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Biomedical subjects

R C Darling

Publications and source records attributed to R C Darling.

At least 55 records · Page 3Linked to original sources
PubMed1996

Fate of the excluded abdominal aortic aneurysm sac: long-term follow-up of 831 patients.

PURPOSE: Nonresective treatment of the infrarenal abdominal aortic aneurysm by proximal and distal ligation of the aneurysm sac (exclusion) combined with aortic bypass has been previously reported. A 10-year experience with 831 patients undergoing this procedure was reviewed. METHODS: From 1984 to 1994, 831 (761 elective, 70 urgent) of 1103 patients being treated for abdominal aortic aneurysm underwent repair with the retroperitoneal exclusion technique. Perioperative morbidity and mortality, estimated blood loss, transfusion requirements, natural history of the excluded aneurysm sac, and long-term survival were all assessed. RESULTS: The operative mortality rate for patients undergoing exclusion and bypass was 3.4%. The incidence of nonfatal perioperative complications was 5.2%. Colon ischemia requiring resection occurred in 2 (0.2%) of the 831 patients. Estimated blood loss was 638 +/- 557 cc (50 to 330 cc). On follow-up 17 (2%) patients were found to have patent aneurysm sacs as detected by duplex examination. Fourteen patients required surgical intervention. No cases of graft infection or aortoenteric fistula have been noted. CONCLUSION: Retroperitoneal exclusion and bypass is a viable alternative to traditional open endoaneurysmorraphy in surgery for abdominal aortic aneurysm. Most excluded aneurysm sacs have thrombosis without any long- or short-term complications; however, in a small number of patients delayed rupture of patent aneurysm occurs, thus emphasizing the need for diligent follow-up and appropriate intervention.

Adult↗
PubMed1996

Results of 1000 consecutive elective abdominal aortic aneurysm repairs.

In order to identify major risks for death and complications from elective repair of abdominal aortic aneurysm, the authors analyzed their experience with the last 1000 such repairs over a 15-year period. Of the patients, 772 were men and 228 were women; average age was 70 (range 37-92) years. Some 20% of the patients had severe chronic obstructive pulmonary disease and 33% had baseline creatinine level > 115 mumol/l. Fifteen patients were dialysis-dependent and 24% (242/1000) had significant cardiac disease. Operation used a retroperitoneal approach in 834 patients and a transperitoneal approach in 166. The perioperative mortality rate was 2.4%, but this did not change either chronologically or with technique: some 50% of the deaths were due to cardiac causes. Renal and pulmonary impairment did not affect mortality or complication; 64% of non-fatal complications were distributed in the renal (17%), pulmonary (19%) and cardiac groups (28%). The authors' experience showed that patients with cardiac disease remain at significant risk for post-abdominal aortic aneurysm repair complications in spite of selective preoperative cardiac evaluation. Renal and pulmonary risk factors did not cause additional mortality or morbidity. They suggest that elective abdominal aortic aneurysm repair can be performed with low mortality and morbidity, even in increasing numbers of high-risk patients.

Adult↗
PubMed1996

Bilateral carotid endarterectomy during the same hospital admission.

The efficacy of carotid endarterectomy for the prevention of strokes has been well demonstrated in recent multicenter randomized trials. However, patients presenting with bilateral significant disease pose a difficult problem to the vascular surgeon. Currently, bilateral carotid endarterectomies are staged at varying intervals between operations, with surgeon and patient weighing the risks of waiting for surgery versus the risks of having both procedures done within a shortened interval. There are few data and no consensus on the optimal time interval between these operations. In order to evaluate the timing of carotid endarterectomies in patients with severe bilateral disease, the authors reviewed their experience with patients who had bilateral procedures performed during one hospitalization. Over the past 5 years, they have performed 204 such carotid endarterectomies in 102 patients. Cervical block anesthesia was used in 99% (201/204) of these procedures. All patients either had symptomatic disease, > 60% stenosis or severe ulcerative plaque as defined by duplex scan and/or preoperative angiography. Symptomatic stenoses were the operative indications in 39% (80/204) of the patients; the remaining 61% (124/204) were symptom-free. The majority of patients (80%; 164/204) had their second procedure performed within 2 days of their first operation. There was no operative mortality and only one permanent neurologic defect in this group for a combined stroke mortality rate of 1%. Three patients (1.5%) had transient neurologic deficits postoperatively which completely resolved by discharge. These data show that bilateral carotid endarterectomies can be performed safely and effectively during one hospital admission with a short interprocedural interval and without an increase in mortality or morbidity.

Aged↗
PubMed1996

Access to the right renal artery from the left retroperitoneal approach.

One of the perceived limitations of the left retroperitoneal approach to the aorta is inadequate access to the right renal artery. Many consider the need for a concomitant right renal artery revascularization a contraindication to performing an aortic reconstruction through the left retroperitoneum. Exposure of the right renal artery can be difficult due to the posterior course of the artery behind the vena cava. However, when the aorta is transected, the right renal artery can be easily approached with anterior and cephalad displacement of the aortic root. Over the past 3 years, 52 patients have had right or bilateral renal artery revascularization via the left retroperitoneal approach; of these procedures, 37 were performed with concomitant aortic procedures. In total, 34 patients had bilateral and 18 had unilateral revascularizations. Five patients had a transaortic endarterectomy performed, and 36 were bypassed with 6-mm expanded polytetrafluoroethylene side limbs from the aortic graft. Indications for revascularization were: 39 for suprarenal aortic bypass, seven for renal salvage and six for primary renovascular hypertension. All reconstructions have remained patent and all have been followed by serial duplex and renal flow scans (follow-up for 1-42 months). The operative mortality rate was 5.8% (3/52). There were no major cardiorespiratory complications in this group. Adequate exposure to the proximal right renal artery can be obtained through the left retroperitoneal approach to the aorta, and successful revascularization of one of both renal arteries can be technically performed with acceptable mortality and morbidity.

Adolescent↗
PubMed1996

Advances in the surgical repair of ruptured abdominal aortic aneurysms.

Over the past two decades, the mortality rate for elective repair of infrarenal abdominal aortic aneurysms has improved to an acceptable level (< 5%). However, surgical results of ruptured abdominal aortic aneurysms have remained fairly constant with about 50% in hospital mortality rates. Growing experience with the use of the left retroperitoneal exposure for elective aortic surgery allowed the authors to extend the use of this technique to the repair of ruptured abdominal aortic aneurysm. The extended left retroperitoneal approach using a posterolateral exposure through the 10th intercostal space allowed the surgeon expeditiously and reliably to obtain supraceliac aortic control by dividing the left crus of the diaphragm in all patients. In total, 104 aortic replacements were performed for ruptured abdominal aortic aneurysm during the past 7 years. Of these patients, 87 were men and 17 women; mean(range) age was 72(52-95) years. Hemodynamic instability (as defined by a systolic blood pressure of < 90 mmHg) was present before surgery in 41% (43/104) of patients. The operative mortality rate was 27.9% (29/104). Preoperative hemodynamic instability, time of operative delay and aortic cross-clamp time did not correlate with operative mortality. The median duration of intensive care unit stay was 4 (range 1-60) days and hospital stay 11 (range 6-175) days. The results of this series identified that a change in the operative technique for the repair of ruptured abdominal aortic aneurysm beneficially affected patient survival. The authors suggest that expeditious supraceliac control without thoracotomy is an excellent alternative and offers an advantage in the surgical management of ruptured abdominal aortic aneurysm.

Aged↗
PubMed1996

Expeditious management of ischemic invasive foot infections.

Management of infected ischemic diabetic limbs requires antibiotic therapy, abscess drainage, and revascularization. However, revascularization is often delayed for several days or weeks as the infection is controlled. In an effort to decrease hospital stay and costs and to increase limb salvage, a series of 974 extremities with distal occlusive disease were managed with autogenous distal bypass. Some 136 of these limbs (125 diabetic) had severe invasive infections. These patients received intravenous antibiotics in all cases and abscess drainage if necessary. Vascular reconstruction was carried out as soon as possible, within 48 h of admission. An in situ bypass was used preferentially (107 cases). Patients were maintained on intravenous antibiotics in the perioperative period. Partial foot amputations, when necessary, were performed in 111 cases, usually 3-5 days after vascular reconstruction. There were no graft infections or major wound infections. There were two cases of skin edge necrosis requiring reoperation due to flap mobilization and consequent ischemia. Urgent revascularization with an autogenous conduit may be carried out in patients with invasive foot infections expeditiously, with high rates of limb salvage. Graft and wound infections are not common in this setting. Costly prolonged pre-bypass hospitalization in these cases is unnecessary.

Amputation, Surgical↗
PubMed1996

In situ prosthetic graft replacement for mycotic thoracoabdominal aneurysms.

Infected aortic aneurysms remain a difficult surgical problem associated with high morbidity and mortality. We report three cases of mycotic thoracoabdominal aneurysms treated by debridement of infected aortic tissue, in situ prosthetic graft replacement, and intensive antibiotic therapy. One early death occurred in a patient with systemic sepsis related to Salmonella enteritidis infection of the thoracic aorta secondary to a colovesical fistula. The two other patients remain alive at 2 years without further complications of the surgery. Bacteriology is as follows: Staphylococcus aureus, Streptococcus pneumoniae, and Salmonella enteritidis. In all patients the operation was performed immediately after the diagnosis was confirmed. Antibiotic therapy was begun intraoperatively and was continued for at least 6 months. Two patients were followed regularly, and there have been no septic recurrences in our 2-year follow-up period. In situ prosthetic graft replacement in conjunction with intensive antibiotic therapy is a viable option in the treatment of mycotic thoracoabdominal aortic aneurysms.

Aged↗
PubMed1995

Does concomitant aortic bypass and renal artery revascularization using the retroperitoneal approach increase perioperative risk?

While elective repair of abdominal aortic aneurysms and aortoiliac occlusive disease is associated with an acceptable (3%) mortality rate, combined aortic and renal revascularization has usually been reported to have a higher perioperative mortality. Over the past 5 years, 785 elective aortic procedures have been performed at the authors' medical center. During the same period, 77 renal artery reconstructions have been performed in 73 patients in conjunction with aortic procedures. All were done using the retroperitoneal approach to the aorta and renal arteries. Indication for concomitant renal artery revascularization included 79% (61 of 77 patients) for either significant stenosis or anatomic involvement, 18% for renovascular hypertension (14 of 73) and 3% (two of 73) for renal impairment. The demographics and risk factors were similar in both groups. Operative mortality rate was 2.9% (23 of 785) in the aortic group and 3% (two of 73) in the combined group. Complications in the combined group were one stroke (1.4%), one re-exploration for bleeding (1.4%), two pulmonary pneumonia (2.7%) and five patients had elevated serum creatinine (> 350 mumol/l) after operation. Of these patients two died, one had an occluded graft and two eventually improved. There was one early graft thrombosis and one late thrombosis. In the authors' experience, concomitant aortic bypass and renal artery revascularization can be performed with an acceptable mortality and morbidity using the retroperitoneal approach.

Adult↗
PubMed1995

Choice of peroneal or dorsalis pedis artery bypass for limb salvage.

BACKGROUND: Arterial bypasses performed for limb salvage have increasingly used peroneal and pedal arteries as outflow. However, few reports have been published that compare the patency of limb salvage of these alternative outflow tracts. In this report, we have examined our experience with peroneal and dorsalis pedis (DP) artery bypasses for limb salvage. METHODS AND MATERIALS: Of more than 3,000 infrainguinal reconstructions performed for limb salvage, 732 were completed to the peroneal artery. During the same period, 238 bypasses were performed to the DP artery. Patient demographics were similar in both groups. The in situ technique was used in 68% of the peroneal bypasses and in 66% of the DP bypasses, respectively. Translocated veins were used in 28% of bypasses, and spliced veins were used in 32%. RESULTS: Secondary patency rates for the DP bypass at 1 and 5 years were 89% and 67%, respectively, as compared with 89% and 78% for the peroneal artery bypass. Limb salvage rates for the DP bypass were 94% at 1 year and 86% at 5 years, as compared with 96% and 93% at 1 and 5 years, respectively, for the peroneal artery bypass. No statistical difference was found. Four (1.7%) hemodynamic failures occurred in the DP group and 10 (1.4%) in the peroneal group. Wound complications were seen in 9 (3%) patients in the DP group and in 11 (1.5%) in the peroneal group. CONCLUSION: This experience indicates that both peroneal and DP bypasses have acceptable patency and limb salvage rates. Selection of one of these two outflow tracts, where a choice exists, may depend on the conduit limitation and adjacent tissue infection; however, both outflow tracts are durable and hemodynamically effective for limb salvage.

Ankle↗
PubMed1995

Arterial reconstruction for limb salvage: is the terminal peroneal artery a disadvantaged outflow tract?

BACKGROUND: Arterial reconstructions performed for limb salvage have increasingly used distal perimalleolar and pedal arteries as outflow tracts. However, a paucity of reports comparing the patency and limb salvage rates of these outflow tracts has been published. In this report we examine our experience with distal peroneal artery reconstructions for limb salvage. METHODS: During the past 14 years 159 bypasses were performed to the distal peroneal artery (within 5 cm of the malleolus), 157 of which were performed by the medial approach and two by the lateral approach. RESULTS: Sixty-three percent of the patients were male, 65% were diabetics, and 43% were smokers; the average age was 72.6 years. Sixty-five percent of the bypasses were performed with the in situ technique. Thirty-one percent of the bypasses were performed with translocated or spliced vein technique, and seven (4%) were performed with prosthetic technique. Secondary patency rates for distal peroneal artery bypass grafts at 1 and 5 years were 86% and 75%. The limb salvage rate for distal peroneal artery bypasses was 87% at 5 years. Four hemodynamic failures occurred in this group. Wound complications requiring revision were seen in one patient with a distal peroneal bypass (0.6%). These results do not differ from our results with other perimalleolar vessels. CONCLUSIONS: Arterial reconstruction to the distal peroneal artery has acceptable patency and limb salvage rates. These bypasses are as effective and durable as other perimalleolar bypasses.

Adult↗
PubMed1995

Foot amputations.

When presented with an ischemic limb with forefoot necrosis of varying amounts, the surgeon often categorizes the need for amputation into toe, ray, transmetatarsal, below-knee, and above-knee. Adherence to this type of algorithm ensures a primary above- or below-knee amputation rate of 10% to 20%. The utility of the more uncommon amputations advocated here is an increase of limbs deemed eligible for revascularization and limb salvage. Furthermore, delaying the amputations until the vascular supply is normalized maximizes tissue salvage and minimizes prolonged hospitalizations with multiple amputations performed as a prelude to major amputation. Although these amputations are often looked upon as an afterthought by many vascular surgeons, careful execution here is as important to effective limb salvage as any distal bypass procedure.

Amputation, Surgical↗
PubMed1995

The use of spliced vein bypasses for infrainguinal arterial reconstruction.

PURPOSE: The use of autogenous vein, whether in situ or excised, for arterial bypass procedures is well accepted. However, this usually requires the presence of a length of good-quality vein of adequate diameter. In patients lacking sufficient length of vein, two or more pieces of vein may be spliced together to complete the reconstruction. The effect of vein splicing on vein bypass patency is not well studied. METHODS: Over a 14-year period, 1956 lower extremity revascularizations were performed with a single autogenous vein, 1806 in situ and 150 excised veins. During the same time, 184 bypasses required splicing vein segments together, of which 111 were in situ bypass procedures, which required splicing of one or more pieces of excised vein to complete the reconstruction (partial in situ bypass). Seventy-three bypasses were completed with multiple pieces of spliced excised vein. The source for the excised, spliced vein segments was the distal ipsilateral greater saphenous vein (GSV) in 40%, accessory ipsilateral GSV in 8%, contralateral GSV in 13%, lesser saphenous vein in 28%, and arm vein in 11%. RESULTS: The 1- and 4-year primary patency rates for the entire spliced vein group were 72% and 45%, with secondary patency rates of 79% and 61%. The 1- and 4-year secondary patency rates of partial in situ bypasses were 80% and 70%, compared with 91% and 83% for in situ bypasses completed without a spliced segment (p < 0.0001). The 1- and 4-year secondary patency rates were 78% and 67% in the spliced excised vein group and 85% and 75% in the single excised vein group (p = not significant). The 4-year limb salvage rates were as follows: in situ (96%), partial in situ (85%), single excised vein (95%), and spliced excised vein (90%). CONCLUSIONS: We conclude that the use of excised vein segments to complete partial in situ bypasses may be associated with a decrement of bypass patency. Use of spliced excised vein segments of good quality for arterial bypass can produce acceptable patency rates. Such spliced autogenous conduits are clearly preferable to prosthetic bypasses for infrageniculate arterial reconstructions. Meticulous technique is a prerequisite for the successful performance of vein-to-vein anastomoses.

Arm↗
PubMed1995

Durability of short bypasses to infragenicular arteries.

OBJECTIVES: The purpose was to test the durability of the use of the unobstructed popliteal or tibial arteries as alternative inflow sources. MATERIALS: We examined 106 such bypasses performed during a 12 year period (1981-93). The indication for surgery was limb salvage in 99.1%. Seventy-five percent of the patients were male, 78% were diabetic and the average age was 59.6 years. The inflow source was the above-knee popliteal artery in 15 cases, the below-knee popliteal artery in 70 cases, the anterior tibial artery in 11 cases and the posterior tibial artery in 10 cases. Adequacy of inflow was determined by angiogram as well as intraoperative pressure measurement when indicated. Outflow was to a distal tibial or plantar arteries in 77.4% of the procedures. Forty-six bypasses were performed by an in situ technique. Excised vein was used as conduit in 60 patients (56.6%); greater saphenous vein (38), lesser saphenous vein (10), cephalic/basilic vein (4), and splice vein (8). RESULTS: Operative mortality was 2.8%. Five year cumulative primary patency was 75.4% with a secondary patency of 82.6%. Five year cumulative limb salvage was 93.5%. Patency rate was not significantly different for various inflows or outflows. Only four of the 106 bypasses ultimately required a reconstruction from the femoral level for proximal progression of disease. Bypasses performed using an in situ technique showed a significantly better 5 year cumulative secondary patency rate (96.3%) than those done with excised vein (70.5%), p < .05 CONCLUSION: Results of this study indicate that use of the popliteal or tibial arteries as an inflow source in the absence of significant proximal disease carries acceptable results, especially when using the vein in situ.

Adolescent↗
PubMed1995

Long-term results of in situ saphenous vein bypass. Analysis of 2058 cases.

OBJECTIVE: The authors evaluated the long-term patency and outcome of patients undergoing infrainguinal reconstruction using the in situ saphenous vein. SUMMARY BACKGROUND DATA: The in situ saphenous vein bypass has demonstrated excellent patency and limb salvage rates in numerous studies. The authors previously reported their early results with these bypass procedures, and this article represents their long-term experience with 2058 in situ saphenous vein bypasses during a 20-year period. This comprises the largest series with long-term follow-up of in situ saphenous vein bypasses in the literature. METHODS: From 1975 to 1995, 3148 autogenous vein bypasses were performed at the authors' institution, of which 2058 used the saphenous vein in situ. The indication for operation was limb-threatening ischemia in 1875 of 2058 patients (91%). In 88% of patients with an intact ipsilateral saphenous vein, an in situ bypass was completed successfully. One thousand twenty-three bypasses (69%) were terminated at the infrapopliteal level. Of these bypasses, 1562 of 2058 (76%) were completed using the closed in situ technique. RESULTS: The 30-day patency rate was 96%, and the cumulative secondary patency was 91%, 81%, and 70% at 1, 5, and 10 years, respectively. Limb salvage rates using the in situ bypass were 97%, 95%, and 90% at 1, 5, and 10 years, respectively. CONCLUSION: The infrainguinal inflow source, length of bypass, specific outflow vessel, or vein diameter did not have a significant effect on immediate or long-term bypass performance. These data suggest that the in situ saphenous vein is an excellent conduit for femoropopliteal and femoral to infrageniculate bypasses for limb salvage.

Adolescent↗
PubMed1994

Pelvic ischemia following aortoiliac reconstruction.

Clinically evident compromise of parietal or visceral pelvic function secondary to interruption of pelvic blood flow occurs infrequently after aortoiliac reconstruction. Certain patterns of aortoiliac or occlusive aneurysmal disease or graft infection may require exclusion of the hypogastric or profunda femoral arteries. In these situations collateral blood flow or retrograde iliac flow may be insufficient to perfuse the pelvis and may cause ischemia. We present three cases of postoperative pelvic ischemia and describe our efforts to restore pelvic perfusion.

Aged↗