by the surgeons should be thorough to allow the patient to be aware of all possible sequels and consequences.

Which therapy to prevent post-thyroidectomy hypocalcemia?

Hypocalcemia is one of the most frequent complications after total extracapsular thyroidectomy (TET). In most of cases it is a transient phenomenon. The aim of this study is to evaluate if and how the oral administration of calcium or calcium combined with D-vitamin could effectively prevent post-thyroidectomy hypocalcemia. A randomized prospective study was performed, recruiting 120 patients who underwent total thyroidectomy. The patients in our series were randomly assigned to one of two groups: group A--patients who received calcium lactogluconate/calcium carbonate (mg 300 per day); group B--patients who received calcium carbonate/cholecalciferol therapy (calcium carbonate: 1500 mg per day; cholecalciferol 400 UI per day). The groups were well matched for age, sex and pathologies. Patients of both A and B groups were divided in two subgroups: those operated on for benign thyroid diseases (A1 and B1) and those operated on for malignancy (A2, B2). Serum calcium assays, performed 24, 48 and 72 hours after surgery, showed mean values of calcemia higher in patients of the B1 and B2 group. Statistical analysis was performed using a Student's t test. Mean serum calcium concentrations on post-operative day one, two and three were higher in patients of the group B (p<<0.01). Early and combined oral administration of both calcium and vitamin D seemed to prove major efficacy in preventing and treating post-operative hypocalcemia, showing mean serum calcium levels higher than those of patients who received only oral calcium administration. Nevertheless, further studies are necessary to validate these data.

Major complications in thyroid surgery: utility of bipolar vessel sealing (Ligasure Precise)

In the present study the Authors tried and assess the advantages of the standard sutureless thyroidectomy performed by the Ligasure Vessel Sealing System, thanks to the use of the dedicated Precise handle. The Authors compared the efficacy of haemostasis and the economical impact of the device, in terms of drug administration and costs. The Authors comparatively analyzed 120 total extracapsular thyroidectomies (TET) performed by the standard operative technique (Group A, control) and 70 TET achieved by the "sutureless technique" (Group B, case). There was a statistically significant decrease of transient postoperative hypocalcemia (5.71% vs 7.5%) and also of mean operative time (about 20 minutes) in patients of the group B. Non significant decrease of other kind of complications (postoperative hemorrhage, transient and permanent inferior laryngeal palsy, stupor of the superior laryngeal nerve, seromas) were also observed. The use of the Ligasure Precise resulted easy, safe and efficient in the Authors' experience. It allowed the decrease of postoperative haemorrhages and mean operative time.

[Interstitial laser photocoagulation in liver tumours: our experience]

Interstitial lasertherapy (ILT) is one of the percutaneous thermal procedures allowing the ablation of primary or secondary hepatic lesions. This technique can be performed without general anaesthesia, since the patient is completely painless, in spite of the high temperatures reached, because there are no sensitive fibers around the lesion. This study includes patients with small hepatocarcinomas (< 2 cm) non peripherically sited, far from the gallbladder and the hepatic hilum. Twenty patients suffering from 24 cirrhotic hepatocarcinomas (two patients showed two nodules) have been enrolled for the present study. Mean diameter of lesions was 1.8 cm (1.3-2 cm). One or more 21 G (length 20 cm) Chiba's needles were inserted under sonographic view into the lesions. The laser energy was switched on at 4 Watts for 4-6 minutes, until an amount of energy of 900-1800 Joule was reached. All the patients were discharged 48 hours after the procedure. Triphasic CT-scan with contrast were performed 7 to 14 days after ILT, in order to check its efficacy. CT-scan showed complete necrosis in all the nodules ranging from 1.5 to 3 cm. All the patients received only one IL T session, whose longest duration was 20 minutes. No major complications occurred. ILT of small hepatocarcinomas is a safe, efficient procedure, also feasible without anaesthesia. Differently from percutaneous radiofrequency, in fact, it shows the advantage of less pain, that can avoid the need for general anaesthesia.

[Bile leakage after laparoscopic cholecystectomy: report of three cases in our experience]

Laparoscopic cholecystectomy (LC) is associated with an higher incidence of bile duct injury than open cholecystectomy. There has been concern and the reason why bile leakages are more frequent with LC is yet unclear. Bile collections can occurr because of major about (75%) or minor (about 25%) injuries. Anyway, external biliary decompression is a key factor in the treatment, in order to avoid an emergency intervention. The Authors report their experience concerning 3 cases of bile leakages among a series of 458 LC. Only in one of the three cases the subhepatic space was not drained and an emergency laparotomy was performed. The Authors, on the basis of their own experience and of the data reported in literature, suggest the routinary intraoperative placement of a drainage into the subhepatic space, to be removed, if no complications occur, one day after surgery.

Thymic neuroendocrine carcinoma (carcinoid) in multiple endocrine neoplasia type 1 syndrome: the Italian series

Neuroendocrine tumors may occur in the setting of multiple endocrine neoplasia type 1 (MEN1) syndrome. Among these, a probably underestimated prevalence of well differentiated neuroendocrine thymic carcinoma (carcinoid), a neoplasm characterized by very aggressive behavior, has been described. We report characterization of the seven Italian cases in which this association occurred among a series of 221 MEN1 patients (41 sporadic and 180 familial cases; prevalence, 3.1%). All of the patients were male, and six of seven (85%) were heavy smokers. No associated hormonal hypersecretion was detected. The first diagnosis was between the second and fifth decades. Familial clusters were present in three of seven (42.8%). No genotype-phenotype correlation was found. All seven cases were associated with hyperparathyroidism. In one patient, prophylactic thymectomy revealed a small nodular lesion suggestive of a thymic carcinoid, providing evidence that preventive thymectomy might prevent additional growth of an occult thymic carcinoid. These findings confirm that thymic carcinoids are associated with a very high lethality, with a near-total prevalence in smoker males. Therefore, prophylactic thymectomy should be considered at neck surgery for primary hyperparathyroidism in MEN1 male patients, especially for smokers, and, due to the frequent familial clusters distribution of this pathology, in subjects with affected relatives presenting this feature. Thus, we recommend screening every patient affected with a neuroendocrine thymic neoplasm for MEN1 syndrome.

Surgical treatment of neuroendocrine tumors of the lung*1

OBJECTIVE

This report reviews the pattern of neuroendocrine (NE) differentiation, lymph-node involvement, extension of surgery, and survival in 125 NE lung tumor patients.

METHODS

Standard diagnostic workup included CT scan, bronchoscopy, bronchial biopsy or Fine Needle Aspiration Biopsy, (111)In-pentetreotide scan (OctreoScan) and mediastinoscopy in selected patients. NE differentiation was assessed based on the morphology and immunohistochemical reactivity for pan-neuroendocrine markers NSE, CGA, and Synaptophysin. For small cell carcinoma (SCC), only clinical stage I and II patients underwent surgery. Several different surgical procedures were utilized, from limited resections to lobectomy, pneumonectomy, and bronchoplastic procedures. Survival was assessed using Kaplan-Meyer method at 5 years.

RESULTS

There were 79 typical carcinoid (TC), eight atypical carcinoid (AC), 18 large cell carcinoma (LCC) and 20 SCC patients. Mean age at diagnosis was 54.6+/-15.2 (ranges from 16 to 77 years) for TC, 68.5+/-9.1 (range 53-81) for AC, 68.7+/-4.6 (range 58-77) for LCC, 64.6+/-7.9 (range 48-82) for SCC. Male/female ratio was 1/1 for TC and AC, 2.6/1 for LCC and 9/1 for SCC. Lymph-node involvement was present in 14% of TC, 0% of AC, 31.5% of LCC, and 45% of SCC. Cancer specific survival was 96% for TC, 87.5% for AC, 37.5% for LCC, and 30% for SCC at 5 years from surgery. Presenting symptoms were invariably of respiratory-related. None had the carcinoid syndrome. History of tobacco abuse ranged from 46% for TC to 100% in SCC. Survival ranged from a minimum of 1 month for SCC to a maximum of 168 months with no evidence of disease for TC. Synchronous multicentric forms were found in 14% of TC. Twenty-one percent (4/19) of the patients with SCC treated by induction therapy and surgery, and in few cases by surgery and adjuvant chemotherapy are alive without the evidence of the disease for 5 years.

CONCLUSIONS

Due to the high percentage of lymph-node involvement and multicentric forms found in our series lobectomy with radical lymph-node dissection appears, in our opinion, the most appropriate surgical treatment in well-differentiated forms, while more limited resection appears sub-optimal. Also, due to the finding of recurrences many years after surgery, the follow-up must be accurate and protracted in this subgroup. Only Small Cell Lung Carcinoma patients in clinical stage I and II underwent surgery with good long-term results.

Locally advanced thyroid cancer: therapeutic options

The authors report on their experience in the management of thyroid cancer, with specific regard to advanced disease. Thyroid carcinomas behave differently according to: pathology, sex, age, grading and size. Differentiated lesions have a favourable outlook, while for less-differentiated tumours the prognosis is dismal. Extent of resection, lymphectomy technique and management of advanced disease remain matters of debate. Of particular interest are those neoplasms invading the upper aerodigestive tract, characterised by a worse prognosis in the case of differentiated tumours (1-6%), indicating an exceedingly aggressive behaviour in what is usually a slowly evolving disease. Surgery, with a curative intent or for palliation, is mandatory. The tumour progressively invades the tracheal lumen and is seldom manageable by alternative, non-surgical methods, and in any case only for short periods of time. Total thyroidectomy with tracheal resection and anastomosis is the surgical technique of choice and, when combined with radiometabolic therapy and/or external radiotherapy, yields survival data comparable with those relating to less advanced differentiated lesions. Tracheal stents and tracheotomy improve the quality of life. Laser therapy is indicated in cases of asphyxia, and as a preliminary step with a view to subsequent radical or palliative treatments.

[Surgical treatment of umbilical hernia in children. Our experience]

AIM

To identify the main parameters which, differently correlated, indicate in which case, age and modality umbilical hernia in children should be surgically repaired.

METHODS

The authors report personal experience on 319 children with umbilical hernia observed in the last 7 years. In 72 cases, on the basis of the evaluation of some parameters, a surgical correction was performed with the technique described.

RESULTS

All the procedures were performed in "day surgery". There were no early complications, neither anesthetic nor surgical. All children showed a good recovery of all functions (feeding, intestinal canalization, walking about) and activities. No middle and long-term complications were observed.

CONCLUSIONS

Umbilical hernia needs a surgical repair only in a few cases and after a careful evaluation of some parameters (age, sex, kind of hernia, size and consistency of the hernial porta, protrusion and expansion). The surgical procedure should guarantee either the safe and prompt repair or the cosmetic result; the use of some devices (anesthetic and surgical) allow to obtain excellent results.

BRAF(V599E) mutation is the leading genetic event in adult sporadic papillary thyroid carcinomas

Activating mutations of BRAF have been identified in a variety of human cancers, most notably melanomas and papillary thyroid carcinomas (PTCs). The aim of the present study was to disclose the role of BRAF mutations in thyroid carcinoma development. Seventy-two thyroid tumors, including 60 PTCs, six follicular adenomas, five follicular carcinomas, and one anaplastic carcinoma, were studied. BRAF mutation screening focused on exon 15 and exon 11 of the gene by single-stranded conformational polymorphism and sequence analysis. Search of RET/PTC expression was conducted with the RT-PCR technique. The molecular genetic study of the BRAF gene showed the presence of a missense thymine to adenine transversion at nucleotide 1796, resulting in the V599E substitution, in 24 of 60 PTCs (40%), none of six follicular adenomas, and none of five follicular carcinomas or one anaplastic carcinoma. Moreover, nine of 60 PTCs (15%) presented RET/PTC expression. A genetico-clinical association analysis showed a statistically significant correlation between BRAF mutation and development of PTCs of the classic papillary histotype (P = 0.038). On the contrary, no link could be detected between expression of BRAF(V599E) and age at diagnosis, gender, dimension, and local invasiveness of the primary cancer, presence of lymph node metastases, tumor stage, and multifocality of the disease. These data clearly confirm that BRAF(V599E) is the more common genetic alteration found to date in adult sporadic PTCs, that it is unique for this thyroid cancer histotype, and that it might drive the development of PTCs of the classic papillary subtype.

[Thyroidectomy for thyroid carcinoma. Our experience]

The surgical management of thyroid carcinoma involves different degrees of lymphadenctomy, according to features such as the nature, the site and the severity of the disease. The authors present their experience in order to contribute to the debate on the standard management of nodal metastasis in well-differentiated thyroid cancers. The authors describe their six years of experience in 302 thyroid cancer patients with a total of 291 thyroidectomies performed. According to the different pathological findings, the treatment involved a monolateral dissection in 42 patients and a bilateral modified neck dissection in 21. A number of anatomical considerations regarding the pathway of lymphatic drains are summarized and follow-up results are also presented. The slow progression of the disease and its low incidence make long-term prospective studies difficult, thus hindering any definitive assessment of lymph node management in well-differentiated thyroid cancers.

Complications of thyroid surgery: analysis of a multicentric study on 14,934 patients operated on in Italy over 5 years

Complication rates associated with thyroid surgery can be evaluated only through analysis of case studies and follow-up data. This study covers postoperative data from 14,934 patients subjected to a follow-up of 5 years. Among them, 3130 (20.9%) underwent total lobectomy (TL), 9599 (64.3%) total thyroidectomy (TT), 1448 (9.7%) subtotal thyroidectomy with a monolateral remnant (MRST), and 757 (5.1%) subtotal thyroidectomy with bilateral remnants (BRST). A total of 6% of the patients had already been operated on. Persistent hypoparathyroidism occurred after 1.7% of all the operations, and temporary hypoparathyroidism was noted in 8.3%. Permanent palsy of the laryngeal recurrent nerve (LRN) occurred in 1.0% of patients, transient palsy in 2.0%, and diplegia in 0.4%. The superior laryngeal nerve was damaged in 3.7%; dysphagia occurred in 1.4% of cases, hemorrhage in 1.2%, and wound infection in 0.3%. No deaths were reported. A significant rate of LRN damage was noted, which has an important impact on the patient's social life. Hypoparathyroidism after total thyroidectomy is an important complication that can be successfully treated by therapy, although it is not always easily managed in special circumstances such as in young persons or pregnant women. The complications associated with thyroid surgery must be kept in mind so the surgeon can carefully evaluate the surgical and medical therapeutic options, have more precise surgical indications, and be able to give the patient adequate information.

[Acute mediastinitis: clinical features and review of a case load]

The term acute mediastinitis describes a number of clinical conditions, usually secondary to diseases of other aetiology with which they tend to share the severity of the clinical picture. In these situations even a timely diagnosis and adequate therapeutic management are not always enough to ensure healing. Over the period 1987-2002 15 patients with acute mediastinitis were observed (8 male, 7 female), aged from 22 to 90 years (mean age: 57.9), distributed as follows: descending necrotising mediastinitis, 4 cases; iatrogenic oesophageal rupture, 2 cases; iatrogenic tracheal rupture, 3 cases; oesophageal perforation (foreign body), 4 cases; Boerhaave's syndrome, 1 case; oesophageal perforation (lye ingestion), 1 case. All patients except one--managed medically--were submitted to mediastinal drainage (surgical or by mediastinoscopy), combined with cervical debridement and drainage in cases of descending necrotising mediastinitis, alimentary tract diversion (cervical oesophagostomy + feeding jejunostomy + gastric decompression) in cases of large oesophageal lesions or if the lesion occurred more than 24 hours before observation, and uni- or bilateral tube thoracostomy. Furthermore, antibiotic therapy was always administered, initially choosing broad-spectrum medications, and subsequently adjusting according to bacterial cultures. Four patients died. In 4 cases (2 descending necrotising mediastinitis, 2 acute mediastinitis secondary to oesophageal perforation) repeated interventions were necessary in order to drain pleural or mediastinal effusions. Acute mediastinitis remains a serious clinical entity, the outlook of which is often poor. Factors influencing outcome are the patient's age and general condition (adequate immune response), a timely diagnosis, preoperative localisation of effusions, an aggressive therapeutic approach including drainage of infection sites in the mediastinum, neck and/or pleural cavities, alimentary tract diversion in cases of oesophageal lesions observed late, adequate antibiotic therapy, and nutritional support (total parenteral/enteral nutrition).

Ret/PTC activation does not influence clinical and pathological features of adult papillary thyroid carcinomas

OBJECTIVE

RET proto-oncogene rearrangements (ret/PTCs) represent the most common genetic alterations found in papillary thyroid carcinomas (PTCs). Correlation of ret/PTC expression with clinical outcome is controversial. The aim of the present study was to analyze the frequency of RET rearrangements in adult PTCs, and to investigate if ret/PTCs influence biological behavior and clinical features of the cancers.

DESIGN

Ret/PTC rearrangements were looked for in tIssue samples of 48 PTCs collected at our institution. Data about clinical and pathological features of the tumors were also reviewed. Three separate association analyses were carried out on the cohort evaluating the effects of, respectively, ret/PTC positivity, preferential RET tyrosine kinase domain (RET-TK) expression, and ret/PTC plus RET-TK positivity, on age, sex, tumor size, staging, number of neoplastic foci, and histological subtype.

METHODS

The genetic study was conducted with the RT-PCR-Southern blot technique. Standard Student's t-test and Fisher exact test were applied for the association analyses.

RESULTS

The molecular genetic study demonstrated the positivity of ret/PTC1 and ret/PTC3 in 13 of 48 tumors (27.1%), and an exclusive or preferential RET-TK expression in 17 cases (35.4%). None of the three genetico-clinical analyses showed any significant association between ret/PTC expression and the clinical and pathological features of the cancers.

CONCLUSIONS

These data indicate that RET rearrangements may not play any distinctive role in driving histotype development and cancer progression in these neoplasms. Moreover, they weaken the possibility of using ret/PTC as a prognostic marker for papillary thyroid carcinomas.

[Complications of total thyroidectomy: incidence, prevention and treatment]

The range of indications for total thyroidectomy in the treatment of thyroid disease is steadily increasing, but any attempt to assess its real efficacy necessarily calls for a knowledge of the incidence of complications, amongst other things in order to provide the patient with complete information regarding the operation before obtaining his or her consent. Retrospective and observational analysis of 14,934 thyroidectomies performed in 42 Endocrine Surgery Units in Italy has made it possible to compare total thyroidectomy (TT) versus subtotal thyroidectomy with a bilateral remnant (ST-BR), subtotal thyroidectomy with a unilateral remnant (ST-UR) and total lobectomy-isthmectomy (TLI). The correlation between the number of total thyroidectomies and each of the other surgical procedures and the number of complications occurring with each of them was also assessed in order to quantify the effective risk of complications by determining the Odds Ratios on the basis of univariate analysis of the variables considered. The cases reviewed consisted of 9,599 TT (64%), 3,130 TLI (21%), 1,448 ST-UR (22%) and 757 ST-BR (5%); 13,023 (87%) cases were suffering from benign disease and 1,911 (13%) from malignancies. Recurrent laryngeal nerve injuries were present in 4.3% of the TT cases with 2.4% transient and 1.3% definitive (as against 3% in ST-BR and 2% in ST-UR with 1.4% and 1.1% transient, and 1% and 0.6% definitive, respectively; and 1.4% transient and 0.6% definitive in TLI). Hypocalcaemia after TT was transient in 14% and definitive in 2.2% (as against transient rates of 5% in ST-BR and ST-UR and 0.4 in TLI; and definitive hypocalcaemia in 0.6%, 0.8% and 0.07%, respectively). Haemorrhage occurred in 1.6% of TT cases (as against 2.1%, 0.5% and 0.4% in ST-BR, ST-UR and TLI, respectively). The Odds Ratios showed that TT presented a 16% higher complication rate than ST-UR which was assigned a value of 1, a 3% higher rate than ST-BR and a 5% lower rate than TLI. This greater incidence of complications with TT is attributable mainly to the greater incidence of transient hypoglycaemia and to a lesser extent to the slightly higher incidence of definitive hypoglycaemia, whereas the incidences of recurrent laryngeal nerve injuries were very similar in TT and ST-BR. Haemorrhagic complications were more frequent in ST-BR than in TT. Bearing in mind that TT is the absolute indication in the more demanding thyroid diseases (tumours, retrosternal goitre, Basedow's disease, recurrences) and in view of its fairly low complication rate, we believe that TT is a safe, reliable procedure, provided it is performed in a technically scrupulous manner. ST-BR is a technique which should be abandoned owing to the fact that its complication rate is comparable to that of TT and to the recurrences it may give rise to. ST-UR may be indicated if the surgeon is not sure of safeguarding the anatomical integrity of the recurrent nerve on one side.

[Prevalence of the neuroendocrine phenotype in thymus neoplasms]

To determine the prevalence of neuroendocrine differentiation in human thymic neoplasms, which are unusual tumours that may range from well-differentiated to overtly malignant, poorly differentiated lesions, an immunohistochemical study was conducted in 23 thymic neoplasms re-classified on the basis of the new 1999 WHO classification. Immunohistochemical evidence of neuroendocrine differentiation in the form of reactivity to the markers synaptophysin, neuron-specific enolase and chromogranin A was found in 6 of 23 tissues (26%). Two of 3 patients with thymic carcinoids (or well-differentiated thymic neuroendocrine carcinoma) were affected by multiple endocrine neoplasia type 1 (MEN-1). Myasthenia gravis was present in 2/6 patients with neuroendocrine differentiation. This study demonstrates the high prevalence of neuroendocrine markers in human thymic neoplasms. Whether and in what percentage of cases immunohistochemical reactivity may be correlated with clinical behaviour and outcome remains a controversial issue. Finally, the association between thymic carcinoids and MEN-1 is a strong indication for clinical and possibly genetic screening of all patients presenting this feature, just as all MEN-1 patients have to undergo thoracic imaging and prophylactic thymectomy in selected cases.

The role of silicone stents in the treatment of cicatricial tracheal stenoses

OBJECTIVE

Tracheal stenting for cicatricial stenoses is reserved for patients whose lesions are deemed inoperable for local or general reasons. The aim of our study was to verify the long-term results of silicone tracheal stents in such a clinical setting.

METHODS

Clinical data of 45 patients treated by tracheal silicone stents, between 1987 and 1999, were reviewed. All patients had highly symptomatic cicatricial stenoses; they were selected for stenting rather than for surgery because of local and general conditions. This series has been divided in two groups according to the purpose of stenting: bridge to surgery or definitive treatment. Follow-up ranged between 12 and 83 months. Twenty-seven patients received a Montgomery T tube (Hood Laboratories, Pembroke, Mass), 16 a Dumon stent (Novatech, Plan de Gras, France), and 2 a Dynamic stent (Rusch, Kernen, Germany).

RESULTS

No procedure-related mortality was observed. Nine patients underwent curative resection and reconstruction after a variable stenting period; one had a recurrent stenosis and was treated for palliation with a T tube. Tracheal stenting was performed for palliation as a definitive treatment in 37 patients. Among this group, 11 patients died of unrelated causes at a median of 10 months after the endoscopic treatment. The stent was permanently removed in 10 after a median interval of 32 months (range 9-70 months); in 4 others, symptomatic recurrence of the stenosis was observed within 6 weeks of stent removal. None of the patients successfully decannulated had a completely normal tracheal lumen but all remained asymptomatic because the residual stenosis was mild or well tolerated for concomitant limitation of physical activity.

CONCLUSIONS

Long-term treatment with a silicone stent was safe and well tolerated in cicatricial tracheal stenoses. This procedure can be considered as a bridge to curative surgery or as a definitive treatment. The latter, generally performed for palliation, may provide satisfactory therapeutic results in selected patients, even in the presence of severe circumferential stenoses.

[Surgical treatment of thyroid cancer in 243 cases]

The incidence of thyroid cancer, which accounts for 1-2% of all malignancies, constantly increasing. Its management requires an integrated approach, in which the surgeon plays a pivotal role, providing the basis for further treatment. At present, the extent of exeresis, the lymph-node dissection technique and the management of upper respiratory-digestive tract infiltration are still debatable issues. The authors report on their experience with 243 surgically treated thyroid malignancies over the period from January 1986 to December 1999. The operations performed were: total thyroidectomy 226 cases, lobo-isthmectomy 3 cases, total thyroidectomy + lung metastasectomy 1 case, total thyroidectomy + SE quadrantectomy 1 case, total thyroidectomy + monolateral modified neck dissection 30 cases, total thyroidectomy + bilateral modified neck dissection 17 cases, total thyroidectomy + radical neck dissection 1 case, total thyroidectomy + tracheal sleeve resection 5 cases. In 9 cases, extensive tracheal involvement (5.5 cm), age or neoplastic histology allowed only palliative treatment (endoscopic recanalization + tracheal endoprosthesis or tracheostomy. Nd-Yag laser endoscopic recanalization was performed in 2 patients as a preliminary stage in subsegmental radical treatment, and in 5 cases for palliation. Recurrent laryngeal nerve palsy occurred in 3 cases, long-term hoarseness in 2, and hypoparathyroidism in 4. The overall mean hospital stay was 4.8 days. Of 299 patients still alive, 215 are free of disease. Surgery is the treatment of choice, with the goal of completely removing the neoplasm, together with any anatomical structures involved in infiltration (muscles, respiratory-digestive tract, lymph nodes). Satisfactory palliation can be achieved by endoprosthesis deployment or tracheostomy in all cases where surgery is ruled out due to extent of disease, patient age or histological type.

[Central venous access systems in the oncologic patient]

BACKGROUND

A safe and dependable venous access is mandatory in order to perform cancer chemotherapy and monitor blood values in the neoplastic patient. Prolonged infusions of medications with sclerosing action may damage the vessel wall, inducing chemical thrombophlebitis. Furthermore, extravasation of necrotizing compounds may be a danger to the patient. The application of totally implantable venous access systems (VAS) started in 1982, in the United States of America, where at present 500,000 devices are implanted annually. In Italy such method has been introduced in a later period, with a constantly growing trend. VAS devices have evolved since their first presentation, and so have application techniques: the original surgical route has been supported by the percutaneous one, considered most appropriate by several Centers. In this study, personal experience concerning application of VAS in cancer patients is presented.

METHODS

From July 1994 to February 1998, at the General Thoracic Surgery Dept. of the University of Perugia, 198 VAS have been implanted in 195 patients. During the first period all the systems have been applied by surgical cutdown of the cephalic vein (150 cases). In the last 12 month the percutaneous technique for vein puncture has been adopted in 48 patients.

RESULTS

Immediate and late complications have occurred: among the former, pneumothorax, hematoma, malposition; among the latter, infection, subclavian vein thrombosis, catheter rupture. The results are analysed after an extensive review of the international literature; pros and cons of the different implantation techniques and the technical aspects useful for preventing complications are underlined.

[Conservative surgery in the treatment of rectal tumors. Our experience, 1986-1997]

OBJECTIVE

Our institution's experience with low anterior resection for primary rectal cancer was reviewed to determine cancer treatment results and to identify risk factors for pelvic recurrence.

METHODS

Ninety-two patients treated for primary rectal cancer between 1986 and 1997 were studied retrospectively. All cases was classified according to Astler-Coller. Median follow up was 46 months.

RESULTS

Actuarial 5-year survival for all patients was 79%. Among 28 patients who relapsed, only 9 pelvic recurrence was detected with an actuarial rate of 15% at 5 years. Lymph nodes involvement were associated with increased risk for pelvic recurrence.

DISCUSSION

Low anterior resection permitted by circular stapler provides good treatment for mid-rectal cancers and for some distal rectal cancers. Pelvic recurrence is not correlated with neoplasm localization, T stage and short distal resection margins, but only with the presence of lymph nodes involvement. This result increase the value of the hypothesis that search the pelvic recurrence origin in a extra-parietal disease respect anastomotic disease.

CONCLUSION

Fundamental to prevent pelvic recurrence is the surgical technique that have to remove lymph node en bloc with the rectum doing a dissection along the endopelvic fascia to Denonvillers fascia so to take away completely the mesorectum.

Resection with curative intent after endoscopic treatment of airway obstruction

BACKGROUND

Endoscopic treatment of malignant central airway obstructions usually is done for palliation. The exact role of such a procedure as preparatory to operation remains controversial.

METHODS

From 1987 through 1996, 24 patients at our institution underwent tracheobronchial pulmonary resection after preliminary endoscopic treatment. During the same period, 304 patients underwent 449 operative rigid bronchoscopies for airway obstructions, most involving the use of a neodymium:yttrium-aluminum-garnet laser. The indications for operation were squamous cell carcinoma in 14 patients, bronchial gland tumors in 8 patients, and papillary thyroid cancer infiltrating the trachea in 2 patients. The total resection rate was 9.5% (5% for squamous cell carcinoma, 75% for low-grade malignant bronchial tumors, and 75% for papillary thyroid cancer). The median period between operative rigid bronchoscopy and operation was 18 days.

RESULTS

No complications were observed after endoscopic treatment. There were two perioperative deaths (adult respiratory distress syndrome after carinal resection and pulmonary embolism after pneumonectomy) and one major complication (poor postoperative pulmonary function after pneumonectomy). No anastomotic complications were observed in the tracheobronchoplastic procedures. Follow-up was possible in every patient but 1: 6 patients died at a median of 30.5 months after operation (range, 3 to 46 months), 2 patients are alive with disease, and the rest are alive without evidence of disease at a median of 21 months (range, 2 to 61 months).

CONCLUSIONS

Most patients who require endoscopic therapy for malignant airway obstructions are not candidates for operative resection. Preliminary endoscopic relief of obstruction can increase operability and improve surgical results in a highly selected group of patients.

Bone heterograft for chest wall reconstruction after sternal resection

BACKGROUND

Experimental and clinical results of chest-wall reconstruction with bone heterograft after sternectomy are reported.

METHODS

Seven dogs underwent subtotal or total sternectomy and reconstruction by implantation of a cortico-spongy bone heterograft sandwiched between two layers of a reabsorbable mesh.

RESULTS

No major postoperative complications were observed. The implant has shown favorable mechanical and biological properties. Six and 9 months after operation all animals were sacrificed and pathologic examination showed good incorporation of the implanted bone with only partial resorption of its spongiosa. Subsequently, 2 patients underwent sternal resection with different indications and reconstruction was achieved by the technique developed experimentally. No complications were observed. Excellent immediate chest-wall stabilization was obtained, persisting for a follow-up period longer than 6 months.

CONCLUSIONS

In comparison with autologous bone, sterile bone heterograft seems to offer the same mechanical properties with a significantly reduced surgical trauma.

[Picotamide: use in chronic obliterative arteriopathies of the lower limbs]

In the present study the authors evaluated treatment efficiency and patient compliance of medium-term therapy with Picotamide, given in doses of 900 mg/die for the first 15 days, and 600 mg/die up to the completion of a three-month period, to 50 patients affected by vaso-occlusive arterial disease of the lower limbs. At follow-up visits the following controls have been carried out: CW Doppler sonography of the lower limbs, Maximum Walking Distance (M.W.D.), Red blood cell count, White blood cell count, Platelet count, Haemoglobin and Fibrinogen levels. At the end of the three-month therapy period the Ankle-Arm parameters remained unchanged.

[Surgery of pulmonary and hepatic metastases]

In recent years surgery for hepatic and pulmonary metastases has been undertaken with a curative intent in a growing percentage of cases. In the present study the Authors evaluate their own experience in such a field, and summarize the state of the art, as it appears from a review of the international literature. At present, the subject is not settled, as several aspects are matter of debate (prognostic significance of free interval, tumor doubling time, number and location of metastatic lesions, histologic type, and stage, of the primary tumor, approach to synchronous metastases, accuracy of preoperative diagnosis), with different therapeutic implications according to the hepatic or pulmonary site. Pulmonary metastases should be managed by resection through a median sternotomy, in order to allow thorough exploration of both lungs. Hepatic lesions (from colorectal primaries) should be resected with a free margin not less than 1-2 cm. The need for uniformity of selection criteria and for the establishment of protocols including adjuvant therapy is strongly felt.