Design of highly sensitive nano-biosensor for diagnosis of hydatid cyst based on gold nanoparticles.

Cystic echinococcosis, a zoonotic parasitic infection, is a major public health and economic concern, with worldwide distribution. The development of sensitive diagnostic methods for hydatid disease is important. We designed a highly sensitive nano-biosensor for the diagnosis of hydatid cyst based on gold nanoparticles (AuNPs). AuNPs were synthesized. Echinococcus granulosus antigen was coated on the ELISA microwells. Then, the E. granulosus IgG antibody was added to the microwells. After incubation and washing, the Ag-Ab complex was incubated with a human IgG HRP​-conjugated antibody. Then, the synthesized AuNPs and tetramethylbenzidine (TMB), as a chromogenic substrate of HRP, were added to the reaction. Finally, the absorption rate was measured by spectrophotometry. The results showed that the enzyme peroxide and TMB change the color of the reaction from red to yellow by oxidizing AuNPs. The sensitivity and specificity of the designed method were investigated. The linear equation and regeneration of nanobiosensor designed for red color Y = 0.0312X + 0.649, R2 9962 and for yellow color Y = 0.013X + 0.398, R2 9851 were determined. The limit of detection of the designed nanobiosensor was 0.001 µg mL-1. The results confirmed that the designed nanobiosensor was completely specific for the detection of E. granulosus antibody.

Randomized Clinical Trial of Epidural Compared with Conventional Analgesia after Minimally Invasive Colorectal Surgery.

BACKGROUND: The effectiveness of thoracic epidural analgesia (EA) vs conventional IV analgesia (IA) after minimally invasive surgery is still unproven. We designed a randomized controlled trial comparing EA with IA after minimally invasive colorectal surgery. STUDY DESIGN: A total of 87 patients who underwent minimally invasive colorectal procedures at a single institution between 2011 and 2014 were enrolled. Eight patients were excluded and 38 were randomized to EA and 41 to IA. Pain was assessed with the Visual Analogue Scale and quality of life with the Overall Benefit of Analgesia Score daily until discharge. RESULTS: Mean age was 57 ± 14 years, 43% of patients were female, and mean BMI was 28.6 ± 6 kg/m2. The 2 groups were similar in demographic characteristics and distribution of diagnoses and procedures. Epidural analgesia had a higher incidence of hypotensive systolic blood pressure (<90 mmHg) episodes (9 vs 2; p < 0.05) and a trend toward longer Foley catheter duration (3 ± 2 days vs 2 ± 4 days; p > 0.05). Epidural and IA had equivalent mean lengths of stay (4 ± 3 days vs 4 ± 3 days), daily Visual Analogue Scale scores (2.4 ± 2.0 vs 3.0 ± 2.0), and Overall Benefit of Analgesia Scores (3.2 ± 2.0 vs 3.2 ± 2.0), and similar time to start oral diet (2.8 ± 2 days vs 2.2 ± 1 days). Epidural analgesia patients used a higher total dose of narcotics (147.5 ± 192.0 mg vs 98.1 ± 112.0 mg; p > 0.05). Epidural and IV analgesia had equivalent total hospital charges ($144,991 ± $67,636 vs $141,339 ± $75,579; p > 0.05). CONCLUSIONS: This study indicates that EA has no added clinical benefit in patients undergoing minimally invasive colorectal surgery. A trend toward higher total narcotics use and complications with EA was demonstrated.

Retrorectal Tumors: A Comprehensive Literature Review.

IMPORTANCE: Retrorectal tumors are rare lesions that comprise a multitude of histologic types. Reports are limited to small single-institution case series, and recommendations on the ideal surgical approaches are lacking. OBJECTIVE: The purpose of the study was to provide a comprehensive review of the epidemiology, pathologic subtypes, surgical approaches, and clinical outcomes of retrorectal tumors. EVIDENCE REVIEW: We conducted a review of the literature using PubMed and searched the reference lists of published studies. RESULTS: A total of 341 studies comprising 1708 patients were included. Overall, 68 % of patients were female. The mean age was 44.6 ± 13.7 years. Of all patients, 1194 (70 %) had benign lesions, and 514 patients (30 %) had malignant tumors. Congenital tumors (60.5 %) were the most frequent histologic type. Other pathologic types were neurogenic tumors (14.8 %), osseous tumors (3.1 %), inflammatory tumors (2.6 %), and miscellaneous tumors (19.1 %). Biopsy was performed in 27 % of the patients. Of these patients, incorrect diagnoses occurred in 44 %. An anterior surgical approach (AA) was performed in 299 patients (35 %); a posterior approach (PA) was performed in 443 (52 %), and a combined approach (CA) was performed in 119 patients (14 %). The mean length of stay (LOS) of PA was 7 ± 5 days compared to 8 ± 7 days for AA and 11 ± 7 days for CA (p < 0.05). The overall morbidity rate was 13.2 %: 19.3 % associated with anterior approach, 7.2 % associated with posterior approach, and 24.7 % after a combined approach (p < 0.05). Overall postoperative recurrence rate was 21.6 %; 6.7 % after an anterior approach, 26.6 % after a posterior approach, and 28.6 % after a combined approach (p < 0.05). A minimally invasive approach (MIS) was employed in 83 patients. MIS provided shorter hospital stays than open surgery (4 ± 2 vs. 9 ± 7 days; p < 0.05). Differences in complication rate were 19.8 % in MIS and 12.2 % in open surgery and not statistically significant. CONCLUSIONS AND RELEVANCE: Retrorectal tumors are most commonly benign in etiology, of a congenital nature, and have a female predominance. Complete surgical resection is the cornerstone of retrorectal tumor management. A minimal access surgery approach, when feasible, appears to be a safe option for the management of retrorectal tumors, with shorter operative time and length of stay.

Adhesive Small Bowel Obstruction in the United States: Has Laparoscopy Made an Impact?

Adhesions account for 74 per cent of admissions for small bowel obstruction (SBO). There is a lack of data regarding the usage and outcomes of laparoscopy (LS) for SBO. A retrospective review of urgent admissions for SBO using the Nationwide Inpatient Sample 2001 to 2011 was conducted. Among the estimated 3,948,987 SBO admissions, 36.7 per cent underwent operative management and LS was performed in 26.5 per cent with a 22.5 per cent conversion rate. Admissions increased by 3.1 per cent annually, whereas nonoperative management increased by 3.8 per cent annually. Operative management increased by 1.8 per cent annually, whereas LS increased by 8.9 per cent annually and open surgery decreased by 0.6 per cent annually. LS small bowel resection increased by a mean of 25 per cent annually. LS was associated with a 24.4 per cent in-hospital morbidity with intra-abdominal abscess/enteric fistulas (8.3%) and ileus (8.9%) as the most common complications. In-hospital mortality was 0.9 per cent with length of stay of 13 ± 9 days and a hospital charge of $80,080 ± 6,634. The majority of patients were operated on hospital day (HD) 1 (43.0%). Patients who underwent LS on HD >7 had a higher risk-adjusted mortality compared with earlier HD (odds ratio = 2.63; 95% confidence interval: 2.40-2.89; P < 0.01). There has been an increase in admissions for SBO and an increase in LS over the past 11 years. There seems to be an increase in mortality and morbidity with a later HD operation.

Laparoscopic Versus Open Loop Ileostomy Reversal: Is there an Advantage to a Minimally Invasive Approach?

BACKGROUND: Ileostomy reversals are commonly performed procedures after colon and rectal operations. Laparoscopic ileostomy reversal (LIR) with lysis of adhesions has potential benefits over conventional open surgery. The aim of this study was to compare outcomes of laparoscopic and open ileostomy reversal. METHODS: 133 consecutive patients undergoing ileostomy reversal at our institution between June 2009 and August 2013 were analyzed using a retrospective database. The group comprised 53 laparoscopic cases and 80 open cases, performed by four surgeons at a single center. The data were analyzed for patient demographics, operative characteristics, postoperative outcomes, and 30-day morbidity and mortality. RESULTS: The two groups had comparable mean age, gender distribution, ASA scores, and BMI. The laparoscopic group had a significantly longer duration of surgery compared to the open reversal group (109 versus 93 min, p < 0.05). However, this group underwent more lysis of adhesions (60.4 % versus 26.3 %, p < 0.01) as well as concurrent stoma site mesh reinforcement (32.1 % versus 6.3 %, p < 0.01). In the laparoscopy group, 20.7 % of patients underwent intra-corporeal ileo-ileal anastomosis. There were no significant differences between the laparoscopic and open groups with regard to estimated blood loss (31 versus 40 ml, respectively) or mean length of stay (5.3 vs. 5.7 days, respectively). The rates of overall 30-day morbidity (16.9 % for laparoscopic vs. 21.3 % for open) as well as rates of specific complications were equivalent between groups. 30-day mortalities were not noted in either group. CONCLUSION: LIR is safe and effective with low perioperative morbidity and mortality. The use of laparoscopy as an option in terms of concomitant hernia repair and lysis of adhesions may be considered in selected patients.

Colorectal Cancer Resections in the Aging US Population: A Trend Toward Decreasing Rates and Improved Outcomes.

IMPORTANCE: The incidence of colorectal cancer in elderly patients is likely to increase, but there is a lack of large nationwide data regarding the mortality and morbidity of colorectal cancer resections in the aging population. OBJECTIVE: To examine the surgical trends and outcomes of colorectal cancer treatment in the elderly. DESIGN, SETTING, AND PARTICIPANTS: A review of operative outcomes for colorectal cancer in the United States was conducted in a Nationwide Inpatient Sample from January 1, 2001, through December 31, 2010. Patients were stratified within age groups of 45 to 64, 65 to 69, 70 to 74, 75 to 79, 80 to 84, and 85 years and older. Postoperative complications and yearly trends were analyzed. A multivariate logistic regression was used to compare in-hospital mortality and morbidity between individual groups of patients 65 years and older and those aged 45 to 64 years while controlling for sex, comorbidities, procedure type, diagnosis, and hospital status. MAIN OUTCOMES AND MEASURES: In-hospital mortality and morbidity. RESULTS: Among the estimated 1,043,108 patients with colorectal cancer sampled, 63.8% of the operations were performed on those 65 years and older and 22.6% on patients 80 years and older. Patients 80 years and older were 1.7 times more likely to undergo urgent admission than those younger than 65 years. Patients younger than 65 years accounted for 46.0% of the laparoscopies performed in the elective setting compared with 14.1% for patients 80 years and older. Mortality during the 10 years decreased by a mean of 6.6%, with the most considerable decrease observed in the population 85 years and older (9.1%). Patients 80 years and older had an associated $9492 higher hospital charge and an increased 2½-day length of stay vs patients younger than 65 years. Compared with patients aged 45 to 64 years, higher risk-adjusted in-hospital mortality was observed in patients with advancing age: 65 to 69 years (odds ratio, 1.32; 95% CI, 1.18-1.49), 70 to 74 years (2.02; 1.82-2.24), 75 to 79 years (2.51; 2.28-2.76), 80 to 84 years (3.15; 2.86-3.46), and 85 years and older (4.72; 4.30-5.18) (P < .01). Compared with patients aged 45 to 64 years, higher risk-adjusted morbidity was noted in those with advancing age: 65 to 69 years (odds ratio, 1.25; 95% CI, 1.21-1.29), 70 to 74 years (1.40; 1.36-1.45), 75 to 79 years (1.54; 1.49-1.58), 80 to 84 years (1.68; 1.63-1.74), and 85 years and older (1.96; 1.89-2.03) (P < .01). CONCLUSIONS AND RELEVANCE: Most operations for colorectal cancer are performed on the aging population, with an overall decrease in the number of cases performed. Despite the overall improved mortality seen during the past 10 years, the risk-adjusted mortality and morbidity of the elderly continue to be substantially higher than that for the younger population.

Morbidity of diverting ileostomy for rectal cancer: analysis of the American College of Surgeons National Surgical Quality Improvement Program.

There is controversy regarding the potential benefits of diverting ileostomy after low anterior resection (LAR). This study aims to examine the morbidity associated with diverting ileostomy in rectal cancer. A retrospective review of LAR cases was performed using the American College of Surgeons National Surgical Quality Improvement Program (2005 to 2011). Patients who underwent LAR with and without diversion were selected. Demographics, intraoperative events, and postoperative complications were reviewed. Among the 6337 cases sampled, 991 (16%) received a diverting ileostomy. Patients who were diverted were younger (60 vs 63 years), predominantly male (64 vs 53%), and more likely to have received pre-operative radiation (39 vs 12%). There was no significant difference in steroid use, weight loss, or intraoperative transfusion. Postoperatively, there was no significant difference in length of stay, rate of septic complications, wound infections, and mortality. The rate of reoperation was lower in the diverted group (4.5 vs 6.9%). Diversion was associated with a higher risk-adjusted rate of acute renal failure (OR 2.4; 95% CI (1.2, 4.6); P < 0.05). The use of diverting ileostomy reduces the rate of reoperation but is associated with an increased risk of acute renal insufficiency. These findings emphasize the need for refinement of patient selection and close follow-up to limit morbidity.

Volume and outcome relationship in bariatric surgery in the laparoscopic era.

BACKGROUND: The relationship between volume and outcomes in bariatric surgery is well established in the literature. However, the analyses were performed primarily in the open surgery era and in the absence of national accreditation. The recent Metabolic Bariatric Surgery Accreditation and Quality Improvement Program proposed an annual threshold volume of 50 stapling cases. This study aimed to examine the effect of volume and accreditation on surgical outcomes for bariatric surgery in this laparoscopic era. METHODS: The Nationwide Inpatient Sample was used for analysis of the outcomes experienced by morbidly obese patients who underwent an elective laparoscopic stapling bariatric surgical procedure between 2006 and 2010. In this analysis, low-volume centers (LVC < 50 stapling cases/year) were compared with high-volume centers (HVC ≥ 50 stapling cases/year). Multivariate analysis was performed to examine risk-adjusted serious morbidity and in-hospital mortality between the LVCs and HVCs. Additionally, within the HVC group, risk-adjusted outcomes of accredited versus nonaccredited centers were examined. RESULTS: Between 2006 and 2010, 277,760 laparoscopic stapling bariatric procedures were performed, with 85% of the cases managed at HVCs. The mean number of laparoscopic stapling cases managed per year was 17 ± 14 at LVCs and 144 ± 117 at HVCs. The in-hospital mortality was higher at LVCs (0.17%) than at HVCs (0.07%). Multivariate analysis showed that laparoscopic stapling procedures performed at LVCs had higher rates of mortality than those performed at HVCs [odds ratio (OR) 2.5; 95% confidence interval (CI) 1.3-4.8; p < 0.01] as well as higher rates of serious morbidity (OR 1.2; 95% CI 1.1-1.4; p < 0.01). The in-hospital mortality rate at nonaccredited HVCs was 0.22% compared with 0.06% at accredited HVCs. Multivariate analysis showed that nonaccredited centers had higher rates of mortality than accredited centers (OR 3.6; 95% CI 1.5-8.3; p < 0.01) but lower rates of serious morbidity (OR 0.8; 95% CI 0.7-0.9; p < 0.01). CONCLUSION: In this era of laparoscopy, hospitals managing more than 50 laparoscopic stapling cases per year have improved outcomes. However, nonaccredited HVCs have outcomes similar to those of LVCs. Therefore, the impact of accreditation on outcomes may be greater than that of volume.

Early intervention to promote medical student interest in surgery and the surgical subspecialties.

OBJECTIVE: Concerns about projected workforce shortages are growing, and attrition rates among surgical residents remain high. Early exposure of medical students to the surgical profession may promote interest in surgery and allow students more time to make informed career decisions. The objective of this study was to evaluate the impact of a simple, easily reproducible intervention aimed at increasing first- and second-year medical student interest in surgery. DESIGN: Surgery Saturday (SS) is a student-organized half-day intervention of four faculty-led workshops that introduce suturing, knot tying, open instrument identification, operating room etiquette, and basic laparoscopic skills. Medical students who attended SS were administered pre-/post-surveys that gauged change in surgical interest levels and provided a self-assessment (1-5 Likert-type items) of knowledge and skills acquisition. PARTICIPANTS: First- and second-year medical students. OUTCOME MEASURES: Change in interest in the surgical field as well as perceived knowledge and skills acquisition. RESULTS: Thirty-three first- and second-year medical students attended SS and completed pre-/post-surveys. Before SS, 14 (42%) students planned to pursue a surgical residency, 4 (12%) did not plan to pursue a surgical residency, and 15 (46%) were undecided. At the conclusion, 29 (88%) students indicated an increased interested in surgery, including 87% (13/15) who were initially undecided. Additionally, attendees reported a significantly (p < 0.05) higher comfort level in the following: suturing, knot tying, open instrument identification, operating room etiquette, and laparoscopic instrument identification and manipulation. CONCLUSIONS: SS is a low resource, high impact half-day intervention that can significantly promote early medical student interest in surgery. As it is easily replicable, adoption by other medical schools is encouraged.

Risk factors for venous thromboembolism in critically ill trauma patients who cannot receive chemical prophylaxis.

BACKGROUND: Standard venous thromboembolism (VTE) prevention for critically ill trauma patients includes sequential compression devices and chemical prophylaxis. When contraindications to anticoagulation are present, prophylactic inferior vena cava filters (IVCF) may be used to prevent pulmonary emboli (PE) in high-risk patients, but specific indications are lacking. We sought to identify independent predictors of VTE in critically-ill trauma patients who cannot receive chemical prophylaxis in order to identify a subset of patients who may benefit from aggressive screening and/or prophylactic IVCF placement. METHODS: All trauma patients in the surgical ICU from 2008 to 2009 were prospectively followed. Patients with an ICU length of stay ≥2 days who had contraindications to prophylactic anticoagulation were included. Screening duplex exams were obtained within 48 h of admission and then weekly. CT-angiography for PE was obtained if clinically indicated. Patients were excluded if they did not receive a duplex or if they had a post-injury VTE prior to ICU admission. Data regarding VTE rates (lower extremity [LE] DVT or PE), demographics, past medical history (PMH), injuries, and surgeries were collected. Univariate and multivariable analyses were performed to identify independent predictors of VTE with a p<0.05. RESULTS: 411 trauma patients with a mean age of 48 (SD 22) years and 8 (SD 9) ICU days were included. 72% were male and the mean ISS was 22 (SD 13). 30 (7.3%) patients developed VTE: 28 (6.8%) with LEDVT and 2 (0.5%) with PE. Risk factors for VTE with a p<0.2 on univariate analysis included: PMH of DVT, injury severity score (ISS), extremity fractures (Fx), and a pelvis or LE extremity Fx repair. After logistic regression, only PMH of DVT (OR=22.6) and any extremity Fx (OR=2.4) remained as independent predictors. CONCLUSION: VTE occur in 7% of critically injured trauma patients who cannot receive chemical prophylaxis. Aggressive screening and/or prophylactic IVCF placement may be considered in patients with a PMH of DVT or extremity fractures when anticoagulation is prohibited.

Corneal endothelial cell loss during phacoemulsification: bevel-up versus bevel-down phaco tip.

PURPOSE: To compare corneal endothelial cell loss during cataract extraction by phacoemulsification with 2 different phaco-tip positions. SETTING: Ophthalmic Research Center and Department of Ophthalmology, Labbafinejad Medical Center, Shahid Beheshti Medical University, Tehran, Iran. DESIGN: Randomized clinical trial. METHODS: Eyes scheduled for cataract extraction were randomly assigned stop-and-chop phacoemulsification with the phaco tip in the conventional bevel-up position or with the phaco tip in the bevel-down position. During surgery, the effective phacoemulsification time (EPT) was recorded. Preoperative endothelial cell parameters were compared with measurements taken 3 months postoperatively. RESULTS: Each group comprised 30 eyes (30 patients). There were no statistically significant differences in age, sex, anterior chamber depth, axial length, or EPT between the 2 groups. The mean preoperative endothelial cell density (ECD) was 2544 cells/mm(2) ± 64 (SD) in the bevel-up group and 2471 ± 59 cells/mm(2) in the bevel-down group (P=.610). Postoperatively, both groups had a significant decrease in ECD. The mean endothelial cell loss was 5.9% in the bevel-up group and 13.6% in the bevel-down group (P=.012). The percentage of hexagonal cells and coefficient of variation in cell size were not different between the 2 groups preoperatively or postoperatively; however, after surgery, there was a significant decrease in the percentage of hexagonal cells in both groups. CONCLUSION: Corneal endothelial cell loss during phacoemulsification was significantly higher when the phaco tip was in the bevel-down position than in the conventional bevel-up position. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.