Isabel Lauer

Microvascular submandibular gland transfer for severe cases of keratoconjunctivitis sicca.

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.

Quality of salivary tears following autologous submandibular gland transplantation for severe dry eye.

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.

Salivary gland scintigraphy using technetium-99m-pertechnetate after autotransplantation of the submandibular salivary gland in the correction of dry eye

Abstract. The aim of the study was to determine whether salivary gland scintigraphy using technetium-99m pertechnetate is suitable for checking the vitality and function after autotransplantation of the submandibular salivary gland in patients with dry eye syndrome. To this end, 56 scintigraphic studies in 20 patients have so far been performed. In addition, these scans were evaluated by a region of interest (ROI) technique in order to examine tracer uptake in the early and late stages after surgery. We have been able to prove that in this special respect, too, the salivary gland scintigraphy is suitable for assessing reliably the vitality and function of the transplanted gland. The secretion into the eye and thus the patency of the efferent duct can also be displayed. This proved to be particularly valuable in those cases in which at first no secretion could be seen in the clinical examination. In patients with uncertain excretory function, we were able to distinguish between non-vitality and lack of patency of the secretory duct. Using ROI evaluation, no significant decrease in the salivary function has been detected in long-term follow-up, now extending to 1 year after surgery.

A Comparative Study on the Protection Profile of Lidocaine, Amifostine, and Pilocarpin on the Parotid Gland during Radiotherapy

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.

Early and late immunohistochemical and ultrastructural changes associated with functional impairment of the lachrymal gland following external beam radiation

The aim of this study was to investigate scintigraphic, immunohistological and ultrastructural changes associated with radiation‐induced dysfunction of the lachrymal gland in an established experimental animal model. Ten rabbits were randomized into two groups and used for the study; in the control as well as experimental group, the Schirmer‐test, lachrymal gland scintigraphy, and immunohistological and ultrastructural investigations were carried out prior to irradiation and 72 h as well as 1 month after single‐dose irradiation with 15 Gy. Seventy‐two hours after irradiation, secretion reduction evaluated by the Schirmer‐test was evident. At this phase, we could observe a decrease in the expression of α‐SMA and a re‐distribution of tenascin‐C matrix. Ultrastructural changes of acinar and myoepithelial cells were noticed; simultaneously, disturbance in the primary 99mTcO4– uptake as well as significant reduction of the lachrymal ejection fraction was assessed scintigraphically. These changes were still evident 1 month following irradiation but became less intensive. Single‐dose irradiation with 15 Gy implicates a functional impairment of the lachrymal gland, which is associated with early immunohistological and ultrastructural alterations. These changes may represent objective surrogate parameters for radiogenic dysfunction and prerequisites for further investigations on radioprotection of lachrymal glands during radiotherapy of the periorbital region.

Scintigraphic evaluation of lacrimal glands using a rabbit experimental model

The aim of this study was to establish an experimental model to evaluate functional changes in lacrimal gland parenchyma using gamma scintigraphy. Although the lacrimal glands of the rabbit have frequently been used for ophthalmological research, scintigraphic evaluation of these glands has received far less attention and we could not find any reports concerning this topic in the literature. Ten rabbits were used for the study; in 4 of them, the orbital region was dissected to provide the topographic anatomy of the lacrimal glands. Four rabbits underwent a static scintigraphy after excision of a unilateral lacrimal gland. Changes in the pattern of tracer uptake indicated the exact position of the gland on the scintiscan. One rabbit served as a control, and another one was used to prove the surgical accessibility of the gland. Using a frontal projection of the head the 99mTcO–4 uptake of the rabbit lacrimal glands could be identified and evaluated in the upper lateral region of the scintiscan. In conclusion, the lacrimal glands of the rabbit provide an appropriate experimental model to study quantitative disturbances of lacrimal secretion using scintigraphy and enable the assignment of functional impairment to morphological changes of the lacrimal parenchyma.