Peter Sieg
University of Lübeck
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Featured researches published by Peter Sieg.
Clinical Oral Investigations | 2001
Zimmermann Ce; Börner Bi; Hasse A; Peter Sieg
Abstract. The free microvasclar fibula and soft tissue transfer has become a widely used method to reconstruct the head and neck region. Only few reports focus on the donor site morbidity of purely mandibular reconstructions. On the basis of the hospital charts, a standardized patient interview and a standardized physical examination, the present study evaluates the early and late donor site morbidity in 42 mostly oncologic patients after an average follow-up interval of 34 months. Of these, 16 patients (38.1%) exhibited complicated wound healing that did not correlate with the patients age, sex, type of transplant, use of a skin graft, result of preoperative angiography, rate of postoperative mobilization or the incidence of late donor site morbidity. At the time of follow-up examination, about one-fourth of the patients reported discomfort, pain or swelling. Objective findings included sensory deficits in 76.3%, motor deficits in 39.5% and reduced strength in 44.7% of the patients. Even though objectively measured morbidity exceeded subjectively perceived morbidity, it can be concluded that there is significant early and late donor site morbidity, which should be considered when opting for a fibula graft. Patients should be informed accordingly.
Plastic and Reconstructive Surgery | 2000
Peter Sieg; Gerd Geerling; Hartwig Kosmehl; Isabel Lauer; Kirsten Warnecke; Helmut von Domarus
Free submandibular salivary gland transfer was investigated as a surgical method for the treatment of severe keratoconjunctivitis sicca. In an animal model, we examined the tolerance of warm ischemia of the submandibular gland. After temporary interruption of the blood supply (1 to 6 hours), the morphologic changes in the submandibular gland were analyzed histologically and immunohistochemically in 41 rabbits. From 1.5 hours ischemia onward, an increasing structural damage of the parenchyma with emphasis on the secretory cells was seen. Six hours of ischemia caused total necrosis of the salivary gland. Our clinical experience includes 24 highly selected patients suffering from keratoconjunctivitis sicca, in whom we transferred 31 autologous submandibular glands to the temple for permanent autologous tear substitution within the past 4 years. The glands were implanted into a pocket prepared in the temporalis muscle, and the nourishing vessels were anastomosed to the superficial temporal artery and vein. The submandibular duct was implanted into the upper lateral conjunctival fornix. The transferred glands were left denervated. In addition to the clinical examination, scintigraphy with Tc 99m pertechnetate was used to document the graft’s viability after the transfer. Viable incorporation with longstanding secretory function occurred in 26 of the 30 transplanted denervated salivary glands. The resulting lubrication of the treated eyes was irregular for up to 3 months in almost every case. One year after surgery, all patients with a viable transplant developed at least occasional epiphora, which was surgically managed by reducing the size of the graft in 10 patients. No severe side effects were seen in this series. The ophthalmologic evaluation of the method included the assessment of dry eye symptoms and of the volume and quality of ocular lubrication (Schirmer test, fluorescein break-up time), the pathology of the ocular surface (rose bengal staining), and the need for pharmaceutical tear substitutes. One year after surgery, 18 of 27 cases assessed were judged as significantly improved by these tests.
American Journal of Ophthalmology | 2010
Maria Borrelli; Christina Schröder; John Dart; John Richard O. Collin; Peter Sieg; Ian A. Cree; Melville Matheson; John M. Tiffany; Gordon Proctor; Jaap A. Van Best; Nick Hyde; Gerd Geerling
PURPOSE To evaluate the long-term results of autologous submandibular gland transplantation in eyes with cicatrizing conjunctivitis and to determine biomechanical and biochemical features of the resulting salivary tear film. DESIGN Prospective, observational case series. METHODS Fifteen eyes with cicatrizing conjunctivitis with a viable autologous submandibular gland transplantation were compared with 10 eyes with cicatrizing conjunctivitis and a failed submandibular gland transplantation or no submandibular gland transplantation. Best-corrected visual acuity, frequency of tear substitute instillation, severity of dry eye discomfort, lid margin erythema, conjunctival hyperemia, corneal epithelial edema, tear film break-up time, Schirmer test results, and corneal fluorescein and conjunctival Rose Bengal staining were evaluated. In a subgroup central corneal thickness and sensitivity, corneal epithelial barrier function, conjunctival and lid margin flora, and conjunctival impression cytologic analysis results were evaluated. In 3 patients, preoperative and postoperative tear samples were analyzed for viscosity, surface tension, and presence of mucins. RESULTS Submandibular gland autotransplantation resulted in long-term improvement of subjective, objective, and some ocular surface parameters. Salivary mucins were detectable in salivary tears after submandibular gland transplantation. The viscosity of salivary tears was more similar to normal saliva and the surface tension was intermediate between the 2 original secretions. CONCLUSIONS Submandibular gland autotransplantation provides long-term relief from pain and reduces the need for frequent installation of lubricants.
Graefes Archive for Clinical and Experimental Ophthalmology | 1999
Gerd Geerling; Kai Honnicke; Christina Schröder; Carsten Framme; Peter Sieg; Isabel Lauer; Horst Pagel; Martin Kirschstein; Michael Seyfarth; Alfred Michael Marx; Horst Laqua
Abstract · Background: This study aimed to characterise the composition of the pre-ocular fluid after transplantation of the autologous submandibular gland (SMG) for patients with severe dry eye. · Methods: Stimulated and unstimulated pre-ocular fluid from 15 patients (17 eyes) with a viable SMG graft (“SMG-salivary tears”), as well as normal tears and SMG saliva (20 normal subjects/ 20 eyes), was sampled. As global tear parameters, fern pattern analysis and SDS gel electrophoresis were performed. As specific quality parameters, total protein content, secretory immunoglobulin A (SIgA), lysozyme, amylase, sodium, potassium and osmolality were measured using routine laboratory methods. The flow rate of SMG-salivary tears was determined in 5 patients by means of sequential scintillography. · Results: The fern pattern of SMG-salivary tears was coarse and thus more similar to normal SMG saliva than tears. SDS gel electrophoresis of the SMG-salivary tears showed albumin and two unidentified proteins in addition to the normal tear pattern. Osmolality and total protein content of SMG-salivary tears were higher than in normal SMG saliva, but still lower than in normal tears. High activities of normal tear antibacterial proteins (SIgA, lysozyme and amylase) were detected in the salivary tears. Stimulation of the secretion did not alter the composition of SMG-salivary tears. The flow rate of SMG-salivary tears was closer to that of normal tears than normal SMG saliva. · Conclusion: Salivary tears resulting from SMG-transplantation represent condensed SMG saliva. Thus their quality is intermediate between normal tears and normal SMG saliva. High levels of secretory proteins demonstrate that the gland maintains an active function. Surgical denervation and residual tear components from the ocular surface are the most likely factors to cause the complex differences between normal SMG saliva and SMG-salivary tears. The effects of this secretion on the ocular surface are currently being evaluated in a clinical and laboratory study.
Transplantation | 2008
Gerd Geerling; J. R. Garrett; Katherine L. Paterson; Peter Sieg; J R O Collin; Guy Carpenter; S G Hakim; I Lauer; Gordon Proctor
Free submandibular gland autotransplantation is used to treat absolute tear deficiency. Although disconnected from any peripheral innervation, most transplants show increasing secretion for years. We have evaluated the secretory activity and autonomic innervation of such transplants. Secretory activity of glands in response to parasympatholytics and parasympathomimetics was evaluated by Schirmer’s test and Technetium scintigraphy. Submandibular gland tissue specimens taken before and after transplantation were examined histologically. Relative hypersecretion during the first postoperative week suddenly decreased but then slowly increased during the first postoperative year. Hypersecretion was significantly reduced by parasympatholytics while carbachol rapidly increased secretion. Histology of transplanted glandular tissue showed parenchymal atrophy. Cholinesterase-positive nerves were abundant and in a similar distribution to normal with scattered positive ganglion cells. Adrenergic axons were fewer than normal and irregularly distributed. Early hypersecretion may be due to release of neurotransmitters from degenerating terminal axons. This is followed by a period of minimal secretion during which hypersensitivity of acinar cells develops. With spontaneous reinnervation, secretion is accentuated by external sympathetic vasomotor adrenergic drive. This shows that submandibular glands can remain viable despite complete separation from their normal nerve supply and are capable of regaining a substantial secretory activity for years.
Clinical Oral Investigations | 2011
Samer G. Hakim; Hartwig Kosmehl; Peter Sieg; Thomas Trenkle; Hans-Christian Jacobsen; Geza Attila Benedek; Julika Ribbat; Oliver Driemel
Differential diagnosis of the keratocystic odontogenic tumor (KCOT) still represents a challenging problem especially if compared with the dentigerous cyst, which is similar in clinical and radiological course. Histological assessment of this entity may therefore draw crucial attention since various radical procedures are recommended for such lesions in contrast to dentigerous cysts. Since recent reports could prove the involvement of wingless(Wnt)-signaling pathway and β-catenin in the pathogenesis of many odontogenic and neoplastic lesions indicating impairment of cell–cell adhesion, we investigated the expression of two Wnt-signaling pathways, Wnt-1 and Wnt-10A as well as β-catenin and E-cadherin along with other related proteins in both lesions. We found a significant down-regulation in the expression of cell adhesion proteins β-catenin and E-cadherin along with alteration of Wnt-1 and Wnt-10A expression in the epithelium of KCOT. We assessed a specific focal distribution pattern of p63 in the suprabasal cell layer and a significant up-regulation of cyclin D1. Furthermore, laminin α-2 was a characteristic marker labelling only the basement membrane of dentigerous cysts. These results provide a new hypothesis explaining a molecular mechanism to understand initiating and development of KCOTs and an alternative therapeutic approach, especially for syndromal patients, where these multilocal lesions may involve and destroy wide orofacial bony structures.
Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2006
Peter Sieg; Hans-Christian Jacobsen; Samer G. Hakim; Dirk Hermes
Superficial ulnar artery is a well‐known vascular anomaly that may cause special risks because of possible impairment of the vessel by mistake during harvesting fasciocutaneous forearm flaps.
Cancer Research | 2005
Samer G. Hakim; Hartwig Kosmehl; Isabel Lauer; Roger Nadrowitz; Thilo Wedel; Peter Sieg
The aim of this study was to evaluate the individual and the synergetic radioprotective effect of lidocaine, amifostine, and pilocarpin on the parotid gland. Forty-nine rabbits were randomized into seven groups (n = 7)--control, irradiated sham-treated, irradiated/lidocaine-pretreated, irradiated/amifostine-pretreated, irradiated/pilocarpin-pretreated, irradiated/lidocaine + pilocarpin-pretreated, and irradiated/amifostine + pilocarpin-pretreated groups. One week before irradiation (15 Gy) and 72 hours as well as 1 month afterward, the parotid gland was investigated morphologically, sialoscintigraphically, and immunohistochemically with the use of tenascin-C and alpha smooth muscle actin. Compared with control animals, there was a significant reduction of the salivary ejection fraction in the irradiated untreated group 72 hours following radiation. Only animals pretreated with lidocaine or amifostine (alone or combined with pilocarpin) showed a slight nonsignificant reduction of salivary ejection fraction. Immunohistochemically, we observed a significant loss of alpha smooth muscle actin and an up-regulation of tenascin-C expression in irradiated/untreated glands. These changes were less evident in animals pretreated with lidocaine or lidocaine + pilocarpin. Amifostine and pilocarpin did not show any influence on tenascin-C or alpha smooth muscle actin expression. Ultrastructural damage was observed in irradiated untreated and pilocarpin-pretreated glands. In contrast, lidocaine and amifostine could largely preserve the glandular ultrastructure. One month postradiation, all changes were regressive regardless of treatment protocol. Potential radioprotective agents show different effects on both morphology and function of the parotid gland. Associated immunohistochemical and ultrastructural findings could prove the prevailed protection profile of lidocaine. This may provide a prophylactic approach in the field of radioprotection of salivary glands.
Plastic and Reconstructive Surgery | 2004
Peter Sieg; Samer G. Hakim; Hans-Christian Jacobsen; Bassam Saka; Dirk Hermes
During 10 charity missions in developing countries, 14 patients of a total of 374 children with cleft lip and palate deformities were treated for rare facial clefts. There were three midline clefts (Tessier no. 0 cleft, n = 1; Tessier no. 14 cleft, n = 2), four oblique facial clefts (Tessier no. 3 cleft, n = 2; Tessier no. 5 cleft, n = 2), and seven lateral facial clefts (Tessier no. 7 cleft). Surgical treatment focused on cleft repair by soft-tissue reconstruction apart from two Tessier no. 14 clefts, in which the bony gap was also closed using bone grafts from the iliac crest. The postoperative course was uneventful except for one local wound infection that was treated successfully using oral antibiotics. This article summarizes the authors’ experience with the surgical management of these malformations and considers the limitations under conditions of charity missions in developing countries. Furthermore, some rare forms of cleft formation are added to the existing literature.
International Journal of Oral and Maxillofacial Surgery | 2003
Peter Sieg; Samer G. Hakim; S. Bierwolf; D. Hermes
The aim of this study is to provide valid data concerning the thickness of the subcutaneous fat layer in seven donor regions which are most commonly used for soft tissue replacement in the head and neck region. Furthermore the study focuses on differences in thickness of this layer depending on the nutritional status and sex. In 100 volunteers the thickness of the subcutaneous fat layer was evaluated using ultrasound in seven potential donor regions: radial and ulnar forearm, lateral upper arm, scapular and parascapular region, abdominal/supra-umbilical region and the lateral calf. Volunteers were divided into 4 groups: male and female, slender (body mass index [BMI] < 25) and adipose (BMI > 30). Data obtained was compared and differences were proven to be statistically significant (Students t-test, P<0.05). The largest thickness was found in the supra-umbilical region followed by the lateral upper arm whereas the ulnar forearm region had the smallest thickness. Depending on the BMI the supra-umbilical and the lateral upper arm regions showed the most wide variation. Depending on sex the most noticeable variation in thickness of the subcutaneous layer was seen in the lateral calf region with a significant larger tissue layer in females.