Ernest S. Chiu

Anterior and middle cranial fossa skull base reconstruction using microvascular free tissue techniques: surgical complications and functional outcomes.

Surgical ablation for oncologic disease requiring skull base resection can result in both facial disfigurement and a complex wound defect with exposed orbital content, oral cavity, bone, and dural lining. Inadequate reconstruction can result in brain abscesses, meningitis, osteomyelitis, visual disturbances, speech impairment, and altered oral intake. This study assesses the functional outcomes of patients who undergo anterior and middle cranial fossa skull base reconstruction using microsurgical free tissue transfer techniques. Using a prospectively maintained database, a 10-year, single institution retrospective chart review was performed on patients who had surgery for anterior and middle cranial base tumor resections. The type of resection, reconstruction method, complication rate, and functional outcomes were reviewed. From 1992 to 2003, 70 patients (49 men, 21 women) with a mean age of 54 (age 6–78) underwent anterior and middle cranial skull base tumor resection and reconstruction. The patients were divided into the following groups: maxillectomy with orbital content preservation (n = 21), orbitomaxillectomy with palatal preservation (n = 26), and orbitomaxillectomy with palatal resection (n = 23). The average length of hospital stay was 12.6 days. The vertical rectus abdominis myocutaneous flap was used in the majority of cases to correct midface defects. Two flaps required emergent re-exploration; however, there were no flap failures. Early and late postoperative complications were investigated. Cerebrospinal fluid was observed infrequently (7%) and did not require additional surgical intervention. Intracranial abscesses were encountered rarely (1.4%). Patients who had maxillectomy with orbital preservation and reconstruction had minor ophthalmologic eyelid changes that occurred frequently. Patients who required palatal reconstruction had a normal or intelligible speech (93%) and unrestricted or soft diet (88%). Using a multidisciplinary surgical team approach, there is an increasing role for reconstruction of complex oncologic midface resection defects using microvascular surgical techniques. Early/late complications and functional problems after anterior cranial base resections are uncommon when free tissue transfer is used concomitantly.

Breast reconstruction with perforator flaps.

BACKGROUNDnPerforator flaps represent the latest in the evolution of soft-tissue flaps. They allow the transfer of the patients own skin and fat in a reliable manner, with minimal donor-site morbidity. The powerful perforator flap concept allows transfer of tissue from numerous, well-described donor sites to almost any distant site with suitable recipient vessels. Large-volume flaps can be supported reliably with perforators from areas such as the abdomen, buttock, or flank and transferred microsurgically for breast reconstruction.nnnINDICATIONSnThe ideal tissue for breast reconstruction is fat with or without skin, not implants or muscle. Absolute contraindications specific to perforator flaps in the authors practice include history of previous liposuction of the donor site, some previous donor-site surgery, or active smoking (within 1 month before surgery).nnnTECHNIQUEnPerforator flaps are supplied by blood vessels that arise from named, axial vessels and perforate through or around overlying muscles and septa to vascularize the overlying skin and fat. During flap harvest, these perforators are meticulously dissected free from the surrounding muscle, which is spread in the direction of the muscle fibers and preserved intact. The pedicle is anastomosed to recipient vessels in the chest, and the donor site is closed without the use of mesh.nnnCONCLUSIONnPerforator flaps allow for safe, reliable tissue transfer from a variety of sites and provide ideal tissue for breast reconstruction, with minimal donor-site morbidity.

Three- and four-dimensional computed tomographic angiography studies of the supraclavicular artery island flap.

Background: The supraclavicular artery island flap is a useful regional option in head and neck reconstruction. Previous studies have recorded pedicle length, caliber, and ink injection studies of the supraclavicular artery. This study presents a three- and four-dimensional appraisal of the vascular anatomy and perfusion of the supraclavicular artery island flap using a novel computed tomographic technique. Methods: Ten supraclavicular artery island flaps were harvested from fresh cadavers. Each flap was injected with contrast media and subjected to dynamic computed tomographic scanning using a GE Lightspeed 16-slice scanner. Static computed tomographic scanning was also undertaken using a barium-gelatin mixture. Images were viewed using both General Electric and TeraRecon systems, allowing the appreciation of vascular territory (three-dimensional) and analysis of perfusion flow (four-dimensional). Results: The entire skin paddle was perfused in the majority (nine of 10) of flaps. One of the flaps was perfused only 50 percent. In this case, the pedicle artery was found to be much smaller than the other flap pedicles. Direct linking vessels and recurrent flow by means of the subdermal plexus were found to convey the flow of contrast between adjacent perforators. This explains how perfusion extends to adjacent perforators by means of interperforator flow, and how perfusion is maintained all the way to the distal periphery of the flap. Conclusions: Using this imaging technique, the authors elucidated the vascular anatomy of the supraclavicular artery island flap. This study confirms previous clinical findings that the supraclavicular artery island flap is a reliable option and gives surgeons new information for future flap refinement.

Body mass index affects proliferation and osteogenic differentiation of human subcutaneous adipose tissue-derived stem cells

BackgroundObesity is associated with a higher risk of developing cancer and co-morbidities that are part of the metabolic syndrome. Adipose tissue is recognized as an endocrine organ, as it affects a number of physiological functions, and contains adipose tissue-derived stem cells (ASCs). ASCs can differentiate into cells of multiple lineages, and as such are applicable to tissue engineering and regenerative medicine. Yet the question of whether ASC functionality is affected by the donor’s body mass index (BMI) still exists.ResultsASCs were isolated from patients having different BMIs (BMI-ASCs), within the ranges of 18.5-32.8. It was hypothesized that overweight BMI-ASCs would be more compromised in early adipogenic and osteogenic potential, and ability to form colonies in vitro. BMI was inversely correlated with ASC proliferation and colony forming potential as assessed by CyQUANT proliferation assay (fluorescence- based measurement of cellular DNA content), and colony forming assays. BMI was positively correlated with early time point (day 7) but not later time point (day 15) intracytoplasmic lipid accumulation as assessed by Oil-Red-O staining. Alizarin red staining and RT-PCR for alkaline phosphatase demonstrated that elevated BMI resulted in compromised ASC mineralization of extracellular matrix and decreased alkaline phosphatase mRNA expression.ConclusionsThese data demonstrate that elevated BMI resulted in reduced ASC proliferation, and potentially compromised osteogenic capacity in vitro; thus BMI is an important criterion to consider in selecting ASC donors for clinical applications.

Nipple-areola reconstruction following chest-wall irradiation for breast cancer: is it safe?

Radiation therapy (RT) is considered by some to be a contraindication to nipple-areola reconstruction (NAR) particularly in patients with breast implant reconstruction. In this retrospective chart review, all patients who underwent breast reconstruction with tissue expanders and implants from 1997–2003 were reviewed. A subset of patients with a history of radiation therapy (pre- or postoperative) was identified. Postoperative complications, surgical technique, and the time course of reconstructive procedures were analyzed. Thirteen percent of patients with a history of RT had NAR compared with 36% of similarly reconstructed patients without a history of RT. Reconstruction was accomplished using a variety of local flaps, with an overall complication rate of 25%. Nipple-areola reconstruction after chest-wall irradiation in patients reconstructed with breast implants should be performed in carefully selected patients. Acceptable surgical candidates demonstrate resolution of acute radiation changes, no evidence of late radiation changes, and appropriate thickness of the mastectomy skin flaps.

Microvascular free tissue transfer in organ transplantation patients: is it safe?

Background: Traditionally, organ transplantation has been synonymous with patients with poor prognosis and outcome. Surgeons felt that the risks posed by immunosuppressive drugs outweighed the benefits of non–life-threatening procedures. With the enormous advances in the field of organ transplantation, a growing number of transplant patients present for a variety of surgical procedures. The objective of this report was to study the surgical outcome of organ transplantation patients who required reconstructive surgery using free tissue transfer. Methods: A multicenter retrospective study was conducted on organ transplant patients who underwent elective microvascular free flap procedures. Patient chart review included cause of organ failure, medications, reconstruction site, flap choice, days hospitalized, complications, and outcome. Results: Five independent medical centers participated in the study. Nineteen organ transplant patients required free flaps. Free flaps were used to reconstruct a variety of surgical defects, including breast, head and neck, and upper and lower extremities. There were no flap losses. Flaps used included musculocutaneous (n = 13), fasciocutaneous (n = 5), and osteocutaneous (n = 1) free flaps. Hospital length of stay ranged from 3 to 17 days. Complications included loss of skin graft, suture line dehiscence, and hematoma formation. Delayed wound healing was observed in two patients. Conclusions: In the properly selected patient, microvascular free tissue transfer can be performed safely and with acceptable surgical outcome. Contrary to popular belief, delayed wound healing from immunosuppressive agents was uncommon. Free tissue transfer in healthy organ transplant patients can be considered in reconstructive surgery decision making.