Defining probabilities of bowel resection in deep endometriosis of the rectum: Prediction with preoperative magnetic resonance imaging.

AIM: Deep endometriosis of the rectum is a highly challenging disease, and a surgical approach is often needed to restore anatomy and function. Two kinds of surgeries may be performed: radical with segmental bowel resection or conservative without resection. Most patients undergo magnetic resonance imaging (MRI) before surgery, but there is currently no method to predict if conservative surgery is feasible or whether bowel resection is required. The aim of this study was to create an algorithm that could predict bowel resection using MRI images, that was easy to apply and could be useful in a clinical setting, in order to adequately discuss informed consent with the patient and plan the an appropriate and efficient surgical session. METHODS: We collected medical records from 2010 to 2016 and reviewed the MRI results of 52 patients to detect any parameters that could predict bowel resection. Parameters that were reproducible and with a significant correlation to radical surgery were investigated by statistical regression and combined in an algorithm to give the best prediction of resection. RESULTS: The calculation of two parameters in MRI, impact angle and lesion size, and their use in a mathematical algorithm permit us to predict bowel resection with a positive predictive value of 87% and a negative predictive value of 83%. CONCLUSIONS: MRI could be of value in predicting the need for bowel resection in deep endometriosis of the rectum. Further research is required to assess the possibility of a wider application of this algorithm outside our single-center study.

Multicentre external validation of the BIMC model for solid solitary pulmonary nodule malignancy prediction.

OBJECTIVES: To provide multicentre external validation of the Bayesian Inference Malignancy Calculator (BIMC) model by assessing diagnostic accuracy in a cohort of solitary pulmonary nodules (SPNs) collected in a clinic-based setting. To assess model impact on SPN decision analysis and to compare findings with those obtained via the Mayo Clinic model. METHODS: Clinical and imaging data were retrospectively collected from 200 patients from three centres. Accuracy was assessed by means of receiver-operating characteristic (ROC) areas under the curve (AUCs). Decision analysis was performed by adopting both the American College of Chest Physicians (ACCP) and the British Thoracic Society (BTS) risk thresholds. RESULTS: ROC analysis showed an AUC of 0.880 (95 % CI, 0.832-0.928) for the BIMC model and of 0.604 (95 % CI, 0.524-0.683) for the Mayo Clinic model. Difference was 0.276 (95 % CI, 0.190-0.363, P < 0.0001). Decision analysis showed a slightly reduced number of false-negative and false-positive results when using ACCP risk thresholds. CONCLUSIONS: The BIMC model proved to be an accurate tool when characterising SPNs. In a clinical setting it can distinguish malignancies from benign nodules with minimal errors by adopting current ACCP or BTS risk thresholds and guiding lesion-tailored diagnostic and interventional procedures during the work-up. KEY POINTS: • The BIMC model can accurately discriminate malignancies in the clinical setting • The BIMC model showed ROC AUC of 0.880 in this multicentre study • The BIMC model compares favourably with the Mayo Clinic model.

Multicenter external validation of two malignancy risk prediction models in patients undergoing 18F-FDG-PET for solitary pulmonary nodule evaluation.

OBJECTIVES: To achieve multicentre external validation of the Herder and Bayesian Inference Malignancy Calculator (BIMC) models. METHODS: Two hundred and fifty-nine solitary pulmonary nodules (SPNs) collected from four major hospitals which underwent 18-FDG-PET characterization were included in this multicentre retrospective study. The Herder model was tested on all available lesions (group A). A subgroup of 180 SPNs (group B) was used to provide unbiased comparison between the Herder and BIMC models. Receiver operating characteristic (ROC) area under the curve (AUC) analysis was performed to assess diagnostic accuracy. Decision analysis was performed by adopting the risk threshold stated in British Thoracic Society (BTS) guidelines. RESULTS: Unbiased comparison performed In Group B showed a ROC AUC for the Herder model of 0.807 (95 % CI 0.742-0.862) and for the BIMC model of 0.822 (95 % CI 0.758-0.875). CONCLUSIONS: Both the Herder and the BIMC models were proven to accurately predict the risk of malignancy when tested on a large multicentre external case series. The BIMC model seems advantageous on the basis of a more favourable decision analysis. KEY POINTS: • The Herder model showed a ROC AUC of 0.807 on 180 SPNs. • The BIMC model showed a ROC AUC of 0.822 on 180 SPNs. • Decision analysis is more favourable to the BIMC model.

Enhanced characterization of solid solitary pulmonary nodules with Bayesian analysis-based computer-aided diagnosis.

The aim of this study was to prospectively assess the accuracy gain of Bayesian analysis-based computer-aided diagnosis (CAD) vs human judgment alone in characterizing solitary pulmonary nodules (SPNs) at computed tomography (CT). The study included 100 randomly selected SPNs with a definitive diagnosis. Nodule features at first and follow-up CT scans as well as clinical data were evaluated individually on a 1 to 5 points risk chart by 7 radiologists, firstly blinded then aware of Bayesian Inference Malignancy Calculator (BIMC) model predictions. Raters' predictions were evaluated by means of receiver operating characteristic (ROC) curve analysis and decision analysis. Overall ROC area under the curve was 0.758 before and 0.803 after the disclosure of CAD predictions (P = 0.003). A net gain in diagnostic accuracy was found in 6 out of 7 readers. Mean risk class of benign nodules dropped from 2.48 to 2.29, while mean risk class of malignancies rose from 3.66 to 3.92. Awareness of CAD predictions also determined a significant drop on mean indeterminate SPNs (15 vs 23.86 SPNs) and raised the mean number of correct and confident diagnoses (mean 39.57 vs 25.71 SPNs). This study provides evidence supporting the integration of the Bayesian analysis-based BIMC model in SPN characterization.

Distribution of Solid Solitary Pulmonary Nodules within the Lungs on Computed Tomography: A Review of 208 Consecutive Lesions of Biopsy-Proven Nature.

BACKGROUND: The solitary pulmonary nodule (SPN) is a common radiologic abnormality on chest x-rays or computed tomography (CT) scans of the lungs. The differential diagnosis of SPNs is particularly wide as it includes a multitude of benign as well as malignant entities. Nodule location within the lungs has been proposed as a predictive feature in the literature. This study aims at illustrating the distribution within the lungs of a large current series of consecutive SPNs according to their histological subtype, which was definitely proved at core biopsy. MATERIAL/METHODS: Two hundred-eight SPNs referred to our center for characterization were reviewed in this single-centre retrospective study. Histological subtypes were defined following the IASLC/ATS/ERS and WHO (2004) histological classification. RESULTS: This study provides evidence with respect to the prevalence of adenocarcinomas and other non-neuroendocrine primary lung cancer types in the right upper lobe. It also provides new evidence with respect to the prevalence of carcinoid tumors in the middle and right lower lobe, with a tendency to occur in the central lung parenchyma. CONCLUSIONS: This work updates existing knowledge of solid SPNs location within the lungs by providing a current picture of SPN distribution according to their nature.

CT Imaging Features in the Characterization of Non-Growing Solid Pulmonary Nodules in Non-Smokers.

BACKGROUND: A disappearing or persistent solid pulmonary nodule is a neglected clinical entity that still poses serious interpretative issues to date. Traditional knowledge deriving from previous reports suggests particular features, such as smooth edges or regular shape, to be significantly associated with benignity. A large number of benign nodules are reported among smokers in lung cancer screening programmes. The aim of this single-center retrospective study was to correlate specific imaging features to verify if traditional knowledge as well as more recent acquisitions regarding benign SPNs can be considered reliable in a current case series of nodules collected in a non-smoker cohort of patients. MATERIAL/METHODS: Fifty-three solid SPNs proven as non-growing during follow-up imaging were analyzed with regard to their imaging features at thin-section CT, their predicted malignancy risk according to three major risk assessment models, minimum density analysis and contrast enhanced-CT in the relative subgroups of nodules which underwent such tests. RESULTS: Eleven nodules disappeared during follow-up, 29 showed volume loss and 16 had a VDT of 1121 days or higher. There were 48 nodules located peripherally (85.71%). Evaluation of the enhancement after contrast media (n=29) showed mean enhancement ±SD of 25.72±35.03 HU, median of 18 HU, ranging from 0 to 190 HU. Minimum density assessment (n=30) showed mean minimum HU ±SD of -28.27±47.86 HU, median of -25 HU, ranging from -144 to 68 HU. Mean malignancy risk ±SD was 15.05±26.69% for the BIMC model, 17.22±19.00% for the Mayo Clinic model and 19.07±33.16% for the Gurney's model. CONCLUSIONS: Our analysis suggests caution in using traditional knowledge when dealing with current small solid peripheral indeterminate SPNs and highlights how quantitative growth at follow-up should be the cornerstone of characterization.

Thoracic Aortic Pseudoaneurysm after Esophageal Perforation and Mediastinitis Caused by Accidental Ingestion of a Mutton Bone: A Case Report on Staged Endoscopic and Endovascular Treatments.

BACKGROUND: Esophageal perforation involving the thoracic aorta is a rare but potentially life-threatening event. Esophageal wall dehiscence, aortoesophageal fistula, mycotic aneurysms, or mediastinitis may complicate this challenging condition, and a multidisciplinary approach is mandatory. Aggressive endoscopic and medical therapy followed by thoracic endovascular aneurysm repair (TEVAR) may be a valuable approach to reduce the mortality rate of this catastrophic event. CASE REPORT: A 79-year-old man presented at the emergency department with a 2-day history of worsening dysphagia and fever, suddenly appeared after consuming mutton meat. Esophagogastroduodenoscopy and computed tomography (CT) scan at admission showed a bone fragment penetrating the esophagus very close to the thoracic aorta, associated with signs of mild mediastinitis. After endoscopic removal of the bone, an esophageal fistula occurred. A conservative approach by means of endoscopic clipping of the esophageal perforation, nasojejunal tube for enteral nutrition and broad spectrum antibiotic therapy was preferred at this stage. Control chest X-ray with oral water-soluble contrast (Gastrografin) and repeat CT at 10- and 20-day follow-up showed a complete resolution of the esophageal fistula and mediastinitis. On the other hand, an increase of the aortic pseudoaneurysm was noted. This was treated by means of TEVAR. Subsequent clinical evolution was uneventful, and the patient was discharged in optimal clinical conditions with a 4-week course of home antibiotic therapy. The 6-month follow-up was uneventful. CONCLUSIONS: Foreign body esophageal perforation causing mediastinitis and aortic pseudoaneurysm is a very rare and challenging situation that requires a strict follow-up and an intensive multidisciplinary approach. A staged approach, first by endoscopy followed by endovascular treatment, may be safe and effective in selected patients.

Solid pulmonary nodule risk assessment and decision analysis: comparison of four prediction models in 285 cases.

OBJECTIVES: The aim of this study was to compare classification results from four major risk prediction models in a wide population of incidentally detected solitary pulmonary nodules (SPNs) which were selected to crossmatch inclusion criteria for the selected models. METHODS: A total of 285 solitary pulmonary nodules with a definitive diagnosis were evaluated by means of four major risk assessment models developed from non-screening populations, namely the Mayo, Gurney, PKUPH and BIMC models. Accuracy was evaluated by receiver operating characteristic (ROC) area under the curve (AUC) analysis. Each model's fitness to provide reliable help in decision analysis was primarily assessed by adopting a surgical threshold of 65 % and an observation threshold of 5 % as suggested by ACCP guidelines. RESULTS: ROC AUC values, false positives, false negatives and indeterminate nodules were respectively 0.775, 3, 8, 227 (Mayo); 0.794, 41, 6, 125 (Gurney); 0.889, 42, 0, 144 (PKUPH); 0.898, 16, 0, 118 (BIMC). CONCLUSIONS: Resultant data suggests that the BIMC model may be of greater help than Mayo, Gurney and PKUPH models in preoperative SPN characterization when using ACCP risk thresholds because of overall better accuracy and smaller numbers of indeterminate nodules and false positive results. KEY POINTS: • The BIMC and PKUPH models offer better characterization than older prediction models • Both the PKUPH and BIMC models completely avoided false negative results • The Mayo model suffers from a large number of indeterminate results.

Treatment of popliteal artery aneurysms by means of cryopreserved homograft.

BACKGROUND: Autologous saphenous vein is considered the gold standard conduit in the femoral-popliteal revascularization for popliteal artery aneurysms (PAAs). In several cases, it may be absent or unsuitable for length or diameter and so it may be considered unfit for a conduit. In such patients, a synthetic graft or the endovascular correction can be useful, but results are controversial. In this retrospective case series, we have analyzed the safety and efficacy of the cryopreserved homograft (CHg) as a conduit in the PAA revascularization. METHODS: In the period between January 2005 and December 2013, 54 PAAs have been treated with an arterial CHg. Indications to surgery were asymptomatic aneurysm with >25-mm diameter in 30 cases (55.6%), ischemic symptoms in 20 (37%), and compressive symptoms in 4 (7.4%). An urgent treatment was performed in 8 cases (14.8%) for severe ischemic symptoms. All cases have been operated by the same vascular team: a posterior surgical approach was preferred whenever possible (33 cases, 61.1%). All patients received a clinical and radiologic follow-up, and all data were collected in a specific database. A >10-mm diameter increase of the conduit was considered significant for an aneurysmatic degeneration. RESULTS: The primary outcomes were complications and reoperation rate, limb salvage, and primary and secondary patency. Secondary outcome was the incidence of aneurysmatic degeneration of the CHg. Mean diameter of the homografts was 6.3 mm (range, 4-8 mm). In the 30-day postoperative period, 7 PAAs (13%) developed a complication: 3 wound infections, 3 graft thrombosis, and 1 anastomotic bleeding. Six cases needed a reoperation: 2 surgical revascularizations, 2 wound debridement, and 1 anastomotic hemostasis; 1 major amputation was necessary for graft failure after the revascularization. Mean follow-up was 34.8 months (range, 1-96). Five cases (9.3%) developed a graft complication with 4 reoperations necessary (7.4%): 2 grafts required a percutaneous transluminal angioplasty for a perigraft stenosis and 2 underwent a femorodistal bypass in CHg for severe ischemic symptoms after CHg occlusion. Another one CHg occlusion was treated conservatively because it was clinically asymptomatic. Primary patency was 96.3%, 93.9%, and 88.3% at 12, 36, and 60 months, respectively; secondary patency was 98.1% at 12, 36, and 60 months. Freedom from amputation resulted in 98.1%. No aneurysmatic degeneration was observed. Univariate and multivariate analysis showed urgent surgery to be independent risk factors for complications, reoperations, and CHg occlusion (P < 0.05). CONCLUSIONS: In this retrospective study, the use of CHg showed to be safe and effective in the surgery of PAAs, either in the short or in the long-term follow-up. Urgent surgery can be considered predictive of graft failure. In our experience, CHg can be considered a good alternative conduit to the autologous saphenous vein.

Assessing probability of malignancy in solid solitary pulmonary nodules with a new Bayesian calculator: improving diagnostic accuracy by means of expanded and updated features.

OBJECTIVES: A crucial point in the work-up of a solitary pulmonary nodule (SPN) is to accurately characterise the lesion on the basis of imaging and clinical data available. We introduce a new Bayesian calculator as a tool to assess and grade SPN risk of malignancy. METHODS: A set of 343 consecutive biopsy or interval proven SPNs was used to develop a calculator to predict SPN probability of malignancy. The model was validated on the study population in a "round-robin" fashion and compared with results obtained from current models described in literature. RESULTS: In our case series, receiver operating characteristic (ROC) analysis showed an area under the curve (AUC) of 0.893 for the proposed model and 0.795 for its best competitor, which was the Gurney calculator. Using observational thresholds of 5% and 10% our model returned fewer false-negative results, while showing constant superiority in avoiding false-positive results for each surgical threshold tested. The main downside of the proposed calculator was a slightly higher proportion of indeterminate SPNs. CONCLUSIONS: We believe the proposed model to be an important update of current Bayesian analysis of SPNs, and to allow for better discrimination between malignancies and benign entities on the basis of clinical and imaging data. KEY POINTS: • Bayesian analysis can help characterise solitary pulmonary nodules • Volume doubling time (VDT) is a good predictor of malignancy • A VDT of between 25 and 400 days is highly suggestive of malignancy • Nodule size, enhancement, morphology and VDT are the best predictors of malignancy.

Perioperative and long-term results of laparoscopic spleen-preserving distal pancreatectomy with or without splenic vessels conservation: a retrospective analysis.

BACKGROUND AND OBJECTIVES: Laparoscopic spleen-preserving distal pancreatectomy can be performed with or without splenic vessels conservation. The formation of perigastric varices is the main long-term complication and represents the area of major concern among surgeons. Aim of this paper was to evaluate the outcomes of patients who underwent spleen-preserving distal pancreatectomy (with or without splenic vessels conservation) at our institution. METHODS: Retrospective search of an electronic database from 1999 through 2007. Standard statistical methods were used. RESULTS: 43 individuals were analyzed. Postoperative morbidity was 56%. Patients managed by splenic vessels conservation were 36; in the remaining seven splenic vessels resection was performed. Pathologic details and the rate postoperative complications were not different between the two groups. Two splenectomies were necessary for postoperative splenic infarction (one in each group). 28 patients accepted the follow-up protocol. At 12 months, the rate of perigastric varices was 60.0% after splenic vessels resection and 21.7% after splenic vessels conservation (P = 0.123). No gastrointestinal bleeding occurred at a median follow-up of 69 months (37-139). CONCLUSION: Laparoscopic spleen-preserving distal pancreatectomy is feasible. A moderate risk of postoperative splenic infarction has to be taken into account, and the formation of perigastric varices may be interpreted as a paraphysiologic phenomenon, especially after splenic vessels resection.