Cerebral revascularization using omentum and muscle free flap for ischemic cerebrovascular disease

Surgical techniques and indications for treatment of adult moyamoya disease

Moyamoya disease (MMD) is a chronic, progressive cerebrovascular disease involving the occlusion or stenosis of the terminal portion of the internal carotid artery (ICA) and the proximal anterior and middle cerebral arteries. Adults with MMD have been shown to progressively accumulate neurological and cognitive deficits without treatment, with a mortality rate double that of pediatric patients with MMD. Surgical intervention is the mainstay of treatment to prevent disease progression and improve clinical outcomes. Several different types of bypasses can be utilized for revascularization in MMD, including indirect, direct, and combined forms of extracranial-to-intracranial (EC-IC) bypass. Overall, the choice of appropriate technique requires consideration of the age of the patient, preoperative hemodynamics, neurologic status, and territories most at risk and in need of revascularization. Here, we will review the indications and surgical techniques for the treatment of adult MMD. Step-by-step instructions for performing several bypass variants with technical pearls are discussed.

Omentum a powerful biological source in regenerative surgery

The Omentum is a large flat adipose tissue layer nestling on the surface of the intra-peritoneal organs. Besides fat storage, omentum has key biological functions in immune-regulation and tissue regeneration.

Omentum biological properties include neovascularization, haemostasis, tissue healing and regeneration and as an in vivo incubator for cells and tissue cultivation. Some of these properties have long been noted in surgical practice and used empirically in several procedures.

In this review article, the author tries to highlight the omentum biological properties and their application in regenerative surgery procedures. Further, he has started a process of standardisation of basic biological principles to pave the way for future surgical practice.

The Laparoscopically Harvested Omental Free Flap: A Compelling Option for Craniofacial and Cranial Base Reconstruction

Background Management of craniofacial and cranial base tumors is a challenge due to the anatomic intricacies associated with the calvarium, the pathological diversity of lesions that present, and the potential complications. Clinical outcomes in laparoscopically harvested omentum free flaps for cranial base and craniofacial reconstruction are presented in this paper, in the largest case series to date. Methods A retrospective single-center experience for over 10 years with laparoscopically harvested omentum flaps used to reconstruct craniofacial and cranial base defects. Results A total of 13 patients underwent craniofacial or cranial base reconstruction using laparoscopically harvested omentum free flaps. The mean patient age was 48 years. The anterior skull base represented the most common site of reconstruction. A total of 12 of the flaps survived (92%), with one flap failure due to infection. All patients demonstrated satisfactory aesthetic and functional outcomes. There were no perioperative or intra-abdominal complications. Conclusions The laparoscopically harvested omentum free flap is a safe and effective tool in the armamentarium of the reconstructive surgeon. It is the ideal option to treat complex, three-dimensional subcutaneous defects, such as those encountered in craniofacial and cranial base reconstruction. Its unique angiogenic and immunologic capacity makes it an excellent flap for the previously irradiated and/or infected wound bed.

Omental Approach to Functional Recovery After Cerebrovascular Disease

OBJECTIVE

To review and synthesize the clinical literature regarding risks and benefits of omentum transplantation and transposition surgery in patients with ischemic stroke of other etiology (non-MMD) and Moyamoya disease (MMD), and to evaluate the evidence for biological underpinnings of the presumed physiologic effects of omentum transplantation and transposition on vascularization of brain parenchyma.

METHODS

Articles were searched on scientific databases using predefined key terms. Data abstraction was based on the clinical course as reported in the articles. For further analysis, patients were divided into groups according to their diagnosis (MMD or non-MMD). Descriptive statistics were computed for better integration of the results.

RESULTS

The final literature review contained 15 articles (11 case series, 4 single case studies) with data on 93 patients (29 non-MMD, 64 MMD). At post-assessment 56% of patients showed substantial gains in functional domains (24% in the non-MMD group, 71% in the MMD group) and 92% demonstrated improvements of cerebral vascularization (55% in the non-MMD group, 98% in the MMD group). Differences in improvement became apparent with regard to the initial symptomatology wherein transient ischemic attacks were related to superior recovery rates and language pathologies showed least improvement.

CONCLUSIONS

Surgical revascularization using omental tissue has shown good success rates, particularly for recurrent transient ischemic attacks and prevention of further strokes and should be considered as treatment option for selected patients. Experimental data on the physiologic basis for postoperative improvement delivered convincing evidence for its arteriogenic potential and recent developments in omental stem cell research suggest a role in recovery from long-standing neurological deficits.

Less invasive pedicled omental-cranial transposition in pediatric patients with moyamoya disease and failed prior revascularization

BACKGROUND

Patients with moyamoya disease and progressive neurological deterioration despite previous revascularization pose a major treatment challenge. Many have exhausted typical sources for bypass or have ischemia in areas that are difficult to reach with an indirect pedicled flap. Omental-cranial transposition has been an effective, but sparingly used technique because of its associated morbidity.

OBJECTIVE

We have refined a laparoscopic method of harvesting an omental flap that preserves its gastroepiploic arterial supply.

METHODS

The pedicled omentum can be lengthened as needed by dividing it between the vascular arcades. It is transposed to the brain via skip incisions. The flap can be trimmed or stretched to cover ischemic areas of the brain. The cranial exposure is performed in parallel with pediatric surgeons. We performed this technique in 3 pediatric patients with moyamoya disease (aged 5-12 years) with previous superficial temporal artery to middle cerebral artery bypasses and progressive ischemic symptoms. In 1 patient, we transposed omentum to both hemispheres.

RESULTS

Blood loss ranged from 75 to 250 mL. After surgery, patients immediately tolerated a diet and were discharged in 3 to 5 days. The ischemic symptoms of all 3 children resolved within 3 months postoperatively. Magnetic resonance imaging at 1 year showed improved perfusion and no new infarcts. Angiography showed excellent revascularization of targeted areas and patency of the donor gastroepiploic artery.

CONCLUSION

Laparoscopic omental harvest for cranial-omental transposition can be performed efficiently and safely. Patients with moyamoya disease appear to tolerate this technique much better than laparotomy. With this method, we can achieve excellent angiographic revascularization and resolution of ischemic symptoms.

Revascularizing the upper basilar circulation with saphenous vein grafts: operative technique and lessons learned

BACKGROUND

The purpose of this study was to report our operative technique and lessons learned using saphenous vein conduits to revascularize the rostral basilar circulation (ie, bypass to the posterior cerebral or superior cerebellar arteries). We also review the evolution of this technique for the treatment of vertebrobasilar insufficiency (VBI) and complex posterior fossa aneurysms.

METHODS

Data were collected retrospectively for 8 consecutive patients undergoing rostral basilar circulation saphenous vein bypass grafts at our institution between 1989 and 2004 for the treatment of VBI or in conjunction with Hunterian ligation of complex posterior circulation aneurysms. The indications for treatment, pre- and postoperative neurologic status, angiographic results, operative complications, and long-term clinical outcomes were analyzed for each patient.

RESULTS

With clinical and angiographic follow-up ranging from 3 months to 15 years, 7 of 8 bypasses remained patent, 3 of 3 aneurysms remained obliterated, and 4 of 5 patients with VBI experienced resolution of their preoperative symptoms. There were no surgery-related deaths, but 2 patients did experience major neurologic morbidity. The outcomes for the 217 total patients reported in the literature were as follows: 135 excellent (62%), 26 good (12%), 30 poor (14%), and 26 dead (12%).

CONCLUSIONS

Despite the risk of serious neurologic complications with this procedure, when one considers the natural history of untreated patients, saphenous vein revascularization of the rostral basilar circulation remains an acceptable option. Although surgical technique has varied, patient selection criteria, graft patency, and patient outcomes have been relatively constant over the past 25 years.

Surgical management of moyamoya syndrome

Moyamoya syndrome, a vasculopathy characterized by chronic progressive stenosis at the apices of the intracranial internal carotid arteries, is an increasingly recognized entity which is associated with cerebral ischemia. Diagnosis is made on the basis of clinical and radiographic findings, including a characteristic stenosis of the internal carotid arteries in conjunction with abundant collateral vessel development. Adult moyamoya patients often present with hemorrhage, leading to rapid diagnosis. In contrast, children usually present with transient ischemic attacks or strokes, which may prove more difficult to diagnose because of patient's inadequate verbal and other skills, leading to delayed recognition of the underlying moyamoya. The progression of disease can be slow, with rare, intermittent events, or it can be fulminant, with rapid neurologic decline. However, regardless of the course, it is apparent that moyamoya syndrome, both in terms of arteriopathy and clinical symptoms, inevitably progresses in untreated patients. Surgery is generally recommended for the treatment of patients with recurrent or progressive cerebral ischemic events and associated reduced cerebral perfusion reserve. Many different operative techniques have been described, all with the main goal of preventing further ischemic injury by increasing collateral blood flow to hypoperfused areas of the cortex, using the external carotid circulation as a donor supply. This article discusses the various treatment approaches, with an emphasis on the use of pial synangiosis, a method of indirect revascularization. The use of pial synangiosis is a safe, effective, and durable method of cerebral revascularization in moyamoya syndrome and should be considered as a primary treatment for moyamoya, especially in the pediatric population.

Utility of the omentum in the reconstruction of complex extraperitoneal wounds and defects: donor-site complications in 135 patients from 1975 to 2000

OBJECTIVE

To examine donor-site complications after omental harvest for the reconstruction of extraperitoneal wounds and defects.

SUMMARY BACKGROUND DATA

The omentum, with its immunologic and angiogenic properties, is a versatile organ with well-documented utility in the reconstruction of complex wounds and defects. However, the need for laparotomy and the potential for intraabdominal complications have been cited as relative contraindications to the use of the omentum as a reconstructive flap. Further, few series have assessed long-term results, and no reports have focused on donor-site complications.

METHODS

Patients who underwent reconstruction of extraperitoneal defects with the omentum at a single university healthcare system were identified by searching discharge databases and office records. Charts were reviewed to determine patient demographics, surgical indications and technique, postoperative complications, and outpatient follow-up. Patients with donor-site complications were compared with patients who had no complications using the Student t test and chi-square analysis. Statistical significance was defined at P <.05.

RESULTS

From 1975 to 2000, the authors successfully harvested 135 omental flaps (64 pedicled, 71 free transfer) for reconstruction of the following defects: scalp (n = 16), intracranial (n = 1), orbitofacial (n = 33), neck (n = 8), upper extremity (n = 7), lower extremity (n = 4), intrathoracic (n = 3), sternal (n = 34), breast (n = 3), chest wall (n = 18), abdominal wall (n = 1), and perineal (n = 7). Donor-site complications in 25 patients (18.5%) included abdominal wall infection (n = 9), fascial dehiscence (n = 8), symptomatic hernia (n = 8), unplanned reexploration (n = 6), postoperative ileus (n = 3), gastrointestinal hemorrhage (n = 2), delayed splenic rupture (n = 1), gastric outlet obstruction (n = 1), and late partial small bowel obstruction (n = 1). Factors associated with increased donor-site complications included the use of pedicled flaps (compared with free tissue transfer), mediastinitis, advanced age, and pulmonary failure. Of note, 53 patients had undergone previous abdominal surgery; of these, 26 patients required extensive adhesiolysis and 4 patients sustained enterotomies. Eleven patients (8.1%) had partial flap loss and three patients (2.2%) had total flap loss. Mean length of stay was 28 days. Average follow-up was 2.4 years. The death rate was 5.9%.

CONCLUSIONS

The omentum can be safely harvested and reliably used to reconstruct a diverse range of extraperitoneal wounds and defects. Donor-site complications can be significant but are usually limited to abdominal wall infection and hernia. Risk factors associated with complications include the use of pedicled flaps, mediastinitis, and pulmonary failure. This low rate of donor-site complications strongly supports the use of the omentum in the reconstruction of complex wounds and defects.

Surgical approaches to vascular anomalies of the child's brain

The population of pediatric patients with cerebrovascular disease presents a unique set of challenges to the neurosurgeon. The wide scope of pathology, including arteriovenous malformations, cavernous malformations and moyamoya disease, coupled with marked advances in diagnosis and treatment of these conditions over the past several years has resulted in a proliferation of the literature related to this subject. The present review provides an overview of current methods of surgical treatment for pediatric cerebrovascular diseases, focusing on indications and use of recent refinements of pre-existing surgical approaches, and newly evolved operative techniques developed to treat these entities.

Thoracic reconstruction with the omentum: indications, complications, and results

This study provides a retrospective analysis of 60 patients who underwent thoracic reconstruction with the omentum. Patients were identified by searching several databases to determine demographics, indications for surgery, operative technique, and postoperative course, including donor and recipient site morbidity. From January 1975 to May 2000, the authors harvested and transferred the omentum successfully (57 pedicled, 3 free) in 60 patients (mean age, 60 years; age range, 21-86 years) for sternal wound infections (N = 34), chest wall resections (N = 17), pectus deformities (N = 2), intrathoracic defects (N = 4), and breast reconstruction (N = 3). The omentum was used as a primary flap in 39 patients and as a salvage flap in 21 patients. Average operative time was 3.9 hours and average hospital stay was 34.3 days. Partial flap loss occurred in 7 patients, with no total flap failures. Morbidity included six abdominal wound infections and seven epigastric hernias. Mortality was 11.7%. The omentum can be harvested safely and used reliably to reconstruct varying thoracic wounds and defects. Specific indications from this series include osteoradionecrosis, chest wall tumors, massive sternal wounds, and refractory mediastinitis. Hultman CS, Culbertson JH, Jones GE, et al. Thoracic reconstruction with the omentum: indications, complications, and results.

The neurochemical basis for the applications of the greater omentum in neurosurgery

The omentum has been utilized in neurosurgery for over 30 years. However, the anatomical and physiological bases for its applications have not been described in great detail. In this paper, we will review the current status of the omentum applications for the management of central nervous system disorders.