Background: Sigmoid volvulus may recur following endoscopic decompression. Flatus tubes are traditionally used to prevent an early recurrence. This study aims to evaluate the recur rence -prev entiv ...e role of the flatus tubes in sigmoid volvulus. Methods: Sigmoid volvulus recurrence was retrospectively analyzed in prospectively collected clinical data of endoscopically decompressed 60 patients, in whom no tube, rectal tube, or sigmoidal tube was used. Results: Mean pain/discomfort scores were higher in rectal and sigmoidal tube groups than that of no tube group (1.2 + or - 0.4, 4.2 + or - 0.9, and 3.5 + or - 0.9, respectively, P < .001). The early recurrence was seen in 3 patients in the no tube group, while no early recurrence was determined during tube placement in the rectal and sigmoidal tube groups (15.0%, 0.0%, and 0.0%, respectively, P < .05, P < .05, and P > .05). The tubes were removed or spontaneously discharged in 13 (65.0%) and 12 patients (60.0%) in the rectal and sigmoidal tube groups, respectively, and sigmoid volvulus recurred in 2 patients in each group following the removal or spontaneous discharge. There was no statistically significant difference between the early recurrence rates of the no tube, rectal tube, and sigmoidal tube groups following the removal or spontaneous discharge of the tubes (15.0%, 15.4%, 16.7%, respectively, P > .05) and in total (15.0%, 10.0%, and 10.0%, respectively, P > .05). Conclusion: Flatus tubes may prevent the early volvulus recurrence during their placement in sigmoid volvulus. Nevertheless, they generally cause pain and discomfort, and they are frequently removed or spontaneously discharged, which suppresses their recur rencepreventive effects. Keywords: Endoscopic decompression, early recurrence, flatus tube, sigmoid volvulus
Introduction: Intestinal knotting syndromes are rare causes of mechanical bowel obstruction, ileo-sigmoid knotting being the most common type. Ileocecal knotting is the rarest type among knot ...syndromes and there are few case reports across the world. Case Presentation: We present a case of ileocecal knotting in a postpartum patient with abdominal distention, vomiting and failure to pass feces and flatus. Plain abdominal radiograph revealed dilated small bowel loops with multiple air fluid levels. Exploratory laparotomy was performed with intra-operative finding of ileocecal knotting with viable bowel, mobile cecum and ascending colon and gangrenous tip of appendix. We untied the knot and performed an appendectomy. Due to intra-operative instability of the patient's vital signs, right hemicolectomy was differed and cecum as well as ascending colon were fixed to right posterolateral abdominal wall. Clinical Discussion: Ileocecal knotting is a very rare finding, and few case reports have been published. The intra-operative findings of the mobile cecum and ascending colon are consistent with previous reports and it is a predisposing factor for knot besides low BMI and young age of our patient. Surgical management is dictated by intra-operative conditions such as viability of the bowel, intraoperative stability of the patient, extent of resection and length of the remaining bowel. Surgical options include en bloc resection of knot with gangrenous bowel and end to end anastomosis or end ileostomy with closure of distal end. Conclusion: Ileocecal knotting should be considered as a differential diagnosis for patients presenting with intestinal obstruction with unusual radiographic findings. Early diagnosis and prompt surgical intervention prevents bowel infarction and enhance the prognosis. Preoperative abdominal CT scan is helpful in such cases with unusual radiographic findings. Keywords: ileocecal knotting, bowel obstruction, knotting, acute abdomen, case report
Adiabatic quantum computation Albash, Tameem; Lidar, Daniel A.
Reviews of modern physics,
01/2018, Letnik:
90, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Adiabatic quantum computing (AQC) started as an approach to solving optimization problems and has evolved into an important universal alternative to the standard circuit model of quantum computing, ...with deep connections to both classical and quantum complexity theory and condensed matter physics. This review gives an account of the major theoretical developments in the field, while focusing on the closed-system setting. The review is organized around a series of topics that are essential to an understanding of the underlying principles of AQC, its algorithmic accomplishments and limitations, and its scope in the more general setting of computational complexity theory. Several variants are presented of the adiabatic theorem, the cornerstone of AQC, and examples are given of explicit AQC algorithms that exhibit a quantum speedup. An overview of several proofs of the universality of AQC and related Hamiltonian quantum complexity theory is given. Considerable space is devoted to stoquastic AQC, the setting of most AQC work to date, where obstructions to success and their possible resolutions are discussed.
Early recognition of bowel ischemia is critical in patients suffering from acute adhesive small bowel obstruction (ASBO). Recent studies attempted to propose a score combining clinical and ...radiological factors to predict the risk of bowel ischemia in patients with ASBO. This study aimed to compare and validate the existing clinical scores with a cohort of surgical patients.
We conducted a retrospective study including all ASBO cases admitted to our institution between January 1, 2005 and December 31, 2019. Based on three existing clinical scores, we calculated the risk of bowel ischemia for each patient. We then divided the cohort into groups based on the risk for bowel ischemia. For each risk-based category, the proportion of patients who underwent surgical resection and were found to have evidence of ischemic bowel was calculated.
A total of 160 patients presenting with 217 episodes of acute ASBO were included. One hundred seventy-one (78.8%) cases were managed nonoperatively while 46 cases (21.2%) required surgery. Sixteen patients (7.3%) were eventually found to have ischemic bowel while 13 required small bowel resection (5.9%). All three clinical scores showed correlation between the calculated risk of ischemia and the intraoperative finding of ischemia. However, all three scores overestimated ischemia rates in the high-risk groups, yielding a PPV of 8.3%-28.5% and a NPV of 93.3%-94.7%.
Current clinical scores for predicting bowel ischemia in patients with ASBO are of high value in ruling out ischemia, yet are of extremely low sensitivity, warranting an overly aggressive and unnecessary surgical approach.
Purpose
We aimed to evaluate the long-term complications and predisposing factors for these complications in patients with malignant ureteral obstruction (MUO) treated with percutaneous nephrostomy ...(PN).
Methods
The records of patients with MUO treated with PN between January 2015 and 2018 were retrospectively reviewed for PN dislodgement, PN obstruction, PN replacement, pyelonephritis, hospitalizations due to PN complications, and other complications due to PN such as macroscopic hematuria, skin infections, or renal/perirenal abscess.
Results
Data for a total of 147 patients (229 renal units RU, 107 males, 40 females) were evaluated. In 174 (76%) RU, PN was replaced due to PN dislodgement. The predisposing factors for PN dislodgement were follow-up time, body mass index (BMI), chemotherapy, diabetes mellitus (DM), low educational level (LEL), pyelonephritis, and catheter-related skin infections (CSRI). The PN was replaced in 40 RU due to obstruction. The predisposing factors for obstruction were follow-up time and BMI. Pyelonephritis developed at least once in 61 (41.5%) patients. Follow-up time, BMI, previous surgery, DM, and LEL were the predisposing factors for pyelonephritis. CSRI developed in 16 RU. Follow-up time, BMI, DM, and LEL were the predisposing factors for CSRI. Macroscopic hematuria developed in 11 patients. Follow-up time, previous surgery, DM, chemotherapy, and LEL were predisposing factors for macroscopic hematuria.
Conclusion
The most common complication in patients with MUO treated with PN was PN dislodgement. However, life-threatening complications such as macroscopic hematuria and severe infections can also occur. Patients with DM, LEL, and chemotherapy are at high risk of PN-related complications.
Purpose
The optimal management of malignant extrinsic ureteral obstruction (MUO) remains unclear. It is necessary to assess the patient prognosis in deciding the adaptation of drainage of renal ...pelvis. In this study, we investigated the clinical outcomes after ureteral stenting for MUO and the predictive factors for overall survival in order to create a risk-stratification model.
Methods
We retrospectively analyzed the clinical and laboratory data of 93 patients with radiologically significant hydronephrosis associated with MUO who underwent successful stent placement between May 2005 and May 2018.
Results
The median survival duration after the initial stent insertion was 266 days. Of the 93 patients, 70 died, and the median interval from the first stent insertion to death was 160 days. Multivariate analysis showed that gastric cancer as the primary disease, poor performance status before stenting, and treatment after stent insertion were significant predictors of survival. According to these three factors, we stratified patients into the following four prognostic groups: no-factor (43 patients), one-factor (23 patients), two-factor (23 patients), and three-factor (4 patients) groups. This classification was effective for predicting survival, and the median survival durations in these groups were 807, 269, 44, and 12 days, respectively (
p
< 0.001).
Conclusions
Our stratification model of patients with a poor prognosis after ureteral stent placement for MUO may allow urologists and clinicians to identify patients who will benefit from ureteral stenting.
Topological phases, such as Chern insulators, are defined in terms of additive indices that are stable against the addition of trivial degrees of freedom. Such topology presents an obstruction to any ...Wannier representation, namely, the representation of the electronic states in terms of symmetric, exponentially localized Wannier functions. Here, we address the converse question: Do obstructions to Wannier representation imply stable band topology? We answer this in the negative, pointing out that some bands can also display a distinct type of "fragile topology." Bands with fragile topology do not admit any Wannier representation by themselves, but such a representation becomes possible once certain additional trivial degrees of freedom are supplied. We construct a physical model of fragile topology on the honeycomb lattice that also helps resolve a recent puzzle in band theory. This model provides a counterexample to the assumption that splitting of an "elementary band representation" introduced in B. Bradlyn et al., Topological quantum chemistry, Nature (London) 547, 298 (2017) leads to bands that are individually topological. Instead, half of the split bands of our model realize a trivial band with exponentially localized symmetric Wannier functions, whereas the second half possess fragile topology. Our work highlights an important and previously overlooked connection between band structure and Wannier functions, and is expected to have far-reaching consequences given the central role played by Wannier functions in the modeling of real materials.
Background
Ureteral stent and subcutaneous ureteral bypass (SUB) placement are commonly used for managing ureteral obstructions. Urinary tract infection (UTI) is a recognized complication.
Objectives
...To determine postoperative incidence of positive urine cultures in cats undergoing ureteral stent and SUB placement and to identify risk factors associated with positive urine cultures.
Design
Retrospective study.
Animals
Forty‐three cats that underwent 48 surgical events.
Procedures
Medical records were reviewed. Cats were included if urine cultures were performed before and after surgery. Variables were compared to identify risk factors.
Results
Urine cultures were positive postoperatively pre‐discharge in 5/20 (25%) cats. Median duration of follow‐up post‐discharge was 209 days (range, 11‐2184 days), with a total of 143 urine cultures performed in cats post‐discharge. Of these, 16 (11%) were positive in 12/48 (25%) cats. Nine different bacteria were identified; Enterococcus spp. (n = 8) predominated as monomicrobic or mixed infections. In 14/16 instances of positive urine cultures, affected cats had lower urinary tract signs, signs of pyelonephritis or both. Cats that received antibiotics postoperatively were significantly less likely to have a positive urine culture compared to those that did not (odds ratio, 0.2, 95% confidence interval, 0.05, 0.8, P = 0.02). Chronic kidney disease, renal implant type and postoperative urinary catheterization were not associated with positive urine cultures.
Conclusions and Clinical Relevance
Postoperatively, occurrence of positive urine cultures was similar to previous reports. Subclinical bacteriuria was less common than UTI. Postoperative urinary catheterization has been speculated to increase risk of bacteriuria, but this was not the case in this cohort.
PDF
