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PubMed2006

A novel microsurgery method for intact plant tissue at the single cell level using ArF excimer laser microprojection.

A novel microsurgery technique for the partial removal of rigid cell-walls in intact plant tissue is established. Using a size-variable slit, an ArF excimer laser was microprojected on the surface of the targeted cell, and this method enabled the area- and depth-controllable processing of the cortical structure of plant cells including the cuticle and cell wall layer. In epidermal cells of all tested plants, viabilities of more than 90% were retained 24 h after irradiation. Scanning electron microscope (SEM) observation revealed that the cuticle layer of the irradiated region was completely ablated, and the cellulose microfibrils of the secondary cell wall were partially removed; furthermore, 4 days after laser treatment, the regeneration of cell wall fibrils was observed. As a model experiment, the transient expression of synthetic green fluorescent protein (sGFP) was performed by the microinjection of cauliflower mosaic virus (CMV) 35S promoter-derived sGFP gene through an "aperture" in the treated cell surface. Moreover, micron-sized fluorescent beads were successfully introduced by the same method into the onion cells indicating that this method can be used to introduce foreign materials as large as organelles.

Caulimovirus↗

PubMed1990

Nd:YAG-laser in the microsurgery of frontobasal meningiomas.

Forty-three patients with big frontobasal meningiomas underwent a microsurgical removal of the tumor. The 1.32 microns Nd:YAG-laser has proved useful in this prospective series particularly with the contactless shrinkage of the tumors and the necrotization of the dural and bony attachments. Tumor shrinkage was achieved by radiating the tumor surface with the Nd:YAG-laser. This technique facilitated the microsurgical dissection and reduced the blood loss by half. The Nd:YAG-laser necrotization of the dural and bony attachments reduced the recurrence rate following grade two resections from 20% to zero. The postoperative quality of life was excellent with a complete rehabilitation in 76% of the patients. The use of the 1.32 microns Nd:YAG-laser improved significantly the results of microsurgery for frontobasal meningioma.

Adult↗

PubMed1983

Fluorescein angiography after retinal detachment microsurgery.

The eyes of 78 patients who underwent retinal detachment microsurgery (82 eyes) were prospectively evaluated postoperatively with fluorescein angiography. Of these 14.6% showed angiographic evidence of cystoid macular oedema (CMO.). A significantly greater risk of developing cmo was discovered in aphakic eyes (30% CMO.) as compared to phakic eyes (7% CMO.) and in eyes where the maculae were detached pre-operatively (23% CMO.), as compared to eyes where the maculae were attached pre-operatively (5% CMO.). Eyes which had undergone several surgical procedures for retinal reattachment (38% CMO.) were compared to eyes which had undergone only one surgical procedure (6.5% CMO.). It was found that 4.9% of the 82 eyes showed cellophane premacular membrane without dye leakage. A further 6% of the eyes showed premacular membranes associated with dye leakage. No statistically significant risk factor associated with the development of macular pucker was disclosed in this series.

Adolescent↗

PubMed2001

Anorectal sphincter function and rectal barostat study in patients following transanal endoscopic microsurgery.

BACKGROUND AND AIMS: This study evaluated the effect of transanal endoscopic microsurgery (TEM) on anorectal sphincter functions and determined the risk factors for anorectal dysfunctions (including incontinence). PATIENTS AND METHODS: A study group of 33 patients with small, mobile rectal tumors (adenoma and carcinoma) located up to 12 cm from the anal verge underwent anorectal motility studies (using pull-through anorectal manometry and rectal barostat) and endoanal ultrasound prior to surgery and 3 weeks and 6 months after TEM; controls were 20 healthy volunteers. RESULTS: Resting and squeeze anal pressures were reduced 3 weeks after TEM. Resting anal pressure remained reduced 6 months after surgery; the changes were related to low preoperative levels and to the internal anal sphincter defects rather than to the procedure duration or the type of surgery. High-pressure zone length and vector volume were decreased 3 weeks after TEM and restored 6 months later. Rectoanal inhibitory reflex, reflex sphincter contraction, rectoanal pressure gradients, threshold and maximal tolerable volume of rectal sensitivity, and compliance were significantly changed 3 weeks after TEM; only rectal wall compliance remained low at 6 months. The rectoanal inhibitory reflex, reflex sphincter contraction, rectal sensitivity, and compliance were related to the extent and type of excision (partial or full thickness). Anal ultrasound revealed internal anal sphincter defects in 29% of patients studied 3 weeks after TEM. Only 76% of patients were fully continent. Disturbed anorectal function (including partial fecal incontinence) was observed in up to 50% of patients at 3 weeks. Partial and moderate anorectal dysfunction was found in 21% patients 6 months after surgery. The main risk factors of anorectal dysfunctions following TEM included: postoperative internal anal sphincter defects, low preoperative resting anal pressure, disturbed rectoanal coordination, extent (>50% of wall circumference) and the depth (full thickness) of tumor excision. CONCLUSION: TEM has a relevant but temporary effect on anorectal motility. As a result of TEM procedures 21% of the patients had disturbed anorectal functions, mostly due to the extent or depth of tumor excision (influencing rectal compliance and rectoanal coordination), and to the sphincter defects lowering resting anal pressure. Preoperative anorectal motility studies and anal ultrasound allow the identification of patients with the risk of postoperative anorectal dysfunctions.

Adenocarcinoma↗

PubMed2002

Transanal endoscopic microsurgery--lessons from a single UK centre series.

OBJECTIVES: Transanal endoscopic microsurgery (TEM), a minimally invasive technique has been employed in the excision of benign and selected malignant rectal tumours since 1983. We present a single surgeon's series of 102 procedures. PATIENTS AND METHODS: A retrospective case note review of 102 procedures performed over a 6-year period between 1996 and 2001. RESULTS: One hundred and two TEM procedures were performed on 100 patients. 68 for adenomas, 19 potentially curative excisions for carcinoma, 13 palliative procedures for advanced carcinoma and 2 for solitary rectal ulcer syndrome (SRUS). Four adenomas recurred and were successfully treated by various procedures. None went on to develop malignancy, or a further recurrence. Of the cancers, six T1 and 10 T2 were excised with curative intent. Three T3 cancers were excised before endorectal ultrasound was available in the unit and went on to have definitive procedures. One T1 and two T2 carcinomas were not completely histologically excised. These patients were offered definitive procedure and there have been no recurrences. 11 patients underwent palliative TEM procedures, 2 went on to have a recurrence of symptoms. Both underwent a successful second TEM procedure. CONCLUSIONS: Although longer term follow up is still required, TEM appears to be an effective method of excising benign tumours and T1 carcinomas of the rectum. The role of TEM in the treatment of T2 carcinomas is, as yet, unclear and needs further evaluation although the results of our series and others are encouraging.

Journal Article↗

PubMed2003

The use of postoperative ACTH levels as a marker for successful transsphenoidal microsurgery in Cushing's disease.

OBJECTIVES: The declines of ACTH and other POMC metabolites immediately after tumor extirpation do not predict the complete tumor removal of an ACTH-secreting pituitary adenoma in Cushing's disease. However, the pituitary surgeon should be in a position to evaluate the surgical result as soon as possible for the eventual planning of early repeat surgery. So far, subnormal serum cortisol levels after surgery are widely accepted as the criterion for cure. We investigated whether the early postoperative ACTH concentration is a reliable marker for the initial surgical outcome as well as the long-term remission. METHODS: In a prospective study, 147 patients undergoing primary transsphenoidal microsurgery for Cushing's disease between 1990 and 1996 were investigated. The early postoperative ACTH courses were reviewed and compared with the long-term outcome. ACTH measurements were performed immediately after tumor excision, 1, 2, 4, 8, and 12 hours later, and the following morning. Further ACTH levels were determined on various days of the hospital stay. Glucocorticoids were not given until hypocortisolism was proven. RESULTS: Ninety-five patients (65 %) presented with subnormal ACTH levels (< 10 ng/l) during their postoperative stay, of whom two patients (2 %) experienced recurrence of disease after 66 and 100 months. Of 29 procedures with early postoperative ACTH levels ranging from 10-20 ng/l (20 %), one patient received further treatment for persistent (3.5 %) and one patient for recurrent Cushing's disease (3.5 %). Of 12 patients (8 %) with early postoperative ACTH levels in between 20 to 30 ng/l, one patient received further treatment for persistent (8 %) and four patients for recurrent disease (33 %). ACTH levels of more than 30 ng/l, found in 11 patients (7 %), were accompanied by persistent (8 patients, 73 %) or recurrent (2 patients, 18 %) Cushing's disease. CONCLUSION: Subnormal (< 10 ng/l) or low normal (< 20 ng/l) postoperative ACTH levels within the first 7 days after surgery can be regarded as early markers for complete removal of an ACTH adenoma as well as indicators for long-term outcome in Cushing's disease. The risks of persistence or recurrence of Cushing's disease rise with the level of early postoperative ACTH values. Normal ACTH levels should result into further evaluation of the ACTH-cortisol secretion, for example by stimulation- or suppression tests.

Adenoma↗

PubMed1997

Nonlinear absorption: intraocular microsurgery and laser lithotripsy.

The paper reviews the principles of nonlinear absorption with reference to the present major clinical applications of plasma-mediated effects: intraocular microsurgery and laser lithotripsy. Emphasis is laid on the analysis of the working mechanisms, sources of collateral damage, and on strategies for both the optimization of efficacy and the minimization of side effects.

Absorption↗

PubMed1998

The efficiency of CO2 elimination during high-frequency jet ventilation for laryngeal microsurgery.

UNLABELLED: For adequate and safe use of high-frequency jet ventilation (HFJV), reliable monitoring of the PCO2 status and course is necessary. Because of improved handling and performance, recently available transcutaneous PCO2 monitoring devices such as MicroGas 7650 (Kontron Instruments Medical Sensors, Basel, Switzerland) should enable more effective surveillance of CO2 elimination and, subsequently, better control of subglottic HFJV. Adult patients (n = 164) undergoing laryngeal microsurgery during total i.v. anesthesia were assessed. The resulting transcutaneous PCO2 values, as well as the necessary driving pressure settings, were analyzed to define the CO2 elimination capacity of each patient. Therefore, an individual CO2 elimination coefficient (ECCO2) was calculated. The frequency distribution of the obtained ECCO2 values showed a normal distribution with a median at 0.79 and a range between 0.30 and 2.17. A significant difference in the frequency of obstructive lung disease was found between two patient subpopulations separated by the 25th percentile at an ECCO2 value of 0.63. Other co-factors of CO2 elimination during HFJV were age, gender, and body weight, whereas height and ventilation duration were not involved. We conclude that the individual assessment of ECCO2 enables one to find adequate ventilator settings, resulting in lower airway pressure and less cooling and drying of the tracheobronchial mucosa. IMPLICATIONS: CO2 elimination during high-frequency jet ventilation can be assessed by calculating the CO2 elimination coefficient (ECCO2) of each patient from the required driving pressure and the resulting transcutaneous CO2 partial pressure. The frequency distribution of ECCO2 in a typical laryngological patient population was analyzed, and a value of 0.63 was found to be a characteristic limit between sufficient and difficult CO2 elimination. The individual assessment of ECCO2 enables one to find adequate ventilator settings, resulting in lower airway pressure and less cooling and drying of the tracheobronchial mucosa.

Adult↗

PubMed2002

Role of laser-induced plasma formation in pulsed cellular microsurgery and micromanipulation.

We investigate experimentally the physical processes underlying pulsed cellular microsurgery and micromanipulation using nanosecond 532- and 1064-nm laser pulses focused at high numerical aperture. We find that the laser parameters employed for many microirradiation techniques are congruent with those leading to optical breakdown in water. We determine the size and shape of the laser-induced plasma, pressure of the emitted shock wave, and size and energy of the cavitation bubble formed by the expanding plasma. We discuss implications of the results for biophysical microirradiation procedures.

Cells↗

PubMed2006

Transanal endoscopic microsurgery: a necessary requirement?

INTRODUCTION: There has been a gradual introduction of transanal endoscopic microsurgery (TEM) into UK practice although the uptake remains variable. This study aimed to assess the availability, application and referral pattern of TEM amongst colorectal surgeons. METHODS: A questionnaire was sent to all consultant members of the Association of Coloproctology. This considered their practice, the availability, application and referral pattern for TEM, and their views on application regarding a selection of rectal tumour scenarios. RESULTS: There were 142 replies representing 116 hospitals and 297 colorectal surgeons. The median catchment area was 280,000 (range 70,000-1,000,000). TEM was available in 18% of hospitals and 72% either performed or referred patents for TEM. Of 21 units performing TEM, 15 received referrals. From 305 TEM procedures performed over the previous year, 206 were referred cases. Eighty-five per cent of consultants considered TEM a necessary technique for optimum management of rectal lesions. Although 61% of consultants considered endoanal excision optimal for low benign rectal tumours, 58% said TEM was optimal for midrectal lesions and between 30% and 55% for high rectal lesions depending if the tumour position was anterior or posterior, respectively. One-third of consultants would perform TEM for a low T1 rectal carcinoma although half would proceed to anterior resection. DISCUSSION: TEM is considered to have a significant role in the optimal management of rectal lesions. The presence of the technique in a limited number of hospitals does appear to provide adequate resources although audit should continue to be centralized.

Colorectal Surgery↗

PubMed1998

Laser microsurgery permits fungal plasma membrane single-ion-channel resolution at the hyphal tip.

A method for formation of high-electrical-resistance seals on the Neurospora crassa plasma membrane, allowing resolution of single-ion-channel activity by patch clamp electrophysiology, is reported. Laser microsurgery permits access to the hyphal apex without enzymatic cell wall digestion and loss of morphological polarity. Cell wall reformation is delayed by brefeldin. This method can allow full characterization of apical plasma membrane channels, which are implicated in tip growth.

Journal Article↗

PubMed1976

[A new ceiling microscope suspension for plastic and reconstructive microsurgery].

Since 1969, 168 microsurgical interfascicular nerve transplantations have been performed in the Department for Hand Surgery and Plastic Surgery in the Surgical Clinic of the University of Erlangen. Since the end of 1974, the Zeiss Operation Microscope OPMI 2 has been hung from an electrohydraulic ceiling suspension and has proved invaluable. The construction and function of the apparatus is described. Such suspension of the microscope in combination with original Hanau operation lights, facilitates microsurgery in hand and plastic surgical procedure by saving space, reducing operating time and providing a better opportunity of ensuring sterility in the operating field.

Humans↗

PubMed2002

Cushing's disease resulting from pituitary corticotrophic microadenoma. Treatment results from transsphenoidal microsurgery and gamma knife radiosurgery.

Cushing's disease and its associated clinical syndrome reflect the effects of excess cortisol on the individual. The cause of Cushing's disease is ordinarily an ACTH-secreting benign pituitary adenoma. The diagnosis of Cushing's disease is established by sophisticated endocrine testing and comprehensive imaging studies. Because of the devastating effects of excess cortisol, therapy that provides prompt and effective normalization of serum cortisol is essential. Currently this goal is best achieved by transsphenoidal microsurgery. This paper reviews the clinical presentation, laboratory analysis, surgical management and outcome in patients with Cushing's disease.

Adenoma↗

PubMed1998

Complications following transanal endoscopic microsurgery.

Transanal Endoscopic Microsurgery (TEM) was clinically introduced by Buess et al. In 1983 for the removal of adenomas from the rectal cavity. Later, the indications were extended to the excision of pT1 low-risk carcinomas in curative and to tumors in higher stages in palliative intent. Training courses for this method have been conducted since 1985 and several hundred surgeons have been taught this procedure in Germany and other countries. Because TEM is gaining international recognition it is worthwhile to review the complications of the method.

Journal Article↗

PubMed1976

[Neuroleptics and microsurgery of the ear].

In the field of research into new methods, we attempted to determine the primary effect, i.e. neuroleptic effects following the intensity of reactions to stimulation in patients undergoing microsurgery of the ear, comparing in particular the quantities of analgesic necessary and used during general anesthetic to ensure both clinically visible protection and, above all, suppression of the effects of stimulation at the level of recordings of arterial and venous pressures. This permits, in our opinion, one to evaluate the dose necessary but also, determine whether or not a drug belongs to the category of neuroleptics which are interesting for the anesthetist.

Analgesics↗

PubMedDate not supplied

Local excision of rectal cancer with transanal endoscopic microsurgery (TEM).

BACKGROUND: Local excision for T1 rectal cancers with Transanal Endoscopic Microsurgery (TEM) is an accepted standard of care. However for T2/T3 rectal cancers, the high local failure indicates that this is not a valid option. MATERIALS AND METHODS: Between 1990 and 2000, 83 patients with rectal adenocarcinoma underwent complete full thickness local excision. The mean diameter of the tumor was 3.4+/-1.7 cm, 60% were located more than 5 cm from the anal verge; 43% of patients received radiation therapy (26 pre- and 10 postoperatively). RESULTS: Postoperative complications occurred in 15 patients (18%); there were no postoperative deaths. Mean follow-up was 37 months (range 18-118). The pathological stage was: Tis 9, T1 39, T2 23, T3 12. The overall local recurrence rate was 0% for Tis, 13% for T1, 17% for T2 and 50% for T3. Recurrence was managed surgically in 65% and nonsurgically in 35% because of advanced disease or poor general condition. Overall 5-year survival rates were 100%, 92%, 75% and 69% for Tis, T1, T2 and T3, respectively. CONCLUSION: Local excision with TEM is effective for early (Tis, T1) rectal cancers. Patients with T2 tumors can be treated with preoperative chemoradiation and subsequently local resection. Patients with T3 should not be treated with local excision unless they are unable to tolerate more extensive surgery.

Adult↗

PubMed1996

Technique of transanal endoscopic microsurgery (TEM).

Early stages of rectal cancer, well and ~oderately differentiated, have a l~w r~te of regional spread a~d therefore may be treated by conservative therapy. 1-3 Transanal Bnrloscopic MIcrosurgery (TEM)was In- troduced into clinical practice' by G. Buess in 1983.This technique allows for the local treatment of be- nign lesions and the early stages of rectal cancer through a modified rectoscope, yielding good exposure of the operative field with-three-dimensional vision; mucosectomy and full thickness excision procedures can be performed. TEM benefits are the same as other minimally invasive techniques: less pain, reduced morbid- ity, faster recovery time, and an absence of skin scars. In the present paper, the authors report the technique and the results of the experience of 89TEM procedures for the treatment of rectal tumors.

Journal Article↗

PubMed1987

[Lasers in gynecological microsurgery. Comparative experimental study].

Forty Wistar female rats were the subject of a laser resection of the uterine horn with microsurgical anastomosis, comparing the effect of various available lasers with blade section. The animals were divided in four groups. The first group, with 10 animals, underwent a resection of each uterine horn, using the CO2 laser, with a one layer anastomosis using ethilon 10/10, under microscope. Five of them were examined one week later and the five others three weeks later, with evaluation of the adhesions, patency of the anastomosis and its histological examination. The three other groups underwent a resection using an Argon laser, Yag laser or scissors. With the Yag laser, the lumen disappeared completely and the mucosa as well as the musculosa were totally destroyed. In the other groups, adhesions were noted as well as a variable inflammatory reaction, in early and late evaluations. However, this reaction is minimal after a resection with scissors, moderate after CO2 laser, significant after Argon laser. It is concluded that only the CO2 laser is suitable for gynecological microsurgery; however, the only advantage over a scissor resection is a faster operating time and a better hemostasis; the other parameters are in favor of blade resection. Thus, it seems that laser resection is not an ideal procedure in humans, for tubal resection before anastomosis.

Animals↗