Katsumi Kawasaki

Surgical strategy of abdominal aortic aneurysm with preoperative renal failure

OBJECTIVES To determine the effect of preoperative renal failure on the outcome of patients suffering from infrarenal abdominal aortic aneurysm (AAA). METHOD During the period from January 1979 to August 1995, 364 patients with AAA were admitted to our hospital and 323 underwent elective repair. The patients were retrospectively analysed in three groups. Group I was composed of 273 patients with a normal renal function who underwent an aneurysm repair. Group II was composed of 50 patients who demonstrated a preoperative renal dysfunction (creatinine above 2.0 mg/dl or creatinine clearance below 40 ml/min) and underwent an operation, including three patients maintained on chronic haemodialysis. Group III was composed of 18 patients with a renal dysfunction who did not undergo repair, including one patients maintained on chronic haemodialysis. RESULTS The operative mortality rate of groups I and II were 0.4% and 2.0%, respectively, although no significant difference was observed. The incidence of postoperative cardiac and pulmonary complications were also comparable in two groups. No patients required acute haemodialysis. The 5-year survival rate of group II (44%) was significantly higher than that of group III (20%), and seven of the 18 patients (39%) in group III ultimately died of a rupture of the AAA. CONCLUSIONS Patients with chronic renal failure can undergo an abdominal aortic aneurysm repair based on the same indications as those without renal failure.

The effect of overweight status on the short-term and 20-y outcomes after hepatic resection in patients with hepatocellular carcinoma

BACKGROUND We aimed to evaluate the impact of body mass index (BMI) on the short- and long-term outcomes of hepatic resection in patients with hepatocellular carcinoma (HCC). METHODS We performed 371 hepatic resections in HCC patients whom we categorized into two groups based on BMI: BMI ≥ 25 (n = 77) and BMI <25 (n = 294). We compared surgical outcomes between groups. RESULTS The incidence of postoperative complications in the BMI ≥ 25 group was comparable to those in the BMI <25 group. However, patients in the BMI <25 group showed a significantly worse long-term prognosis than those in the BMI ≥ 25 group (P < 0.01). The results of multivariate analyses showed that BMI <25 was an independent and prognostic indicator of long-term outcome after hepatic resection in HCC patients. CONCLUSIONS A BMI ≥ 25 is not a risk factor for mortality or postoperative complications, and is considered to provide a better long-term prognosis (>20 y) than a BMI <25 in patients with HCC after hepatic resection. Further studies are needed to determine whether these results apply to other patient populations outside Japan where BMI ≥ 30 is more prevalent.

The effect of probucol on intimal thickening of autologous vein grafts in hyperlipidemic rabbit

Probucol is used to treat hypercholesterolemia and also has an anti-atherogenic effect. The effects of probucol on intimal thickening of autologous vein graft in hyperlipidemic rabbits with poor distal run-off were investigated. A poor distal run-off model was prepared in the right hindlimb of 18 rabbits allocated to four groups depending on diet: normolipidemic commercial diet, (NL group, n = 5); hyperlipidemic diet (HL group, n = 5); commercial diet with 1% probucol (NP group, n = 4); and hyperlipidemic diet with 1% probucol (HP group, n = 4). After 4 weeks the femoral vein grafts were implanted into normal (n = 18) or poor (n = 18) runoff limbs. Vein grafts were harvested 4 weeks after implantation. Intimal thickening of the graft was measured and macrophages therein examined immunohistochemically. The serum cholesterol level was not reduced by probucol treatment. The mean flow rate of the graft was significantly reduced in the poor run-off limb. On histological examination intimal thickening in the poor run-off limb was significantly greater than that of controls, while intimal thickening in the HL and HP groups was enhanced compared with that in the NL and NP groups, respectively. Mean intimal thickening in each limb in HP group rabbits was significantly lower than that in HL rabbits (microm): control (HL/HP): 99.4(7.4)/58.8(0.7) (P < 0.05); poor run-off (HL/HP): 155.3(9.6)/130.3(7.3) (P < 0.O5). There was no difference between NL and NP (microm): control (NL/NP): 44.6(24.7)/31.5(12.8); poor run-off (HL/HP): 115.3(13.8)/97.5(34.0). In addition, enhanced intimal thickening due to poor distal run-off was not suppressed. Immunohistochemical staining showed intimal macrophage infiltration in the HL and HP groups; however, macrophage infiltration in grafts in the HP group was less than in the HL group. In conclusion, under hyperlipidemic conditions, probucol decreased intimal thickening enhancement of the vein graft, and suppressed intimal macrophage infiltration. These findings were similar to the anti-atherogenic effect of probucol in the native artery. Hence, probucol administration after vascular reconstruction with vein grafts in patients with hyperlipidemia may be beneficial.

Inhibition of 12(S)-hydroxyeicosatetraenoic acid (12-HETE) production suppressed the intimal hyperplasia caused by poor-runoff conditions in the rabbit autologous vein grafts.

The efficacy of OPC-29030, a newly developed inhibitor of 12(S)-hydroxyeicosatetraenoic acid (12-HETE) production, was evaluated on intimal hyperplasia of experimental autologous vein grafts in a distal poor-runoff model and a hyperlipidemic model in rabbits. First, rabbits were divided into two groups, the distal poor-runoff group (PR group) and the hyperlipidemic group (HL group). After 4 weeks preparing the PR model and the HL model, the femoral vein was implanted into the ipsilateral femoral artery. Then they were subdivided into two groups, depending on the diet provided; diet group with 0.1% OPC-29030 (OPC-29030 group) and normal diet group (control group). At 4 weeks, the grafts were harvested, and intimal hyperplasia of the graft was measured with an ocular cytometer. Intimal cell proliferation was determined by bromodeoxyuridine (BrdU) incorporation at 2 weeks after surgery. In addition, the effect of OPC-29030 on the proliferation or migration of rat aortic smooth muscle cells in culture was investigated. In the in vivo study in the PR group, the intimal hyperplasia and the plasma 12-HETE levels in the OPC-29030 group were significantly inhibited, compared with those of the control group. However, in the HL group, the intimal hyperplasia in both the OPC-29030 and control groups showed a remarkable degree of intimal hyperplasia. There was no significant difference between those two groups. Furthermore, there was no significant difference in the plasma 12-HETE levels in the HL group irrespective of the presence of OPC-29030. The BrdU labeling index at 2 weeks after grafting was significantly lower in the OPC-29030 group compared with that in the control group in the PR group. In the in vitro study, OPC-29030 did not inhibit smooth muscle cell proliferation; however, OPC-29030 inhibited the migration. These results demonstrate the efficacy of OPC-29030 in reducing the degree of intimal hyperplasia under PR conditions, but not under hyperlipidemic conditions. The mechanism of reducing the intimal hyperplasia may be that OPC-29030 inhibited 12-HETE production, which did not inhibit proliferation while inhibiting migration of the smooth muscle cell. These results suggested the possible involvement of 12-HETE with the intimal hyperplasia under PR conditions.

Comparison of retroperitoneal and transperitoneal approach for reconstruction of abdominal aortic aneurysm in patients with previous laparotomy

Although the standard surgical approach for repair of infrarenal abdominal aortic aneurysm (AAA) has been the transperitoneal approach, several reports have suggested the usefulness of retroperitoneal aortic reconstruction. However, the superiority of the retroperitoneal compared with transperitoneal approach is still controversial. To compare the efficacy of the retroperitoneal with that of the transperitoneal approach in elective AAA resection, 19 consecutive cases with previous laparotomies were randomly reviewed. From January 1990 through December 1992, 94 consecutive patients underwent elective reconstructions of an infrarenal AAA. Among them, 75 patients had had no previous surgery of any kind. In all of them, the transperitoneal approach was used (Group I). Nineteen other patients who had various laparotomies were randomly divided into two groups. The transperitoneal approach was used in 10 patients (Group II), and the retroperitoneal approach was used in 9 patients (Group III). Thus, the patients were separated into three groups and the intra- and postoperative parameters were compared. Surgical data including operative time, intraoperative blood loss, and aortic cross-clamping time did not differ significantly between the transperitoneal approach in the patients without laparotomy (Group I) and the retroperitoneal approach (Group II). In addition, the postoperative recovery including the initiation of alimentation and postoperative hospitalization also did not differ significantly between the two groups. However, there was a significant difference in the operative time and the blood loss between the retroperitoneal approach (Group II) and transperitoneal approach (Group III) in the patients with previous laparotomy. In addition, the postoperative parameters including the initiation of oral intake was sooner and hospitalization was significantly shorter in the retroperitoneal group (Group II) than in the transperitoneal group (Group III) with previous laparotomy. There was no incidence of postoperative adhesive ileus in the patients with the retroperitoneal approach (Group II). The results demonstrated no important advantage for the retroperitoneal approach compared with routine transperitoneal approach in the patients without previous laparotomy. However, in the patients with previous laparotomies, the retroperitoneal approach is a preferable alternative to the transperitoneal route.

Usefulness of duplex scanning for following prosthetic grafts in above-knee femoropopliteal bypass: A new indicator for identification of failing grafts

To assess the utility of routine duplex surveillance for prosthetic grafts in above-knee femoropopliteal bypass, 33 prosthetic grafts (expanded polytetrafluoroethylene; ePTFE 26, externally supported Dacron graft; EXS 7) were prospectively entered into a surveillance protocol from April 1990 through August 1994. Peak systolic flow velocity (PSFV), measured in two segments (midportion of the graft and host popliteal artery), was performed every 3 months. The mean value at the last point is compared between the patent group (n=28) and the occluded group (n=5). The means ± standard deviation (SD) of PSFV at the midportion of the graft are not significantly different in either group (patent group 36.4±7.0 cm/second, occlusive group 34.9±10.0 cm/second). For PSFV at the host popliteal artery, there is a tendency for the means ± SD of PSFV in the patent group to be superior to those in the occluded group (patent group 39.9±12.0 cm/second, occluded group, 29.6±7.4 cm/second). The mean rate of PSFV at the midgraft to PSFV at the popliteal artery (midgraft-popliteral artery index; MPI) in the occluded group is significantly lower than that of the patent group (patent group 1.2±0.3, occlusive group; 0.8±0.2,p<0.01), whereas all anklebrachial index (ABI) of the occluded group at the last point is higher than 0.85. Measurements of PSFV in two segments and calculation of MPI by using duplex scanning are more reliable in identifying failing prosthetic grafts than is determination of ABI.