Muscle rupture after minimal trauma of the spastic muscle: three case reports of patients with spinal cord injury.

STUDY DESIGN: Retrospective study of three cases. OBJECTIVES: To report three cases of muscle rupture caused by minimal trauma in spinal cord injury (SCI) patients with severe spasticity and a literature review of the underlying mechanisms. SETTING: Department of Physical and Rehabilitation Medicine, University Hospitals Leuven, Belgium METHODS: Retrospective study of three cases of muscle ruptures in SCI patients with severe spasticity. All muscle lesions were diagnosed by ultrasound. Literature review (Pubmed) was performed to identify extrinsic and intrinsic risk factors. RESULTS: According to the literature and our clinical findings, several structural and mechanical alterations of the spastic muscle in combination with specific stretching during therapy or a transfer can cause a muscle rupture after minimal trauma. CONCLUSION: To the authors' knowledge, this is the first report of muscle rupture due to spasticity in SCI patients. Altered mechanical properties of the spastic muscle in combination with extreme stretching may cause partial or complete ruptur. Although this is a rare complication of spasticity, medical staff and therapists should be aware of the risk factors in order to prevent and quickly identify muscle lesions.

Gelatin sponge plug to seal fetoscopy port sites: technique in ovine and primate models.

Amniotic fluid leakage and rupture of membranes are common complications of fetoscopy. We describe a plug technique for leakproof removal of endoscopic cannulas. Thirty gelatin sponge plugs were introduced in 5 pregnant ewes and 5 pregnant rhesus monkeys. In the primate model no evidence of amniorrhexis was noted on postoperative ultrasonography. Myometrium and membranes at the port sites were intact at term. A gelatin sponge plug technique may facilitate leakproof port removal after fetoscopy.

Natural protective mechanisms against endoscopic white-light injury in the fetal lamb eye.

OBJECTIVE: To evaluate light transmission, possible light trauma, and techniques for protection of the fetal eyes during intrauterine videoendoscopic surgery in a sheep model. METHODS: In vitro studies were done at various gestational ages, including spectrometry of light output by a halogen light source and telescope and light transmission by spectrophotometry in the range of 180-3000 nm through amniotic fluid (AF) and fetal eyelids. In vivo electron-microscopic, morphologic analysis of the retinas of 65-, 95-, 108-, and 112-day-old fetal lambs with (n = 8) and without (n = 8) 30 minutes' light exposure to the open eye was also done. RESULTS: The light spectrum at the tip of the telescope was 400-750 nm, with a maximum irradiance of 3x10(-3) W/cm2 at 580 nm. In the ultraviolet spectrum (less than 300 nm), irradiance was less than 0.5x10(-3) W/cm2. Light transmission through ovine AF ranged from 30% at 300 nm to 89% at 700 nm at 84 days' gestation, decreasing to less than 0.01% (300 nm) and 70% (700 nm) at 112 days. Fetal eyelids did not transmit more than 1% of light (any wavelength). After direct in vivo light exposure, no retinal damage was found. Photoreceptors were present from 108 days onward, but chromophores were scant or absent at all ages studied. CONCLUSION: The light spectrum of a standard endoscope is limited to 400-750 nm; ultraviolet light is filtered out. The AF transmits harmful blue light poorly. Fetal eyelids seem to protect the eye by extremely low transmission and light dispersion. Even with the eye open, no morphologic retinal damage was found. The strong light sources used with fetal endoscopy did not appear to pose a threat to the fetal retina.

Experience with fetoscopic cord ligation.

OBJECTIVE: In the case of a monochorionic multiple pregnancy with one non-viable fetus who compromises its co-twin, fetoscopic cord ligation may be performed. We describe our fetoscopic cord ligation technique and discuss the efficacy of cord ligation for salvaging the co-twin, based on available data. STUDY DESIGN: Descriptive case series of four cases and review of the cases published up to 1996. RESULTS: We performed four successful ligations. Of the 23 reported cases, which include the present series, two ligations failed. Four fetuses died in utero, and 17 were born alive at a mean of 8 weeks following the procedure. Two babies died in the perinatal period, a third after 60 days. Preterm uterine contractions do not seem to be a clinical problem. Preterm prelabour rupture of the membranes (PPROM) complicates about 40% of cases, the majority occurring prior to 32 weeks. CONCLUSION: Fetoscopic cord ligation is a feasible procedure with a 71% survival rate and a high risk for PPROM.

Access techniques in endoscopic fetal surgery.

Endoscopic surgery may in the future become an attractive alternative to open fetal surgery. Herein, we present our evolving experience with minimal access techniques in sheep and nonhuman primate models. Fifty-two pregnant sheep (term = 145 d) were used. All underwent laparotomy. Cannulas were 5 mm diameter with balloon fixation device. In group I (95-105 d, n = 22, and 70-74 d, n = 19), a total of 119 cannulas were placed by open hysterotomy and pursestring suture through myometrium and membranes. In group II (n = 11), access was obtained by Seldinger guidewire technique. Eight cannulas were introduced over a dilator and 7 were radially expanding endoscopic cannulas. Fifteen cannulas were also placed in 5 pregnant Rhesus monkeys using Seldinger and radially expanding techniques. Cannula removal was followed by insertion of a collagen sponge plug and oversewing of the myometrium. Mini-hysterotomies with purse-stringing provided excellent access to the amniotic cavity, without dissection of the membranes. Classic Seldinger technique with forward dilatation was equally effective, but caused stretching of membranes. In sheep and in primates, Seldinger technique with radial dilatation allowed safe access without membrane separation. Leak-proof removal of the cannulas was achieved in all primates. Open hysterotomy with purse-string and balloon-tipped cannula provides efficient and safe access to the gravid sheep uterus. Seldinger technique allows equally secure access, and alleviates the need for hysterotomies. Radial dilatation of the porthole eliminates forward dissection of the membranes, both in sheep and primate models. This method, and collagen plug insertion upon completion of the endoscopic procedure, may provide a truly minimally invasive approach to in-utero surgery.

Amnioinfusion with Hartmann's solution: a safe distention medium for endoscopic fetal surgery in the ovine model.

In this study, we have investigated the maternal effects of distending the uterine cavity with Hartmann's solution in 2nd trimester equivalent pregnant sheep. In 7 pregnant ewes, double endoscopic cannulation of the amniotic cavity was performed under general anesthesia, and 1 liter of Hartmann's solution at 38 degrees C, radiolabeled with 99mTc-red blood cells, was infused. Maternal central venous pressure, hematocrit, serum and amniotic fluid osmolarity, and amniotic fluid volume were measured at nine time points within a 2-hour period. Over this time interval, no significant fluid shift to the maternal compartment was observed. We detected no adsorption of radioactivity to the fetus or membranes, and no diffusion of radioactivity to maternal or fetal tissues was noticed. We conclude from these experiments that following double cannulation and intra-amniotic infusion of Hartmann's solution into the 2nd-trimester pregnant ovine uterus, no significant shift of fluid to the maternal compartment was observed over a 2-hour time period.

The effect of open and endoscopic fetal surgery on uteroplacental oxygen delivery in the sheep.

Open fetal surgery predictably results in postoperative uterine contractions and often in premature labor, but its intraoperative effects on the uterus are not known. In 10 pregnant ewes (108 to 115 days' gestation), uterine artery flow, uterine venous oxygen saturation, arterial saturation, and uterine electromyography were recorded simultaneously (control). Six ewes underwent a stapled hysterotomy, and four underwent placement of three endoscopic surgery cannulas and amnioinfusion. Uterine contractions were present 52% of the time (range, 34% to 72%), and there was no significant difference between control, hysterotomy, and endoscopic access. Uterine artery blood flow and uteroplacental oxygen delivery at rest decreased (to 73% of control) after hysterotomy (P < .05), but not after endoscopy. Fetal + uteroplacental oxygen consumption did not differ significantly between the groups. In conclusion, (1) uteroplacental oxygen delivery after hysterotomy alone decreased to levels critical for adequate fetal oxygenation; (2) endoscopy did not alter uteroplacental oxygen delivery; and (3) during open fetal surgery, further oxygen demand/delivery mismatch is likely, by traction on uterine and umbilical vessels and fetal stress.

Gasless laparoscopy in infants: the rabbit model.

Laparoscopic operations can be performed in neonates and infants, but carbon dioxide pneumoperitoneum may be more dangerous than in adults. Therefore the concept of gasless laparoscopy is especially attractive for small children. The authors have developed an animal training model of gasless infant laparoscopy using the rabbit. Eleven New Zealand white rabbits (mean weight, 2.2 kg) were premedicated with fentanyl (10 micrograms intramuscularly) and maintained under inhalation anesthesia by mask, with halothane (1.0 to 2.5%) in oxygen and nitrous oxide (1:1). The animals were neither intubated nor mechanically ventilated. Heart rate and oxygen saturation were monitored by pulse oximetry. A supraumbilical incision was made through the peritoneum, and an abdominal wall elevator was inserted. A 4-mm-diameter 30 degrees endoscope was introduced at the same site, allowing excellent visualization of the abdominal cavity. Three additional 5-mm cannulas were placed, and a standard Nissen fundoplication was performed in all 11 animals. In seven of these, a left nephrectomy was also performed. Five-millimeter pediatric instruments and 1.7- and 2.7-mm laryngoscopic instruments were used. The rabbit can serve as a training model for laparoscopy in the infant. Gasless laparoscopy, using abdominal wall elevation, may be particularly useful in very small patients.

Intrauterine endoscopic creation of urinary tract obstruction in the fetal lamb: a model for fetal surgery.

OBJECTIVE: Our purpose was to evaluate the feasibility of intrauterine endoscopic fetal surgery in a fetal lamb model by creating a urinary tract obstruction. STUDY DESIGN: Lower urinary tract obstruction was created by ligation of the urethra and urachus in 21 fetal lambs, eight at 95 to 105 days' gestation (term 145 days) and 13 at 70 to 75 days. The endoscopic approach consisted of a 0-degree 5 mm telescope, three 5 mm cannulas, uterine distention by amnioinfusion, and adapted instrumentation. Intrauterine fetal monitoring included temperature and pulse oximetry registration. RESULTS: In 20 cases the urachus could be identified and ligated inside the umbilical cord. The urethra was ligated in the anterior abdominal wall (n = 7) or obstructed at the level of the penis (n = 13). Mean fetal heart rate was 147 +/- 35 beats/min, and fetal temperature at the end of intervention was 38.14 degrees +/- 2.1 degrees C. The overall postoperative survival rate was 76%. CONCLUSION: Urinary tract obstruction can be created endoscopically in the fetal lamb. This operation can serve as a model for endoscopic fetal surgery.

Infrared fetoscopy in the sheep.

The strong light sources used in fetoscopy and embryoscopy may cause eye injuries to the fetus. To circumvent this potential hazard, we have successfully used an infrared light source and infrared video camera to perform 'night vision' fetoscopy in a fetal lamb model.