Aleksandar Tomic

Unilateral nephrectomy causes an early abrupt decrease in plasma arginine and simultaneous reduction in glomerular filtration rate in living kidney donors.

OBJECTIVES Living donor kidney transplantation is regarded as beneficial to allograft recipients and not particularly detrimental to the donors. Recently we have documented a reduced glomerular filtration rate (GFR) in living kidney donors (LKDs). Considering kidneys as essential for l-arginine (Arg) metabolism, in the present study we analyzed plasma Arg and related compounds comparing them with the function of remaining kidney in LKDs after donation. DESIGN AND METHODS We analyzed GFR, plasma Arg, asymmetric dimethylarginine (ADMA), citrulline (Cit), glutamine (Gln), ornithine (Orn), phenylalanine (Phe), tyrosine (Tyr), thiobarbituric acid reactive substances (TBARS), urea, creatinine, nitrite, nitrate and their sum (NOx) in blood samples taken from LKDs before, immediately after (0-time) and 1, 2, 3, 7 and 14 days following surgery. RESULTS Gradual and moderate creatinine increase and albumin decrease were associated with decreased GFR. An abrupt decrease in Arg occurred, staying below baseline level throughout the 14 days. Also decreases in Gln, Cit, Orn, increase in Phe and TBARS, and unaltered ADMA, nitrite and NOx concentrations were obtained. Despite increased net protein catabolism (indicated by elevated Phe/Tyr ratios) lack of Arg, suggested by decreased molar Arg/Phe ratios, occurred. Decreased molar Arg/Gln suggests an early but transient decrease in Arg synthesis. CONCLUSION Unilateral nephrectomy causes an early abrupt decrease in plasma arginine and reduction in glomerular filtration rate in LKDs that was associated with increased net protein breakdown in the peripheral tissues and elevated oxidative damage, which has to be considered in their therapy.

Endovascular repair of ruptured abdominal aortic aneurysm

Introduction. Rupture of an abdominal aortic aneurysm (AAA) is a potentially lethal state. Only half of patients with ruptured AAA reach the hospital alive. The alternative for open reconstruction of this condition is endovascular repair (EVAR). We presented a successful endovascular reapir of ruptured AAA in a patient with a number of comorbidities. Case report. A 60-year-old man was admitted to our institution due to diffuse abdominal pain with flatulence and belching. Initial abdominal ultrasonography showed an AAA that was confirmed on multislice computed tomography scan angiography which revealed a large retroperitoneal haematoma. Because of patient’s comorbidites (previous surgery of laryngeal carcinoma and one-third laryngeal stenosis, arterial hypertension and cardiomyopathy with left ventricle ejection fraction of 30%, stenosis of the right internal carotid artery of 80%) it was decided that endovascular repair of ruptured AAA in local anaesthesia and analgosedation would be treatment of choice. Endovascular grafting was achieved with aorto-bi-iliac bifurcated excluder endoprosthesis with complete exclusion of the aneurysmal sac, without further enlargment of haemathoma and no contrast leakage. The postoperative course of the patient was eventless, without complications. On recall examination 3 months after, the state of the patient was well. Conclusion. The alternative for open reconstruction of ruptured AAA in haemodynamically stable patients with suitable anatomy and comorbidities could be emergency EVAR in local anesthesia. This technique could provide greater chances for survival with lower intraoperative and postoperative morbidity and mortality, as shown in the presented patient.

Endovascular repair of mycotic aneurysm of the descending thoracic aorta: diagnostic and therapeutic dilemmas-two case reports with 1-year follow-up.

A mycotic aneurysm of the thoracic aorta is a rare diagnosis with high mortality. We present two cases of endovascular reconstruction of mycotic descending thoracic aorta. Specific or nonspecific bacterial or other infectious agent in serial samples of blood, urine, cerebrospinal fluid, and pleural puncture was not detected in the first case, but we found in sputum sample Mycobacterium tuberculosis in the second patient. We empirically began by administering broad-spectrum intravenous antibiotics in the first case, with preoperative antibiotic prophylaxis and antituberculotic drugs therapy in the second case, and continued with the same medication for 4 months after endovascular repair. Control computed tomographic scans 6 months after reconstruction showed no endoleak in both patients. Repair of mycotic descending thoracic aortic aneurysms by endoluminal stent graft is reasonable alternative to open surgical intervention. A broad-spectrum antibiotic therapy has a high significance in the treatment of patients with mycotic aneurysm.

Renal transplantation promptly restores excretory function but disturbed L-arginine metabolism persists in patients during the early period after surgery.

The synthesis and whole body metabolism of L-arginine (Arg) are disturbed in renal diseases. Renal transplantation represents the best therapy in the end-stage of these diseases. In the present we compared alterations of plasma Arg and related compounds with renal excretory function in patients with end-stage renal disease, before and after kidney transplantation. Arg, asymmetric dimethylarginine (ADMA), citrulline (Cit), glutamine (Gln), ornithine (Orn), phenylalanine (Phe), tyrosine (Tyr), urea, creatinine, albumin, and nitrate were analyzed in patients before, immediately after (0-time) and 1, 2, 3, 7 and 14 days following living donors kidney transplantation. Healthy subjects were controls. Glomerular filtration rate (GFR) and amino acid molar ratios were calculated. Before transplantation creatinine, urea, Cit, Gln, ADMA, and nitrate were above, while GFR and Arg were below controls, confirming disturbed excretory and metabolic renal functions in patients with renal disease. Renal transplantation promptly normalized creatinine, urea, GFR, Cit, and nitrate. However, regardless of increased molar Phe/Tyr ratios, indicating increased net protein catabolism in peripheral tissues, low Arg and elevated ADMA concentrations persisted throughout the examined period. Alterations of other amino acids also suggest similarly disturbed Arg metabolism in patients after kidney transplantation. In conclusion, renal transplant promptly restored its excretory function, but increased net protein catabolism, disturbed Arg metabolism and endothelial dysfunction in entire body of these patients were not improved throughout the early period after the operation. That has to be considered in their therapy.

Elective visceral hybrid repair of type III thoracoabdominal aortic aneurysm

INTRODUCTION According to the classification given by Crawford et al. type III thoracoabdominal aortic aneurysm (TAAA) is dilatation of the aorta from the level of the rib 6 to the separation of the aorta below the renal arteries, capturing all the visceral branch of aorta. Visceral hybrid reconstruction of TAAA is a procedure developed in recent years in the world, which involves a combination of conventional, open and endovascular aortic reconstruction surgery at the level of separation of the left subclavian artery to the level of visceral branches of aorta. CASE REPORT We presented a 75-years-old man, with elective visceral hybrid reconstruc tion of type III TAAA. Computerized scanning (CT) angiography of the patient showed type III TAAA with the maximum transverse diameter of aneurysm of 92 mm. Aneurysm started at the level of the sixth rib, and the end of the aneurysm was 1 cm distal to the level of renal arteries. Aneurysm compressed the esophagus, causing the patient difficulty in swallowing act, especially solid food, and frequent back pain. From the other comorbidity, the patient had been treated for a long time, due to chronic obstructive pulmonary disease and hypertension. In general endotracheal anesthesia with epidural analgesia, the patient underwent visceral hybrid reconstruction of TAAA, which combines classic, open vascular surgery and endovascular procedures. Classic vascular surgery is visceral reconstruction using by-pass procedure from the distal, normal aorta to all visceral branches: celiac trunk, superior mesenteric artery and both renal arteries, with ligature of all arteries very close to the aorta. After that, by synchronous endovascular technique a complete aneurysmal exclusion of thoracoabdominal aneurysm with thoracic stent-graft was performed. The postoperative course was conducted properly and the patient left the Clinic for Vascular Surgery on postoperative day 21. Control CT, performed 3 months after the surgery showed that the patients vascular status was uneventful with functional visceral by-pass and with good position of a stent-graft without a significant endoleak. CONCLUSION Visceral hybrid reconstruction represents a complementary surgical technique to that with open reconstruction of TAAA. This approach is far less traumatic to a patient, and is especially important in patients with lot of comorbidities, because there is no need for thoracotomy, and ischemic-reperfusion injury of the body is reduced to a minimum.

Vascular access for hemodialysis via the iliac vessels.

Although creating vascular access for hemodialysis (HD) is a routine procedure in most cases, there are situations where routine approaches are no longer an option, and the surgeon needs to be creative in order to construct vascular access for rare and difficult cases (1-4). We present a 44-year-old man with dwarfism (28 kg, 100 cm), admitted to the hospital for creation of vascular access for HD. The patient was immobile because of multiple musculoskeletal deformities, but was fully alert and had preserved intelligence. The patient had developed kidney failure aged 22 because of multiple urinary tract anomalies. In the past the patient had Continuous Ambulatory Peritoneal Dialysis (CAPD) for two years, followed by HD three times a week for the last 20 years. Over the years, the patient also developed secondary chronic anemia, hyperparathyroidism and severe hypotension (BP=60/40 mmHg). After thrombosis of the last HD vascular access, right brachial artery was used for dialysis as a temporary solution with unsatisfactory results, and new vascular access was necessary. Color Doppler examination revealed that all major veins in the neck, arms, and legs were thrombosed. MSCT angiography of the lower limbs and pelvis, with phlebography of the pelvic veins revealed severe atherosclerotic changes on arterial vessels with preserved blood flow (Fig. 1). Because of patient posture and deformities, the abdominal wall was the only place accessible for a graft loop, and the right iliac vessels were the only option for vascular access (Fig. 1). The iliac vessels were accessed with an extra-peritoneal approach through a right Gibson incision. A polytetrafluoroethylene (PTFE) graft 5 mm, 50 cm long (GORE-TEX®, Stretch Vascular Graft, USA), was placed subcutaneously in a loop manner on the right side of the abdominal wall around the umbilicus. The graft was anastomosed to the external iliac artery and vein in “end-to-side” fashion, using PTFE CV-7 suture (GORE-TEX®, Sutures, USA) (Fig. 2). The patient was discharged home on the 10th postoperative day, and had his first successful HD using this graft twenty days later. The patient had anticoagulances following the operation (Fraxiparine 0,3 s.c.) for ten days. After that, the patient commenced maintenance therapy with warfarin. Similar angioaccess grafts have been used in the lower part of the abdominal wall (“bikini” bypass) as Hemla has suggested (5), but in this case femoral veins were thrombosed and we used iliac vessels. Moini et al. (6) reports the common iliac artery as an inflow in contrast to the external iliac artery which was more accessible in this case. Therefore, we decided to use an approach and vessels normally used during kidney transplant surgery. We used a 5 mm instead of a 6 mm graft which is usually advocated because of small caliber vessels with a greater chance of JV A _1 0_ 11 20 Fig. 1 MSCT angiography of the lower limbs and pelvis. Patient posture and multiple associated deformities can be seen in the picture depicted in the right corner.