Rib-sparing scalenectomy for neurogenic thoracic outlet syndrome: Early results.

OBJECTIVE: Neurogenic thoracic outlet syndrome (NTOS) is no longer either "controversial" or "disputed"; however, its optimal surgical management remains unclear. Many thoracic outlet decompression procedures are performed by first rib resection, usually via a transaxillary route. METHODS: A retrospective review of a prospectively maintained NTOS database was performed. Patients with NTOS associated with a cervical rib and those with recurrent NTOS were excluded from the present analysis. All study patients had satisfied a 5-point clinical diagnostic protocol and had experienced a positive response to a local anesthetic scalene block. Surgical decompression included anterior, minimus, and middle scalenectomy and brachial plexus neurolysis via a supraclavicular incision and pectoralis minor tenotomy through a small vertical infraclavicular incision. No first ribs were excised. All the patients had completed QuickDASH (11-item version of the Disability of the Arm, Shoulder, and Hand questionnaire) preoperatively and at 3 or 6 months postoperatively. RESULTS: From 2011 to 2019, 504 thoracic outlet decompression procedures had been performed in 442 patients. The average operative time was 1.15 hours, and the average hospital length of stay was 1.05 days. Major complications, including intraoperative arterial injury, postoperative wound hematoma requiring reoperation, and chylothorax, occurred in 7 patients (1.4%). All but 2 patients (99.6%) had symptomatic improvement. Using a more rigorous definition of operative success of ≥50% improvement in the 3- or 6-month QuickDASH score, 458 rib-sparing NTOS operations (90.9%) were successful. In contrast to the mean preoperative QuickDASH score of 62.6, the average postoperative QuickDASH score was 25.2 (P = .001). CONCLUSIONS: These results suggest that (1) adherence to a rigorous preoperative diagnostic regimen, including performance of a scalene block, ensures, at the least, that surgery for NTOS can be successfully restricted to patients actually with the condition; (2) fibrotic, contracted scalene muscles are the cause of NTOS; (3) the first rib does not require removal for successful surgical treatment of NTOS; and (4) 90% of the patients so treated can expect significant early symptomatic and functional improvement.

Ischemic Toe Ulceration Due to Foreign Body Embolus From Hydrophilic Polymer-Coated Intravascular Device.

Hydrophilic polymer coatings are now widely applied to catheters and other intravascular devices used in neurovascular, cardiovascular, and peripheral vascular procedures. Emboli consisting of these materials have been previously identified in biopsies and autopsies following pulmonary infarction, stroke, gangrene, or death. We report a case involving a nonhealing foot ulcer that appeared following cardiac catheterization, stenting, and automatic implanted cardiac defibrillator (AICD) implantation in a patient without other evidence of significant peripheral artery disease. An 85-year-old woman with chronic atrial fibrillation, aortic valve stenosis, and coronary artery disease underwent coronary stenting and AICD implantation for ventricular tachycardia and syncope. She developed a toe ulcer shortly thereafter, which did not respond to standard treatment. A histological examination following amputation of the toe found amorphous basophilic material in capillaries adjacent to the edge of the ulcer, which was similar to material associated with hydrophilic polymer coatings. Ischemia and infarcts following endovascular procedures should not be presumed to result from thrombus or vascular disease, even if intravascular devices appear intact or properly placed after the procedure. To help establish the incidence of ischemia caused by hydrophilic polymer device coatings, if excision of ischemic or infarcted tissue after endovascular procedures using coated devices becomes necessary, the tissue should be evaluated microscopically. Surgeons should also consider the tolerance of distal organs to infarct or ischemia when selecting coated intravascular devices.

Highlighting nerves and blood vessels for ultrasound-guided axillary nerve block procedures using neural networks.

Ultrasound images acquired during axillary nerve block procedures can be difficult to interpret. Highlighting the important structures, such as nerves and blood vessels, may be useful for the training of inexperienced users. A deep convolutional neural network is used to identify the musculocutaneous, median, ulnar, and radial nerves, as well as the blood vessels in ultrasound images. A dataset of 49 subjects is collected and used for training and evaluation of the neural network. Several image augmentations, such as rotation, elastic deformation, shadows, and horizontal flipping, are tested. The neural network is evaluated using cross validation. The results showed that the blood vessels were the easiest to detect with a precision and recall above 0.8. Among the nerves, the median and ulnar nerves were the easiest to detect with an F -score of 0.73 and 0.62, respectively. The radial nerve was the hardest to detect with an F -score of 0.39. Image augmentations proved effective, increasing F -score by as much as 0.13. A Wilcoxon signed-rank test showed that the improvement from rotation, shadow, and elastic deformation augmentations were significant and the combination of all augmentations gave the best result. The results are promising; however, there is more work to be done, as the precision and recall are still too low. A larger dataset is most likely needed to improve accuracy, in combination with anatomical and temporal models.

Automatic Segmentation and Probe Guidance for Real-Time Assistance of Ultrasound-Guided Femoral Nerve Blocks.

Ultrasound-guided regional anesthesia can be challenging, especially for inexperienced physicians. The goal of the proposed methods is to create a system that can assist a user in performing ultrasound-guided femoral nerve blocks. The system indicates in which direction the user should move the ultrasound probe to investigate the region of interest and to reach the target site for needle insertion. Additionally, the system provides automatic real-time segmentation of the femoral artery, the femoral nerve and the two layers fascia lata and fascia iliaca. This aids in interpretation of the 2-D ultrasound images and the surrounding anatomy in 3-D. The system was evaluated on 24 ultrasound acquisitions of both legs from six subjects. The estimated target site for needle insertion and the segmentations were compared with those of an expert anesthesiologist. Average target distance was 8.5 mm with a standard deviation of 2.5 mm. The mean absolute differences of the femoral nerve and the fascia segmentations were about 1-3 mm.

Reporting standards of the Society for Vascular Surgery for thoracic outlet syndrome: Executive summary.

Thoracic outlet syndrome (TOS) is a group of disorders all having in common compression at the thoracic outlet. Three structures are at risk: the brachial plexus, the subclavian vein, and the subclavian artery, producing neurogenic (NTOS), venous (VTOS), and arterial (ATOS) thoracic outlet syndromes, respectively. Each of these three are separate entities, though they can coexist and possibly overlap. The treatment of NTOS, in particular, has been hampered by lack of data, which in turn is the result of inconsistent definitions and diagnosis, uncertainty with regard to treatment options, and lack of consistent outcome measures. The Committee has defined NTOS as being present when three of the following four criteria are present: signs and symptoms of pathology occurring at the thoracic outlet (pain and/or tenderness), signs and symptoms of nerve compression (distal neurologic changes, often worse with arms overhead or dangling), absence of other pathology potentially explaining the symptoms, and a positive response to a properly performed scalene muscle test injection. Reporting standards for workup, treatment, and assessment of results are presented, as are reporting standards for all phases of VTOS and ATOS. The overall goal is to produce consistency in diagnosis, description of treatment, and assessment of results, in turn then allowing more valuable data to be presented.

Reporting standards of the Society for Vascular Surgery for thoracic outlet syndrome.

Thoracic outlet syndrome (TOS) is a group of disorders all having in common compression at the thoracic outlet. Three structures are at risk: the brachial plexus, the subclavian vein, and the subclavian artery, producing neurogenic (NTOS), venous (VTOS), and arterial (ATOS) thoracic outlet syndromes, respectively. Each of these three are separate entities, though they can coexist and possibly overlap. The treatment of NTOS, in particular, has been hampered by lack of data, which in turn is the result of inconsistent definitions and diagnosis, uncertainty with regard to treatment options, and lack of consistent outcome measures. The Committee has defined NTOS as being present when three of the following four criteria are present: signs and symptoms of pathology occurring at the thoracic outlet (pain and/or tenderness), signs and symptoms of nerve compression (distal neurologic changes, often worse with arms overhead or dangling), absence of other pathology potentially explaining the symptoms, and a positive response to a properly performed scalene muscle test injection. Reporting standards for workup, treatment, and assessment of results are presented, as are reporting standards for all phases of VTOS and ATOS. The overall goal is to produce consistency in diagnosis, description of treatment, and assessment of results, in turn then allowing more valuable data to be presented.

Extensive congenital abdominal aortic aneurysm and renovascular disease in the neonate.

Primary congenital abdominal aortic aneurysm is an extremely rare entity, with only 15 patients reported in the literature. Options for repair are often limited secondary to branch vessel size and other anatomic limitations. We present a neonate diagnosed with an abdominal aortic aneurysm on prenatal ultrasound. A postpartum computed tomography angiogram revealed an extensive type IV thoracoabdominal aortic aneurysm extending to the aortic bifurcation and resulting in bilateral renal artery stenosis. The unique features of this patient and challenges in management are discussed.

Techniques in carotid artery surgery.

The major objective in carotid endarterectomy is to achieve safe and complete removal of intimal plaque and provide lasting, nonstenotic closure. Controversy exists as to which technical variation best achieves this. In this paper, the authors review the operative nuances and outcomes with conventional and eversion endarterectomy, with a focus on the latter. The views expressed reflect specific neurosurgical and vascular perspectives in the context of a multi-disciplinary stroke unit, where carotid stenosis is managed with all available open and endovascular means. The neurosurgical approach was almost entirely conventional endarterectomy with primary repair, while the vascular surgeons used the eversion method with few exceptions.

Dacron femoral-popliteal bypass grafts in good-risk claudicant patients.

PURPOSE: To evaluate prosthetic femoral-popliteal (FP) grafts as bypass conduits in favorable patients with refractory calf claudication. SETTING: University-affiliated urban teaching hospital. METHODS: Cohort study of patency of 6-mm Dacron FP grafts used to treat patients with medically refractory calf claudication meeting the following criteria: nonsmoker; above-knee popliteal artery as an appropriate target vessel; > or =2-vessel tibial outflow; and postoperative anticoagulation and antiplatelet therapy. End points included primary and secondary FP graft patency, need for and outcome of subsequent intervention, limb amputation, and survival. RESULTS: From January 1998 through March 2001, 92 patients underwent 100 Dacron bypass grafts for medically refractory claudication. All underwent serial postoperative graft surveillance using duplex ultrasound. Using the Society for Vascular Surgery/International Society of Cardiovascular Surgery criteria life-table, primary patency was 84%, assisted primary patency was 88%, and secondary patency was 90% at 5 years. Two patients (2%) died during a mean follow-up period of 49 months (range 30 to 68). No limbs required amputation. Among 9 limbs in which Dacron FP bypass failed, 8 underwent subsequent successful autogenous bypass to the popliteal artery. CONCLUSION: In highly selected subjects with favorable features known to increase the likelihood of prosthetic graft patency, prosthetic FP grafts function well. Such patients undergo a simpler, more straightforward procedure than when autogenous FP bypass is performed. Subsequent success of autogenous FP repeat bypass suggests that previous prosthetic FP bypass does not threaten lower-extremity arterial outflow.

Recurrent neurogenic thoracic outlet syndrome.

BACKGROUND: Although 90% of patients with neurogenic thoracic outlet syndrome (NTOS) experience "excellent" or "good" results after thoracic outlet decompression, recurrent symptoms may develop in certain patients. METHODS: This is a retrospective review of patients with NTOS who developed recurrent symptoms of upper extremity/shoulder/neck pain, weakness and limitation of motion at least 3 months after initial relief of symptoms by surgical decompression. Diagnostic procedures and outcomes of reoperative surgery were assessed. RESULTS: Among almost 500 patients undergoing initial successful thoracic outlet decompression for symptoms of NTOS during the last decade, 17 redeveloped classic NTOS symptoms (3 of them bilaterally) at intervals from 3 to 80 months (mean 18 months) after the initial operative procedure. Ultimate diagnoses included incomplete first-rib resection (n = 1), compression of the brachial plexus by an ectopic band (n = 1), persistent brachial plexus compression by an intact first (n = 2) or second (n = 1) rib, brachial plexus compression by the pectoralis minor tendon (n = 13) and adherent residual scalene muscle (n = 14). Anterior scalene muscle block was positive in 9 patients later found to have recurrent symptoms from adherent residual scalene muscle. Among these 20 cases of osseous or musculotendinous causes of recurrent NTOS, all had "excellent" or "good" results from repeat surgery to eliminate the underlying structural problem (removal of intact or residual rib, pectoralis minor tenotomy, brachial plexus neurolysis, or a combination of these). CONCLUSIONS: Complete excision of cervical or first ribs and subtotal excision (instead of simple division) of the scalene muscles will decrease the incidence of recurrent NTOS. Pectoralis minor tenotomy should be considered part of complete thoracic outlet decompression. Anterior scalene muscle block accurately predicts outcome of reoperation for certain types of recurrent NTOS.

Operative management of distal ischemia complicating upper extremity dialysis access.

BACKGROUND: Ischemia distal to a functioning arteriovenous dialysis access is an infrequent but potentially serious complication that can be difficult to manage while maintaining access patency. METHODS: Retrospective review was made of all patients requiring operative intervention for dialysis access-induced distal ischemia from 1998 to 2002 in a tertiary vascular surgery referral practice. RESULTS: Twelve patients had 13 hands with ischemic changes requiring intervention after placement of hemodialysis access. Ischemia was successfully treated in all cases by distal revascularization-interval ligation. Dialysis access patency was better than expected. CONCLUSIONS: Distal revascularization-interval ligation is the optimal management for dialysis access-induced ischemia and should be attempted whenever possible.

Abdominal aortic reconstruction in infected fields: early results of the United States cryopreserved aortic allograft registry.

OBJECTIVE: Aortic reconstructions for primary graft infection (PGI), mycotic aneurysm (MA), and aortic graft-enteric erosion (AEE) bear high morbidity and mortality rates, and current treatment options are not ideal. Cryopreserved grafts have been implanted successfully in infected fields and may be suitable for abdominal aortic reconstructions. Registry data from several institutions were compiled to examine results of cryopreserved aortic allograft (CAA) placement. METHODS: The experience of 31 institutions was reviewed for CAAs inserted from March 4, 1999, to August 23, 2001. Indications for CAA, organisms, mortality, and complications were identified. RESULTS: Fifty-six patients, 43 men and 13 women, with a mean age of 66 years (range, 44 to 90 years) had in situ aortic replacement with CAA. Indications for CAA placement were PGI in 43 patients (77%), MA in seven (14%), AEE in four (7%), and aortic reconstruction with concomitant bowel resection in two (4%). Infectious organisms were identified in 33 patients (59%); the most frequent organism was Staphylococcus aureus in 17 (52%). Thirty-one patients (55%) needed an additional cryopreserved segment for reconstruction. The mean follow-up period was 5.3 months (range, 1 to 22 months). One patient died in the operating room, and the 30-day surgical mortality rate was 13% (7/56). Seven additional patients died during the follow-up period, yielding an overall mortality rate of 25% (14 patients). Two patients (4%) had graft-related mortality as the result of hemorrhage from the CAA and persistent infection. Graft-related complications included persistent infection with perianastomotic hemorrhage in five patients (9%), graft limb occlusion in five (9%), and pseudoaneurysm in one (2%). Three patients (5%) needed amputation. CONCLUSION: In situ aortic reconstruction with CAA in infected fields carries a high mortality rate, but most deaths are not the result of allograft failure. However, CAA infection and lethal hemorrhage caused by graft rupture occurs and is concerning. Early reinfection was not reported. Late graft-related complications, such as reinfection, thrombosis, or aneurysmal changes, are unknown. Preliminary data from this registry fail to justify the preferential use of CAA for PGI, MA, or AEE. A multicenter, randomized study is needed to compare results with established techniques.