Using meta-learning to recommend an appropriate time-series forecasting model.

BACKGROUND: There are various forecasting algorithms available for univariate time series, ranging from simple to sophisticated and computational. In practice, selecting the most appropriate algorithm can be difficult, because there are too many algorithms. Although expert knowledge is required to make an informed decision, sometimes it is not feasible due to the lack of such resources as time, money, and manpower. METHODS: In this study, we used coronavirus disease 2019 (COVID-19) data, including the absolute numbers of confirmed, death and recovered cases per day in 187 countries from February 20, 2020, to May 25, 2021. Two popular forecasting models, including Auto-Regressive Integrated Moving Average (ARIMA) and exponential smoothing state-space model with Trigonometric seasonality, Box-Cox transformation, ARMA errors, Trend, and Seasonal components (TBATS) were used to forecast the data. Moreover, the data were evaluated by the root mean squared error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and symmetric mean absolute percentage error (SMAPE) criteria to label time series. The various characteristics of each time series based on the univariate time series structure were extracted as meta-features. After that, three machine-learning classification algorithms, including support vector machine (SVM), decision tree (DT), random forest (RF), and artificial neural network (ANN) were used as meta-learners to recommend an appropriate forecasting model. RESULTS: The finding of the study showed that the DT model had a better performance in the classification of time series. The accuracy of DT in the training and testing phases was 87.50% and 82.50%, respectively. The sensitivity of the DT algorithm in the training phase was 86.58% and its specificity was 88.46%. Moreover, the sensitivity and specificity of the DT algorithm in the testing phase were 73.33% and 88%, respectively. CONCLUSION: In general, the meta-learning approach was able to predict the appropriate forecasting model (ARIMA and TBATS) based on some time series features. Considering some characteristics of the desired COVID-19 time series, the ARIMA or TBATS forecasting model might be recommended to forecast the death, confirmed, and recovered trend cases of COVID-19 by the DT model.

Laparoscopic splenectomy in patients with idiopathic thrombocytopenic purpura and very low platelet count.

Background: Chronic idiopathic thrombocytopenic purpura (ITP), is an autoimmune disease associated with a reduction in circulating blood platelets under 150±109g/L which persists longer than 6 months without any specific cause. With the current study, we aimed to evaluate the efficacy and safety of laparoscopic splenectomy in ITP patients with a very low platelet count and normal coagulation status. Methods: From April 2007 to January 2012, laparoscopic splenectomy was performed on 60 patients with chronic ITP who could not achieve a sustained recovery after steroid therapy. Results: Patients consisted of male/female ratio of 24 (40%):36 (60%) with the mean age of 53±15.1 years. All patients had normal coagulation state even with very low platelet count (below 5×103) before laparoscopic splenectomy. The mean operative time was 140.00±15.00 minutes. Blood transfusion was required in 10 (16.7%) and 8 (13.3%) patients before and after the operation, respectively. Preoperative transfusion of PRBC was not statistically significant between groups (P=0.265). Bleeding complications during within or after surgery was rare (5.0%). Convalescence was rapid and the mean hospital stay was 3.58±0.68 days (1-14 days) which shows that there was no significant difference in operative time and after operative hospitalization time among the three groups (P=0.070). The patients made a good uneventful recovery and were followed for at least one week who exhibited no postoperative problems. Conclusion: Laparoscopic splenectomy should be considered initially in the management of ITP. Also, very low platelet count should not be contraindicated for laparoscopic splenectomy in ITP patients and sometimes perioperative platelet transfusion may be unnecessary.

Transhiatal versus transthoracic esophagectomy for esophageal SCC: outcomes and complications.

BACKGROUND: Transhiatal esophagectomy (THE) and transthoracic esophagectomy (TTE) are both accepted procedures for esophageal cancer but still the most effective surgical approach continues to be controversial. This study aimed to determine post-operative complications and outcomes of TTE compared with THE. METHODS: A retrospective analysis was performed on data of 243 adult patients with resectable esophageal cancer who underwent THE or TTE between December 2016 and October 2018. Demographic data, consisting of preoperative co-morbidities, disease stage, and perioperative morbidity and mortality were collected. RESULTS: Among the patients, 99 individuals (40.7%) had a transhiatal resection and 144 (59.3%) had a transthoracic resection. Most patients (83.1%) were above 50 years old with no significant difference between groups (p = 0.297). The frequency distribution of comorbidities was similar in both groups. The most common site of the tumor in TTE group was middle esophagus and in THE group was lower esophagus. The most common complication was recurrence of dysphagia which was more common in THE group without significant difference. The other complications including pulmonary and cardiac events, tracheal and recurrent laryngeal nerve injury, chylothorax and anastomosis stricture did not differ between the groups. The operative mortality within 30 days after the operation was 2.8% with significant difference favored the THE group (THE 0%, TTE 5.2%, p = 0.033). CONCLUSION: Because of the controversies, the decision on the type of surgical technique in esophageal cancer treatment hinges on patient's co-morbidities, cancer stage, tumor location and surgeon's experience.

Consequences of Lost Gallstones During Laparoscopic Cholecystectomy: A Review Article.

BACKGROUND: Laparoscopic cholecystectomy (LC) has become a popular and widespread procedure for the treatment of gallstone disease. There is still an increasing concern about specific complications of LC due to gallbladder perforation and spillage of bile and stones. Although unretrieved intraperitoneal gallstones rarely become symptomatic, their infective complications may cause serious morbidities even after a long interval from LC. METHODS: We performed a review of the literature on the diagnosis, prevention, consequences, and management of lost gallstones. All studies with a focus on lost gallstones or perforated gallbladder were analyzed to evaluate the postoperative complications. RESULTS: Between 1991 and 2015, >250 cases of postoperative complications of spilled gallstones were reviewed in the surgical literature. The most common complications are intraperitoneal abscesses and fistulas. Confusing clinical pictures due to gallstones spreading in different locations makes diagnosis challenging. Even asymptomatic dropped gallstones may masquerade intraperitoneal neoplastic lesions. CONCLUSIONS: Every effort should be made to prevent gallbladder perforation; otherwise, they should be retrieved immediately during laparoscopy. In cases with multiple large spilled stones or infected bile, conversion to open surgery can be considered. Documentation in operative notes and awareness of patients about lost gallstones are mandatory to early recognition and treatment of any complications.

Difficulties in the diagnosis and management of alveolar hydatid disease: A case series.

BACKGROUND: Alveolar echinococcosis (AE) is a chronic, rare and sometimes lethal parasitic infection in humans, caused by the larval stage of the fox tapeworm Echinococcus multilocularis. This study aimed to investigate the clinical aspects and treatment outcomes of patients with alveolar hydatid disease. METHODS: The medical records of patients with alveolar echinococcosis admitted between 1997 and 2012 were reviewed. Diagnosis was confirmed by physical examination, ultrasonography and CT scanning and MRI. Various treatment techniques were used such as complete liver resection in seven (38.89%) patients, biliary bypass in two (11.11%) patients, laparotomy and tumor biopsy in eight (44.44%) patients and long term medical treatment in one (5.56%) patient. After discharge, all patients were followed to determine the effect of treatment, complications, recurrences and survival. RESULTS: A total of 18 patients with mean age of 46.11±15.14 years (range 23-74 years) were studied. The disease was more prevalent in women than men (78.9% vs 4, 21.1%, P=0.021). Fourteen (77.78%) patients live in Chenaran, a town located in Khorasan, Iran). Death occurred in (22.22%) patients after an average period of 45.70±7.50 months after disease onset. 14 remaining patients survived after a mean follow-up duration of 54.60±29.17 months. CONCLUSION: Diagnosis of alveolar echinococcosis should be considered in endemic area. Early diagnosis and treatment is associated with excellent outcome.

Evaluation and Comparison of the Early Outcomes of Open and Laparoscopic Surgery of Liver Hydatid Cyst.

BACKGROUND AND AIM: Surgery is the mainstay for treatment of liver hydatid cyst. Different surgical procedures have been suggested, but it is important to select the most appropriate treatment to obtain the best results with the lowest rate of recurrence and minimal morbidity and mortality. The aim of this study was to evaluate the early outcomes of open and laparoscopic surgery of hydatidosis. MATERIALS AND METHODS: In this study, 75 patients with uncomplicated liver hydatid cyst were assigned prospectively to either groups of laparoscopic surgery (37, 50.68%) or open procedure (36, 49.32%) during the period of 2007 to 2012. Conversion to open surgery was required in 2 patients (2.67%), who were excluded from the study. Patients were followed for about 17.86±17.64 months. RESULTS: Participants included 73 patients: 49 (67.12%) female and 24 (32.88%) male patients, with the mean age of 38.97±16.48 years. There was no statistically significant difference between the 2 groups with regard to the sex, the occupation, and the mean diameter of the cysts. Bilious staining of the cyst content was observed in 23 (35.94%) patients during surgery, and a maximum diameter of 91 mm was considered as a cut point for predicting postoperative fistula with 69.2% sensitivity and 41.1% specificity. The mean duration of operation, postoperative pain, the hospitalization time, and the time to return to work were significantly lower in the laparoscopic group. Postoperative biliary fistula, cyst cavity infection, and wound infection were not different between the 2 groups. CONCLUSIONS: Laparoscopic surgery seems to be effective and safe, with low morbidity rates for uncomplicated cysts in accessible segments of the liver.

The role of prophylactic cefazolin in the prevention of infection after various types of abdominal wall hernia repair with mesh.

OBJECTIVE: There are controversies about the benefits of prophylactic antibiotics in the prevention of postoperative surgical site infection (SSI) in mesh herniorrhaphy for a long time. This study aimed to evaluate the effectiveness and efficacy of systemic prophylactic cefazolin in prevention of wound infection in various types of hernia repair with mesh materials. METHODS: This is a prospective randomized control study. We evaluated wound infection rates in 395 patients with various kinds of hernia who underwent elective mesh repair using polypropylene mesh from 2007 to 2011. A total of 237 (60.0%) patients received prophylactic cefazolin (study group) and the remaining 158 (40.0%) patients did not receive any prophylactic antibiotics (control group). Patients were followed for infection at the following periods after the operation by an independent surgeon: 10 days, 30 days, 12 months, and then annually for at least 2 years. RESULTS: Eight (2.03%) patients had infection in the site of surgery [2 (1.27%) in the control group and 6 (2.53%) in the study group]. The distribution of infection was not significantly different between the two groups (p = 0.364). The superficial infections were managed by drainage and irrigation. One patient from the study group developed deep SSI and was readmitted and subsequently received antibiotic therapy, drainage, and debridement. CONCLUSION: Preoperative administration of single-dose cefazolin for prosthetic hernia repairs did not markedly decrease the risk of wound infection. Our results do not support the use of cefazolin as a prophylactic antibiotic for various kinds of abdominal wall hernia repair with mesh.

Concomitant splenic and hepatic hydatidosis: report of two cases and review of the literature.

Hydatid disease has a worldwide spreading. The most common site of the disease is the liver, lungs, kidney, bones, and brain. Splenic hydatid disease has been reported to constitute 2% to 6% of patients with abdominal hydatid disease. Because of the rarity of splenic hydatid disease, the probable concomitance of the liver and splenic hydatid cysts should be taken into consideration by clinicians, especially in nonendemic areas. In this report, we present two patients with concomitant splenic and liver hydatid cysts that underwent splenectomy and cystostomy-capitonage.

Study of treatment results and early complications of tube drainage versus capitonnage after the unroofing and aspiration of hydatid cysts.

OBJECTIVE: There is controversy concerning the management of the remaining cavity after the evacuation of a cyst in patients who have undergone surgical operation for liver hydatidosis. This study compares the results of capitonnage and tube drainage of the remaining cavity. METHODS: In this retrospective study, participants were selected from two groups of patients with a liver hydatid cyst who underwent capitonnage or tube drainage from 2004 to 2012. The patients were followed for 6-24 months. The data of age, sex, involved liver lobe, size of the cyst, complications, drain duration, and hospital stay were analyzed. RESULTS: Participants included 155 patients consisting of 96 (61.94%) females and 59 (38.06%) males. Most cysts were in the right lobe, and the most common diameter of the cysts was greater than 10 cm. Capitonnage was performed on 90 (58.06%) patients and the tube drainage procedure was performed on the remaining 65 (41.94%) patients. In the tube drainage group and the capitonnage group, the operative times were 2.21 ± 0.65 hours and 2.53 ± 0.35 hours, respectively; the hospital stays were 5.695 ± 3.37 days and 4.43 ± 2.96 days, respectively; the drain duration was 9.2 ± 1.7 days and 2.1 ± 0.4 days, respectively; and the time to return to work was 14.7 ± 2.3 days and 8.3 ± 10.4 days, respectively. All variables were statistically significant, except for the operative time. Cavity infection and biliary fistula were identified in three patients and six patients, respectively, in the tube drainage group and identified in two patients and three patients, respectively, in the capitonnage group. This difference was not statistically significant. CONCLUSION: This study demonstrated that capitonnage versus the tube drainage method may result in a shorter hospital stay, decreased time to return to work, and low rate of morbidity and complications.