The autogenous saphenous vein is considered the best bypass graft material for arterial bypasses below the inguinal ligament. However, a synthetic graft or prosthesis is considered an acceptable ...alternative, especially when the distal anastomosis is situated above the knee. Some studies even suggest that patency rates for vein and synthetic grafts are comparable, whereas others indicate that a vein graft is superior to a prosthetic graft, even above the knee.
To test the hypothesis that both vein grafts and synthetic prostheses are equally beneficial in the above-knee position, we performed a systematic review of available studies comparing the patency of saphenous vein and polytetrafluoroethylene (PTFE) as bypass material. English and German medical literature from 1966 to 2002 was searched using Medline, and 25 articles meeting our inclusion and exclusion criteria were selected.
The patency of venous bypasses was superior to that of PTFE bypasses at all time intervals studied. After 2 years, the primary patency rate of venous bypasses was 81% as compared to 67% for PTFE bypasses, and after 5 years it was 69 and 49%, respectively. After 5 years, the secondary patency of PTFE bypasses reached 60%. When only randomized trials were considered, venous bypasses were again superior to PTFE bypasses at all intervals studied. After 2 years, the primary patency rate of venous and PTFE bypasses was 80 and 69%, respectively, and after 5 years it was 74 and 39%, respectively.
Since both randomized and retrospective studies comparing venous with PTFE bypasses showed that vein grafts were ‘better’ than PTFE prostheses, the null hypothesis that there is no difference between the two types of graft material was rejected (p=0.008).
We conclude from this systematic review that if a saphenous vein is available, a venous bypass should be chosen at all times, even if patients have an anticipated short life expectancy (<2 years). If the saphenous vein is absent or not suitable for bypass grafting, PTFE is a good alternative as bypass material.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Highlights • Prevotella intermedia is a rare causative agent for aortitis and has, to the best knowledge of the authors, not been described in the literature before. • Patients with a suspected ...aortitis should be referred to a vascular center with experience in the medical and surgical treatment of this specific and potentially mortal disease. • Acute aortitis is a challenging clinical entity, which should be managed with a multidisciplinary team.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
For a femorotibial bypass graft the material of choice is autologous vein. The question remains whether prosthetic material is a reasonable alternative for limb salvage, if autologous vein is not ...available. From 1991 to 1998, 83 consecutive femorotibial bypass procedures were performed in 70 patients. Thin-walled, ringed 6-mm polytetrafluoroethylene (PTFE) was used, as autologous vein was not available. The indication for the femorotibial bypass was critical ischemia due to atherosclerotic occlusive disease in all cases. Three patients died in the hospital or within 30 days of the operation, resulting in a perioperative mortality rate of 3.6%. After 5 years, 33 patients had died (40%) and 3 patients were lost to follow-up (3.6%). Primary patency was 64.2% after 6 weeks and 18% +/- 5% after 5 years. Secondary patency was 74.1% after 6 weeks and 22.3% +/- 6% after 5 years. When we compared primary and secondary patency for distal anastomosis, there was no difference between the three crural arteries. The limb salvage rate was 61.9% +/- 7% after 5 years. From these results we conclude that, with a limb salvage of 61.9%, PTFE is an acceptable alternative for a femorotibial bypass graft in patients with critical ischemia, if autologous vein is not available.
A prospective randomized multicenter study was performed to assess whether the results of pylorus-preserving pancreaticoduodenectomy (PPPD) equal those of the standard Whipple (SW) operation, ...especially with respect to duration of surgery, blood loss, hospital stay, delayed gastric emptying (DGE), and survival.
PPPD has been associated with a higher incidence of delayed gastric emptying, resulting in a prolonged period of postoperative nasogastric suctioning. Another criticism of the pylorus-preserving pancreaticoduodenectomy for patients with a malignancy is the radicalness of the resection. On the other hand, PPPD might be associated with a shorter operation time and less blood loss.
A prospective randomized multicenter study was performed in a nonselected series of 170 consecutive patients. All patients with suspicion of pancreatic or periampullary tumor were included and randomized for a SW or a PPPD resection. Data concerning patients' demographics, intraoperative and histologic findings, as well as postoperative mortality, morbidity, and follow-up up to 115 months after discharge, were analyzed.
There were no significant differences noted in age, sex distribution, tumor localization, and staging. There were no differences in median blood loss and duration of operation between the 2 techniques. DGE was observed equally in the 2 groups. There was only a marginal difference in postoperative weight loss in favor of the standard Whipple procedure. Overall operative mortality was 5.3%. Tumor positive resection margins were found for 12 patients of the SW group and 19 patients of the PPPD group (P < 0.23). Long-term follow-up showed no significant statistical differences in survival between the 2 groups (P < 0.90).
The SW and PPPD operations were associated with comparable operation time, blood loss, hospital stay, mortality, morbidity, and incidence of DGE. The overall long-term and disease-free survival was comparable in both groups. Both surgical procedures are equally effective for the treatment of pancreatic and periampullary carcinoma.
The objective of this study was to describe the kinds of complications and their incidence after peripheral vascular surgery of the lower limb, coding for causes and effect on the patient. In this ...prospective study, a standardized complication registration system was used at the Red Cross Hospital, The Hague. All patients (n = 373) receiving an infrainguinal bypass graft during the period January 1, 1996 to December 31, 1999 were included. All postoperative complications occurring during admission were coded. In 29% of the patients 153 complications were coded. Early occlusions of the graft occurred 36 times, wound infections 21 times and postoperative hemorrhages 20 times. Postoperative retention of urine was seen most frequently of all nonspecific complications (n = 22). In 43 cases the patient needed medication or a blood transfusion for his complication. In 42 cases a re-intervention was necessary. Complications led to a prolonged stay in the hospital in 20 cases. Six patients died during admittance (mortality 1.6%). An error in surgical therapy and error in nonsurgical therapy were the cause of the complication in 108 cases (out of 153). The advantage of this complication registration is that it describes all complications, not just the specific ones. Furthermore, by categorizing all complications we force ourselves to look for errors in nonsurgical therapy and surgical technique and to describe the effect of the complication.
The new 2019 guideline of the European Society for Vascular Surgery (ESVS) recommends consideration for elective iliac artery aneurysm (eIAA) repair when the iliac diameter exceeds 3.5 cm, as opposed ...to 3.0 cm previously. The current study assessed diameters at time of eIAA repair and ruptured IAA (rIAA) repair and compared clinical outcomes after open surgical repair (OSR) and endovascular aneurysm repair (EVAR).
This retrospective observational study used the nationwide Dutch Surgical Aneurysm Audit (DSAA) registry that includes all patients who undergo aorto-iliac aneurysm repair in the Netherlands. All patients who underwent primary IAA repair between 1 January 2014 and 1 January 2018 were included. Diameters at time of eIAA and rIAA repair were compared in a descriptive fashion. The anatomical location of the IAA was not registered in the registry. Patient characteristics and outcomes of OSR and EVAR were compared with appropriate statistical tests.
The DSAA registry comprised 974 patients who underwent IAA repair. A total of 851 patients were included after exclusion of patients undergoing revision surgery and patients with missing essential variables. eIAA repair was carried out in 713 patients, rIAA repair in 102, and symptomatic IAA repair in 36. OSR was performed in 205, EVAR in 618, and hybrid repairs and conversions in 28. The median maximum IAA diameter at the time of eIAA and rIAA repair was 43 (IQR 38-50) mm and 68 (IQR 58-85) mm, respectively. Mortality was 1.3% (95% CI 0.7-2.4) after eIAA repair and 25.5% (95% CI 18.0-34.7) after rIAA repair. Mortality was not significantly different between the OSR and EVAR subgroups. Elective OSR was associated with significantly more complications than EVAR (intra-operative: 9.8% vs. 3.6%, post-operative: 34.0% vs. 13.8%, respectively).
In the Netherlands, most eIAA repairs are performed at diameters larger than recommended by the ESVS guideline. These findings appear to support the recent increase in the threshold diameter for eIAA repair.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
An inverter topology that has been developed for geophysical surveying applications makes it possible to achieve very fast current reversal in magnetic field coils. The inverter also makes it ...possible to generate waveforms that contain a variable high-frequency spectrum superimposed on a high-amplitude low-frequency fundamental. A feature, which is attractive from an implementation point of view, is that a low-voltage source such as a battery can be combined with high-voltage transistors to meet high dynamic requirements. Two variations of the topology are discussed, namely, a clamped and unclamped version. The proposed inverter was successfully implemented in two aircraft-mounted geophysical surveying systems achieving substantial performance improvement over the older systems. A 40-kW system was constructed for a fixed-wing aircraft and a smaller, battery-operated system was implemented on a helicopter.
La ciencia es todo un cuento Klinkert, Liliana M P
Revista Universidad EAFIT,
01/2017, Volume:
52, Issue:
169
Journal Article
Por otro lado, en la Categoría II (13 a 17 años), el primer lugar lo logró Carolina Muñoz Benítez, de 17 años y estudiante del Colegio San José de Las Vegas, con La esperanza del recuerdo, inspirado ...en el proyecto de Justicia Transicional. Además, a María Duque Betancur, de 10 años y estudiante del Colegio Jesús María, le otorgaron una mención especial por el cuento Corazón moreno, inspirado en el taller: ¿Cómo nos afecta la desigualdad? "La ciencia es más grande de lo que podemos imaginar" A Salomé Ríos Hoyos, ganadora del primer lugar en la Categoría I con el cuento Deinococco Cavache, siempre le han llamado la atencion la biología y la ciencia, áreas en las que le gustaría ser profesora cuando sea grande. "Los invito a que sean sujetos políticos" Carolina Muñoz Benítez, ganadora del primer lugar en la Categoría II con el cuento La esperanza del recuerdo, manifiesta que se inspiró en la justicia transicional porque considera que, a pesar de ser un tema jurídico, el trasfondo de las normas en una sociedad ayuda a la convivencia.
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