Clifford J. Buckley

Ultrasonic evaluation of the palmar circulation: A useful adjunct to radial artery cannulation

Summary A means for evaluation of the palmar circulation using the Doppler ultrasonic velocity detector is described. The test was applied to a population of 70 normal volunteers (140 hands). Our investigation showed that between 4.8 and 12.8 patients per 1,000 can be expected to have acute ischemia of the hand after cannulation of the radial artery. An additional 25 to 50 patients per 1,000 would have to rely on poor collateral circulation for continued viability of the hand. Routine clinical use of this test in patients who may require cannulation of the radial artery is recommended.

Gallbladder disease in children and adolescents

Seventy-nine patients, twenty years old or younger, with cholecystitis underwent cholecystectomy during a five year period at Santa Rosa Medical Center. There was a considerable delay in diagnosis in many cases. Etiologic factors differed with race and age; however, the disease appears to be quite similar in adolescents and adults. Hemolytic disease was present in all five blacks but in none of the remaining seventy-four patients. Patients younger than ten years of age are more likely to have congenital anomalies or infectious etiologies for the gallbladder disease. Cholecystectomy was associated with minimal morbidity and no mortality in this series. Cholecystitis should be considered early in the child or adolescent with unexplained abdominal pain, and oral cholecystograms proved to be a safe and reliable method of diagnosis.

Results of the Nellix system investigational device exemption pivotal trial for endovascular aneurysm sealing

OBJECTIVE The Nellix EndoVascular Aneurysm Sealing system (Endologix, Inc, Irvine, Calif) is a novel approach to abdominal aortic aneurysm (AAA) endovascular repair whereby biocompatible polymer is employed to exclude and to seal the AAA sac. We report 30-day results of the U.S. pivotal trial. METHODS Consecutive, eligible, consenting patients were enrolled at 29 sites in the United States and Europe. Inclusion criteria required an asymptomatic infrarenal AAA, with aortic neck length ≥10 mm and angle to the sac ≤60 degrees, aortic neck diameter of 18 to 32 mm, aneurysm blood lumen diameter ≤6 cm, common iliac artery lumen diameter of 9 to 35 mm, access artery diameter ≥6 mm, and serum creatinine level ≤2 mg/dL. Follow-up at 30 days included clinical assessment and computed tomography angiography evaluation of endoleaks and device integrity as assessed by a core laboratory. The primary safety end point is the incidence of independently adjudicated 30-day major adverse events (MAEs), with success defined as superiority with reference to the Society for Vascular Surgery open repair control group (56%). RESULTS Between January and November 2014, 150 trial patients having a mean AAA diameter of 5.8 cm were enrolled and treated with the Nellix system with 100% procedural success. One early death (0.7%) occurred secondary to multisystem organ failure. All 149 surviving patients completed 30-day follow-up. There were no aneurysm ruptures, conversions, limb thromboses, stent fractures, or stent kinking. Five early MAEs occurred in four patients (2.7%) and included one death, bowel ischemia (1), renal failure (2), and respiratory failure (1). One (0.7%) secondary intervention to treat inadvertent coverage of a renal artery was performed. The core laboratory identified nine (6%) endoleaks (one type I, eight type II) on 30-day computed tomography angiography. Freedom from MAE was 97.3% (95% confidence interval, 93.3%-99.0%). CONCLUSIONS In selected patients, perioperative outcomes with the Nellix system for endovascular aneurysm sealing are encouraging, with very low 30-day morbidity and mortality and high procedural success. The primary safety end point has been achieved. Longer term follow-up is in progress.

Device-specific aneurysm sac morphology after endovascular aneurysm repair: Evaluation of contemporary graft materials

OBJECTIVE This study analyzed device-specific aneurysm sac morphology after endovascular aneurysm repair (EVAR) with low-permeability devices. METHODS Between September 2004 and May 2006, 122 patients were treated with EVAR. Three different devices were implanted: 47 Zenith (Cook, Indianapolis, Ind), 46 AneuRx (Medtronic, Santa Rosa, Calif) with Resilient Dacron Graft Material, and 29 Excluder (W. L. Gore & Associates, Flagstaff, Ariz) with low-porosity polytetrafluoroethylene (PTFE). Patients were followed up at 1, 6, and 12 months and then biannually with computed tomography (CT) angiography. Standard axial two-dimensional CT measurements were obtained and compared with preoperative imaging. The preoperative scan served as a baseline, and the minor axis diameter, measured at the largest axial cut of the abdominal aortic aneurysm, was compared with the same measurement at follow-up. RESULTS Patient age, sex, and preoperative aneurysm morphology were similar among groups. Patients receiving the Zenith endograft had a significantly larger neck diameter; however, there was no difference in the neck length between groups. The rate of type II endoleaks was similar for the Zenith (17%), AneuRx (17%), and Excluder (14%). At 1, 6, 12, and 18 months, all three grafts were associated with sac shrinkage. The resulting decreases in mean aneurysm size at 18 months and corresponding shrinkage were Zenith, 11%, 6.4 +/- 1.8 mm; AneuRx, 18.9%, 12.7 +/- 2.7 mm; and the Excluder, 5.5%, 3.3 +/- 0.9 (P < .05). The sac size in the 19 patients with a type II endoleak decreased 8.06% compared with a 15.43% decrease in sac size in patients without endoleak at 6 months. No significant sac expansion > or =5 mm has been observed among any of the groups to date. CONCLUSIONS Sac regression with all devices appears to have been favorably influenced by the new generation of graft materials and is improved compared with published reports of older generation graft materials for the AneuRx and Excluder. However, there is a trend toward greater sac regression with devices using Dacron vs PTFE. The relationship of aneurysm morphology and long-term effects on aortic stent grafts is yet to be determined.

One-year pivotal trial outcomes of the Nellix system for endovascular aneurysm sealing

Objective: The Nellix EndoVascular Aneurysm Sealing (EVAS) System (Endologix, Inc, Irvine, Calif) is a novel approach to abdominal aortic aneurysm (AAA) treatment whereby polymer is used to fill the AAA sac. We report 1‐year results of the investigational device exemption pivotal trial. Methods: Eligible patients were treated at 30 sites in the United States and Europe. Inclusion criteria required an asymptomatic infrarenal AAA, with a neck length ≥10 mm and ≤60° angle, iliac artery blood lumen diameter 9 to 35 mm, access artery diameter ≥6 mm, and serum creatinine ≤2 mg/dL. Follow‐up included computed tomography angiography scans at 30 days, 6 months, and 1 year that were evaluated by a core laboratory. The primary safety end point was 30‐day major adverse events (MAEs), which were compared with a performance goal of <56% (the Society for Vascular Surgery open repair control group rate). The primary effectiveness end point was treatment success at 1 year, which was compared with a performance goal of >80%. Treatment success required procedural technical success and absence of AAA rupture during follow‐up, conversion to open surgical repair, endoleak (type I or III) at 1 year, migration >10 mm causing complications or requiring secondary intervention, aneurysm enlargement, or secondary procedures through 1 year for resolution of endoleak, device obstruction or occlusion, or device defect. Results: Of 150 treated patients, 149 (99.3%) completed 1‐year follow‐up. The MAEs rate at 30 days was 2.7% (95% confidence interval, 0.7%‐6.7%), satisfying the primary safety end point (<56%). The 1‐year treatment success was 94% (95% confidence interval, 88.6%‐97.4%), achieving the primary effectiveness end point (>80%). At 1 year, key secondary outcomes included 6.7% MAEs, 4.7% serious device‐related events, 1.3% AAA‐related mortality, 3.7% secondary interventions, and 0.7% surgical conversions. MAEs through 1 year included death (n = 6), stroke (n = 3), bowel ischemia (n = 2), renal failure (n = 2), respiratory failure (n = 2), and myocardial infarction (n =1). One iatrogenic AAA rupture occurred and one AAA rupture was reported during follow‐up. AAA sac enlargement (>5 mm) was 1.5% at 1 year. Endoleaks were present in four patients (3.1%) at 1 year (1 type Ib and 3 type II). Migration >10 mm occurred in three patients (2.3%), but none required secondary intervention. Conclusions: Outcomes with this novel endovascular therapy for AAA, the Nellix EVAS System, are encouraging. The primary safety and effectiveness end points have been met. Low morbidity, low mortality, and high procedural and treatment success were achieved despite the inevitability of a learning curve and unique risks associated with a new device and technique. Long‐term follow‐up is in progress.

Randomized controlled trial comparing the safety and efficacy between the FUSION BIOLINE heparin-coated vascular graft and the standard expanded polytetrafluoroethylene graft for femoropopliteal bypass

OBJECTIVE Despite improvements in endovascular therapy for lower extremity arterial disease, open surgical revascularization is still required when the disease is extensive. Although autogenous vein is the conduit of choice for open femoropopliteal bypass, prosthetic grafts can be an acceptable alternative when adequate vein is not available. The FUSION BIOLINE heparin-coated vascular graft (Maquet Endovascular, Wayne, NJ) was developed to improve the patency rate associated with standard prosthetic grafts. The current study, the FINEST Trial (Comparison of Safety and Primary Patency Between the FUSION BIOLINE Heparin-Coated Vascular Graft and EXXCEL Soft ePTFE), was designed to assess the clinical outcome of heparin-coated and standard vascular grafts in a prospective, randomized, controlled, multicenter trial. METHODS During a 25-month period ending in June 2012, 209 eligible patients scheduled to undergo elective prosthetic femoral to above-knee or below-knee popliteal bypass were randomized to receive a standard expanded polytetrafluoroethylene (ePTFE) graft or the heparin-coated FUSION BIOLINE vascular graft. Among 203 patients in the efficacy analysis, claudication was the presenting symptom in 147 (72.4%), and the site of the distal anastomosis was at the above-knee level in 174 (85.7%). Grafts were assessed by duplex ultrasound imaging and ankle-brachial indices performed postoperatively at discharge and at 30 days, 6 months, and 12 months. The primary efficacy end point was primary patency of the study graft. The primary safety end point was the composite of major adverse events and periprocedural death. Secondary end points included the time to hemostasis of bleeding at the anastomotic suture hole and primary assisted and secondary patency. RESULTS The primary patency rates at 6 months were 86.4% for the FUSION BIOLINE heparin-coated vascular graft group compared with 70.0% for the standard ePTFE group, a difference of 16.4% (95% confidence interval, 2.7%-29.9%; P = .006), and the respective rates at 12 months were 76.5% and 67.0% (95% confidence interval, -4.8% to 23.0%; P = .05). The mean time to hemostasis of bleeding at the suture hole was 3.5 minutes in the FUSION BIOLINE group and 11.0 minutes in the standard ePTFE group (P < .0001). Major adverse events were significantly lower in the FUSION BIOLINE group, occurring in 17.1%, compared with 30.7% in the standard ePTFE group (P = .033), principally a result of a lower rate of major graft reinterventions through 12 months in the FUSION BIOLINE group (16.2% vs 30.7%). CONCLUSIONS Data from this randomized multicenter study demonstrated improved midterm patency, less bleeding at the suture hole, and lower major adverse events with the FUSION BIOLINE heparin-coated vascular graft compared with standard ePTFE grafts. Although the ultimate long-term benefit of the graft cannot be ascertained with the data currently available, the utility of the FUSION BIOLINE vascular graft appears promising.

Inherent problems with randomized clinical trials with observational/no treatment arms

Randomized clinical trials (RCTs) offering an observation/no treatment (OBS/NoRx) arm as control and which are focused on the management of a condition with potentially life-threatening consequences, however small the risk, often experience a significant rate of crossover to treatment by those randomized to the OBS/NoRx arm. Results of these trials when analyzed on intent-to-treat basis often fail to resolve the issue at which they were directed. The authors have observed this in trials of abdominal aortic aneurysms with this design and use these to exemplify the dilemmas RCTs of such design create, with crossovers ranging from 27% to over 60% (EVAR II, UKSAT, ADAM, PIVOTAL). Results of these trials are frequently used as level I medical evidence and their potential impact on clinical decision making and reimbursement can be quite significant and long-lasting. Recommendations regarding trial end points and suggestions to mitigate the high crossover effect are offered. It may be that some clinical conditions dealing with potentially life-threatening problems should not be studied in randomized prospective clinical trials containing an OBS/NoRx arm.

Experience with central high flow arteriovenous fistulas in patients requiring chronic parenteral chemotherapy or hemodialysis

Abstract Fifty central high flow arteriovenous fistulas were constructed using bovine arterial heterograft during the past four years to provide vascular access in forty-four patients requiring cyclic infusion chemotherapy or chronic hemodialysis. Overall long-term patency of thirty-six axillary-axillary and fourteen axillary-internal jugular fistulas was approximately 80 per cent, and of those fistulas that failed, 87 per cent were successfully revised. All failures occurred within the first year after construction and were confined to the group of patients receiving cyclic infusion chemotherapy. Most of the failures could be directly related to constant rather than intermittent use of the fistulas. Complications other than graft occlusion occurred in three patients and prompted surgical intervention—in one patient for brachial artery thrombosis, in one for unilateral facial edema after axillary-internal jugular fistula, and in one for aneurysmal degeneration of the midsegment of one axillary-axillary graft. There was no operative mortality, and there were no septic, hemorrhagic, or significant wound healing complications in this high risk group of patients. Hemodynamic evaluations of both acute and chronic fistulas showed an approximate 20 per cent increase in cardiac output, cardiac index, and right ventricular stroke work index which were subjectively and objectively well tolerated in those patients studied. Ease and comfort of cannulation of these fistulas for blood sampling, infusion chemotherapy, and hemodialysis were uniformly acceptable to both nurses and patients. Central high flow arteriovenous fistulas have proved a safe, durable, well tolerated means of providing vascular access in patients whose usual routes have been exhausted but who remain candidates for cyclic infusion chemotherapy or chronic hemodialysis.

Intussusception of the Appendiceal Stump

Intussusception of the appendiceal stump is a rare complication of appendec tomy. A patient is described in detail and the eighteen previously reported instances are reviewed. Symptoms associated with this entity were abdominal pain (95%), vomiting (47%), blood per rectum (26%), and a palpable abdominal mass (68%). The onset of symptoms occurred within two weeks following appendectomy in 84% of the patients. Barium enema examination was diagnostic in 87.5% of patients in whom it was performed. The diagnosis of intussusception of the appendiceal stump in the postoperative period is difficult because of the nonspecificity of symptoms, the paucity of physical findings, and the intermittent nature of the partial bowel obstruction. Early diagnosis and appropriate treatment are facilitated by a thorough knowledge of this rare complication of appendectomy.

Splenectomy: Its place in operations for inflammatory disease of the pancreas

Involvement of the spleen or its vasculature in inflammatory disease of the pancreas may result in life-threatening hemorrhage. Retrospective analysis of six patients having direct splenic involvement and/or occlusion of the splenic vein secondary to pancreatitis or pseudocyst showed that removal of the spleen as a portion of an appropriately timed operation for complications of pancreatitis uniformly resulted in an uncomplicated course and survival (3 patients). Leaving the spleen in place when it was directly involved in a pseudocyst and/or when the splenic vein was occluded resulted in postoperative bleeding, the requirement for reoperation, and death from septic sequelae (2 patients). One patient died of progressive respiratory and renal failure because initial operation was inappropriately delayed. We recommend splenectomy as a portion of an appropriately timed operation for complications of pancreatitis when the splenic vessels are involved and/or when the spleen is directly involved in a pseudocyst or lesser sac collection.