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Revista Brasileira de Anestesiologia

Print version ISSN 0034-7094
On-line version ISSN 1806-907X

Rev. Bras. Anestesiol. vol.56 no.2 Campinas Mar/Apr. 2006 



Bilateral blockade of the pudend nerve to hemorrhoidectomy in achondroplasic patient. Case report*


Bloqueo bilateral del nervio pudendo para hemorroidectomía en paciente acondroplásico. Relato de caso



Bruno Salomé de Morais, TSA, M.D.I; Marcos Guilherme Cunha Cruvinel, TSA, M.D.I; Yerkes Pereira Silva, M.D.II; Dener Augusto Diniz, TSA, M.D.I; Carlos Henrique Viana de Castro, TSA, M.D.III

IAnestesiologista do Hospital Lifecenter
IIAnestesiologista do Hospital Lifecenter; Especialista em Pediatria; Mestre e Doutorando em Pediatria pela UFMG
IIIDiretor Clínico e Anestesiologista do Hospital Lifecenter

Correspondence to




BACKGROUND AND OBJECTIVES: The achondroplasic dwarfism or achondroplasia is the most common form of dwarfism and occurs, in most of the cases, as a result of spontaneous genetic alteration. The anesthesia in these patients presents several particularities. The objective of the present report was to describe an achondroplasic patient case, with a previous history of surgical procedure of the vertebral column for medullar decompression, submitted to haemorrhoidectomy through the bilateral blockade of the pudend nerves.
CASE REPORT: Male patient, 47 years old, achondroplasic, hospitalized to perform hemorrhoidectomy. Upon physical examination, he presented a shortened neck with limited extension of the head, Mallampati class IV, thyromental distance of 6 cm and opening of the mouth of 3.5 cm. The vertebral column presented thoracic kyphosis and severe lumbar lordosis, in addition to a surgical scar in the lumbar region. A bilateral blockade of the pudend nerves was performed with ropivacaine at 1%, via transperineal, with isolated needle measuring 0.8 mm x 100 mm 21G (Stimuplex A100 BBraun, Melsungen, Germany) connected to the peripheral nerve stimulator (Stimuplex-DIG, BBraun).The patient was positioned in ventral decubitus and the surgery started after 15 minutes of anesthetic administration. During the entire procedure, the patient remained conscious and did not report pain or discomfort. Up to the moment his hospital discharge (22 hours after the performance of the blockade), the patient did not mention pain, discomfort, nausea, vomit, motor blockade, urinary retention or incontinence. After his discharge from the hospital, he evolved well presenting evacuation after 31 hours from surgery.
CONCLUSIONS: The case illustrated the use of the bilateral blockade of the pudend nerves, with the help of the neurostimulator, as an isolated anesthetic techniques for hemorrhoidectomy.

Key words: ANESTHETIC TECHNIQUES, Regional: pudend nerve blockade; DISEASES: achondroplasy; SURGERY, Hemorrhoidectomy.


JUSTIFICATIVA Y OBJETIVOS: El enanismo acondroplásico o acondroplasia es la forma más común de enanismo y ocurre en la mayoría de los casos por alteración genética espontánea. La anestesia de esos pacientes presenta varias particularidades. El objetivo del presente relato fue el de describir un caso de paciente acondroplásico, con previo historial de intervención quirúrgica de la columna para descompresión medular, sometido a Hemorroidectomía a través de bloqueo bilateral de los nervios pudendos.
RELATO DEL CASO: Paciente del sexo masculino, 47 años, acondroplásico, que fue ingresado para la realización de hemorroidectomía.Al hacérsele el examen físico presentaba el cuello acortado con extensión limitada de la cabeza, Mallampati clase IV, distancia tireomentoniana de 6 cm y abertura de la boca de 3,5 cm. La columna vertebral presentaba cifosis torácica y lordosis lumbar acentuada, además de cicatriz quirúrgica en la región lumbar. Fue realizado el bloqueo bilateral de los nervios pudendos con ropivacaina a 1%, por vía transperineal, con una aguja aislada de 0,8 mm x 100 mm 21G (Stimuplex A100 BBraun, Melsungen, Germany) conectada al estimulador de nervios periféricos (Stimuplex-DIG, BBraun).El paciente fue colocado en decúbito ventral y la cirugía iniciada después de 15 minutos da administración del anestésico. Durante todo el procedimiento, el paciente permaneció consciente y no relató ningún dolor o incomodidad. Hasta el momento del alta hospitalaria (22h después de la realización del bloqueo), el paciente no refirió dolor, incomodidad, náusea, vómito, bloqueo motor, retención o incontinencia urinaria. Después del alta, evolucionó bien presentando evacuación después de 31 horas de efectuada la cirugía.
CONCLUSIONES: El caso mostró el uso del bloqueo bilateral de los nervios pudendos, con el auxilio del neuroestimulador como técnica anestésica aislada para la hemorroidectomía.




The achondroplasic dwarfism or achondroplasy is the most common form of dwarfism with an approximate incidence of 1.5 for each 10,000 live newborns 1. Although the trunk and the vertebral column have nearly the normal size, patients present short stature since birth due short limbs. The mean height of the affected adults is 132 cm for men and 122 cm for women 2.

The anesthesia of these patients presents several particularities (Chart I) 1. The objective of this report was to describe the case of an achondroplasic patient, already submitted to medullar descompression with the placement of metallic rods from L1 to S1, referred to be submitted to hemorrhoidectomy.




Male patient, 47 years old, 1.36 m tall, 56 kg weight, physical status ASA II, with a previous surgical history of medullar decompression due to congenital narrowing of the medullar canal, with the fixation of vertebrae and placement of metallic rods from L1 to S1. He reported that in the period prior to medullar decompression, he evolved with pain and paraparesia in the lower limbs which got better after surgical treatment.

He was referred to be submitted to open hemorrhoidectomy (Milligan-Morgan technique) due to grade 3 hemorrhoids. He seemed anxious, rosy, hydrated, blood pressure of 131 x 78 mmHg and heart rate at 76 bpm. Upon the examination of the airways, he presented his neck shortened with limited extension of the head; class IV Mallampati, thyromental distance of 6 cm and opening of the mouth of 3.5 cm. The vertebral column presented thoracic kyphosis and severe lumbar lordosis in addition to a surgical scar in the region of the lumbar column.

After venoclysis with a 20G catheter and monitoring with continuous electrocardiography in derivations DII and V5, pulse oximeter and noninvasive automatic blood pressure measurements (pediatric cuff taking up 2/3 of the left arm), the patient was given 5 µg of sufentanil and 2 mg of mida-zolam, intravenously. Then, he was placed in the position of lithotomy for the performance of the bilateral blockade of the pudend nerves. The ischiatic tuberosities were located and marked bilaterally with a dermographic pen, being traced an imaginary line of 2 cm posterial-medial and then marking the site for the insertion of the needle. After antisepsis of the region with PVPi, the skin was infiltrated with 10 mg of 1% lidocaine with a 13 x 4.5 mm needle. The path of the punction was infiltrated with 50 mg of 1% lidocaine through a 25 x 7 mm needle. An insulated needle (0,8 mm x 100 mm 21G) was used (Stimuplex A100 BBraun, Melsungen, Germany) connected to the neurostimulator (Stimuplex-DIG, BBraun) which was initially setted current of 1.5 mA, with time of stimulation of 0.1 ms and frequency of 2 Hz. The needle was introduced perpendicularly to the skin initially on the right side. After the introduction of 3 cm, the ipsilateral contraction of the anal sphincter was detected. The electric current was decreased up to 0.55 mA when it was still possible to observe the minimum contraction of the anal sphincter and it was decided to inject the local anesthetic (100 mg of 1% ropivacaine - 10 mL) slowly, after negative aspiration of blood into the syringe. The same procedure was done on the left side after the disappearance of the stimulus with 0.6 mA and introduction of 3.5 cm of the needle. The patient was positioned in ventral decubitus and the surgery has begun after 15 minutes from the administration of local anesthetics. During the entire procedure, the patient remained conscious and did not report pain or discomfort. Dexamethasone (10 mg) were administered intravenously in the beginning and 1.5 g of dipyrone and 30 mg of ketorolac at the end of the procedure, when the patient was referred to the postanesthetic recovery room and then transferred to the room where he began early walking. He received as part of the multimodal therapy of the pain ketorolac (30 mg) every 8 hours and dipyrone (1 g) every 6 hours during the first 24 after surgery. Up until the moment of hospital discharge (22 hours after the performance of the blockade), the patient had not reported pain (VAS = 0) or discomfort, and did not present nausea, vomit, motor blockade, urinary retention or incontinence. He affirmed 100% satisfaction with the anesthetic technique used, developing well after hospital discharge, presenting painless evacuation, 31 hours after surgery.



Achondroplasia, a dominant autossomic inheritance, constitutes the most common form of dwarfism, being that 80% to 90% of the achondroplasic children are born in families with normal parents and siblings. It is due to a mutation in the gene of the receptor of type 3 fibroblast growth factor having as a consequence degeneration in the ability to form bones from the cartilage. As common findings, it is noted the stenosis of the foreamen magno, relative megacephaly, prominent forehead, nose in the shape of a button, antiverted nostrils, deformity in wedge of the three first lumbar vertebrae, cervical kyphosis, marked lumbar lordosis, very short limbs at the expense of the proximal segments, trident configuration little hands, pulmonar hypertension, which may lead to cor pulmonale, sleep apnea, which predisposes the patient to a higher risk of obstruction of the airways after sedation or anesthesia induction with airway alterations (Chart II), which classifies them as risk patients for difficult intubation. However, the intellectual development is normal, just as life expectance of those who survive their first year of life 2.



The hemorrhoidary disease causes symptoms in 4.4% of the population, being that 90% of the anorectal surge-ries can be performed in ambulatory regimen although the patients could present severe postoperative pain 3. Several anesthetic techniques can be used, such as the spinal, epidural, the field blockade, venous sedation and balanced general anesthesia.

The neuraxial blockade (spinal and epidural), with the addition or not of opioids to local anesthetics, promotes good surgical conditions; however, it may have as an inconvenience a longer motor blockade, cephalalgia post-perforation of dura-mater and urinary retention. The general balanced anesthesia is associated with higher costs and the worst postoperative pain control 4. Neck hyperextension should be avoided du-ring laryngoscopy for intubation considering the hypothesis of stenosis of the foramen magnum, being the use of optical fiber the elected technique for the intubation of the achondroplasic patients. Venous sedation has the disadvantage of being difficult to maintain the permeability of the upper airways, when the surgery is performed in ventral decubitus, especially taking into consideration that the achondroplasic patients may present higher difficult in ventilation and maintenance of the airways permeability 5.

The achondroplasic patients suffer from neurological symptoms due to the narrowing of the spinal canal, which often needs decompressive surgery 6. The previous surgery of the vertebral column is not an absolute counter indication to the neuraxial blockade; however, technical difficulties and alterations in the dispersion of local anesthetic may occur.

This patient presented previous surgery with the installation of a metallic plate in the segment of L1 to S1 and, in accordance with his physical examination, intubation and ventilation difficulties were identified due to the limitation in the neck extension and its Mallampati IV classification.

The pudend nerves are formed by the posterior branches of S2, S3 and S4 and are divided into four branches: lower anal nerves, perineal nerves, posterior labial nerves (woman), posterior scrotum nerves (man), dorsal nerve of the clitoris (woman) and dorsal nerve of the penis (man)7. The anesthesia of the pudend nerves with peripheral nerve stimulator is characterized as being a simple technique, one of fast execution and safe, being able to provide adequate anesthesia and analgesia without adverse effects of opioids in the neuraxial, motor blockade and the risk of post-perforation of dura-mater cephalgia, all undesirable characteristics to ambulatorial surgeries. The anesthesia of the pudend nerves is a good technique in the anorectal surgeries, in the perineal surgeries and labor analgesia8,9. Imbelloni et al. 10 evaluated the analgesia with the blockade of the pudend nerves in patients submitted to hemorrhoidectomy under spinal anesthesia, using a nerve stimulator through the transperineal technique. In the study, 51% of the patients did not need any postoperative analgesic and 77% of the patients considered it an excellent technique.

It is of utmost importance that the anesthesiologist foresees the possible difficulties imposed to the anesthetic performance as well as the measures to be adopted in order to overcome these difficulties, in accordance with the peculiarities of each patient. The case has illustrated the possibility of the use of bilateral blockade of the pudend nerves, with help of the neurostimulator as unique anesthetic technique for the performance of hemorrhoidectomy, avoiding the airways manipulation in patients counter indicated as to neuroaxial blockade and difficult airway.



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Correspondence to:
Dr. Bruno Salomé de Morais
Rua Ajax Correa Rabelo, 160 - Mangabeiras
30210-040 Belo Horizonte, MG

Submitted for publication 11 de julho de 2005
Accepted for publication 03 de janeiro de 2006



* Received from Departamento de Anestesiologia do Hospital Lifecenter, Belo Horizonte, MG

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