Impact on beef cattle productivity of infection with anthelmintic-resistant nematodes.

ABSTRACTAims: The main goal of the current study was to evaluate, on a commercial beef cattle farm, the impact of infection with gastrointestinal nematodes resistant to both ivermectin (IVM) and moxidectin (MXD) on the productivity of calves.Methods: Male Aberdeen Angus calves, aged 9-11 months, with faecal nematode egg counts (FEC) ≥200 epg and body weight ≥190 kg, were allocated to two herds. Herd A (n = 90) grazed a maize-winter forage crop rotation and Herd B (n = 90) grazed a 2-year-old Agropyrum pasture. On Day 0 in each herd, calves were randomly allocated into five groups (n = 18), which were treated with 0.2 mg/kg IVM; 0.2 mg/kg MXD; 3.75 mg/kg ricobendazole (RBZ), both IVM and RBZ, or remained untreated. Faecal samples collected on Days -1 and 19 were used to determine the percentage reduction in FEC, and genera of the nematodes were determined by the identification of the third-stage larvae recovered from faecal cultures. Total weight gain was determined from body weights recorded on Days -1 and 91.Results: Overall mean reduction in FEC was 42% for IVM, 67% for MXD, 97% for RBZ and 99% for IVM + RBZ. The reduction in FEC for Cooperia spp. was ≤78% for IVM and MXD, and for Haemonchus spp. was 0 and 36% for IVM and MXD, respectively, confirming the presence of parasites resistant to both anthelmintics. Only IVM + RBZ treatment resulted in 100% efficacy against Haemonchus spp. The overall estimated mean total weight gain for calves treated with IVM was 15.7 (95% CI = 11.9-19.7) kg and for calves treated with IVM + RBZ was 28.8 (95% CI = 25-32.5) kg (p < 0.001). Mean total weight gain for calves treated with MXD was 23.5 (95% CI = 19.7-27.2) kg.Conclusions and clinical relevance: In calves naturally infected with resistant nematodes, under the production system assessed here, weight gains were lower in calves treated with anthelmintics that were moderately or highly ineffective compared to those treated with highly effective anthelmintics. These results demonstrate to farmers and veterinarians the importance of a sustainable and effective nematode control under field conditions.

Categorisation of air quality monitoring stations by evaluation of PM(10) variability.

Air Quality Monitoring Networks (AQMNs) are composed by a number of stations, which are typically classified as urban, suburban or rural, and background, industrial or traffic, depending on the location and the influence of the immediate surroundings. These categories are not necessarily homogeneous and distinct from one another, regarding the levels of the monitored pollutants. A classification providing groups with these features is of interest for air quality management and research purposes, and therefore, other classification criteria should be explored. In this work, the variations of PM10 concentrations in 43 stations in the AQMN of the Basque Country in the period 2005-2012 have been studied to group them according to common characteristics. The characteristic variations in time are synthesised by the autocorrelation function (ACF), with both daily and hourly data, and by the average diurnal evolution pattern of the normalised concentrations on a seasonal basis (Evol-P). A methodology based on k-means clustering of these features is proposed. Each classification gives a different piece of information that has been phenomenologically related with specific dispersion and emission dynamics. The classification based on Evol-Ps is found to be the most influential one when comparing PM10 levels between groups. A combination of these categorisations provides 5 groups with significantly different levels of PM10, improving the discrimination of the conventional classification. Our results indicate that the time series of the pollutant concentrations contain enough information to provide an objective classification of the monitoring stations in an AQMN.

Structure of Meson-Baryon interaction vertices.

We present a microscopic derivation of the form factors of strong-interaction piNN and piNDelta vertices within a relativistic constituent quark model. The results are compared with form factors from phenomenological meson-baryon models and recent lattice QCD calculations. We give an analytical representation of the vertex form factors suitable for applications in further studies of hadron reactions.

Coupled-channel evaluations of cross sections for scattering involving particle-unstable resonances.

How does the scattering cross section change when the colliding bound-state fragments are allowed particle-emitting resonances? This question is explored in the framework of a multichannel algebraic scattering method of determining nucleon-nucleus cross sections at low energies. Two cases are examined, the first being a gedanken investigation in which n + 12C scattering is studied with the target states assigned artificial widths. The second is a study of neutron scattering from 8Be, a nucleus that is particle unstable. Resonance character of the target states markedly varies evaluated cross sections from those obtained assuming stability in the target spectrum.

Effect of organosolv and soda pulping processes on the metals content of non-woody pulps.

In this work the effect of different pulping processes (ethyleneglycol, diethyleneglycol, ethanolamine and soda) of tow abounded raw materials (empty fruit bunches - EFB and rice straw) on the ash, silicates and metals (Fe, Zn, Cu, Pb, Mn, Ni and Cd) content of the obtained pulps have been studied. Results showed that pulps obtained by diethyleneglycol pulping process presented lower metals content (756 microg/g and 501 microg/g for EFB and rice straw pulp, respectively) than soda pulps (984 microg/g and 889 microg/g). Ethanolamine pulps presented values of holocellulose (74% and 77% for EFB and rice straw pulp, respectively), alpha-cellulose (74% and 69%), kappa number (18.7 and 18.5) and viscosity (612 and 90 6ml/g) similar to those of soda pulp, and lower lignin contents (11% and 12%).

Predicting narrow states in the spectrum of a nucleus beyond the proton drip line.

Properties of particle-unstable nuclei lying beyond the proton drip line can be ascertained by considering the (usually known) properties of its mirror neutron-rich system. We have used a multichannel algebraic scattering theory to map the known properties of the neutron-14C system to those of the proton-14O one from which we deduce that the particle-unstable 15F will have a spectrum of two low-lying broad resonances of positive parity and, at higher excitation, three narrow negative-parity ones. A key feature is to use coupling to Pauli-hindered states in the target.

Role of the Pauli principle in collective-model coupled-channel calculations.

A multichannel algebraic scattering theory, to find solutions of coupled-channel scattering problems with interactions determined by collective models, has been structured to ensure that the Pauli principle is not violated. By tracking the results in the zero coupling limit, a correct interpretation of the subthreshold and resonant spectra of the compound system can be made. As an example, the neutron-12C system is studied defining properties of 13C to 10 MeV excitation. Accounting for the Pauli principle in collective coupled-channels models is crucial to the outcome.

[Radiotherapy treatment under anesthesia in pediatrics]. / Tratamiento radioterápico bajo anestesia en pediatría.

A four-year-old boy received 30 sessions of radiotherapy, at a rate of one session daily for five days every week, under anesthesia with midazolam and propofol in spontaneous ventilation. Monitoring was by pulse oximetry and capnography; no adverse events were recorded. The presence of an anesthesiologist during diagnostic and therapeutic procedures outside the operating room is essential, given that lack of cooperation can make the procedure difficult or impossible to perform. Radiotherapy under anesthesia is a special case because it is scheduled daily, and care must be taken to interfere as little as possible with a child's meals or other activities.

Limb salvage after successful pedal bypass grafting is associated with improved long-term survival.

OBJECTIVES: Assessments of outcome after reconstruction for critical limb ischemia frequently ignore functional result and long-term morbidity and mortality. This study was undertaken to identify factors affecting long-term clinical outcome and survival after pedal bypass grafting. METHODS: The clinical data of 256 consecutive patients who underwent pedal bypass grafting for critical limb ischemia over a 12-year period were retrospectively analyzed. RESULTS: A total of 174 men and 82 women (median age, 70 years; range, 30-91 years) underwent 280 pedal bypass graft placements with autologous vein. Seventy-five percent of the patients were diabetic, and 20% had renal insufficiency (serum creatinine level > 2 mg/dL). The in-hospital mortality rate was 1.6% (4/256). The mean follow-up was 2.7 years (range, 0.1-10.1 years). Rates of primary and secondary patency, limb salvage, and survival at 5 years were 58%, 71%, 78%, 60%, respectively. A total of 160 limbs (57%) required additional interventions. Nineteen early graft thrombectomies/revisions and nine early amputations were performed. One hundred thirty-eight late interventions included 31 graft salvage procedures, 27 wound debridements, and 34 minor and 42 major amputations. At last follow-up or death, 219 (78%) limbs were being used for ambulation. End-stage renal disease (ESRD) and composite vein grafts predicted limb loss (P <.001, P <.001, respectively). Overall survival at 5 years was 60%. Survival after amputation was 79%, 53%, and 26% at 1, 3, and 5 years. Amputation and ESRD predicted higher mortality (P =.014, P =.0001, respectively). CONCLUSIONS: Pedal bypass grafting resulted in good functional limb salvage, but at the expense of multiple interventions in more than half the cases. ESRD and composite vein graft were associated with poor long-term limb salvage. Amputation after bypass grafting was associated with significantly worse long-term survival.

Pedal bypass for limb salvage: impact of diabetes on long-term outcome.

Use of pedal bypass can salvage limbs of patients with critical ischemia. The aim of this study was to evaluate the results of surgical revascularization of pedal arteries in diabetic patients and to assess the impact of diabetes on long-term outcome. We performed a retrospective analysis of all consecutive pedal bypasses done between January 1, 1987 and December 31, 1997. Demographic data, surgical indications, operative variables, and postoperative results including graft patency and limb salvage were compared between diabetic and nondiabetic patients. The results of this comparison showed that pedal bypass can safely and effectively relieve critical ischemia in diabetic patients. Diabetics have less early graft thrombosis and superior long-term graft patency. Despite higher incidence of renal insufficiency or failure and more tissue loss, diabetics can achieve similar excellent limb salvage rates. This outcome justifies aggressive revascularization of pedal arteries in diabetic as well as nondiabetic patients with critical limb ischemia.

The benefits of secondary interventions in patients with failing or failed pedal bypass grafts.

BACKGROUND: Autogenous bypass grafts to pedal arteries have successfully salvaged limbs and restored function in patients with critical ischemia. The benefits of secondary interventions to save failing or already failed grafts remains uncertain. METHODS: A retrospective analysis was made of consecutive pedal bypasses performed between 1987 and 1998. Patency and limb salvage by life-table analysis and variables affecting outcome were compared with the log-rank test. RESULTS: Two hundred thirteen patients, 144 males, 69 females (mean age 68 years, range 30 to 91) underwent pedal bypass grafting in 228 limbs using autogenous vein grafts (nonreversed saphenous vein, n = 190; reversed, n = 15; composite, n = 23). One-hundred fifty-seven patients were diabetic, 34 had renal insufficiency (serum creatinine >2.0), and 14 were on dialysis. Gangrene or ulceration were present in 224 patients, rest pain in 24. Cumulative primary and secondary patency rates were 57% and 67% at 5 years. Limb salvage was 78% at 5 years. Secondary interventions in 46 patients included patch angioplasty/surgical revision (n = 28), thrombectomy (n = 15), thrombolysis (n = 11), and balloon angioplasty (n = 6). Patency in 19 of 26 (73%) failed grafts and in 19 of 20 (95%) failing grafts could be restored initially. Cumulative 2-year patency and limb salvage rates following reinterventions were 36% and 58%, respectively. Patency rates and limb salvage for failed grafts (7%, 44%) were significantly worse than those for failing grafts (81%, 77%; P <0.0001, P <0.05, respectively). All patients with renal insufficiency who underwent reinterventions for failed or failing grafts required major amputation within 1 year (P <0.0001 versus those without renal insufficiency). CONCLUSION: Autogenous pedal bypass grafts are durable operations with excellent long-term patency and limb salvage rates. Revision of failing grafts has been effective using both endovascular and surgical techniques. Failed grafts have poor long-term patency and moderate limb salvage rates, and our data do not justify secondary procedures to attempt to save failed grafts in patients with renal insufficiency.

Mid-term results of endoscopic perforator vein interruption for chronic venous insufficiency: lessons learned from the North American subfascial endoscopic perforator surgery registry. The North American Study Group.

PURPOSE: The safety, feasibility, and early efficacy of subfascial endoscopic perforator surgery (SEPS) for the treatment of chronic venous insufficiency were established in a preliminary report. The long-term clinical outcome and the late complications after SEPS are as yet undetermined. METHODS: The North American Subfascial Endoscopic Perforator Surgery registry collected information on 148 SEPS procedures that were performed in 17 centers in the United States and Canada between August 1, 1993, and February 15, 1996. The data analysis in this study focused on mid-term outcome in 146 patients. RESULTS: One hundred forty-six patients (79 men and 67 women; mean age, 56 years; range, 27 to 87 years) underwent SEPS. One hundred and one patients (69%) had active ulcers (class 6), and 21 (14%) had healed ulcers (class 5). One hundred and three patients (71%) underwent concomitant venous procedures (stripping, 70; high ligation, 17; varicosity avulsion alone, 16). There were no deaths or pulmonary embolisms. One deep venous thrombosis occurred at 2 months. The follow-up periods averaged 24 months (range, 1 to 53 months). Cumulative ulcer healing at 1 year was 88% (median time to healing, 54 days). Concomitant ablation of superficial reflux and lack of deep venous obstruction predicted ulcer healing (P <.05). Clinical score improved from 8.93 to 3.98 at the last follow-up (P <. 0001). Cumulative ulcer recurrence at 1 year was 16% and at 2 years was 28% (standard error, < 10%). Post-thrombotic limbs had a higher 2-year cumulative recurrence rate (46%) than did those limbs with primary valvular incompetence (20%; P <.05). Twenty-eight of the 122 patients (23%) who had class 5 or class 6 ulcers before surgery had an active ulcer at the last follow-up examination. CONCLUSIONS: The interruption of perforators with ablation of superficial reflux is effective in decreasing the symptoms of chronic venous insufficiency and rapidly healing ulcers. Recurrence or new ulcer development, however, is still significant, particularly in post-thrombotic limbs. The reevaluation of the indications for SEPS is warranted because operations in patients without previous deep vein thrombosis are successful but operations in those patients with deep vein thrombosis are less successful. Operations on patients with deep vein occlusion have poor outcomes.

The Romanomermis iyengari parasite for Anopheles pseudopunctipennis suppression in natural habitats in Oaxaca State, Mexico.

In September and November 1996 Romanomermis iyengari Welch, a parasite of larval mosquitoes, was released in 44 natural larval habitat sites of Anopheles pseudopunctipennis Theobald in an attempt to reduce the larval populations of this important malaria vector. The selected treatment sites ranged in size from 5 to 500 m2. The study was carried out in Pochutla District of Oaxaca State, on the Pacific coast of Mexico. Chemical pesticides to reduce vector populations have been the principal tool in malaria suppression campaigns. However, the excessive use of these chemicals has created pesticide resistance and other serious collateral problems. Therefore, a biological control project using agents that are pathogens of Anopheles larvae was initiated in 1996. The principal objective was to establish mass rearing capacities for R. iyengari. Detailed methodology for rearing and introducing these nematodes into mosquito larval habitats was established at the National Polytechnic Institute of Oaxaca State. Before application of the parasites to larval habitats, site characteristics were determined, including size, depth, aquatic vegetation, salinity, pH, conductivity, temperature, and pretreatment larval density. With a compressed air sprayer, infective mermithid parasites were released at rates of either 2,000 or 3,000/m2, and the parasites produced high levels of infection. Anopheles populations were sampled 72 h posttreatment, and the larvae obtained were taken to the laboratory and examined through microscopic dissection to determine infection levels and mean parasitism. Nematode parasitism ranged from 85 to 100% at all the treatment sites, even though no previous information concerning field parasitism of An. pseudopunctipennis by R. iyengari has been reported. In addition, a significant reduction of mosquito larval density at the treatment sites was found five days after the nematode application. Levels of parasitism were indicative of the number of mosquito larvae killed by the treatment since infected larvae never progressed to the pupal stage. Results from sampling nine of the sites 2 months after the initial application of nematodes indicated that a high number of mosquito larvae were infected by parasites that had emerged from eggs previously deposited in the stratum. This work suggests the potential of this mermithid to reduce An. pseudopunctipennis populations in Oaxaca State.

Endoscopic perforator vein division with ablation of superficial reflux improves venous hemodynamics.

PURPOSE: Hemodynamic consequences of incompetent perforator vein interruption have not been well documented. The effects of perforator interruption, with or without ablation of superficial venous reflux, on venous function in patients with advanced chronic venous insufficiency was studied. METHODS: Calf muscle pump function, venous incompetence, and outflow obstruction were assessed by means of strain-gauge plethysmography (SGP) before and within 6 months after subfascial endoscopic perforator surgery (SEPS). SEPS was performed with laparoscopic instrumentation and CO2 insufflation. Concomitant high ligation or saphenous vein stripping was performed in 24 limbs (77%). RESULTS: Twenty-six patients, 18 women and 8 men, with a mean age of 50 years (range, 20 to 77 years) underwent SEPS. Preoperative evaluation confirmed superficial reflux in 65% of limbs, deep venous reflux in 77% of limbs, and perforator incompetence in 97% of limbs. All limbs had advanced venous dysfunction (C3, C4, C5, C6). All active ulcers (C6, n = 12) healed after surgery (mean, 32 +/- 3 days), and only 1 recurred during a mean follow-up period of 11 months (range, 1 to 43 months). Clinical score improved from 6.58 +/- 0.50 to 2.19 +/- 0.25 (P <.0001). Improved calf muscle pump function was demonstrated by means of postoperative SGP and was indicated by increased refill volume (RV: 0.27 +/- 0.06 vs 0.64 +/- 0.10 mL/100 mL tissue, P <.01). Venous incompetence also improved, as evidenced by prolonged duration to refill after exercise (T90: 7. 71 +/- 1.20 vs 16.71 +/- 1.98 seconds, P <.001) and a decrease in RV after passive drainage (3.23 +/- 0.19 vs 2.63 +/- 0.15 mL/100 mL tissue, P <.01). Improved refill rate (RR) correlated with improvements in clinical scores (P <.01, r = 0.77). CONCLUSION: SEPS with ablation of superficial reflux improved calf muscle pump function, reduced venous incompetence, and produced excellent midterm clinical results. However, functional improvement directly related to SEPS requires further investigation. This study supports adding SEPS to ablation of superficial reflux in patients with advanced chronic venous insufficiency.

Factors affecting clinical outcome following endoscopic perforator vein ablation.

BACKGROUND: Despite good outcomes reported with minimally invasive, subfascial endoscopic perforator surgery (SEPS), some patients demonstrate poor healing or recurrence of venous ulcers. The goal of this study was to identify factors that lead to failure of SEPS. METHODS: Forty-eight consecutive patients who had undergone 57 SEPS procedures were analyzed. Mean follow-up was 17 +/- 2 months (range 2 weeks to 52 months). RESULTS: All active ulcers (n = 22) at the time of surgery healed in an average of 99 +/- 37 days (range 11 to 670). Eight limbs had poor healing of their ulcer (>40 days); five (9%) new/recurrent ulcers developed postoperatively. Deep venous obstruction was associated with delayed ulcer healing (316 +/- 171 versus 51 +/- 14 days, P < 0.01) and ulcer recurrence (P < 0.0001). Poor ulcer healing and recurrence were not associated with lipodermatosclerosis, edema, ulcer duration >3 months, or previous recurrences. Ulcer size >2 cm (P < 0.05) and combined ilio-femoral and popliteal/tibial reflux were associated with poor ulcer healing (P < 0.05). CONCLUSIONS: SEPS could not prevent recurrent or new ulceration in 9% of limbs. Venous outflow obstruction was associated with ulcer recurrence and prolonged ulcer healing. Multilevel deep venous reflux and ulcer size >2 cm were also associated with delayed healing.

Reconstruction of the superior vena cava: benefits of postoperative surveillance and secondary endovascular interventions.

PURPOSE: Superior vena cava (SVC) reconstructions are rarely performed; therefore the need for surveillance and the results of secondary interventions are unknown. METHODS: During a 14-year period 19 patients (11 male, 8 female; mean age 41.9 years, range 8 to 69 years) underwent SVC reconstruction for symptomatic nonmalignant disease. Causes included mediastinal fibrosis (n = 12), indwelling foreign bodies (n = 4), idiopathic thrombosis (n = 2), and antithrombin III deficiency (n = 1). Spiral saphenous vein graft (n = 14), polytetrafluoroethylene (n = 4), or human allograft (n = 1) was implanted. RESULTS: No early death or pulmonary embolism occurred. Four early graft stenoses or thromboses (spiral saphenous vein graft, n = 2, polytetrafluoroethylene, n = 2) required thrombectomy, with success in three. During a mean follow-up of 49.5 months (range, 4.7 to 137 months), 95 imaging studies were performed (average, five per patient; range, one to 10 studies). Venography detected mild or moderate graft stenosis in seven patients; two progressed to severe stenosis. Two additional grafts developed early into severe stenosis. Four of 19 grafts occluded during follow-up (two polytetrafluoroethylene, two spiral saphenous vein graft). Computed tomography failed to identify stenosis in two grafts, magnetic resonance imaging failed to confirm one stenosis and one graft occlusion, and duplex scanning was inconclusive on graft patency in 10 patients. Angioplasty was performed in all four patients with severe stenosis, with simultaneous placement of Wallstents in two. One of the Wallstents occluded at 9 months. Repeat percutaneous transluminal angioplasty was necessary in two patients, with placement of Palmaz stents in one. Only one graft occlusion and one severe graft stenosis occurred beyond 1 year. The primary, primary-assisted, and secondary patency rates were 61%, 78%, and 83% at 1 year and 53%, 70%, and 74% at 5 years, respectively. CONCLUSION: Long-term secondary patency rates justify SVC grafting for benign disease. Postoperative surveillance with contrast venography is indicated in the first year to detect graft problems. Endovascular techniques may salvage and improve the patency of SVC grafts.

Safety, feasibility, and early efficacy of subfascial endoscopic perforator surgery: a preliminary report from the North American registry.

PURPOSE: The North American Subfascial Endoscopic Perforator Surgery (NASEPS) Registry was established to evaluate the safety, feasibility, and efficacy of minimally invasive endoscopic Linton operations for treatment of chronic venous insufficiency. METHODS: Retrospective analysis was performed on the clinical data of 151 patients who underwent attempt at 158 SEPS in 17 medical centers in the United States and Canada between June 1993 and February 1996. RESULTS: SEPS was completed on 155 limbs of 148 patients, 81 male and 67 female (mean age, 56 years; range, 27 to 87 years). Three procedures were aborted. Seven patients had bilateral procedures (data from one limb were analyzed). One hundred four limbs (70%) had active ulcers, and 22 (15%) had healed ulcers. A single endoscopic port without insufflation was used in 66 procedures (45%) and laparoscopic instrumentation, with two or three ports, in 82 (55%), with CO2 insufflation in 78 (53%). A tourniquet was used on 112 patients (76%). Concomitant venous procedures were performed in 106 patients (72%; saphenous stripping in 71, high ligation in 17, varicosity avulsion in 85). No early deaths or thromboembolism occurred. Complications included wound infections (9), superficial thrombophlebitis (5), cellulitis (4), and saphenous neuralgia (10). Seven patients with wound infection had open ulcers; nine of 10 with neuralgia had concomitant procedures. A roll-on tourniquet caused skin necrosis in one patient. The clinical score improved from 9.4 to 2.9 after surgery (p < 0.0001). Mean follow-up was 5.4 months; 31 patients had > or = 6 months follow-up. Ulcers healed in 88% (75 of 85); recurrence or new ulcer was reported in 3% (4 of 120). CONCLUSIONS: The SEPS modified Linton operation appears safe, with no postoperative deaths or early thromboembolism. Wound infection after SEPS remains important. Early results indicate rapid ulcer healing. Prospective evaluation of long-term results is warranted.

Surgical technique and preliminary results of endoscopic subfascial division of perforating veins.

PURPOSE: Direct surgical ligation of incompetent perforating veins has been reported to effectively treat severe chronic venous insufficiency. It is associated, however, with significant wound complications. We evaluate our early experience with endoscopic subfascial division of the perforating veins. METHODS: From August 5, 1993, to December 31, 1994, 11 legs in nine patients (five male and for female) were treated with endoscopic subfascial division of perforating veins. Nine of the 11 legs had active or recently healed venous ulcers. Mean duration of the ulcerations was 5.6% years. Standard laparoscopic equipment with 10-mm ports was used to perform clipping and division of medial perforating veins through two small incisions made just below the knee, avoiding the area of ulcer and lipodermatosclerosis. Carbon dioxide was insufflated at a pressure of 30 mm Hg into the subfascial space to facilitate dissection, and a pneumatic thigh tourniquet was used to obtain a bloodless operating field. Concomitant removal of superficial veins was performed in eight limbs. Mean follow-up was 9.7 months (range, 2 to 13 months). RESULTS: A mean of 4.4 perforating veins (range, 2 to 7) were divided; tourniquet time averaged 58 minutes (range, 30 to 72). Wound infection of a groin incision and superficial thrombophlebitis were early complications; each occurred in one patient. In seven legs the ulcer healed or did not recur and symptoms resolved. In three legs, the ulceration improved, and in one it was unchanged. CONCLUSIONS: Endoscopic subfascial division of perforating veins seems to be a safe technique, with favorable early results obtained in a small number of patients. This preliminary experience supports further clinical trials to evaluate this technique.

Aortic reconstruction in kidney transplant recipients.

Renal transplantation has increased the longevity of patients with uremia. An increasing number undergo aortic reconstruction, which exposes the transplanted kidney to ischemic injury. To evaluate the risk for renal failure, loss of the transplant, and methods of renal protection, we reviewed our experience. Clinical data were reviewed for 10 consecutive patients (7 men, 3 women; mean age 52.7 years [range 32 to 75 years]) with a transplanted kidney who underwent aortic reconstruction between 1977 and 1994 at our institution. Mean interval between renal transplantation and aortic reconstruction was 5.9 years (range 1 month to 12.7 years). Seven patients required emergency repair because of dissection (2 patients), aneurysm rupture (4 patients), or symptomatic aneurysm (1 patient); three underwent elective repair. Reasons for reconstruction included aortic dissection (2 patients), aneurysm of the descending thoracic (2 patients), thoracoabdominal (1 patient), or abdominal aorta (3 patients), and aortoiliac occlusive disease (2 patients). Patients with thoracic or thoracoabdominal reconstructions underwent repair with atriofemoral, aortofemoral, or femorofemoral shunt placement or bypass. Of the five abdominal aortic reconstructions, the kidney was protected with aortofemoral shunt placement in one patient and cold renal perfusion in three. In two of them, topical cooling of the kidney also was used. One patient with acute aortic dissection died at 39 days as a result of respiratory failure. Loss of the recently transplanted kidney was caused by acute rejection. One patient had a transient increase in serum creatinine concentration. Eight no worsening of renal function, and none of the nine survivors lost the transplanted kidney. We concluded that aortic reconstruction can be safely performed in kidney transplant recipients. Patients in whom thoracic or thoracoabdominal aortic reconstruction was required were protected with an atriofemoral or aortofemoral bypass or shunt. Patients undergoing abdominal aortic reconstruction did well when cold renal perfusion with or without local cooling of the transplant was used for renal protection. Transplanted kidneys appeared to tolerate ischemic injury similarly to native kidneys.