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We present a full Bayesian analysis of multiplicative double seasonal autoregressive (DSAR) models in a unified way, considering identification (best subset selection), estimation, and prediction problems. We assume that the DSAR model errors are normally distributed and introduce latent variables for the model lags, and then we embed the DSAR model in a hierarchical Bayes normal mixture structure. By employing the Bernoulli prior for each latent variable and the mixture normal and inverse gamma priors for the DSAR model coefficients and variance, respectively, we derive the full conditional posterior and predictive distributions in closed form. Using these derived conditional posterior and predictive distributions, we present the full Bayesian analysis of DSAR models by proposing the Gibbs sampling algorithm to approximate the posterior and predictive distributions and provide multi-step-ahead predictions. We evaluate the efficiency of the proposed full Bayesian analysis of DSAR models using an extensive simulation study, and we then apply our work to several real-world hourly electricity load time series datasets in 16 European countries.

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BACKGROUND: In differentiated thyroid cancer (DTC) patients, cervical nodal metastasis is a negative prognostic factor. Preoperative imaging plays an important role in treatment planning for nodal metastasis and recurrence. The aim of the study is to compare the diagnostic performance of the diffusion-weighted magnetic resonance imaging (DW-MRI) and the F-18 flurodeoxyglucose positron emission computed tomography ([18F]FDG PET/CT) in detection of cervical nodal deposits in DTC patients. MATERAL AND METHODS: The study was conducted on 30 patients, each performed both modalities just before the surgery. The gold standard was the pathological specimens with post-operative clinico-radiological follow-up, to assess the diagnostic performance of each modality. RESULTS: Based on pathological and post-operative clinico-radiological follow up data. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) and accuracy were 84%, 80%, 50%, 95% and 83% for PET/CT compared to 84%, 60%, 42.8%, 91.3% and 80% for DW-MRI. On comparing the diagnostic performance of combined DW-MRI and PET/CT to each modality alone, the sensitivity and NPV were improved to 96% and 80% respectively. CONCLUSIONS: [18F]FDG PET/CT study is a valuable diagnostic modality for the assessment of cervical nodal deposits in DTC patients, surpassing DW-MRI. Combined PET/CT and DW-MRI techniques seemed to have synergistic performance, mainly in terms of sensitivity and NPV, for detection of nodal metastases.

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BACKGROUND: Submental artery island flap (SIF) is a viable alternative to free flaps for selected oral-cavity defects, however, concerns about its oncologic safety still exists. A novel harvesting technique and its outcome is described in here. METHODS: This is a prospective study for patients with lateralized oral tongue and/or floor of mouth (FOM) cancers who undergone reconstruction using pedicled SIF based on contralateral submental vessels (CSIF) following resection. RESULTS: Forty-one patients were included. Twenty-four patients had T2, 13 had T3, and 4 had T1 tumors. The largest flap skin paddle was 15 × 9 cm. One patient sustained complete and five sustained partial flap loss. Three patients developed tongue tethering. Median follow-up was 13.6 months. Locoregional recurrence occurred in 11 patients (26.8%); 6 oral-cavity recurrences (14.6%), 6 ipsilateral, and 1 contralateral neck recurrences (2.4%). CONCLUSION: CSIF is a reliable flap that addresses the oncologic controversy and overcomes the disadvantages of ipsilateral flap.

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BACKGROUND AND AIM: Thoracodorsal artery perforator flap (TDAP) is one of the relatively new techniques in breast reconstruction. In this study, we try to evaluate the outcome of this flap in oncoplastic procedures. METHODS: This study included 40 patients of stage II breast cancer who underwent partial mastectomy with skin excision at the National Cancer Institute of Cairo University between 2011 and 2014. The resultant defects were immediately reconstructed using the thoracodorsal artery perforator flap. Operative time and complication rates were recorded. The cosmetic outcome was assessed through a questionnaire. RESULTS: The mean operative time was 227min. The total complication rate was 20% with flap congestion being the most common complication. The cosmetic outcome was acceptable with 80% of patients rating their outcome as either good or excellent. The subjectively assessed functional outcome showed a mean time of 10days postoperative for patients to regain their full range of shoulder movements. CONCLUSION: Thoracodorsal artery perforator flap can play a significant role in oncoplastic surgery and breast reconstruction with acceptable cosmetic and functional outcome.

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BACKGROUND AND PURPOSE: The submental flap is gaining popularity as a simple technique for reconstruction of small to moderate size defects of the oral cavity. However, its role in composite defects involving the jaw is not clearly defined. Indeed, controversy exists about the flap's interference with an oncologically sound neck dissection PATIENTS AND METHODS: A total of 21 patients with oral cavity cancers over a three year period were included. All patients underwent surgical resection and immediate reconstruction with submental flap except one patient who had delayed reconstruction with reversed flap. The flap was used for reconstruction of intra-oral soft tissue defect in 13 patients and composite defects in 8 patients. RESULTS: Of 21 patients 12 were males and 9 were females, age ranged from 32 to 83 years. The primary tumor sites included buccal mucosa (7), tongue (4), alveolar margin (3), floor of mouth (5) and lip (2). Eventually in this study, we adopted completing the neck dissection first before flap harvest. Complete flap loss occurred in 2 whereas 3 patients had partial flap loss. Follow up ranged from 3 to 44 months, one patient died from metastatic disease. Four patients developed neck recurrences. CONCLUSION: The submental flap is a valid option for reconstruction of intra-oral soft tissue as well as composite oral defects particularly in elderly patients. However, oncologically sound neck dissection should be assured.

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Hepatic artery (HA) reconstruction is a crucial step in living donor liver transplantation (LDLT). However, many important aspects specific to this challenging step are still inadequately documented. From August 2001 through March 2007, we performed a total of 133 cases of LDLT at Dar El-Fouad Hospital. The magnifying loupe was used for performing microanastomoses in the first 31 cases, and the operating microscope was used for 98 cases. There were 128 adult and five pediatric patients. One hundred twenty-five patients received right lobe grafts, and seven patients received left lobe grafts. One patient died intraoperatively and was excluded from analysis. Arterial complications occurred in four patients of the first group (4/30, 13%) in the form of early thrombosis. One patient underwent successful interventional thromboembolectomy, two patients underwent surgical reexploration with revision of anastomoses; these three patients survived. The fourth patient died from fulminant liver failure. Regarding the second group, all arterial anastomoses were patent after reconstruction. Signal problems occurred in the form of intraoperative intermittent flow and postoperative no diastole phenomenon. Our overall arterial complication rate was 4.5%; however, we lost only one patient due to HA thrombosis (0.8%). Microsurgical reconstruction of the HA carries its own challenges. The use of operating microscope reduces the risk of complications, and aggressive interference including salvage surgery maximizes the success of HA reconstruction.

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BACKGROUND: Autologous breast reconstruction using the extended latissimus dorsi flap has been infrequently reported. In the current study, the authors are reporting their own clinical experience with this method. A review of the literature is also discussed. MATERIALS AND METHODS: Over a three year period, 14 patients underwent breast reconstruction using the extended latissimus dorsi (LD) flap. Patients with small to medium sized breasts were selected. The age of the patients ranged from 29 to 42 years with a follow-up period ranging from six to 18 months. The indications, flap-related complications and donor site morbidity and aesthetic results were evaluated. RESULTS: The main indication to use the flap was dorsal donor site preference by patients. The remaining patients were either not suitable for a flap from the abdomen or wished to get pregnant and were offered the dorsal donor site. Neither total nor partial flap loss was recorded but donor site morbidity was mainly due to seroma, which was treated conservatively in all patients, except for one who required surgery. Another two patients suffered from wound breakdown and distal necrosis of the back flaps. Mild contour deformity was also noted on the back of all patients but caused no major concern. Indeed, the overall patient satisfaction was very high. CONCLUSION: The extended LD flap proved to be a good option for autologous breast reconstruction in selected patients. Patients should be warned of the potential for seroma and mild contour back deformity.

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BACKGROUND: Reconstruction of head and neck defects can pose many challenges to the reconstructive head and neck surgeon. Achieving the best cosmetic and functional results without compromising the safety of oncologic surgery are the primary reconstructive goals. Speech and articulation are particularly important in oral reconstructive procedures. In addition, preservation of the integrity and function of the donor sites should always be considered in all reconstructive procedures. AIM OF THE STUDY: The aim of the study is to evaluate different reconstructive options in complex defects of the head and neck region after resection of malignant tumours. The feasibility of the reconstructive ladder starting from simple techniques such as local flaps and skin grafts up to free flaps will be assessed. PATIENTS AND METHODS: In this study we evaluated different reconstructive procedures used in 50 patients with complex head and neck defects undertaken at the department of surgery at the National Cancer Institute between July 2003 and December 2007. RESULTS: The average age of patients was 52 years and the range was 26-67 years. Most of the tumours were either squamous cell carcinoma (74 %) or Basal cell carcinoma (20 %). Tumour sites included the nose (6 %), lip (10 %), cheek (12 %) scalp (6 %) as well as mucosal defects of the oral cavity (40 %) and the hypopharynx (20 %). We used local flaps and skin grafts in reconstruction in 36 % of cases and pedicled flaps in 32% while free flaps were used in 32 % of cases. Complications occurred in 32 % of patients of which total flaps loss constituted 6 % and partial flap loss 4 %. Minor complications such as oro-cutaneous fistulae, wound infection, seroma and haematoma were noticed in 22 % and all of them were treated conservatively. The final functional and aesthetic results were satisfactory in 60% of cases while poor results were encountered in patients who suffered some degree of flap loss. KEY WORDS: Head and neck reconstruction - Pedicled flaps - Free flaps.

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BACKGROUND: It is well recognized that recurrent disease can occur following malignancy in the head and neck region. This is particularly true for basal cell & squamous cell carcinoma, whereby recurrence may occur many years following initial surgery or other modalities. We report here on skin malignancy occurring in the scalp with skull invasion down to the dura mater. Composite resection of scalp, craniectomy, dural resection and reconstruction including a free tissue transfer was analyzed. PURPOSE: To evaluate our experience in full thickness scalp resection and reconstruction. PATIENTS AND METHODS: At the National Cancer Institute, Cairo University, twelve patients with locally advanced tumors of the scalp invading the calvarium were treated with wide local excision of the scalp combined with underlying craniectomy and dural resection if needed. Reconstruction was completed using fascial graft for the dura, methyl methacrylate for the skull, and either giant rotational flap or free tissue transfer. RESULTS: Between 1998 and 2002, twelve patients with locally advanced tumors of the scalp were subjected to this surgery. All patients successfully tolerated the procedure and completely recovered with minimal morbidity with acceptable cosmetic results. CONCLUSION: With the advent of free tissue transfer to cover large defects in the skull and the availability of polymethyl methacrylate (bone cement) for cranioplasty, large defects in the calvarium can be successfully resected and grafted with satisfactory outcome, improved salvage rate, and prolonged survival.

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