Acid-base status during reconstructive surgery of the abdominal aorta.

Abolition of a temporary occlusion of the circulation in the legs during surgical reconstruction of the abdominal aorta generally exerts but little influence on the patient's acid-base status. The changes in acid-base status can be corrected by the patient himself. Routine administration of sodium bicarbonate or Tham is unnecessary. However, respiration, circulation and electrolyte balance should be carefully monitored to ensure that any disturbances in this respect can immediately be given adequate treatment. Determination of the acid-base status during the operation is a valuable aid in evaluation of the patient's condition and can be used as a guideline in therapy.     

Characteristics of reconstructive surgery in occlusion of the abdominal aorta

For the 10-year period, 70 patients with occlusion of the abdominal aorta were operated on (10% of the patients operated on for Leriche's syndrome). Severe ischemia of the lower extremities was noted in 25 (35.8%) patients. Low occlusion was diagnosed in 24, middle--in 15, high--in 31 patient. In low and middle occlusion, the end-to-side anastomosis was performed in 17 patients, end-to-end--in 49. In 4 patients, the axillary-femoral shunting was performed. In 32 of 48 cases, the patency of the inferior mesenteric artery was restored. Correction of renal blood flow was performed in 2 patients. Good results were obtained in 92.8% of the cases. The lethality was 7.1%.     

Increased glomerular filtration rate in patients after reconstructive surgery on the abdominal aorta

Fifty-three patients undergoing elective reconstructive surgery on the abdominal aorta were included in a prospective study to obtain information on postoperative glomerular filtration rate (GFR) in relation to increased fluid and sodium intake and decreased plasma colloid osmotic pressure (COP). GFR, extracellular fluid volume (ECV) and COP were measured before operation and on the first and fourth day after surgery. GFR and ECV were measured by means of the single injection residue detection method using the inulin analogue polyfructosan-S as marker. The compiled GFR values increased from 92.3 to 103.7 ml min-1 1.73 m-2 (P less than 0.002) on the first day, and to 105.3 ml min-1 1.73 m-2 (P less than 0.001) on the fourth day after surgery. Concomitantly, ECV increased from 8.9 litres 1.73 m-2 (P less than 0.025) respectively. Positive linear correlation was found on the first postoperative day between GFR per 1.73 m2 and ECV per 1.73 m2 (r = 0.33, P less than 0.05) and between GFR per 1.73 m2 and extracellular sodium content per 1.73 m2 (r = 0.38, P less than 0.01). COP was not correlated to GFR per 1.73 m2. The postoperative increase in GFR found in this study is most likely to be the result of increased ECV and renal plasma flow. Whether other factors are also involved remains unknown.     

Ureteral injury in abdominal vascular reconstructive surgery.

Iatrogenic ureteral injuries in vascular reconstructive surgery are rarely reported. We present a case of ureteral transection during repair of an aortic aneurysm in a patient with a previously placed aortobifemoral graft. In reported series of surgical ureteral injuries, 17 of 381 injuries occurred during vascular procedures. A review of the literature and management scheme for ureteral complications in the presence of prosthetic vascular grafts is presented in light of current endourologic materials and techniques.     

Ultrasonic diagnosis of aneurysms of the abdominal aorta and its state after reconstructive surgery

The article generalizes the results of examination of 44 patients for diagnosing aneurysms of the abdominal aorta and its complications with the use of the ultrasonic method. Aneurysms were detected in 27 patients, dissecting aneurysm was found in 7 of them and rupture of the aneurysm in one patient. Operation was carried out on 16 patients, all of them were kept under dynamic observation beginning from the 3rd-5th postoperative day. Various postoperative complications were noted in 4 patient in different periods.     

Coarctation of the abdominal aorta and multiple renal artery stenosis. Case report

A case of coarctation of the abdominal aorta associated with multiple stenotic renal arteries is reported. The patient was operated upon with successful thoraco-abdominal aortic bypass and direct reimplantation of 3 renal arteries on the graft. Surgical techniques for treatment of coarctation are discussed.     

Choice of the approach in the performance of reconstructive surgery of the abdominal aorta]

The experience with surgical treatment of 630 patients with the use of extraperitoneal and transabdominal approaches to the abdominal aorta is summarized. Their advantages and disadvantages are noted. The expediency to use a new extraperitoneal approach to suprarenal and infrarenal portions of the abdominal aorta has been proved. The results of a topographic-anatomic study are presented. The technique for performance of a new approach to the abdominal aorta at this region, its advantages over the existing approaches are described.     

Early prognostic factors of the surgery of aneurysms of the abdominal aorta with renal artery clamping]

The aneurysms of the abdominal aorta requiring suprarenal clamping are rare. Suprarenal clamping was required for only 43 of 544 aneurysms operated electively from 1981 to 1989. Twenty-five patients had a juxtarenal aneurysm, without any normal aortic segment under the renal arteries, and suprarenal clamping was therefore necessary while the upper anastomosis was being established (group I). Eighteen patients had an aneurysm enclosing the root of at least one renal artery (group II). Several prognostic factors have been assessed: patient's age, presence of preoperative renal insufficiency, of arterial hypertension or of coronary insufficiency, and revascularization method. Five patients died. Four of them belonged to group II and were over 75 years old. All presented with a preoperative renal insufficiency. Two of these deaths were caused by mesenteric infarction. Four cases of regressive postoperative renal insufficiency were observed in patients for whom renal clamping had lasted longer than 45 minutes. This study allowed outlining three prognostic factors: the patient's age, preoperative renal insufficiency, a period of renal ischemia exceeding 40 minutes. On the other hand, the severity of hypertension had no predictive value. Coronary insufficiency requires a strict hemodynamic surveillance, but is not a contraindication for revascularization.     

Intra-abdominal pressure and renal function after surgery to the abdominal aorta

It has been suggested that an elevated intra-abdominal pressure (IAP) can impair renal function. In a prospective longitudinal study, the IAP of 42 patients admitted to an intensive care unit after abdominal aortic surgery was monitored. When compared with the other patients, the 22 patients (53%) who developed renal impairment had higher IAP (17.8 +/- 6.0 mmHg versus 14.1 +/- 4.8 mmHg; P less than 0.01) and APACHE II scores (15.6 +/- 6.0 versus 9.8 +/- 4.6; P less than 0.01). Each of the 10 patients who were re-explored because of haemodynamic instability and oliguria had an IAP of greater than 18 mmHg (positive predictive value = 85%, negative predictive value = 62%). Following re-exploration, the urinary output increased by 115 +/- 40 mL/h (P less than 0.01), and the IAP decreased by 10 +/- 3 mmHg (P less than 0.01). Although it is concluded that an IAP greater than 18 mmHg is a significant risk factor for the development of impaired renal function, it was not possible to prove a causal relationship between these events. Nevertheless, such a relationship has been demonstrated in animal and human models.     

Pathophysiology, prophylaxis and treatment of reperfusion syndrome in the surgery of abdominal aorta aneurysm

The peroxidal oxidation of the lipids state was studied up, as well as of the whole blood neutrophils functional activity, hemodynamics and microcirculation of lower extremities in surgical treatment of the abdominal aorta aneurysm. The main significance in the reperfusional syndrome pathophysiology, caused by temporary overcompression of aorta, has the neutrophils activation, their interrelationship with the endothelium cells and the activity lowering of the tissue antioxidant system, manifestated by vascular spasm, which is mostly expressed in the patients with stenotic affection of the lower extremities arteries. Positive effect was noted in application of preparation corvitin, which has antioxidant action.     

Clinical and biochemical evaluation of different types of anesthesia during reconstructive surgery on the abdominal aorta

Reconstructive operations for occlusive injuries of the aorta and main arteries are followed by substantial changes in the clinico-biochemical indices. The investigation carried out in 100 patients has shown the degree of these changes to depend on the kind of anesthesia. The most favourable kind for the group under study was found to be the general anesthesia with sodium hydroxybutyrate.     

Role of reconstructive surgery in post-traumatic occlusions of the renal artery. Apropos of a case

Post-traumatic thrombosis of the renal artery was detected in a patient with multiple injuries. Based on findings in this case and those reported in the literature, the difficulties of early diagnosis, the viability of the renal parenchyma and the hypertensive risk of revascularization are discussed and an attempt made to define the place of arterial surgery in post-traumatic thrombosis of renal artery.     

The effects of arterial pressure during normothermic kidney perfusion

Background

Ex vivo normothermic perfusion (EVNP) can reverse some of the detrimental effects of ischemic injury. However, in kidneys with warm and cold ischemic injury the optimal perfusion pressure remains undetermined. The aim of this study was to evaluate the effects of two different arterial pressures during EVNP.

Methods

Porcine kidneys underwent static cold storage for 23 h followed by 1 h of EVNP using leukocyte depleted blood at a mean arterial pressure of either 55 or 75 mm Hg. After this, kidneys were reperfused for 3 h to assess renal function and injury. This was compared with a control group that underwent 24 h cold storage.

Results

During EVNP, kidneys perfused at 75 mm Hg had a higher renal blood flow, increased oxygen consumption (median 59.9 mL/min/g (range 30.1–78.6] versus 31.8 [8.2–53.8] mL/min/g; P = 0.026), and produced more urine (P = 0.002) than kidneys perfused at 55 mm Hg. During ex vivo reperfusion, renal blood flow was significantly higher in the 75 mm Hg and 55 mm Hg groups compared with the control (area under the curve median 75 mm Hg 462 [228–745], 55 mm Hg 454 [254–923] versus control 262 [215–442] mL/min/100g.h; P = 0.040). There was a significant loss of renal function and increase in tubular injury in the 55 mm Hg group kidneys (P = 0.001, 0.007). Levels of endothelin 1 were significantly reduced in the 75 mm Hg group (P = 0.026).

Conclusions

A mean arterial pressure of 75 mm Hg during EVNP resulted in less tubular damage and less endothelial injury during ex vivo reperfusion compared with kidneys perfused at 55 mm Hg.