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Gregory K Hartig

Publications and source records attributed to Gregory K Hartig.

11 recordsLinked to original sources
PubMed2007

Planned postradiotherapy neck dissection: Rationale and clinical outcomes.

OBJECTIVES: In this study, we examine pathology results and clinical outcome for patients with locoregionally advanced squamous cell carcinoma of the head and neck (SCCHN) who present with advanced neck disease and undergo planned postradiotherapy neck dissection. STUDY DESIGN: Review of all patients with SCCHN treated with primary radiation (or chemoradiation) and postradiotherapy neck dissection at the University of Wisconsin between 1992 to 2005 was performed. One hundred seven neck dissections were identified in 93 patients, 79 unilateral and 14 bilateral. All major treatment and outcome parameters were examined with particular emphasis on the postradiotherapy neck dissection. RESULTS: Thirty of 107 neck dissection specimens (28%) showed evidence of residual carcinoma on pathologic review. The mean number of lymph nodes identified at neck dissection for the entire cohort was 21 per specimen (range, 1-60) with 1.3 nodes per positive neck dissection demonstrating residual carcinoma. No correlation was found between the type of neck dissection performed and the presence of residual nodal disease. Eighty-two evaluated patients (93%) remain free of regional disease recurrence, whereas six patients have subsequently manifested neck recurrence. Four of the six patients who developed regional recurrence showed residual carcinoma in their neck dissection specimen. Five of these patients underwent comprehensive neck dissection (levels I-V); one underwent selective neck dissection (<levels I-V). CONCLUSION: Approximately one-fourth of the patients in this series showed pathologic evidence of residual carcinoma in the neck at the time of postradiotherapy neck dissection. The majority of these cases showed microscopic residual carcinoma in a single lymph node. Although in the early postradiotherapy setting, we cannot accurately predict the viability and growth potential of microscopic residual carcinoma in lymph nodes, these findings, combined with the modest overall morbidity of selective neck dissection, suggest that planned postradiotherapy neck dissection should be strongly considered for patients presenting with advanced neck disease. This remains a prevailing clinical practice at our institution.

Aged↗
PubMed2006

Cutaneous tissue flap viability following partial venous obstruction.

BACKGROUND: Venous outflow obstruction is the most common cause of tissue failure after microvascular reconstructive surgery. If it is not recognized early, there is an increased risk of tissue damage and loss. Currently, however, there are no adequate models for the study of this clinical problem. The purpose of this study was to develop a partial congestion model for the study of skin flap physiology in response to varying levels of occluded venous outflow. METHODS: Nine mixed-breed pigs were equally divided into three experimental groups (0 percent, 20 percent, and 50 percent venous outflow) to determine the effects of varying venous outflow on cutaneous flap color, oxygen tension, and edema. A cutaneous pedicle flap model and a partial congestion system were used to observe changes in variable venous obstruction. RESULTS: Only 0 percent venous outflow resulted in progressive color change across time. In addition, 0 percent venous outflow demonstrated significantly different oxygen tension levels relative to the other groups. Twenty percent venous outflow resulted in significant edema formation relative to the other groups. The 50 percent group showed an increase in oxygen tension from the second hour of venous obstruction to the end of the experiment. CONCLUSIONS: Tissue flap color is the clinical standard on which flap health is measured. After 8 hours, only complete venous occlusion resulted in significant color change. However, physiological changes that could affect tissue flap health were noted with only partial venous occlusion, including the development of edema formation. Accordingly, subtle color change could indicate partial venous congestion and may warrant intervention by the surgeon.

Animals↗
PubMed2005

Parotid area lymph node metastases from cutaneous squamous cell carcinoma: implications for diagnosis, treatment, and prognosis.

BACKGROUND: Parotid area lymph node metastasis from primary scalp and facial cutaneous cancers is a poorly recognized clinical entity partly because of the long time lapse between the index lesion and regional spread. METHODS: A retrospective review of the University of Wisconsin Tumor Registry and Head and Neck Oncology Tumor Board was performed over a 10-year period from 1989 to 1999. One hundred two patients with a malignant parotid mass were identified. Of these, 20 patients were identified with parotid region squamous cell carcinoma and prior index skin cancer of the face or scalp. These patients were analyzed regarding presentation, diagnostic evaluation, interval between index lesion and metastasis, treatment method, and long-term outcome. RESULTS: Approximately 20% of patients (20 of 102) in this series with a malignant parotid mass had presumed metastasis from an identifiable skin primary tumor. The mean time from index lesion to presentation of regional spread was 13.5 months. Seventy percent of the patients (14 of 20) underwent surgery followed by radiation as locoregional therapy, whereas 30% underwent surgery alone. Six (30%) of 20 patients required some degree of facial nerve sacrifice. Three patients (15%) experienced subsequent locoregional failure. Two of six patients from the surgery alone group and one of 14 patients who received surgery plus radiation therapy experienced locoregional relapse. CONCLUSIONS: Parotid area lymph node metastases from scalp and facial cutaneous carcinomas require aggressive therapy to optimize locoregional control. The addition of radiotherapy after parotidectomy is important and should be considered for optimal disease control. Selective neck dissection or radiation may be warranted at the time of parotidectomy. This combined approach is associated with high locoregional control rates and is generally well tolerated.

Carcinoma, Squamous Cell↗
PubMed2003

Comparing a mechanical device with medicinal leeches for treating venous congestion.

OBJECTIVE: To compare mechanical device therapy to medicinal leech therapy for treating venous congestion. STUDY DESIGN: Fasciocutaneous flaps of 9 x 7-cm (porcine model, n = 11) were elevated and the associated veins clamped for 15 hours. Device-treated flaps (n = 6) were treated with up to 3 devices/flap. Leech-treated flaps (n = 5) were treated with 75 leeches/flap (5 leeches/hour). Treatment evaluation parameters included: blood volume removed, skin color, surface perfusion, tissue oxygen tension, and endpoint histology. RESULTS: No significant differences were seen in blood volume removed, surface perfusion, and oxygen tension. However, significant differences were seen in skin color change over time. Histological assessment showed mild congestion in 5/5 leech-treated flaps and 2/6 device-treated flaps. CONCLUSION: Device therapy was comparable to leech therapy for decongesting a 9 x 7-cm flap over a 15-hour period. However, digital images and significant differences in skin color change over time demonstrate that device therapy promotes more global decongestion versus leech therapy.

Animals↗
PubMed2003

Comparison of resorbable poly-L-lactic acid-polyglycolic acid and internal Palmaz stents for the surgical correction of severe tracheomalacia.

Tracheomalacia (TM) is associated with expiratory airway collapse and potentially fatal respiratory distress. Internal and external tracheal stents and, recently, resorbable biopolymers have been used to treat this condition. In this study, the efficacy and biocompatibility of internal Palmaz stents and external poly-L-lactic acid-polyglycolic acid (PLPG) stents were compared in a model of severe TM induced in piglets. The tracheas were repaired with one of two stenting methods, and the animals survived for up to 16 weeks. Weight gain, adverse respiratory signs and symptoms, tracheal or lung histopathologic changes, and internal and external tracheal diameters were measured. The animals in the PLPG group uniformly were free of respiratory distress and tracheal stenosis or inflammation, whereas all animals in the Palmaz group developed respiratory distress as a result of pneumonia or tracheal stenosis caused by intraluminal granulation tissue. In conclusion, superior efficacy of external, resorbable PLPG stents was found relative to internal Palmaz stents for the surgical repair of severe TM.

Animals↗
PubMed2003

Morphological and functional changes of human vocal fold fibroblasts with hepatocyte growth factor.

Fibroblasts produce extracellular matrix and play an important role in wound healing and scarring. Hepatocyte growth factor (HGF) has strong antifibrotic activity, and has been suggested to have therapeutic potential for treatment of fibrotic diseases. In the present in vitro study, morphological and functional changes of human vocal fold fibroblasts with HGF were examined by transmission electron microscopy and enzyme-linked immunosorbent assay to help clarify the potential use of HGF in the prevention or treatment of vocal fold scarring. The HGF stimulated the production of hyaluronic acid (HA) and decreased the production of collagen type I from the fibroblasts in Reinke's space (FbRS), whereas fibronectin production was not affected. The HGF also changed the shape of the FbRS from an oval shape toward a spindle and stellate shape, and developed Golgi apparatus (GA) and rough endoplasmic reticulum (rER) in the FbRS. The fibroblasts in the macula flava (FbMF) presented with much more production of HA and collagen type I than did FbRS, and were more frequently formed in a stellate shape with well-developed GA and rER. The HGF decreased the production of collagen type I from the FbMF, but barely affected the FbMF in terms of the shape of the cells, the development of GA and rER, or the production of HA. These results were interpreted to suggest that the FbMF are not as susceptible to HGF as are FbRS. On the contrary, HGF appeared to activate the FbRS and modify the function. The increased HA and decreased collagen type I production from the FbRS suggest that HGF may be useful in the prevention or treatment of fibrotic vocal fold scarring.

Aged↗
PubMed2002

Evaluation of performance characteristics of the medicinal leech (Hirudo medicinalis) for the treatment of venous congestion.

Medicinal leeches (Hirudo medicinalis) are a standard treatment for venous congestion, a complication that can occur after reconstructive surgery. If the cause of venous congestion cannot be surgically corrected, then medicinal leeches are used to temporarily increase perfusion levels and maintain physiologic requirements within the congested tissue. Leeches increase perfusion within congested tissue by actively drawing off blood as a bloodmeal. Furthermore, the leech bite continues to bleed and relieve congestion after detachment because of the anticoagulation effects of leech saliva left behind in the bite. In a porcine model, a 10 x 10 cm cutaneous flank flap was congested by clamping the venae comitantes. Four medicinal leeches were allowed to attach to the congested flap, and parameters of active feeding and passive bleeding after detachment were recorded. The average bloodmeal volume for the medicinal leeches was 2.45 ml. Average passive bleeding for the first 2 and 4 hours after leech detachment totaled 2.21 and 2.50 ml, respectively, with 90 percent of passive bleeding occurring within 5 hours after detachment. Laser Doppler imaging indicated that the spatial arrangement of surface perfusion increases were localized to a 1.6-cm-diameter circle around the leech head (bite) and corresponded well with the visual return of normal skin tones to the same area. This study provides a realistic and quantitative estimate of the spatial and volumetric characteristics of leech feeding and passive bleeding using a clinically relevant model of acute, severe congestion.

Animals↗
PubMedDate not supplied

Effect of topical mitomycin on skin wound contraction.

OBJECTIVE: To evaluate the effect of different dosing regimens of mitomycin on skin wound contraction. METHODS: Full-thickness skin wounds were created in 5 groups of hairless mice, which represented different dosing regimens or a sterile water control: A, control; B, mitomycin (0.5 mg/mL) applied immediately after creation of the lesion (day 1); C, mitomycin (1.0 mg/mL) applied on day 1; D, mitomycin (0.5 mg/mL) applied on days 1 and 3; and E, mitomycin (1.0 mg/mL) applied on days 1 and 3. Wound surface area was measured immediately after drug application (day 1), and thereafter every 3 to 5 days until day 29 by means of computer-assisted image analysis. RESULTS: All dosing regimens of mitomycin application resulted in an initially exponential rate of wound contraction that was significantly slower than in the sterile water control group, with a significantly larger wound surface area on day 29. Wound area in the control group contracted approximately 9 times more rapidly than in the treatment groups. No difference was observed among the different dosing regimens. CONCLUSION: Application of mitomycin, at the lowest dose and frequency of application used in this study, resulted in improved outcomes with regard to contraction of full-thickness skin wounds.

Administration, Topical↗
PubMedDate not supplied

Testing a device to replace the leech for treating venous congestion.

OBJECTIVE: To test the effectiveness of a device designed to promote decongestion and tissue survival of a fasciocutaneous flap during 15 hours of complete venous obstruction. METHODS: In a porcine model, a 9 x 7-cm fasciocutaneous flap was elevated and the associated veins were clamped, causing complete venous obstruction for 15 hours in 6 control and 6 treatment animals. Up to 3 devices were used to treat the flap in a predetermined pattern. Control flaps were not treated. Measures of treatment efficacy included blood volumes removed; changes in skin color, surface perfusion, and tissue oxygen tension; and end point histologic findings. RESULTS: Control flaps were characterized by progressive darkening of skin color, undetectable surface perfusion, and low levels of oxygen tension. Histologic assessment showed severe congestion and extravasation of blood and distinct signs of necrosis. In contrast, treated flaps had significant improvements in skin color, surface perfusion, and subcutaneous oxygen tension. Histologic analysis showed little, if any, congestion and no signs of necrosis. Mean blood volume removed was 29.5 mL/h. CONCLUSION: The device was effective in decongesting a large area of tissue during 15 hours of complete outflow obstruction, based on quantitative measurements of tissue health and viability.

Animals↗
PubMedDate not supplied

Anastomoses between the cervical branch of the facial nerve and the transverse cervical cutaneous nerve.

Head and neck surgeons must possess a thorough knowledge of facial nerve anatomy to avoid inducing iatrogenic injury during surgery. Anastomoses of the cervical branch (CB) of the facial nerve and the transverse cervical cutaneous nerve (TCCN) are poorly documented in our field. Knowledge of these anastomoses and their positions allows for (1) preservation of high CBs that contribute to lower lip depressor function, and (2) identification of the facial nerve in retrograde dissections. Our objective was to improve understanding of facial nerve anatomy by describing these anastomoses. The communicating branch between the TCCN and the CB was evaluated in 22 adult neck halves (11 cadavers). The facial nerve was exposed, and the CB was traced anteriorly. The TCCN was identified and traced superiorly to its anastomosis(es) with the CB. The distance from each anastomosis to the selected landmarks was recorded. Between the CB and the TCCN, 33 anastomoses were identified, with at least 1 anastomosis per hemineck and 2 anastomoses in 11 heminecks. Anastomoses were identified along the inferior border of the submandibular gland (SMG; 20 specimens) or posterior to the SMG (12 specimens). Five specimens had both anastomoses near the inferior border of the SMG, and 6 specimens had 1 anastomosis near the inferior border and 1 posterior to the SMG. Communication between the TCCN and the CB is regularly present. Its anatomic locations are either posterior to the SMG, often within the parenchyma of the parotid gland, or near the inferior border of the SMG. Awareness of these anastomoses allows a method for identification and preservation of the CB of the facial nerve as well as a starting point for retrograde facial nerve dissections.

Facial Nerve↗