Pietro Giovanoli
University of Zurich
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Featured researches published by Pietro Giovanoli.
Plastic and Reconstructive Surgery | 1999
Manfred Frey; Pietro Giovanoli; Hans Gerber; Michael Slameczka; Edgar Stüssi
The results of neuromuscular reconstructions of the paralyzed face are difficult to assess. Very sophisticated methods are necessary to measure the motor deficits of facial paralysis or the functional recovery in the face. The aim of this development was a relatively simple system for data acquisition, which is easy to handle and which makes it relatively cheap to delegate data acquisition to centers all over the world, which will not be able to derive a data analysis on their own, but will send their data to a center with specialized equipment. A complex mirror system was developed to get three different views of the face at the same time on the video screen. At each investigation, a digital video is taken from a calibration grid and from standardized facial movements of the patient. Secondary analysis of the digital videofilm is made possible at any time later on by the support of a computer program, which calculates distances and movements three-dimensionally from the frontal image and the right and left mirror images. Pathologies of the mimic movements can be identified as well as improvements after surgical procedures by this system. The significant advantage is the possibility to watch the same movement on the video which is under study and to apply any kind of study later on. Taking the video needs only a few minutes, and fatigue of the patients mimic system is prevented. Measurements usually at the endpoints of the movements give excellent information on the quantity of the movement or the degree of the facial palsy, whereas the video itself is very informative regarding the quality of the smile. Specific computer software was developed for standardized three-dimensional analysis of the video-documented facial movements and for data presentation. There are options like two-dimensional graphs of single moving points in the face or three-dimensional graphs of the movements of all measured points at the same time during a standardized facial movement. By a comparison of the right- and left-sided alterations of specific distances between two points during the facial movements, the degree of normal symmetry or pathologic asymmetry is quantified. This system is more suitable for detailed scientific multicenter studies than any other system previously established. A very sensitive instrument for exact evaluation of mimic function is now available.
Burns | 2009
Merlin Guggenheim; Reinhard Zbinden; Alexander E. Handschin; Andreas Gohritz; M.A. Altintas; Pietro Giovanoli
BACKGROUND Our aim is to elucidate shifts in the bacterial spectrum colonising burn wounds and corresponding antibiotic susceptibilities during a 20-year study period. METHODS Microbiological results from burn patients collected between 1986 and 2005 were analysed retrospectively. RESULTS Staphylococcus aureus was isolated most frequently (20.8%), followed by Escherichia coli (13.9%), Pseudomonas aeruginosa (11.8%), coagulase-negative staphylococci (CNS) (10.9%), Enterococcus sp. (9.7%), Enterobacter cloacae (5.6%), Klebsiella pneumoniae (5%), Acinetobacter sp. (3.2%), Proteus mirabilis (2%) and Stenotrophomonas maltophilia (1.4%). Susceptibility of S. aureus to broad-spectrum substances such as ciprofloxacin or penicillinase-stable penicillins has waned, others such as cotrimoxazole or netilmicin remained effective. Not a single resistance against vancomycin was recorded. Increases in methicillin-resistant S. aureus (MRSA) were pronounced (3% in 1986-1997 (the first of the three study periods) to 16% in 1998-2001 and 13% in 2002-2005). Results for methicillin-resistant CNS (MRCNS) show an even greater increase. P. aeruginosa has shown increasing susceptibility against netilmicin (1986-1989: 84%, 2002-2005: 95%). Susceptibility of P. aeruginosa to ceftazidime has decreased markedly. S. maltophilia has shown clinically relevant susceptibility mainly against ciprofloxacin. Acinetobacter sp. have shown little susceptibility to most antibiotics. Imipenem or meropenem have been very reliable reserve antibiotics throughout the study period for the fermenting Enterobacteriaceae (E. coli, K. pneumoniae, E. cloacae and P. mirabilis), with susceptibilities of or near 100%. CONCLUSION In-depth knowledge of the bacteria causing infectious complications and of their antibiotic susceptibilities is a prerequisite for treating burn patients. Our study shows shifts in the microbial spectrum and their antibiogram, which mandate frequent reassessments.
Plastic and Reconstructive Surgery | 1994
Manfred Frey; Jenny A; Pietro Giovanoli; Edgar Stüssi
None of the paresis scoring systems used satisfies an adequate description of all the details necessary to document the degree of facial paresis before and after any treatment. We developed a new documentation system considering all details of the history of the patient and of the treatment that could have any influence on the functional result. The third part of this “international registry for neuromuscular reconstruction in the face” concerns paralysis assessment, including quantitative measurements of the resting and moving face, besides qualitative parameters. A map of standardized static and dynamic points in the face was designed, and three-dimensional measurements of the movements of these facial points were performed with a VICON system in 16 healthy individuals. On the basis of the results, three real static points and representative dynamic points were selected as well as relations of these points most representative for the different facial movements. For data collection, a simple instrument (Freys faciometer) was developed. A preliminary report is given on the clinical application of this new instrument. (Plast. Reconstr. Surg. 93: 1334, 1994.)
Annals of Surgery | 2008
Merlin Guggenheim; Urs Hug; Florian J. Jung; Valentin Rousson; M. C. Aust; Maurizio Calcagni; Walter Künzi; Pietro Giovanoli
Objective:To assess the nature and rates of complications and recurrences after completion lymph node dissection (CLND) following positive sentinel lymph node biopsy (SLNB) in melanoma patients. Summary Background Data:In contrast to SLNB, CLND is associated with considerable morbidity. CLND delays nodal recurrence, thereby prolonging disease-free survival (DFS), but not overall melanoma-specific survival. Elaborate studies on morbidity and recurrence rates after CLND are scarce. Therefore, many controversies concerning extent and nature of CLND exist. Methods:We conducted a retrospective study on 100 melanoma patients, on whom we performed CLND between October 1999 and December 2005. The median observation period was 38.8 months. Results:We performed a total of 102 CLNDs, [46.1% axillary (47/102), 42.2% groin (43/102), 11.8% neck (12/102)]. Groin dissection (GD) and axillary dissection (AD) led to comparable morbidity (47.6% and 46.8%), but complications were more severe in GD, mandating additional surgery in 25.6% (11/43), versus 8.5% (4/47) in AD. Of the GD patients, 18.5% (8/43) were readmitted for complications compared with 10.4% (5/47) of AD patients. Only 8.3% (1/12) of ND patients suffered complications, mandating neither readmittance nor further surgery. During the median observation period, 65 (65%) of these patients showed DFS, and 35 (35%) exhibited recurrences after a median DFS of 12.5 months. Of the recurrences, 31.4% were nodal, 42.9% distant, and 25.7% local/in-transit. Of our AD patients, 28.3% suffered recurrences (13/46), as did 33.3% of the GD (14/42) and 66.7% of the ND patients (8/12). Conclusions:CLND is fraught with considerable morbidity. Local control of the dissected nodal basins was achieved with a modified radical approach in ADs (levels I + II only) and, to a lesser extent, GDs, but not in NDs. Clinical trials are necessary to establish guidelines on the extent of lymphatic dissection.
Plastic and Reconstructive Surgery | 2000
Pietro Giovanoli; Rupert Koller; Claudia Meuli-Simmen; Matthias Rab; Werner Haslik; Martina Mittlböck; Viktor E. Meyer; Manfred Frey
This study was undertaken to quantify the effect of motor collateral sprouting in an end-to-side repair model allowing end organ contact. Besides documentation of the functional outcome of muscle reinnervation by end-to-side neurorrhaphy, this experimental work was performed to determine possible downgrading effects to the donor nerve at end organ level. In 24 female New Zealand White rabbits, the motor nerve branch to the rectus femoris muscle of the right hindlimb was dissected, cut, and sutured end-to-side to the motor branch to the vastus medialis muscle after creating an epineural window. The 24 rabbits were divided into two groups of 12 each, with the second group receiving additional crush injury of the vastus branch. After a period of 8 months, maximum tetanic tension in the reinnervated rectus femoris and the vastus medialis muscles was determined. The contralateral healthy side served as control. The reinnervated rectus femoris muscle showed an average maximum tetanic force of 24.9 N (control 26.2 N, p = 0.7827), and the donor vastus medialis muscle 11.0 N (control 7.3 N, p = 0.0223). There were no statistically significant differences between the two experimental groups (p = 0.9914). The average number of regenerated myelinated nerve fibers in the rectus femoris motor branch was 1185 ± 342 (control, 806 ± 166), and the mean diameter was 4.6 ± 0.6 &mgr;m (control, 9.4 ± 1.0 &mgr;m). In the motor branch to the vastus medialis muscle, the mean fiber number proximal to the coaptation site was 1227 (±441), and decreased distal to the coaptation site to 795 (±270). The average difference of axon counts in the donor nerve proximal to distal regarding the repair site was 483.7 ± 264.2. In the contralateral motor branch to the vastus medialis muscle, 540 (±175) myelinated nerve fibers were counted. In nearly all cross-section specimens of the motor branch to the vastus medialis muscle, altered nerve fibers could be identified in one fascicle distal and proximal to the repair site. The results show a relevant functional reinnervation by end-to-side neurorrhaphy without functional impairment of the donor muscle. It seems to be evident that most axons in the attached segment were derived from collateral sprouts. Nonetheless, the present study confirms that end-to-side neurorrhaphy is a reliable method of reconstruction for damaged nerves, which should be applied clinically in a more extended manner. (Plast. Reconstr. Surg. 106: 383, 2000.)
Infection | 1994
H.-P. Simmen; Hugo Battaglia; Pietro Giovanoli; Jürg Blaser
Low pH (<7.1) and pO2 (<6.5 kPa) and high pCO2 (>8 kPa) of peritoneal fluid have been previously associated with the presence of intra-abdominal infection. These parameters were monitored in drainage fluid following emergency laparotomy in 40 patients operated on for intra-abdominal infections and also in 15 patients who underwent laparotomy for another reason than infection. Significant differences were observed beginning on the fourth postoperative day between the 48 patients who improved or were cured and the seven patients in whom therapy failed due to anastomotic breakdown or abscess formation. Anastomotic leaks or abscesses were radiologically confirmed. In five of the seven failures, complications were first detected by analysis of pH, pO2 and pCO2 before clinical symptoms became evident. Specificity for each of these parameters in drainage fluid samples obtained after the second postoperative day was >94%. Assessment of the three parameters allowed for simple, cost-effective, rapid and early detection of infectious complications following abdominal surgery. Tiefe Werte für pH (<7,1) und pO2 (<6,5 kPa) sowie hohe Werte für pCO2 (>8 kPa) in Peritonealflüssigkeit haben sich als charakteristische Parameter einer bakteriellen Infektion erwiesen. Diese drei Parameter wurden in Drainageflüssigkeiten gemessen, die von 40 Patienten nach notfallmäßiger Laparotomie infolge intraabdominaler Infektion gesammelt wurden. Zum Vergleich wurden auch Drainageflüssigkeiten von 15 Patienten asserviert, die aus anderen Gründen laparotomiert wurden. Vom vierten postoperativen Tag an wurden signifikante Differenzen festgestellt zwischen der Gruppe der 48 Patienten, die geheilt oder gebessert und der Gruppe jener sieben Patienten, deren Therapie wegen Anastomosenleck oder Abszeßbildung als Mißerfolg gewertet wurde. Anastomosenlecks and Abszeßbildungen wurden jeweils radiologisch bestätigt. Bei fünf der sieben Patienten, deren Therapie als Mißerfolg klassifiziert wurde, konnte die Komplikation auf Grund der Analyse von pH, pO2 und pCO2 in Drainagesekreten vermutet werden, bevor klinische Symptome manifest wurden. Die Spezifität aller drei Parameter, die in Drainageflüssigkeiten nach dem zweiten postoperativen Tag gemessen wurden, lag über 94%. Die Messung der drei Parameter erlaubt eine einfache, rasche, kostengünstige und frühe Erkennung infektiöser Komplikationen nach Laparotomien.SummaryLow pH (<7.1) and pO2 (<6.5 kPa) and high pCO2 (>8 kPa) of peritoneal fluid have been previously associated with the presence of intra-abdominal infection. These parameters were monitored in drainage fluid following emergency laparotomy in 40 patients operated on for intra-abdominal infections and also in 15 patients who underwent laparotomy for another reason than infection. Significant differences were observed beginning on the fourth postoperative day between the 48 patients who improved or were cured and the seven patients in whom therapy failed due to anastomotic breakdown or abscess formation. Anastomotic leaks or abscesses were radiologically confirmed. In five of the seven failures, complications were first detected by analysis of pH, pO2 and pCO2 before clinical symptoms became evident. Specificity for each of these parameters in drainage fluid samples obtained after the second postoperative day was >94%. Assessment of the three parameters allowed for simple, cost-effective, rapid and early detection of infectious complications following abdominal surgery.ZusammenfassungTiefe Werte für pH (<7,1) und pO2 (<6,5 kPa) sowie hohe Werte für pCO2 (>8 kPa) in Peritonealflüssigkeit haben sich als charakteristische Parameter einer bakteriellen Infektion erwiesen. Diese drei Parameter wurden in Drainageflüssigkeiten gemessen, die von 40 Patienten nach notfallmäßiger Laparotomie infolge intraabdominaler Infektion gesammelt wurden. Zum Vergleich wurden auch Drainageflüssigkeiten von 15 Patienten asserviert, die aus anderen Gründen laparotomiert wurden. Vom vierten postoperativen Tag an wurden signifikante Differenzen festgestellt zwischen der Gruppe der 48 Patienten, die geheilt oder gebessert und der Gruppe jener sieben Patienten, deren Therapie wegen Anastomosenleck oder Abszeßbildung als Mißerfolg gewertet wurde. Anastomosenlecks and Abszeßbildungen wurden jeweils radiologisch bestätigt. Bei fünf der sieben Patienten, deren Therapie als Mißerfolg klassifiziert wurde, konnte die Komplikation auf Grund der Analyse von pH, pO2 und pCO2 in Drainagesekreten vermutet werden, bevor klinische Symptome manifest wurden. Die Spezifität aller drei Parameter, die in Drainageflüssigkeiten nach dem zweiten postoperativen Tag gemessen wurden, lag über 94%. Die Messung der drei Parameter erlaubt eine einfache, rasche, kostengünstige und frühe Erkennung infektiöser Komplikationen nach Laparotomien.
Plastic and Reconstructive Surgery | 2004
Manfred Frey; Pietro Giovanoli; Chieh-Han John Tzou; Nina Kropf; Susanne Friedl
For patients with facial palsy, lagophthalmus is often a more serious problem than the inability to smile. Dynamic reconstruction of eye closure by muscle transposition or by free functional muscle transplantation offers a good solution for regaining near-normal eye protection without the need for implants. This is the first quantitative study of three-dimensional preoperative and postoperative lid movements in patients treated for facial paralysis. Between February of 1998 and April of 2002, 44 patients were treated for facial palsy, including reconstruction of eye closure. Temporalis muscle transposition to the eye was used in 34 cases, and a regionally differentiated part of a free gracilis muscle transplant after double cross-face nerve grafting was used in 10 cases. Patients’ facial movements were documented by a three-dimensional video analysis system preoperatively and 6, 12, 18, and 24 months postoperatively. For this comparative study, only the data of patients with preoperative and 12-month postoperative measurements were included. In the 27 patients with a final result after temporalis muscle transposition for eye closure, the distance between the upper and lower eyelid points during eye closing (as for sleep) was reduced from 10.33 ± 2.43 mm (mean ± SD) preoperatively to 5.84 ± 4.34 mm postoperatively on the paralyzed side, compared with 0.0 ± 0.0 mm preoperatively and postoperatively on the contralateral healthy side. In the resting position, preoperative values for the paralyzed side changed from 15.11 ± 1.92 mm preoperatively to 13.46 ± 1.94 mm postoperatively, compared with 12.17 ± 2.02 mm preoperatively and 12.05 ± 1.95 mm postoperatively on the healthy side. In the nine patients with a final result after surgery using a part of the free gracilis muscle transplant reinnervated by a zygomatic branch of the contralateral healthy side through a cross-face nerve graft, eyelid closure changed from 10.21 ± 2.72 mm to 1.68 ± 1.35 mm, compared with 13.70 ± 1.56 mm to 6.63 ± 1.51 mm preoperatively. The average closure for the healthy side was from 11.20 ± 3.11 mm to 0.0 ± 0.0 mm preoperatively and from 12.70 ± 1.95 mm to 0.0 ± 0.0 mm postoperatively. In three cases, the resting tonus of the part of the gracilis muscle transplant around the eye had increased to an extent that muscle weakening became necessary. Temporalis muscle transposition and free functional muscle transplantation for reanimation of the eye and mouth at the same time are reliable methods for reconstructing eye closure, with clinically adequate results. Detailed analysis of the resulting facial movements led to an important improvement of the authors’ operative techniques within the last few years. Thus, the number of secondary operative corrections could be significantly reduced. These qualitative and quantitative studies of the reconstructed lid movements by three-dimensional video analysis support the authors’ clinical concept of temporalis muscle transposition being the first-choice method in adult patients with facial palsy. In children, free muscle transplantation is preferred for eye closure, so as not to interfere with the growth of the face by transposition of a masticatory muscle. In addition, a higher degree of central plasticity in children might be expected.
American Journal of Pathology | 2008
Nikolaus Wick; Daniela Haluza; Elisabeth Gurnhofer; Ingrid Raab; Marie-Theres Kasimir; Michael Prinz; Carl-Walter Steiner; Christina Reinisch; Anny Howorka; Pietro Giovanoli; Sabine Buchsbaum; Sigurd Krieger; Erwin Tschachler; Peter Petzelbauer; Dontscho Kerjaschki
Expression of the lymphoendothelial marker membrane mucoprotein podoplanin (podo) distinguishes endothelial cells of both blood and lymphatic lineages. We have previously discovered two distinct subpopulations of lymphatic endothelial cells (LECs) in human skin that were defined by their cell surface densities of podoplanin and were designated LEC podo-low and LEC podo-high. LEC podo-low is restricted to lymphatic precollector vessels that originate from initial LEC podo-high-containing lymphatic capillaries and selectively express several pro-inflammatory factors. In addition to the chemokine receptor protein Duffy blood group antigen receptor for chemokines, these factors include the constitutively expressed chemokine CCL27, which is responsible for the accumulation of pathogenic CCR10+ T lymphocytes in human inflammatory skin diseases. In this study, we report that CCR10+ T cells accumulate preferentially both around and within CCL27+ LEC podo-low precollector vessels in skin biopsies of human inflammatory disease. In transmigration assays, isolated CCR10+ T lymphocytes are chemotactically attracted by LEC podo-low in a CCL27-dependent fashion, but not by LEC podo-high. These observations indicate that LEC podo-low-containing precollector vessels constitute a specialized segment of the initial lymphatic microvasculature, and we hypothesize that these LEC podo-low-containing vessels are involved in the trafficking of CCR10+ T cells during skin inflammation.
Microvascular Research | 2012
Stefan Schlosser; Cyrill Dennler; Riccardo Schweizer; Daniel Eberli; Jens V. Stein; Volker Enzmann; Pietro Giovanoli; Dominique Erni; Jan A. Plock
New theories on the regeneration of ischemic vasculature have emerged indicating a pivotal role of adult stem cells. The aim of this study was to investigate homing and hemodynamic effects of circulating bone marrow-derived mesenchymal stem cells (MSCs) in a critically ischemic murine skin flap model. Bone marrow-derived mesenchymal stem cells (Lin(-)CD105(+)) were harvested from GFP(+)-donor mice and transferred to wildtype C57BL/6 mice. Animals receiving GFP(+)-fibroblasts served as a control group. Laser scanning confocal microscopy and intravital fluorescence microscopy were used for morphological analysis, monitoring and quantitative assessment of the stem cell homing and microhemodynamics over two weeks. Immunohistochemical staining was performed for GFP, eNOS, iNOS, VEGF. Tissue viability was analyzed by TUNEL-assay. We were able to visualize perivascular homing of MSCs in vivo. After 4 days, MSCs aligned along the vascular wall without undergoing endothelial or smooth muscle cell differentiation during the observation period. The gradual increase in arterial vascular resistance observed in the control group was abolished after MSC administration (P<0.01). At capillary level, a strong angiogenic response was found from day 7 onwards. Functional capillary density was raised in the MSC group to 197% compared to 132% in the control group (P<0.01). Paracrine expression of VEGF and iNOS, but not eNOS could be shown in the MSC group but not in the controls. In conclusion, we demonstrated that circulating bone marrow-derived MSCs home to perivascular sites in critically ischemic tissue, exhibits paracrine function and augment microhemodynamics. These effects were mediated through arteriogenesis and angiogenesis, which contributed to vascular regeneration.
Plastic and Reconstructive Surgery | 2006
Manfred Frey; Pietro Giovanoli; Maria Michaelidou
Background: Cross-face nerve grafting combined with functional muscle transplantation has become the standard in reconstructing an emotionally controlled smile in complete irreversible facial palsy. A special problem exists in incomplete or partially recovered facial palsies, when the little existing function should be preserved but the existing function alone is clinically insufficient. Methods: In this situation, cross-face nerve grafting performed by means of end-to-end coaptation to a zygomatic branch of the healthy side and by end-to-side neurorrhaphy to a corresponding branch of the incompletely paralyzed side is proposed to upgrade smile function on the latter side and contribute to more static and dynamic overall symmetry. The interposition nerve graft is set in overlength to preserve the possibility of a later muscle transplantation in case of unsatisfying functional result through the additional neuronal input. The authors have used this concept in seven patients with irreversible partial facial palsy. Three cases have a sufficiently long follow-up to be presented here. Outcome was objectively quantified with three-dimensional video analysis of facial movements. Results: In all three cases, functional improvement and a positive effect on the static and dynamic symmetry of the face could be measured. None of the patients was disappointed by the smile function achieved or wanted to undergo additional muscle transplantation. Conclusion: On the basis of these first clinical experiences, the authors recommend cross-face nerve grafting with overlength and a distal end-to-side neurorrhaphy in patients with irreversible incomplete facial palsy affecting the smile.