Suitable Candidates For Operation Research Articles

TiSiCN as Coatings Resistant to Corrosion and Neutron Activation.

The aim of the present paper was to evaluate the effect of neutron activation on TiSiCN carbonitrides coatings prepared at different C/N ratios (0.4 for under stoichiometric and 1.6 for over stoichiometric). The coatings were prepared by cathodic arc deposition using one cathode constructed of Ti88 at.%-Si12 at.% (99.99% purity). The coatings were comparatively examined for elemental and phase composition, morphology, and anticorrosive properties in 3.5% NaCl solution. All the coatings exhibited f.c.c. solid solution structures and had a (111) preferred orientation. Under stoichiometric structure, they proved to be resistant to corrosive attack in 3.5% NaCl and of these coatings the TiSiCN was found to have the best corrosion resistance. From all tested coatings, TiSiCN have proven to be the most suitable candidates for operation under severe conditions that are present in nuclear applications (high temperature, corrosion, etc.).

Dynamical Behavior of Two Interacting Double Quantum Dots in 2D Materials for Feasibility of Controlled-NOT Operation.

Two interacting double quantum dots (DQDs) can be suitable candidates for operation in the applications of quantum information processing and computation. In this work, DQDs are modeled by the heterostructure of two-dimensional (2D) MoS2 having 1T-phase embedded in 2H-phase with the aim to investigate the feasibility of controlled-NOT (CNOT) gate operation with the Coulomb interaction. The Hamiltonian of the system is constructed by two models, namely the 2D electronic potential model and the matrix model whose matrix elements are computed from the approximated two-level systems interaction. The dynamics of states are carried out by the Crank–Nicolson method in the potential model and by the fourth order Runge–Kutta method in the matrix model. Model parameters are analyzed to optimize the CNOT operation feasibility and fidelity, and investigate the behaviors of DQDs in different regimes. Results from both models are in excellent agreement, indicating that the constructed matrix model can be used to simulate dynamical behaviors of two interacting DQDs with lower computational resources. For CNOT operation, the two DQD systems with the Coulomb interaction are feasible, though optimization of engineering parameters is needed to achieve optimal fidelity.

Treatment Patterns in Women Age 80 and Over With DCIS: A Report From the National Cancer Database

BackgroundDespite an aging population, there are no established treatment guidelines for women with ductal carcinoma in situ (DCIS) age ≥80. Here we describe national treatment patterns and survival outcomes in older women with DCIS. Patients and MethodsWomen age ≥80 diagnosed with DCIS from 2005 to 2014 were identified using the National Cancer Database. χ2, Fisher's exact test, and logistic regression models were used to identify factors influencing receipt of breast surgery, and Kaplan-Meier method and Cox proportional hazard models were used to evaluate overall survival (OS). ResultsA total of 6,070 women with DCIS met inclusion criteria, of which the majority (98%) received surgery. Receipt of surgery was independently associated with age <90. OS was higher for those who received surgery compared to those who did not (HR 2.2 [1.72-2.83] P < .001). ConclusionThe vast majority of patients age ≥80 with DCIS in the National Cancer Database received primary surgical management, which was associated with a significant OS benefit. Considering comorbidities and patient fitness, surgical resection should be considered for all patients age ≥80 who are suitable operative candidates.

Surgical Treatment of Patients with Poorly Differentiated Pancreatic Neuroendocrine Carcinoma: An NCDB Analysis.

Consensus guidelines discourage resection of poorly differentiated pancreatic neuroendocrine carcinoma (panNEC) given its association with poor long-term survival. This study assessed treatment patterns and outcomes for this rare malignancy using the National Cancer Database (NCDB). Patients with non-functional pancreatic neuroendocrine tumors in the NCDB (2004-2016) were categorized based on pathologic differentiation. Logistic and Cox proportional hazard regressions identified associations with resection and overall survival (OS). Survival was compared using Kaplan-Meier and log-rank tests. Most patients (83%) in the cohort of 8560 patients had well-differentiated tumors (panNET). The median OS was 47 months (panNET, 63 months vs panNEC, 17 months; p < 0.001). Surgery was less likely for older patients (odds ratio [OR], 0.97), patients with panNEC (OR, 0.27), and patients with metastasis at diagnosis (OR, 0.08) (all p < 0.001). After propensity score-matching of these factors, surgical resection was associated with longer OS (82 vs 29 months; p < 0.001) and a decreased hazard of mortality (hazard ratio [HR], 0.37; p < 0.001). Surgery remained associated with longer OS when stratified by differentiation (98 vs 41 months for patients with panNET and 36 vs 8 months for patients with panNEC). Overall survival did not differ between patients with panNEC who underwent surgery and patients with panNET who did not (both 39 months; p = 0.294). Poorly differentiated panNEC exhibits poorer survival than well-differentiated panNET. In the current cohort, surgical resection was strongly and independently associated with improved OS, suggesting that patients with panNEC who are suitable operative candidates should be considered for multimodality therapy, including surgery.

Invasive Breast Cancer Treatment Patterns in Women Age 80 and Over: A Report from the National Cancer Database

BackgroundThere are no established treatment guidelines for women with breast cancer aged ≥80 despite increasing representation in the US population. Here we identify national treatment patterns and survival outcomes in women with stage I-III invasive breast cancer. Patients and MethodsWomen age ≥80 diagnosed with stage I-III invasive breast cancer (IBC) were identified from 2005-2014 in the National Cancer Database. χ2, Fisher's exact test, and logistic regression models were used to identify factors influencing receipt of breast surgery, and Cox proportional hazard models were used to evaluate overall survival (OS). ResultsA total of 62,575 women with IBC met inclusion criteria, of which the majority received surgery (94%). Receipt of surgery was associated with White race, age <90, lower stage, and fewer comorbidities. OS was higher for those who received surgery compared to those who did not (HR 3.3 [3.18-3.46] P < .001). Molecular subtype analysis demonstrated improved survival with receipt of surgery or radiation for all subtypes, as well as improved survival with chemotherapy for those with triple negative breast cancer. ConclusionThe vast majority of breast cancer patients aged ≥80 in the National Cancer Database with IBC received primary surgical management, which was associated with a significant OS benefit. Due to this finding, surgical resection should be considered for all patients ≥80 who are suitable operative candidates.

Invited commentary

In this article, the authors have identified endovascular aneurysm repair (EVAR) as a potential risk factor for subsequent development of intra-abdominal cancer. When stratified for computed tomography (CT) vs non-CT surveillance, the cohort undergoing CT surveillance did not have an additional cancer risk, implying that the cancer risk is related to the fluoroscopy exposure from the EVAR procedure itself. Whereas much has been written lately about the short- and long-term risks of radiation exposure, the long-term risk of cancer from a single exposure is thought provoking. In its early days, EVAR was typically offered to higher risk patients not believed to be suitable operative candidates because of concerns about device durability. As durability issues have become less of a concern, EVAR has generally become the standard of care for all anatomically suitable patients regardless of age or risk factors. This paper injects some caution into this approach, particularly in younger, healthier patients with long life expectancy. One could potentially argue about the relevance of statistical vs clinical significance. Because of the large numbers studied, close to 40,000 patients, the cancer difference was statistically significant; however, the hazard ratio was only 1.14 for development of abdominal cancer and 1.11 for any cancer, and absolute differences between the groups were small, but for an outcome as potentially severe as cancer, even small differences need to be taken seriously. I doubt the numbers will be startling enough to significantly change practice patterns. However, efforts to minimize radiation exposure during EVAR need to be continuously emphasized and improved. Because of the nature of the administrative database, the authors are not able to quantify the amount of radiation received during EVAR; however, given the stochastic nature of radiation-induced malignant neoplasms, it is reasonable to assume that there is no safe dose and that every effort to minimize radiation exposure should be employed. This is increasingly relevant as EVAR becomes more complicated and potentially time-consuming with the expansion of fenestrated and branched EVAR. The authors mention some measures, such as C-arm angulation, frame rate, table position, and use of protective materials. Other important adjuncts include expanded use of intravascular ultrasound, two-dimensional and three-dimensional fusion imaging, and use of newer imaging systems with radiation-reducing software packages.1Hertault A. Maurel B. Midulla M. Bordier C. Desponds L. Saeed Kilani M. et al.Minimizing radiation exposure during endovascular procedures: basic knowledge, literature review, and reporting standards.Eur J Vasc Endovasc Surg. 2015; 50: 21-36Abstract Full Text Full Text PDF PubMed Scopus (60) Google Scholar, 2Mohapatra A. Greenburg R.K. Mastracci T.M. Eagleton M.J. Thornsberry B. Radiation exposure to operating room personnel and patients during endovascular procedures.J Vasc Surg. 2013; 58: 702-709Abstract Full Text Full Text PDF PubMed Scopus (78) Google Scholar Whereas this article focuses on the patient risk, risks to the operating surgeons and other operating room personnel cannot be ignored. Radiation risk, both deterministic and stochastic, should also be a standard part of the informed consent process. Anecdotally, I have noted that our younger trainees are often the most aggressive in terms of using protective radiation shielding during procedures. This is encouraging and clearly should become endemic practice in our profession. The opinions or views expressed in this commentary are those of the author and do not necessarily reflect the opinions or recommendations of the Journal of Vascular Surgery or the Society for Vascular Surgery. A population-based cohort study examining the risk of abdominal cancer after endovascular abdominal aortic aneurysm repairJournal of Vascular SurgeryVol. 69Issue 6PreviewEndovascular aneurysm repair (EVAR) has increasingly been used as the primary treatment approach for abdominal aortic aneurysm (AAA). This study examined the hypothesis that EVAR leads to an increased risk of abdominal cancer within the radiation field compared with open AAA repair. Full-Text PDF Open Archive

Surgery for Esophageal Adenocarcinoma: Three field open McKeown procedure has a role in assessment and treatment of extensive locally advanced esophageal adenocarcinoma with a favorable clinical and pathological outcome.

Esophageal adenocarcinoma has seen an increased incidence due to gastroesophageal reflux disease , smoking and obesity. There are no established guidelines for screening of esophageal cancer and many patients present late in their disease process. Most early stage adenocarcinoma of the esophagus is treated with neoadjuvant chemotherapy and radiation follow by surgical resection in suitable operative candidates. We describe a case of locally advanced esophageal cancer, where the patient had a relatively insignificant response to neoadjuvant chemotherapy and radiation, who was then treated by open direct resection of the esophagus and proximal stomach (three field McKeown approach) with lymphadenectomy. The patient did well after surgery apart from pneumonia and increased secretions that required tracheostomy. There were no surgical complications such as anstomotic leak or chylothorax. Pathology showed T2N0 disease.

The role of local excision in invasive adenocarcinoma of the ampulla of Vater.

The role of local excision in invasive adenocarcinoma of the ampulla of Vater.

Natural history of intraductal papillary mucinous neoplasia: How much do we really know?

Information on the natural history of intraductal papillary mucinous neoplasia (IPMN) is currently inadequate due to a lack of carefully orchestrated long-term follow-up on a large cohort of patients with asymptomatic disease. Based on the available data, one can draw the conclusions that main duct IPMN is commonly associated with malignancy and an aggressive operative stance should be taken with resection being offered to most patients who are suitable operative candidates. In contrast, the majority of branch type IPMN with a diameter of less than 3 cm can be safely followed with routine surveillance imaging provided they lack the high-risk covariates of age, symptomatology, nodularity or wall thickness.

The expanded role of palliative procedures with minimally invasive tumor ablation techniques

19548 Background: To effectively and appropriately manage the debilitating symptoms of advanced cancer, physicians must balance the potential promise of palliative interventions against requirements to avoid toxic or futile therapy. Ablative technologies are increasingly used for the local destruction of tumors. This study examines the outcomes of ablative procedures performed with palliative intent. Methods: Minimally invasive ablative procedures (microwave and radiofrequency) to explicitly palliate symptoms of advanced cancer were identified from all procedures performed. Patients were observed for &gt;90 days or until death. Results: There were 175 palliative ablative procedures performed in 129 patients from 1999 to 2004. Ablations were performed most commonly for pain (90%) caused by metastatic (90%), locally advanced (5%), and locally recurrent (5%) disease. Primary malignancies treated were lung (31%), colorectal (14%), renal (11%), breast (9%), sarcoma (9%) and other (26%). Symptom improvement or resolution within 30 days was achieved in 69% (89/129). Median duration of symptom control was 315 days. Recurrence of the primary symptom occurred in 46% (59/129) while treatment of additional symptoms was needed in 22% (29/129). Palliative ablative procedures were associated with postoperative morbidity (25%) and mortality (7%). A postoperative complication reduced the probability of symptom improvement to 25% (p&lt;0.001). Effective symptom relief was associated with improved overall survival (median 408 days vs. 161 days, p&lt;0.001). Conclusions: In carefully selected patients, relief of symptoms following palliative ablative procedures can be expected, but new or recurrent symptoms limit durability. As observed in other palliative procedures, potential benefits are minimized by postoperative complications. Optimal management for these patients with advanced cancer, who are often not suitable candidates for operation, requires the highest level of multidisciplinary care. No significant financial relationships to disclose.

The Rationale for Esophagectomy as the Optimal Therapy for Barrett's Esophagus with High-Grade Dysplasia

The authors determined the incidence of invasive adenocarcinoma after esophagectomy in patients endoscopically diagnosed as having Barrett's esophagus with high-grade dysplasia. Barrett's esophagus is a well-recognized premalignant condition. There is controversy with regard to the optimal treatment of high-grade dysplasia in Barrett's esophagus. Recognizing the morbidity and mortality associated with esophagectomy, some recommend a selective approach, reserving esophagectomy only for evidence of invasive cancer identified through endoscopic surveillance. Other advocate esophagectomy for all suitable operative candidates. The authors reviewed their experience between 1985 and 1995 with 11 patients with high-grade dysplasia arising in Barrett's esophagus diagnosed by endoscopic biopsy and treated by esophagectomy. All patients were white men ranging in age from 47 to 70 years. Ten patients underwent esophagectomy by the Ivor Lewis technique; one had a transhiatal resection. Eight patients (73%) had invasive adenocarcinoma identified after esophagectomy; two (18%) had positive lymph nodes; one required a prolonged hospital stay for an anastomotic leak; two (18%) temporarily suffered delayed gastric emptying. The authors' review identified 85 additional patients previously reported during the same period. Including the current series, 39 patients (41%) had invasive adenocarcinoma identified in the resected specimen. A preponderance of early, potentially curable carcinomas are characteristically found in these patients. A high incidence of endoscopically undetected invasive carcinoma strongly supports esophagectomy as the preferred approach for suitable operative candidates with high-grade dysplasia in Barrett's esophagus.

Barrett's ulcer: A surgical disease?

Between 1973 and 1990, 285 patients with Barrett's esophagus were treated at the Lahey Clinic. Of these patients, 73 had adenocarcinoma in Barrett's esophagus either when first seen or while under surveillance. Of the remaining 212 patients with benign Barrett's esophagus, 30 had endoscopic evidence of a Barrett's ulcer, for a prevalence of 14%. Initial treatment consisted of aggressive medical therapy, including H2 antagonists and antacids as well as the usual dietary and antireflux measures. In 2 to 4 months, 27 patients underwent repeat endoscopy. Continued endoscopic evaluation in this group totaled 109 patient-years, with a range of 2 months to 13 years (median 2.3 years). Complete healing occurred in 23 of the 27 patients (85%) in 2 to 14 months (median 4 months). Recurrent ulcers developed in seven patients, and these ulcers healed with further medical therapy in five patients. Antireflux procedures were performed in four of six patients with nonhealing Barrett's ulcers, 1 to 1.5 cm in size, and all healed. Two patients refused to have an operation. In our experience, the majority of Barrett's ulcers heal with medical therapy. We reserve surgical intervention for otherwise suitable candidates for operation when no evidence of healing is found within 4 months of medical therapy or for the complications of Barrett's ulcer, namely, perforation, uncontrollable hemorrhage, or malignant degeneration, which were not encountered in this series.

Preoperative Pulmonary Evaluation

• Factors related to risk of perioperative pulmonary complications include site of incision, obstructive lung disease, prolonged anesthesia time, smoking history with productive cough, and obesity. Hypercapnia is a consistent indicator of high risk. There is no difference between spinal and general anesthesia with regard to risk of pulmonary complications. In patients being evaluated for lung resection, high-risk indicators include predicted postoperative forced expiratory volume in one second of less than 1000 mL, hypercapnia, severe dyspnea on exertion, or advanced age when it is associated with advanced cardiopulmonary disease. Newer methods of assessing cardiopulmonary reserve may prove useful in identifying which patients with one or more of these risk factors are suitable operative candidates. Prevention of postoperative complications in chronic obstructive pulmonary disease patients should begin in the preoperative period with discontinuation of smoking at least eight weeks before surgery and vigorous pulmonary toilet in the 48 to 72 hours before surgery. Prophylactic lung expansion maneuvers can be effective in decreasing the incidence of postoperative atelectasis in high-risk patients undergoing high-risk operations. ( Arch Intern Med 1988;148:2120-2127)

Preoperative pulmonary evaluation

• Factors related to risk of perioperative pulmonary complications include site of incision, obstructive lung disease, prolonged anesthesia time, smoking history with productive cough, and obesity. Hypercapnia is a consistent indicator of high risk. There is no difference between spinal and general anesthesia with regard to risk of pulmonary complications. In patients being evaluated for lung resection, high-risk indicators include predicted postoperative forced expiratory volume in one second of less than 1000 mL, hypercapnia, severe dyspnea on exertion, or advanced age when it is associated with advanced cardiopulmonary disease. Newer methods of assessing cardiopulmonary reserve may prove useful in identifying which patients with one or more of these risk factors are suitable operative candidates. Prevention of postoperative complications in chronic obstructive pulmonary disease patients should begin in the preoperative period with discontinuation of smoking at least eight weeks before surgery and vigorous pulmonary toilet in the 48 to 72 hours before surgery. Prophylactic lung expansion maneuvers can be effective in decreasing the incidence of postoperative atelectasis in high-risk patients undergoing high-risk operations. (<i>Arch Intern Med</i>1988;148:2120-2127)

Preoperative Pulmonary Evaluation

Factors related to risk of perioperative pulmonary complications include site of incision, obstructive lung disease, prolonged anesthesia time, smoking history with productive cough, and obesity. Hypercapnia is a consistent indicator of high risk. There is no difference between spinal and general anesthesia with regard to risk of pulmonary complications. In patients being evaluated for lung resection, high-risk indicators include predicted postoperative forced expiratory volume in one second of less than 1000 mL, hypercapnia, severe dyspnea on exertion, or advanced age when it is associated with advanced cardiopulmonary disease. Newer methods of assessing cardiopulmonary reserve may prove useful in identifying which patients with one or more of these risk factors are suitable operative candidates. Prevention of postoperative complications in chronic obstructive pulmonary disease patients should begin in the preoperative period with discontinuation of smoking at least eight weeks before surgery and vigorous pulmonary toilet in the 48 to 72 hours before surgery. Prophylactic lung expansion maneuvers can be effective in decreasing the incidence of postoperative atelectasis in high-risk patients undergoing high-risk operations.

Mediastinoscopy and bronchial carcinoma: experience with 600 mediastinoscopies.

Of 600 mediastinoscopies carried out from 1966 to 1973, 479 were performed to assess the operability of a pulmonary carcinoma. Of these, 206 (43%) were positive and 273 (57%) were negative. Of the 161 patients found positive during an initial period, 147 were refused operation; the remaining 14 were considered suitable candidates for operation, either because only one homolateral lymph node site was involved or because there was a concomitant osteoarthropathy. The tumour was irresectable in one of these 14 patients who died after 3-5 months; curative resection was possible in one and palliative resection in 12 patients. These 12 patients all died within a year. Of the 184 patients found negative during an initial period, 149 were treated by operation. The tumour proved irresectable in seven (5%), while curative resection was possible in 113 (76%) and palliative resection in 29 (19%) patients. Comparison with the period 1957-63, when in the same hospital resection was performed after a negative Daniels' (scalene node) biopsy, shows that the tumour was irresectable in 25 (20%) of the 124 patients with a negative biopsy, while curative resection was possible in 43 (35%) and palliative resection in 56 (45%) patients. During a second period, patients with a positive mediastinoscopy were in principle refused operation. Of 89 negative patients, 81 were treated by operation. No tumour was found to be irresectable; curative resection was possible in 63 (78%) and palliative resection in 18 (22%) patients. An operation for bronchial carcinoma was performed on 167 patients between September 1970 and September 1973 after a negative mediastinoscopy in 95, and without mediastinoscopy in 71 patients, either because of a peripheral tumour (70) or because of a tumour relapse after two years (1). The resection was palliative in 11% of the 71 cases, but in only one patient with a peripheral tumour could a mediastinoscopy have been positive. Finally, an operation was performed on one patient with a positive mediastinoscopy and a tumour relapse after six years. A survival study was made of the first 100 patients with pulmonary carcinoma, operated on between September 1970 and March 1972 and with a follow-up from a minumum of two years to a maximum of 3-5 years. The early mortality averaged 10% and was higher after pneumonectomy than after lobectomy. The late mortality was 16% after curative lobectomy, 38% after curative pneumonectomy, and 83% after palliative pneumonectomy. The survival after 2 to 3-5 years was 63%.

An Improved Method of Coronary Arteriography

Upon inspection of current mortality tables, even the most phlegmatic must agree that there is a clear and compelling reason for improving our therapeutic approach to coronary occlusive disease. Add to this the untold suffering and disability resulting from coronary occlusion and the argument literally becomes a “clarion call that brooks no denial.” Since coronary insufficiency is a result of vascular narrowing, coronary surgery appears to be the most promising avenue of attack. Although relativelyfew patientsmight have sufficiently localized lesions to justify surgery, even a small proportion of the half million fatal cases each year would represent a worthwhile salvage. However, if coronary surgery is to be rationally applied, there must first be a means for determining which patients are suitable candidates for operation. No method short of actual visualization-either by radiological technics or under direct inspectioncan accomplish this important objective. Thus, the desirability of a safe, easily-applied, and diagnostically-reliable method of preoperatively demonstrating diseased coronary arteries seems clearly established. Historical Reports of incidental as well as intentional radiological demonstrations of the coronary vessels date back at least to 1933, with Rousth#{246}i1 and Reboul and Racine2 in the vanguard. Since that time, there have been numerous reports describing coronary arteriography in experimental animals. It appears that man’s coronary arteries were first demonstrated during life by Radner3 in 1945. The earliest large series of coronary visualizations in man, however, is attributable to J#{246}nsson4 who used retrograde’ thoracic aortography via a catheter inserted into a peripheral artery. Most of the retrograde aortograms in this series were done for the study of congenital cardiovascular abnormalities; coronary visualization was merely incidental. Other workers512 have used various aortographic technics-including retrograde arterialcatheterization,directneedle puncture of the ascending aorta, and transthoracic left ventricular needling-specifically for the purpose of demonstrating the coronary circulation. With each of these methods, successful demonstration of coronary vessels required invariably large and sometimes overwhelming doses of concentrated iodine-containing contrast media in order to counteract dilution effects. Even then, there was no assurance that the contrast medium would flow into one or both coronary arteries in sufficient concentration to pro