La
escisión
total
del
mesorrecto
se
considera
la
técnica
quirúrgica
gold
standard
para
la
cirugía
de
cáncer
de
recto,
desde
que
en
1982
Heald
et
al
publicaran
un
artículo
seminal
que
demostró
que
este
procedimiento
era
el
responsable
de
un
notable
descenso
en
la
tasa
de
recidiva
local
y
consecuentemente
un
trascendente
aumento
de
la
supervivencia.
La
escisión
total
del
mesorrecto
preserva
la
integridad
de
la
fascia
mesorrectal,
debido
al
hecho
de
que
la
disección
se
lleva
a
cabo
siguiendo
los
planos
embriológicos
anatómicos,
proporcionando
así,
la
obtención
de
un
mesorrecto
óptimo
y
por
consiguiente,
la
reducción
de
la
tasa
de
la
recurrencia
en
un
5-‐10%
.
En
los
últimos
años,
numerosos
estudios
han
tratado
de
demostrar
las
ventajas
del
abordaje
laparoscópico
en
la
escisión
total
del
mesorrecto.
En
relación
a
resultados
a
corto
plazo,
varias
series
y
estudios
prospectivos
aleatorizados,
llevados
a
cabo
por
cirujanos
especialistas
en
cáncer
de
recto,
han
demostrado
las
ventajas
clínicas
postoperatorias
inmediatas
del
abordaje
mínimamente
invasivo.
De
la
misma
manera,
estos
trabajos
también
han
documentado
que
las
características
de
los
espécimenes
patológicos
obtenidos
por
la
vía
laparoscópica
son
similares
a
los
obtenidos
en
cirugía
abierta.
No
obstante,
estas
conclusiones
tan
optimistas,
son
difíciles
de
lograr
en
práctica
diaria.
De
todos
modos,
aún
carecemos
de
los
resultados
a
largo
plazo
derivados
de
los
ensayos
aleatorizados,
por
lo
que
aún
no
se
puede
determinar
si
la
incidencia
de
recidiva
local
difiere
según
sea
el
abordaje
elegido.
A
pesar
de
las
ventajas
que
ofrece
la
cirugía
laparoscópica,
este
enfoque
puede
ser
especialmente
complejo
en
ciertas
situaciones,
tal
y
cómo
refleja
la
tasa
de
conversión
de
hasta
25%
publicada
en
destacadas
series.
En
un
estudio
anterior,
nuestro
grupo
investigó
qué
factores
afectaban
en
el
resultado
clínico
inmediato
del
cáncer
de
recto
abordado
por
laparoscopia,
concluyendo
que
tanto
el
IMC,
el
tamaño
del
tumor
y
el
género
tienen
una
influencia
significativa
en
la
duración
operatoria,
la
tasa
de
conversión
y
la
morbilidad.
Teniendo
en
cuenta
estos
hallazgos
previos,
nace
la
hipótesis
del
trabajo
actual,
qué
consiste
en
determinar
si
existen
factores
preoperatorios,
tanto
clínicos,
quirúrgicos,
como
pelvimétricos,
que
puedan
tener
un
impacto
en
la
calidad
de
las
muestras
patológicas
del
cáncer
de
recto
tras
el
abordaje
laparoscópico.
El
trabajo
actual
es
un
estudio
prospectivo
formado
por
una
serie
consecutiva
de
pacientes
diagnosticados
de
un
adenocarcinoma
de
recto
situado
a
menos
de
12
cm
de
margen
anal,
sometidos
a
escisión
total
del
mesorrecto
laparoscópica
con
preservación
esfinteriana
e
intención
curativa
,
en
el
Hospital
de
la
Santa
Creu
i
Sant
Pau
entre
enero
de
2010
y
julio
de
2012.
Se
excluyeron
tumores
estadiados
como
T1
o
T4,
amputaciones
abdomino-‐perineales,
tumores
perforados
u
obstructivos
y
aquellos
pacientes
que
presentaban
contraindicación
mayor
para
la
cirugía
laparoscópica.
Se
consideraron
más
de
veinte
variables
(ver
Tabla
8)
relacionadas
con
las
características
clínicas
y
anatómicas
del
paciente,
con
el
acto
quirúrgico
y
con
el
tumor.
Cómo
variables
dependientes
se
tomaron
dos
variables
anatomopatológicas
ampliamente
reconocidas:
el
margen
de
resección
circunferencial
y
la
integridad
macroscópica
del
mesorrecto.
Se
llevó
a
cabo
un
estudio
descriptivo,
así
como
un
análisis
univariante
y
multivariante.
¿Cuáles
son
los
principales
puntos
de
interés
en
este
estudio?
En
primer
lugar,
nuestras
conclusiones
ayudan
a
identificar
los
casos
en
los
que
el
mesorrecto
está
en
riesgo
y
para
los
qué
se
requiere
un
cirujano
altamente
especializado.
Además,
nuestros
resultados
relacionados
con
las
mediciones
pelvimétricas
pueden
ser
útiles
en
la
programación
del
acto
quirúrgico,
ya
que
ayudan
a
predecir
el
tiempo
operatorio.
En
el
caso
de
dificultades
intraoperatorias,
el
conocimiento
de
los
factores
obstaculizadores
permite
considerar
al
cirujano
la
conversión
a
cirugía
abierta,
seleccionar
a
priori
la
técnica
de
abordaje,
o
aumentar
el
cuidado
disección
quirúrgica
para
evitar
el
riesgo
de
lesiones
en
el
mesorrecto.
Por
último,
nuestros
datos
finales
ayudan
a
seleccionar
a
los
pacientes
que
podrían
beneficiarse
de
la
cirugía
laparoscópica
y
por
lo
tanto
contribuir
a
la
formación
y
la
curva
de
aprendizaje
de
los
cirujanos
jóvenes. / Background: Pelvic anatomy and tumour features play a role in the difficulty of the
laparoscopic approach to total mesorectal excision in rectal cancer. The aim of the
study was to analyze whether these characteristics also influence the quality of the
surgical specimen.
Material and Methods: We performed a prospective study in consecutive patients
with rectal cancer located less than 12 cm from the anal verge who underwent
laparoscopic surgery between January 2010 and July 2013. Exclusion criteria were
T1 and T4 tumours, abdominoperineal resections, obstructive and perforated
tumours, or any major contraindication for laparoscopic surgery. Dependent
variables were the circumferential resection margin (CMR) and the quality of the
mesorectum.
Results: Sixty-four patients underwent laparoscopic sphincter-preserving total
mesorectal excision. Resection was complete in 79.1% of specimens and CMR
was positive in 9.7%. Univariate analysis showed tumor depth (T status) (P=0.04)
and promontorium-subsacrum angle (P=0.02) independently predicted CRM
positivity. Tumor depth (P<0.05) and promontorium-subsacrum axis (P<0.05)
independently predicted mesorectum quality. Multivariate analysis identified the
promontorium-subsacrum angle (P= 0.012) as the only independent predictor of
CRM.
Conclusion: Bony pelvis dimensions influenced the quality of the specimen
obtained by laparoscopy. These measurements may be useful to predict which
patients will benefit most from laparoscopic surgery and also to select patients in
accordance with the learning curve of trainee surgeons.
Keywords: rectal cancer, total mesorectal excision, laparoscopy, pelvimetry,
quality of mesorectum, circumferential resection margin
Introduction
Total mesorectal excision (TME) has been the gold standard for rectal
cancer surgery since 1982 when Heald et al 1,2 published their seminal paper
showing that this approach led to a sharp decrease in the local recurrence rate and
an increase in survival. TME preserves the integrity of the mesorectal fascia as
dissection is based on the anatomical embryological planes, and it provides an
optimal mesorectum, reducing the recurrence rate by 5-10% 3.
Many studies have tried to show the advantages of the laparoscopic
approach in TME. Regarding short-term outcome, several series and prospective
randomized trials, performed by specifically trained surgeons, have demonstrated
the immediate postoperative clinical advantages of the minimally invasive
approach. They have also shown that features of pathological specimens obtained
by the laparoscopic approach are similar to those obtained in open surgery 4,5.
These positive results, however, are difficult to achieve in general surgical
practice6. As long-term results of large prospective randomized trials are lacking, it
is not yet clear whether the incidence of local recurrence (LR) differs in open and
laparoscopic approaches.
Despite the advantages of the laparoscopic dissection technique, this approach
may be specially challenging in certain situations, and a conversion rate of up to
25% has been reported 3. In a previous study we investigated the factors that had
an impact on immediate clinical outcome, showing that BMI, tumor size and gender
had a significant influence on operative time, conversion and morbidity7. On the
basis of these previous findings, we hypothesized that intraoperative technical
difficulties may have an impact on the quality of the pathological specimen. The
aim of the present study was to analyze preoperatively whether pelvic dimensions
and tumour characteristics also influence the quality of the specimen.
Material and Methods
Patient selection
We performed a prospective study in consecutive patients with rectal cancer
who underwent TME by laparoscopy with curative intent from January 2010 to July
2013. The inclusion criteria were rectal cancer located at or below 12 cm from the
anal verge. Exclusion criteria were patients with a T1 tumor treated by local
excision, preoperative clinical evidence of locally advanced disease (T4),
abdominoperineal resections, obstructive and perforated tumours, and any major
contraindication for laparoscopic surgery. All the patients included in the study
were evaluated by a multidisciplinary team of surgeons, medical oncologists,
radiotherapists, radiologists and pathologists.
Table 1 shows the demographic parameters, pelvimetry measurements, and
surgical and pathological features. All the patients were analyzed on an intentionto-
treat basis, including those converted to open surgery.
The protocol was approved by the ethics committee at our institution and the
study was performed in accordance with the Declaration of Helsinki.
Preoperative staging
All patients underwent a CT scan, an MRI, and a total colonoscopy that
included tumour biopsy. According to the hospital protocol, patients with Stage III
rectal cancer received a long course of preoperative radiochemotherapy (45 Gy for
5 weeks, plus capecitabine (Xeloda®) at a dose of 825 mgr/m2/12 hours/day or
continuous infusion of 5-fluorouracil 225-250 mgr/m2). Patients treated with
neoadjuvant therapy underwent a repeat MRI immediately before surgery to
determine downsizing or downstaging. In patients treated with preoperative
radiochemotherapy, pelvimetrics and tumour measurements were performed in the
MRI post-neoadjuvant treatment.
Radiologic study
Preoperative pelvic MRI images were acquired on a Philips Intera 1.5 Tesla
and Achieva 3 Tesla (Philips Medical System). Pelvis was studied in the three
spatial planes from iliac crests to ischiatic tuberosities using a 3 mm slice
thickness. We measured the promontorium-retropubic, subsacrum-retropubic,
promontorium-subsacrum, and intertuberous axes, the circumferential resection
margin (CRM), and maximum and minimum pelvic diameters, at the tumour level.
We also measured tumour and prostate volume in men.
MRI pelvimetry angles measured were the promontorium-subsacrum, and
the sagittal and coronal depth. The sagittal depth angle was calculated from two
lines drawn tangentially from the sacral promontory and the anterosuperior tip of
the pubis to the superior and inferior edges of the tumour8. Coronal depth angle
was calculated by two lines drawn from the inferior edge of the two sacroiliac joints
to the lateral edges of the tumour.
Volumetric analysis of minor pelvis, rectal ampulla, rectal tumour and prostate was
analyzed using specific software (Osirix, Apple, Cupertino, CA, USA). a DICOM
file was used to make a 3-dimensional reconstruction from planar slices obtained
during the MRI reconstruction .
Pelvimetry measurements were performed by two consultant radiologists
(J.C.P and D.H)
Surgical treatment
Surgery was performed 8 weeks after completion of the neoadjuvant
treatment. All patients in the series underwent laparoscopic sphincter-preserving
low anterior resection (LAR) with TME. The characteristics of the technique are
described in our previous study7. A protective ileostomy was made in all cases.
Pathological analyses
Specimens were examined following the scheme proposed by Quircke9,
including fresh examination of the integrity of the mesorectum and its
corresponding classification (complete: intact mesorectum with only minor
irregularities of a smooth mesorectal surface; nearly complete: rude mesorectum
defects, not disrupting the muscle layer; incomplete: little bulk to mesorectum with
defects down to muscularis propia). To simplify the data, we grouped mesorectal
quality into two subgroups: optimal (complete) and suboptimal (nearly complete
and incomplete groups). The mesorectum surface was stained and fixed in
formalin block. The resection specimens were sectioned in parallel cuts of 0.5 cm
perpendicular to the length of the bowel, allowing measurement of the deepest
point of tumour invasion. Microscopic study was conducted and pCRM and ypCRM
were measured. CRM were considered positive if the tumour was located less than
1 mm from the rectal fascia.
Statistical analysis
Results are given as number of cases and percentages for categorical data,
as mean and standard deviation for quantitative variables. Data were analyzed by
use of bivariate analysis, contingency tables, and the chi squared or Fisher´s exact
test for categorical variables and ANOVA or t test for quantitative variables. The
statistical significance level was set at 5% (alpha= 0.05). All variables that were
significant in univariate analyses and those considered clinically relevant were
entered in a multivariate stepwise (forward selection/backward elimination) to
determine which variables were significant independent risk factors. All the
analyses were performed using SPSS software (version 21.0; SPSS. Inc. Chicago,
IL).
| Identifer | oai:union.ndltd.org:TDX_UAB/oai:www.tdx.cat:10803/285073 |
| Date | 30 October 2014 |
| Creators | Fernández Ananín, Sonia |
| Contributors | Targarona Soler, Eduard M., Trías Folch, Manel, Universitat Autònoma de Barcelona. Departament de Cirurgia |
| Publisher | Universitat Autònoma de Barcelona |
| Source Sets | Universitat Autònoma de Barcelona |
| Language | Spanish |
| Detected Language | Spanish |
| Type | info:eu-repo/semantics/doctoralThesis, info:eu-repo/semantics/publishedVersion |
| Format | 128 p., application/pdf |
| Source | TDX (Tesis Doctorals en Xarxa) |
| Rights | L'accés als continguts d'aquesta tesi queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons: http://creativecommons.org/licenses/by-nc-sa/3.0/es/, info:eu-repo/semantics/openAccess |
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