Hiroo Suami
University of Texas MD Anderson Cancer Center
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Featured researches published by Hiroo Suami.
Annals of Surgical Oncology | 2008
Hiroo Suami; Wei Ren Pan; G. Bruce Mann; G. Ian Taylor
BackgroundCurrent understanding of the lymphatic system of the breast is derived mainly from the work of the anatomist Sappey in the 1850s, with many observations made during the development and introduction of breast lymphatic mapping and sentinel node biopsy contributing to our knowledge.MethodsTwenty four breasts in 14 fresh human cadavers (5 male, 9 female) were studied. Lymph vessels were identified with hydrogen peroxide and injected with a lead oxide mixture and radiographed. The specimens were cross sectioned and radiographed to provide three dimensional images. Lymph (collecting) vessels were traced from the periphery to the first-tier lymph node.ResultsLymph collecting vessels were found evenly spaced at the periphery of the anterior upper torso draining radially into the axillary lymph nodes. As they reached the breast some passed over and some through the breast parenchyma, as revealed in the cross-section studies. The pathways showed no significant difference between male and female specimens. We found also perforating lymph vessels that coursed beside the branches of the internal mammary vessels, draining into the ipsilateral internal mammary lymphatics. In some studies one sentinel node in the axilla drained almost the entire breast. In most more than one sentinel node was represented.ConclusionThese anatomical findings are discordant with our current knowledge based on previous studies and demand closer examination by clinicians. These anatomical studies may help explain the percentage of false-negative sentinel node biopsy studies and suggest the peritumoral injection site for accurate sentinel lymph node detection.
Plastic and Reconstructive Surgery | 2013
David Chang; Hiroo Suami; Roman J. Skoracki
Background: The authors prospectively evaluated the efficacy of lymphovenous bypass in patients with lymphedema secondary to cancer treatment. Methods: The authors prospectively enrolled 100 consecutive patients with extremity lymphedema secondary to cancer treatment. Sixty-five patients underwent lymphovenous bypass with indocyanine green fluorescent lymphangiography. Evaluation included qualitative assessment and quantitative volumetric analysis before and 3, 6, and 12 months after bypass. Results: Lymphovenous bypass was performed in 89 upper extremities and 11 lower extremities. For upper extremity lymphedemas, the mean preoperative volume differential was 32 percent. Symptom improvement was reported by 96 percent of patients and quantitative improvement was noted by 74 percent. The overall mean volume differential reduction was 33 percent at 3 months, 36 percent at 6 months, and 42 percent at 12 months after surgery. The mean volume differential reductions at 3, 6, and 12 months after lymphovenous bypass in patients with stage 1 or 2 lymphedema (58, 52, and 61 percent, respectively) were significantly larger than those in the patients with stage 3 or 4 lymphedema (12, 16, and 17 percent, respectively). Eleven bypasses were performed in seven patients with lower extremity lymphedema, with a mean preoperative volume differential of 38 percent. Only four (57 percent) of these patients reported symptom improvement; postoperative volume measurements were available for only two of these four. Conclusions: Lymphovenous bypass can be effective in reducing lymphedema severity, particularly in patients with early-stage upper extremity lymphedema. Indocyanine green lymphangiography accurately identified functional lymphatic vessels and may have a role in objectively assessing lymphedema severity and patient selection. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.
Plastic and Reconstructive Surgery | 2007
Hiroo Suami; Wei Ren Pan; G. Ian Taylor
Background: There have been very few anatomical reports on the changing lymph structure of the upper limb after axillary dissection despite its clinical significance for predicting skin cancer recurrence in the limb and secondary lymphedema. The authors used both upper limbs harvested from a fresh human cadaver that had undergone unilateral right radical mastectomy and radical axillary dissection for breast cancer. Methods: Hydrogen peroxide was used to identify and inflate the lymphatic vessels. Individual channels were injected with a radiopaque lead oxide mixture and recorded on x-ray film. Results: Results from the normal left upper limb were similar to results from the authors’ previous studies. However, the right limb from the mastectomy side showed remarkable differences and revealed that the lymph node clearance in the axilla had been incomplete on that side. The major difference was the almost complete absence of the superficial lymphatic network in the right arm, proximal to the elbow, because of fibrosis and blockage of the lymphatic channels. A circuitous pathway was identified that bypassed the blocked lymphatics in the arm to reach the deep system. This was facilitated often by backflow through precollectors and avalvular lymph capillaries in the dermis of the forearm, to reach eventually the few remaining lymph nodes in the axilla. Conclusions: Previously undetected lymph channels connecting the superficial and the deep lymphatic system had opened up because of the blockage of superficial lymphatic vessels caused by axillary dissection. It is presumed that these channels prevented lymphedema in this case.
Plastic and Reconstructive Surgery | 2010
Hiroo Suami; David Chang
Summary: Breast cancer–related upper extremity lymphedema is an unsolved iatrogenic complication with a reported incidence ranging from 9 to 41 percent. The increase in volume and recurrent cellulitis of the affected limb cause both physical and mental distress to many breast cancer survivors. However, postmastectomy lymphedema has received little attention, and no curative treatment is available. Conservative treatment with decongestive therapy has been the primary choice for lymphedema treatment, but it is cumbersome and has limited benefits. To date, there is no consensus on surgical procedure and protocol. However, refinements in microsurgical techniques and improved examination devices may lead to the establishment of a standard surgical treatment for lymphedema. This review of surgical procedures for the treatment of postmastectomy lymphedema focuses on microsurgical lymphovenous shunt operations and discusses current issues in surgical treatment and the need for uniform treatment standards.
Plastic and Reconstructive Surgery | 2005
Hiroo Suami; G. Ian Taylor; Wei Ren Pan
Studies of the gross anatomy of the lymphatic system are few and far between when compared with those of other vascular systems. Our knowledge of the anatomy of the lymphatic system is so limited that it seems vastly inadequate in explaining the clinical manifestations caused by its disorder. This study has developed an effective method to identify the lymphatics using hydrogen peroxide, to demonstrate the lymphatic vessels radiographically using a lead oxide suspension, and to dissect them out in adult human cadavers.
Plastic and Reconstructive Surgery | 2007
Hiroo Suami; G. Ian Taylor; Wei Ren Pan
Background: Current understanding of the pattern of lymph channels is largely dependent on the anatomical studies of Sappey performed in the nineteenth century, when mercury was injected into human cadavers and the lymphatics were dissected. These studies have not been repeated because the use of mercury is now prohibited as a result of its toxicity. The aim of this study was to reappraise the gross lymphatic anatomy and lymph node connections using a radiologic technique. A period of 3 years was required for development of a new method. Methods: The definitive technique used hydrogen peroxide to identify lymphatic vessels and to inflate them. The individual channels were injected with a radiopaque lead oxide mixture and recorded on x-ray film. Each channel was dissected meticulously under the surgical microscope and its course examined in relation to the regional lymph nodes. This method was then applied to 14 human cadaver upper limbs obtained from 10 different cadavers. Results: The authors found that the superficial lymphatic vessels course within the subcutaneous fat in close proximity to the main subcutaneous veins. Communication between the superficial and the deep lymphatic systems was not identified in these studies. Conclusions: Most lymph vessels were seen to flow into one main (sentry) lymph node in the axillary region; however, some of the lymph vessels ran along the posterior forearm, bypassing the “sentry” node to reach other smaller nodes.
Plastic and Reconstructive Surgery | 2008
Warren M. Rozen; Kate P. Palmer; Hiroo Suami; Wei R. Pan; Mark W. Ashton; Russell J. Corlett; G. Ian Taylor
Background: Abdominal donor-site flaps based on the deep inferior epigastric artery (DIEA) are the most common flaps used in autologous breast reconstruction. With significant variation in the vascular anatomy of the DIEA, preoperative imaging is desirable. Computed tomographic angiography, recently described for this purpose, uniquely demonstrates the branching pattern of the DIEA. The authors sought to correlate the DIEA branching pattern to the location and course of perforators as a preoperative planning tool for perforator flaps. Methods: Forty-five cadaveric hemi–abdominal walls were used for contrast injection of the DIEA with subsequent radiographic imaging. The branching pattern on radiography was thus correlated to the location and intramuscular course of perforators, from the main DIEA trunk to the point of the penetrating rectus sheath. Results: The DIEA branching pattern correlated closely with the course of perforators. A bifurcating (type II) branching pattern demonstrated a reduced transverse distance traversed by each perforator, whereas a trifurcating (type III) branching pattern demonstrated significantly greater transverse distances (p = 0.0002). Type I vessels were intermediate. Vessel branching type, however, displayed no significant correlation with the number of perforators (p = 0.56). Conclusions: The distances traversed by perforators were significantly reduced with a bifurcating branching pattern of the DIEA, particularly those originating from the lateral branch, and were greatest with a trifurcating branching pattern. Increased transverse distances correlate with greater rectus muscle sacrificed during perforator flap surgery. As computed tomographic angiography is the optimal modality for demonstrating this pattern preoperatively, the authors suggest its use for preoperative assessment in transverse rectus abdominis musculocutaneous and DIEA perforator flaps.
Lymphatic Research and Biology | 2011
Babak J. Mehrara; Jamie C. Zampell; Hiroo Suami; David Chang
Recent advances in surgical management of lymphedema have provided options for patients who have failed conservative management with manual lymphatic massage and/or compression garments. The purpose of this review is to provide a historical background to the surgical treatment of lymphedema and how these options have evolved over time. In addition, we aim to delineate the various types of surgical approaches available, indications for surgery, and reported outcomes. Our goal is to increase awareness of these options and foster research to improve their outcomes.
Plastic and Reconstructive Surgery | 2008
Wei Ren Pan; Hiroo Suami; G. Ian Taylor
Background: Current knowledge of the anatomy of the lymphatic system does not match or explain some of the unexpected clinical and lymphoscintigraphic findings seen in head and neck cancer patients. There is the need, therefore, to remap the lymphatic network of the superficial tissues of the head and neck region. Methods: Eighteen halves of the superficial tissues of the head and neck from nine fresh human cadavers were studied over a 20-month period using a mixture of 6% hydrogen peroxide (Orion Laboratories, Balcatta, Australia) with and without India ink to detect the lymphatic vessels and then inject them with a radiopaque lead oxide mixture (AJAX Chemicals, Sydney, Australia). Results: These unique studies showed (1) lymph capillaries arising from the skin and the galea layers draining sequentially into precollecting lymph vessels, collecting lymphatics, and the first-tier lymph nodes; (2) collecting vessels averaging 0.2 mm in diameter with unusual “lymphatic ampullae” structures and inactive lymph nodes observed often along their course; (3) different network patterns between subjects and between sides of the same subject; (4) similar relationships between lymphatic and venous systems; (5) a lymphaticovenous shunt in the occipital region; (6) lymphatics sometimes bypassing the expected nodes to reach sentinel nodes in the root of the neck; and (7) the lymphatics of the anterior neck lying above the platysma and coursing horizontally, obliquely, and upward toward the mandible. Conclusion: A map of the head and neck lymphatics is presented to aid clinicians with the management of trauma and malignancies in the region.
Lymphatic Research and Biology | 2008
Wei Ren Pan; Hiroo Suami; G. Ian Taylor
BACKGROUND The degenerative process of lymph nodes is poorly documented. METHODS 161 lymph nodes of seven fresh and one embalmed human cadavers in the head and neck were studied. We used 6% hydrogen peroxide, lead oxide injectant, and radiographs to demonstrate lymphatic vessels, and found both solidified and transparent lymph nodes. They were removed, fixed in 10% formalin and sent for histopathology cross section. RESULTS Thirty-eight solidified and 123 transparent lymph nodes were found. A series of histopathological sections show the degenerative process is variable and continuous. Senile involution affects all elements of the lymph node including the cortex, the medulla, and the architecture. CONCLUSION This study provides actual anatomical and histopathological images of lymph nodes in different degenerative stages in the head and neck region. It may help explain some clinical conditions in the elderly, especially their diminished immunological response to infection and cancer metastasis.