Renal fusion or ectopia can present formidable challenges during aortic surgery. To evaluate morbidity and define optimal management, the clinical histories of 120 patients with renal fusion or ectopia who underwent 21 aortic procedures at the authors' institution over a 37-year period were reviewed. Indications for surgery included aortic aneurysm in 16 patients (infrarenal in 15 and thoracoabdominal in one) and aortoiliac occlusive disease in five (with renovascular hypertension in two). The abnormal kidney was detected before surgery in 13 patients (65%) by excretory urography, arteriography, computed tomography, or ultrasonography. Arteriography revealed multiple and/or anomalous renal arteries in nine of 12 patients studied. At surgery, 15 patients (75%) were found to have multiple or anomalous renal arteries. Six required renal revascularization (reimplantation four, endarterectomy one, aortorenal bypass one). The renal symphysis was divided in two patients. There were no operative deaths. Six major complications included bleeding requiring reoperation, renal failure requiring short-term dialysis, pancreatitis, gastrointestinal bleeding, pneumonia and thrombophlebitis. Preoperative aortography is recommended in patients with renal fusion or ectopia because of the high incidence of associated renal artery anomalies. The surgeon must be prepared to preserve or revascularize these anomalous renal arteries. Division of the renal symphysis is rarely required. Although perioperative morbidity is raised, aortic reconstruction in patients with renal fusion or ectopia can be safely performed without increased mortality.
Between 1978 and 1990, 32 patients (15 men and 17 women; mean age 48 (range 15–83) years) underwent 35 operations for renal artery aneurysm (4.2% of 829 renal artery repairs). Eleven patients presented with acute symptoms (nine with hematuria, eight with abdominal pain, two with acute hypertension). Twenty-eight of the 32 patients had chronic hypertension. The diagnosis was confirmed by angiography in all but two. The mean diameter of the renal artery aneurysm was 1.7 (range 0.7–9.0) cm. Seventeen patients had concomitant renal artery stenosis; none of the aneurysms ruptured. Nephrectomy was performed in seven patients and excision of the aneurysm without reconstruction in five. Twenty patients underwent 23 reconstructions using lateral suture (three procedures), vein patch (three), saphenous vein (13), Dacron (three) or composite (vein and hypogastric artery) graft (one). Seven patients underwent ex vivo renal artery repair. There was no perioperative death or secondary nephrectomy. One postoperative graft occlusion was successfully revised. Hypertension improved in 50% of patients. The presence of hypertension, enlargement of a renal artery aneurysm, solitary kidney, bilateral involvement, acute hematuria or potential loss of kidney or renal function may be indications for surgical treatment of an aneurysm > 1.5 cm in diameter. A renal artery aneurysm of any size should be repaired in women who may become pregnant. Where there is branch involvement, ex vivo repair is the procedure of choice for renal salvage.
Cardiovascular actions of ET-B activation in vivo and modulation by receptor antagonism
The endothelin (ET)-B receptor subtype is expressed on vascular endothelial and smooth muscle cells and participates in vasodilatation and vasoconstriction. Controversy exists regarding the role of the ET-B receptor as a mediator of systemic, pulmonary, and renal vasoconstriction in states of marked ET-1 activation. Moreover, the potential activation of endogenous ET-1 with secondary stimulation of the ET-A receptor in response to sarafotoxin S6c (S6c) remains unclear. This study was designed to assess the cardiovascular actions of ET-B activation with S6c in the presence and absence of selective ET-A antagonism with FR-139317 and dual ET-A/ET-B antagonism with SB-209670 in the anesthetized dog. Compared with time control ( n = 5), S6c increased from baseline systemic vascular resistance (SVR) [28 ± 7 vs. 14 ± 3 resistance units (RU), P < 0.05] and pulmonary vascular resistance (PVR) (3.2 ± 0.7 vs. 0.9 ± 0.3 RU, P < 0.05) and decreased cardiac output (CO) (−1.7 ± 0.3 vs. −0.5 ± 0.1 l/min, P < 0.05), with no differences in renal vascular resistance in association with increases in plasma ET-1. S6c also decreased mixed venous oxygen saturation ([Formula: see text]) (56 ± 6 vs. 76 ± 5%, P < 0.05). Selective ET-A receptor antagonism did not affect the actions of S6c, with the exception that ET-A receptor antagonism blocked the increase in SVR to high-dose S6c. Dual ET-A/ET-B receptor antagonism attenuated the increase from baseline in SVR (7 ± 1 vs. 28 ± 7 RU, P < 0.05) and PVR (0.7 ± 0.2 vs. 3.2 ± 0.7 RU, P < 0.05) and decrease from baseline in CO (−0.9 ± 0.1 vs. −1.7 ± 0.3 l/min, P < 0.05) and[Formula: see text] (−7 ± 3 vs. −20 ± 3%, P < 0.05) observed with S6c alone. In summary, this study demonstrates an important role of ET-B receptor activation in vivo, which results in increases in plasma ET-1 and systemic and pulmonary vasoconstriction and reductions in CO and [Formula: see text]. This study also supports a modest role for the ET-A receptor in mediating the systemic vasoconstrictor response to high-dose S6c.
The Effect of Elastic Compression on Tcpo
2
in Limbs with Venous Stasis
A low oxygen tension might contribute to the dermatological changes produced by deep venous insufficiency and venous stasis. Since elastic support is often prescribed for stasis disorders, it would be of value to know whether compression alters the oxygen tension in affected skin. We performed studies in which the transcutaneous Po 2 (TcPo 2 ) was determined for the foot or lower leg in subjects with normal veins (n = 9) or with dermatitis caused by documented deep venous insufficiency (n = 14). Measurements were made using O 2 -sensing electrodes placed 1–2 cm apart; surface temperature was 45°C for one electrode (producing maximal vasodilation of the underlying skin) and 42°C for the other (producing submaximal vasodilation). The vasodilation index (VI = TcPo 2 at 42 °C/TcPo 2 at 45°C) was used as an index of vasomotor tone. In normal limbs, TcPo 2 (mmHg) and VI were affected by the subject's posture (TcPo 2 = 38.8 at 42°C and 61.4 at 45°C when supine; 40.8 at 42°C and 74.6 at 45°C when upright with legs dependent; VI = 0.63 supine and 0.53 upright). In limbs with venous stasis, TcPo 2 and VI were considerably lower (TcPo 2 = 23.6 at 42°C and 51.5 at 45°C when supine; 20.8 at 42°C and 60.5 at 45°C when upright; VI = 0.48 supine and 0.37 upright). Following the application of an elastic wrap to the limbs with stasis, upright values for TcPo 2 and VI were substantially improved (TcPo 2 with compression = 28.8 at 42°C and 62.4 at 45°C; VI = 0.46). We conclude that (1) TcPo 2 is reduced in regions of skin affected by stasis dermatitis, and (2) elastic compression improves TcPo 2 (during upright posture) in limbs with stasis dermatitis.
Popliteal Artery Entrapment Syndrome: Role of Imaging in the Diagnosis
Medical and surgical emergencies occasionally present as ruptured abdominal aortic aneurysms (RAAA). To assess benefits of laparotomies and adverse effects of unnecessary operations, the authors reviewed their experience. Thirteen patients, 9 women, 4 men (mean age: 72 years, range: 41-85) underwent emergency laparotomy between 1988 and 1996 for presumed RAAA and were found to have other surgical or medical emergencies. All the patients presented with hypotension, 12 had abdominal or back pain, four had pulsatile abdominal mass. Rupture was not excluded by computed tomography scan in three or by ultrasonography in two patients. Laparotomy disclosed intact abdominal aorta in all, but seven patients had abdominal aortic aneurysm. Of five surgical emergencies, laparotomy was indicated in four: three for ruptured visceral artery aneurysms, one for perforated duodenal ulcer. The fifth patient required thoracotomy for ruptured thoracic aneurysm. Four of eight medical emergencies were myocardial infarctions. One iatro genic complication required reoperation for bleeding. Mean hospital stay was 18 days; mean hospital charges were $40,771. Seven (54%) early deaths occurred; none were caused directly by the operation. Laparotomy was indicated in one third of deceptive emergencies that present as RAAA. Although mortality, morbidity, and costs were high, iatrogenic surgical complica tions were rare and deaths were not caused by unnecessary operations.
The coexistence of urologic malignancy (UM) and abdominal aortic aneurysm (AAA) is rare. Simultaneous treatment may increase morbidity, whereas staged operations delay necessary treatment. We reviewed our experience to develop guidelines for evaluation and management. Clinical data of all patients diagnosed between 1980 and 1998 with both AAA and UM, who also had staged or simultaneous surgical treatment were reviewed. Four thousand forty-seven patients underwent AAA repair during the study period at our institution. Of these, 18 (0.44%) patients, 16 men and two women (mean age: 74 years, range: 61 to 92) had UM. UM was discovered incidentally in nine patients with AAA with computed tomography (CT) scan (7) and ultrasonography (2). In one patient with AAA, hematuria raised the suspicion of UM. Eight patients were diagnosed with AAA during evaluation of UM by CT scan or ultrasound (7) or during laparotomy (1). Initial signs and symptoms included abdominal pain (33%), gross hematuria (33%), and urinary tract infections (17%), although 33% were asymptomatic. The AAA was symptomatic at first examination in three (17%) patients, 14 (78%) patients had hypertension, and two (11%) had renal insufficiency (overall mean serum creatinine: 1.6, range: 0.8 to 3.7). Mean AAA diameter was 5.8 cm (range: 3.8 to 8 cm). Aortography documented significant contralateral renal artery disease in two patients. Twelve patients underwent simultaneous AAA repair and resection of UM; the operations were staged in six (AAA repair first in 2, nephrectomy first in 4). One patient required emergent repair of a ruptured AAA three days after nephrectomy. UM was treated with nephrectomy in 17 patients, and with bilateral ureterectomy and cystectomy in one. A straight aortic graft was implanted in seven patients, a bifurcated graft in ten, and one had extra-anatomic reconstruction. Two patients required reconstruction of the contralateral renal artery. The 30-day mortality rate was 0% after staged and 6% after simultaneous repair (p= >0.1). Major perioperative complications occurred more frequently after simultaneous (42%) than after staged repair (33%), although the difference was not significant (p= >0.1). Two patients developed postoperative renal failure. Seventeen patients were followed for an average of 3.9 years (14 days to 10.8 years). Three (17%) patients died of recurrent cancer at 1, 10.7, and 10.8 years after surgery. Patients with resectable UM have satisfactory long-term survival, which justifies aggressive treatment of concomitant AAA. Aortography in these patients is suggested to exclude contralateral renal artery disease. Complications were frequent, but simultaneous repair did not increase morbidity or mortality significantly. The risk of AAA rupture after nephrectomy, need to correct contralateral renal artery disease at the time of nephrectomy, and disadvantage of delaying treatment of UM are compelling reasons to favor simultaneous treatment of AAA and UM.
Intraoperative Duplex Ultrasound During Carotid Endarterectomy
The purpose of this study was to examine the technical aspects of intraoperative duplex ultrasound (DUS) following carotid endarterectomy (CEA), suggest criteria to differentiate significant lesions requiring immediate surgical revision from normal or benign defects, and evaluate how frequently intraoperative DUS provides useful or unsuspected information. A retrospective study was performed on all patients who had both CEA and intraoperative carotid DUS between January 1,1990. and January 1,1995. A total of 155 DUS examinations were performed in 149 patients. Findings were grouped into three categories: normal; minor/insignificant lesions; and hemodynamically significant lesions based on the presence or absence of elevated peak systolic velocities, visible stenosis/thrombus, or intimal flap/dissection. Postoperative status was correlated with intraoperative DUS findings. Ninety-one (59%) examinations performed on 87 patients produced normal findings. Forty-seven (30%) examinations performed on 45 patients showed minor abnormalities consisting of insignificant residual plaque, residual external carotid artery stenoses, small intimal flaps, elevated velocities with no associated anatomic lesion, or an arterial kink. Fourteen patients (9%) had significant findings requiring immediate surgical revision. These consisted of large intimal flaps or dissection in six patients, marked residual plaque and significant stenosis in five patients, thrombus in two patients, and a kink in one patient. Three additional patients ( 2 %) had significant findings but were not revised for various reasons. No significant difference was identified in morbidity or mortality rates between those patients with normal findings, those patients with minor technical defects, and those patients with significant abnormalities undergoing immediate surgical revision. However, two of three patients who had significant abnormalities within the common carotid artery that were not revised suffered perioperative ipsilateral strokes. Intraoperative DUS is a safe and accurate method to assess the technical adequacy of CEA. Intraoperative DUS showed significant lesions in 11% of patients. Identification and immediate repair of significant technical defects may decrease perioperative complication rate and long-term restenosis rate.